Festo reports that they invest about 8% of their revenues in research and development. Festo’s draws inspiration for some of its control and automation technology products from the natural world. To help facilitate this, Festo established the Bionic Learning Network, which is a research network linking Festo to universities, institutes, development companies and private inventors. A key goal of this network is to learn from nature and develop “new insights for technology and industrial applications”…. “in various fields, from safe automation and intelligent mechatronic solutions up to new drive and handling technologies, energy efficiency and lightweight construction.”
One of the challenges taken on by the Bionic Learning Network was to decipher how birds fly and then develop robotic devices that can implement that knowledge and fly like a bird. Their first product was the 2011 SmartBird and their newest product is the 2020 BionicSwift. In this article we’ll take a look at these two bionic birds and the significant advancements that Festo has made in just nine years.
On 24 March 2011, Festo issued a press release introducing their SmartBird flying bionic robot, which was one of their 2011 Bionic Learning Network projects. Festo reported:
“The research team from the family enterprise Festo has now, in 2011, succeeded in unraveling the mystery of bird flight. The key to its understanding is a unique movement that distinguishes SmartBird from all previous mechanical flapping wing constructions and allows the ultra-lightweight, powerful flight model to take off, fly and land autonomously.”
“SmartBird flies, glides and sails through the air just like its natural model – the Herring Gull – with no additional drive mechanism. Its wings not only beat up and down, but also twist at specific angles. This is made possible by an active articulated torsional drive unit, which in combination with a complex control system makes for unprecedented efficiency in flight operation. Festo has thus succeeded for the first time in attaining an energy-efficient technical adaptation of this model from nature.”
SmartBird measures 1.07 meters (42 in) long with a wingspan of 2.0 meters (79 in) and a weigh of 450 grams (16 ounces, 1 pound). This is about a 1.6X scale-up in the length and span of an actual Herring Gull, but at about one-third the weight. It is capable of autonomous takeoff, flight, and landing using just its wings, and it controls itself the same way birds do, by twisting its body, wings, and tail. SmartBird’s propulsion system has a power requirement of 23 watts.
On 1 July 2020, Festo introduced the BionicSwift as their latest ultra light flying bionic robot that mimics how actual birds fly.
The BionicSwift, inspired by a Common Swift, measures 44.5 cm (17.5 in) long with a wingspan of 68 cm (26.7 in) and a weight of just 42 grams (1.5 ounces). It’s approximately a 2X scale-up of a Common Swift, but still a remarkably compact, yet complex flying machine with aerodynamic plumage that closely replicates the flight feathers on an actual Swift. The 2011 SmartBird was more than twice the physical size and ten times heavier.
The BionicSwift is agile, nimble and can even fly loops and tight turns. Festo reports: “Due to this close-to-nature replica of the wings, the BionicSwifts have a better flight profile than previous wing-beating drives.” Compare the complex, feathered wing structure in the following Festo photos of the BionicSwift with the previous photos showing the simpler, solid wing structure of the 2011 SmartBird.
A BionicSwift can fly singly or in coordinated flight with a group of other BionicSwifts. Festo describes how this works: “Radio-based indoor GPS with ultra wideband technology (UWB) enables the coordinated and safe flying of the BionicSwifts. For this purpose, several radio modules are installed in one room. These anchors then locate each other and define the controlled airspace. Each robotic bird is also equipped with a radio marker. This sends signals to the anchors, which can then locate the exact position of the bird and send the collected data to a central master computer, which acts as a navigation system.” Flying time is about seven minutes per battery charge.
AquaJelly (2008): replicates the natural underwater movements of a jelly fish in a small, autonomous, peristaltic drive autonomous underwater vehicle that can operate in coordination with several other AquaJellies: https://www.youtube.com/watch?v=N-O8-N71Qcw
At the start of World War II (WW II), US home ownership had dropped to a low of 43.6% in 1940, largely as a consequence of the Great Depression and the weak US economy in its aftermath. During WW II, the War Production Board issued Conservation Order L-41 on 9 April 1942, placing all construction under rigid control. The order made it necessary for builders to obtain authorization from the War Production Board to begin construction costing more than certain thresholds during any continuous 12-month period. For residential construction, that limit was $500, with higher limits for business and agricultural construction. The impact of these factors on US residential construction between 1921 and 1945 is evident in the following chart, which shows the steep decline during the Great Depression and again after Order L-41 was issued.
By the end of WW II, the US had an estimated 7.6 million troops overseas. The War Production Board revoked L-41 on 15 October 1945, five months after V-E (Victory in Europe) day on 8 May 1945 and six weeks after WW II ended when Japan formally surrendered on 2 September 1945. In the five months since V-E day, about three million soldiers had already returned to the US. After the war’s end, the US was faced with the impending return of several millions more veterans. Many in this huge group of veterans would be seeking to buy homes in housing markets that were not prepared for their arrival. Within the short span of a year after Order L-41 was revoked, the monthly volume of private housing expenditures increased fivefold. This was just the start of the post-war housing boom in the US.
In a March 1946 Popular Science magazine article entitled “Stopgap Housing,” the author, Hartley Howe, noted, “ Even if 1,200,000 permanent homes are now built every year – and the United States has never built even 1,000,000 in a single year – it will be 10 years before the whole nation is properly housed. Hence, temporary housing is imperative to stop that gap.” To provide some immediate relief, the Federal government made available many thousands of war surplus steel Quonset huts for temporary civilian housing.
Facing a different challenge in the immediate post-war period, many wartime industries had their contracts cut or cancelled and factory production idled. With the decline of military production, the U.S. aircraft industry sought other opportunities for employing their aluminum, steel and plastics fabrication experience in the post-war economy.
2. Post-WW II prefab aluminum and steel houses in the US
In the 2 September 1946 issue of Aviation News magazine, there was an article entitled “Aircraft Industry Will Make Aluminum Houses for Veterans,” that reported the following:
“Two and a half dozen aircraft manufacturers are expected soon to participate in the government’s prefabricated housing program.”
“Aircraft companies will concentrate on FHA (Federal Housing Administration) approved designs in aluminum and its combination with plywood and insulation, while other companies will build prefabs in steel and other materials. Designs will be furnished to the manufacturers.”
“Nearly all war-surplus aluminum sheet has been used up for roofing and siding in urgent building projects; practically none remains for the prefab program. Civilian Production Administration has received from FHA specifications for aluminum sheet and other materials to be manufactured, presumably under priorities. Most aluminum sheet for prefabs will be 12 to 20 gauge – .019 – .051 inch.”
In October 1946, Aviation News magazine reported, “The threatened battle over aluminum for housing, for airplanes and myriad postwar products in 1947 is not taken too seriously by the National Housing Agency, which is negotiating with aircraft companies to build prefabricated aluminum panel homes at an annual rate as high as 500,000.”……”Final approval by NHA engineers of the Lincoln Homes Corp. ‘waffle’ panel (aluminum skins over a honeycomb composite core) is one more step toward the decision by aircraft companies to enter the field.…..Aircraft company output of houses in 1947, if they come near meeting NHA proposals, would be greater than their production of airplanes, now estimated to be less than $1 billion for 1946.”
In late 1946, the FHA Administrator, Wilson Wyatt, suggested that the War Assets Administration (WAA), which was created in January 1946 to dispose of surplus government-owned property and materials, temporarily withhold surplus aircraft factories from lease or sale and give aircraft manufacturers preferred access to surplus wartime factories that could be converted for mass-production of houses. The WAA agreed.
Under the government program, the prefab house manufacturers would have been protected financially with FHA guarantees to cover 90% of costs, including a promise by Reconstruction Finance Corporation (RFC) to purchase any homes not sold.
Many aircraft manufacturers held initial discussions with the FHA, including: Douglas, McDonnell, Martin, Bell, Fairchild, Curtis-Wright, Consolidated-Vultee, North American, Goodyear and Ryan. Boeing did not enter those discussions and Douglas, McDonnell and Ryan exited early. In the end, most aircraft manufacturer were unwilling to commit themselves to the postwar prefab housing program, largely because of their concerns about disrupting their existing aircraft factory infrastructure based on uncertain market estimates of size and duration of the prefab housing market and lack of specific contract proposals from the FHA and NHA.
The original business case for the post-war aluminum and steel pre-fabricated houses was that they could be manufactured rapidly in large quantities and sold profitably at a price that was less than conventional wood-constructed homes. Moreover, the aircraft manufacturing companies restored some of the work volume lost after WW II ended and they were protected against the majority of their financial risk in prefab house manufacturing ventures.
Not surprisingly, building contractors and construction industry unions were against this program to mass-produce prefabricated homes in factories, since this would take business away from the construction industry. In many cities the unions would not allow their members to install prefabricated materials. Further complicating matters, local building codes and zoning ordnances were not necessarily compatible with the planned large-scale deployment of mass-produced, prefabricated homes.
The optimistic prospects for manufacturing and erecting large numbers of prefabricated aluminum and steel homes in post-WW II USA never materialized. Rather than manufacturing hundreds of thousands of homes per year, the following five US manufacturers produced a total of less than 2,600 new aluminum and steel prefabricated houses in the decade following WW II: Beech Aircraft, Lincoln Houses Corp., Consolidated-Vultee, Lustron Corp. and Aluminum Company of America (Alcoa). In contrast, prefabricators offering more conventional houses produced a total of 37,200 units in 1946 and 37,400 in 1947. The market demand was there, but not for aluminum and steel prefabricated houses.
US post-WW II prefabricated aluminum and steel houses
These US manufacturers didn’t play a significant part in helping to solve the post-WW II housing shortage. Nonetheless, these aluminum and steel houses still stand as important examples of affordable houses that, under more favorable circumstances, could be mass-produced even today to help solve the chronic shortages of affordable housing in many urban and suburban areas in the US.
Some of the US post-WW II housing demand was met with stop gap, temporary housing using re-purposed, surplus wartime steel Quonset huts, military barracks, light-frame temporary family dwelling units, portable shelter units, trailers, and “demountable houses,” which were designed to be disassembled, moved and reassembled wherever needed. You can read more about post-WW II stop gap housing in the US in Hartley Howe’s March 1946 article in Popular Science (see link below).
The construction industry ramped up rapidly after WW II to help meet the housing demand with conventionally-constructed permanent houses, with many being built in large-scale housing tracts in rapidly expanding suburban areas. Between 1945 and 1952, the Veterans Administration reported that it had backed nearly 24 million home loans for WW II veterans. These veterans helped boost US home ownership from 43.6% in 1940 to 62% in 1960.
Two post-WW II US prefabricated aluminum and steel houses have been restored and are on public display in the following museums:
In addition, you can visit several WW II Quonset huts at the Seabees Museum and Memorial Park in North Kingstown, Rhode Island. None are outfitted like a post-WW II civilian apartment. The museum website is here: https://www.seabeesmuseum.com
You’ll find more information in my articles on specific US post-WW II prefabricated aluminum and steel houses at the following links:
3. Post-WW II prefab aluminum and steel houses in the UK
By the end of WW II in Europe (V-E Day is 8 May 1945), the UK faced a severe housing shortage as their military forces returned home to a country that had lost about 450,000 homes to wartime damage.
On 26 March 1944, Winston Churchill made an important speech promising that the UK would manufacture 500,000 prefabricated homes to address the impending housing shortage. Later in the year, the Parliament passed the Housing (Temporary Accommodation) Act, 1944, charging the Ministry of Reconstruction with developing solutions for the impending housing shortage and delivering 300,000 units within 10 years, with a budget of £150 million.
The Act provided several strategies, including the construction of temporary, prefabricated housing with a planned life of up to 10 years. The Temporary Housing Program (THP) was officially known as the Emergency Factory Made (EFM) housing program. Common standards developed by the Ministry of Works (MoW) required that all EFM prefabricated units have certain characteristics, including:
Minimum floor space of 635 square feet (59 m2)
Maximum width of prefabricated modules of 7.5 feet (2.3 m) to enable transportation by road throughout the country
Implement the MoW’s concept of a “service unit,” which placed the kitchen and bathroom back-to-back to simplify routing plumbing and electrical lines and to facilitate factory manufacture of the unit.
Factory painted, with “magnolia” (yellow-white) as the primary color and gloss green as the trim color.
In 1944, the UK Ministry of Works held a public display at the Tate Gallery in London of five types of prefabricated temporary houses.
The original Portal all-steel prototype bungalow
The AIROH (Aircraft Industries Research Organization on Housing) aluminum bungalow, made from surplus aircraft material.
The Arcon steel-framed bungalow with asbestos concrete panels. This deign was adapted from the all-steel Portal prototype.
Two timber-framed prefab designs, the Tarran and the Uni-Seco
This popular display was held again in 1945 in London.
Supply chain issues slowed the start of the EFM program. The all-steel Portal was abandoned in August 1945 due to a steel shortage. In mid-1946, a wood shortage affected other prefab manufacturers. Both the AIROH and Arcon prefab houses were faced with unexpected manufacturing and construction cost increases, making these temporary bungalows more expensive to build than conventionally constructed wood and brick houses.
Under a Lend-Lease Program announced in February 1945, the US agreed to supply the UK with US-built, wood frame prefabricated bungalows known as the UK 100. The initial offer was for 30,000 units, which subsequently was reduced to 8,000. This Lend-Lease agreement came to an end in August 1945 as the UK started to ramp up its own production of prefabricated houses. The first US-built UK 100 prefabs arrived in late May/early June 1945.
The UK’s post-war housing reconstruction program was quite successful, delivering about 1.2 million new houses between 1945 and 1951. During this reconstruction period, 156,623 temporary prefabricated homes of all types were delivered under the EFM program, which ended in 1949, providing housing for about a half million people. Over 92,800 of these were temporary aluminum and steel bungalows. The AIROH aluminum bungalow was the most popular EFM model, followed by the Arcon steel frame bungalow and then the wood frame Uni-Seco. In addition, more than 48,000 permanent aluminum and steel prefabricated houses were built by AW Hawksley and BISF during that period.
In comparison to the very small number of post-war aluminum and steel prefabricated houses built in the US, the post-war production of aluminum and steel prefabs in the UK was very successful.
UK post-WW II prefabricated aluminum and steel houses
In a 25 June 2018 article in the Manchester Evening News, author Chris Osuh reported that, “It’s thought that between 6 or 7,000 of the post-war prefabs remain in the UK…..” The Prefab Museum maintains a consolidated interactive map of known post-WW II prefab house locations in the UK at the following link: https://www.prefabmuseum.uk/content/history/map
In the UK, Grade II status means that a structure is nationally important and of special interest. Only a few post-war temporary prefabs have been granted the status as Grade II listed properties:
In an estate of Phoenix steel frame bungalows built in 1945 on Wake Green Road, Moseley, Birmingham, 16 of 17 homes were granted Grade II status in 1998.
Six Uni-Seco wood frame bungalows built in 1945 – 46 in the Excalibur Estate, Lewisham, London were granted Grade II status in 2009. At that time, Excalibur Estates had the largest number of WW II prefabs in the UK: 187 total, of several types.
Several post-war temporary prefabs are preserved at museums in the UK and are available to visit.
St. Fagans National Museum of History in Cardiff, South Wales: An AIROH B2 originally built near Cardiff in 1947 was dismantled and moved to its current museum site in 1998 and opened to the public in 2001. You can see this AIROH B2 here: https://museum.wales/stfagans/buildings/prefab/
I think the Prefab Museum is best source for information on UK post-WW II prefabs. When it was created in March 2014 by Elisabeth Blanchet (author of several books and articles on UK prefabs) and Jane Hearn, the Prefab Museum had its home in a vacant prefab on the Excalibur Estate in south London. After a fire in October 2014, the physical museum closed but has continued its mission to collect and record memories, photographs and memorabilia, which are presented online via the Prefab Museum’s website at the following link: https://www.prefabmuseum.uk
You’ll find more information in my articles on specific UK post-WW II prefabricated aluminum and steel houses at the following links:
4. Post-WW II prefab aluminum and steel houses in France
At the end of WW II, France, like the UK, had a severe housing shortage due to the great number of houses and apartments damaged or destroyed during the war years, the lack of new construction during that period, and material shortages to support new construction after the war.
To help relieve some of the housing shortage in 1945, the French Reconstruction and Urbanism Minister, Jean Monnet, purchased the 8,000 UK 100 prefabricated houses that the UK had acquired from the US under a Lend-Lease agreement. These were erected in the Hauts de France (near Belgium), Normandy and Brittany, where many are still in use today.
The Ministry of Reconstruction and Town Planning established requirements for temporary housing for people displaced by the war. Among the initial solutions sought were prefabricated dwellings measuring 6 x 6 meters (19.6 x 19.6 feet); later enlarged to 6 × 9 meters (19.6 x 29.5 feet).
About 154,000 temporary houses (the French called then “baraques”), in many different designs, were erected in France in the post-war years, primarily in the north-west of France from Dunkirk to Saint-Nazaire. Many were imported from Sweden, Finland, Switzerland, Austria and Canada.
The primary proponent of French domestic prefabricated aluminum and steel house manufacturing was Jean Prouvé, who offered a novel solution for a “demountable house,” which could be easily erected and later “demounted” and moved elsewhere if needed. A steel gantry-like “portal frame” was the load-bearing structure of the house, with the roof usually made of aluminum, and the exterior panels made of wood, aluminum or composite material. Many of these were manufactured in the size ranges requested by Ministry of Reconstruction. During a visit to Prouvé’s Maxéville workshop in 1949, Eugène Claudius-Petit, then the Minister of Reconstruction and Urbanism, expressed his determination to encourage the industrial production of “newly conceived (prefabricated) economical housing.”
French post-WW II prefabricated aluminum and steel houses
Today, many of Prouvé’s demountable aluminum and steel houses are preserved by architecture and art collectors Patrick Seguin (Galerie Patrick Seguin) and Éric Touchaleaume (Galerie 54 and la Friche l’Escalette). Ten of Prouvé’s Standard Houses and four of his Maison coques-style houses built between 1949 – 1952 are residences in the small development known as Cité “Sans souci,” in the Paris suburbs of Muedon.
Prouvé’s 1954 personal residence and his relocated 1946 workshop are open to visitors from the first weekend in June to the last weekend in September in Nancy, France. The Musée des Beaux-Arts de Nancy has one of the largest public collections of objects made by Prouvé.
Author Elisabeth Blanchet reports that the museum “Mémoire de Soye has managed to rebuild three different ‘baraques’: a UK 100, a French one and a Canadian one. They are refurbished with furniture from the war and immediate post-war era. Mémoire de Soye is the only museum in France where you can visit post-war prefabs.” The museum is located in Lorient, Brittany. Their website (in French) is here: http://www.soye.org
In the U.S., the post-war mass production of prefabricated aluminum and steel houses never materialized. Lustron was the largest manufacturer with 2,498 houses. In the UK, over 92,800 prefabricated aluminum and steel temporary bungalows were built as part of the post-war building boom that delivered a total of 156,623 prefabricated temporary houses of all types between 1945 and 1949, when the program ended. In France, hundreds of prefabricated aluminum and steel houses were built after WW II, with many being used initially as temporary housing for people displaced by the war. Opportunities for mass production of such houses did not develop in France.
The lack of success in the U.S. arose from several factors, including:
High up-front cost to establish a mass-production line for prefabricated housing, even in a big, surplus wartime factory that was available to the house manufacturer on good financial terms.
Immature supply chain to support a house manufacturing factory (i.e., different suppliers are needed than for the former aircraft factory).
Ineffective sales, distribution and delivery infrastructure for the manufactured houses.
Diverse, unprepared local building codes and zoning ordnances stood in the way of siting and erecting standard design, non-conventional prefab homes.
Opposition from construction unions and workers that did not want to lose work to factory-produced homes.
Only one manufacturer, Lustron, produced prefab houses in significant numbers and potentially benefitted from the economics of mass production. The other manufacturers produced in such small quantities that they could not make the transition from artisanal production to mass production.
Manufacturing cost increases reduced or eliminated the initial price advantage predicted for the prefabricated aluminum and steel houses, even for Lustron. They could not compete on price with comparable conventionally constructed houses.
In Lustron’s case, charges of corporate corruption led the Reconstruction Finance Corporation to foreclose on Lustron’s loans, forcing the firm into an early bankruptcy.
From these post-WW II lessons learned, and with the renewed interest in “tiny homes”, it seems that there should be a business case for a modern, scalable, smart factory for the low-cost mass-production of durable prefabricated houses manufactured from aluminum, steel, and/or other materials. These prefabricated houses could be modestly-sized, modern, attractive, energy efficient (LEED-certified), and customizable to a degree while respecting a basic standard design. These houses should be designed for mass production and siting on small lots in urban and suburban areas. I believe that there is a large market in the U.S. for this type of low-price housing, particularly as a means to address the chronic affordable housing shortages in many urban and suburban areas. However, there still are great obstacles to be overcome, especially where construction industry labor unions are likely to stand in the way and, in California, where nobody will want a modest prefabricated house sited next to their McMansion.
You can download a pdf copy of this post, not including the individual articles, here:
Blaine Stubblefield, “Aircraft Industry Will Make Aluminum Houses for Veterans,” Aviation News, Vol. 6, No. 10, 2 September 1946 (available in the Aviation Week & Space Technology magazine online archive)
“Battle for Aluminum Discounted by NHA,” Aviation News magazine, p. 22, 14 October 1946 (available in the Aviation Week & Space Technology magazine online archive)
Nicole C. Rudolph, “At Home in Postwar France – Modern Mass Housing and the Right to Comfort,” Berghahn Monographs in French Studies (Book 14), Berghahn Books, March 2015, ISBN-13: 978-1782385875. The introduction to this book is available online at the following link: https://berghahnbooks.com/downloads/intros/RudolphAt_intro.pdf
Kenny Cupers, “The Social Project: Housing Postwar France,” University Of Minnesota Press, May 2014, ISBN-13: 978-0816689651
On 16 October 1956, architect Frank Lloyd Wright, then 89 years old, unveiled his design for the tallest skyscraper in the world, a remarkable mile-high tripod spire named “The Illinois,” proposed for a site in Chicago.
Also known as the Illinois Mile-High Tower, Wright’s skyscraper would stand 528 floors and 5,280 feet (1,609 meters) tall plus antenna; more than four times the height of the Empire State Building in New York City, then the tallest skyscraper in the world at 102 floors and 1,250 feet (380 meters) tall plus antenna. At the unveiling of The Illinoisat the Sherman House Hotel in Chicago, Wright presented an illustration measuring more than 25 feet (7.6 meters) tall, with the skyscraper drawn at the scale of 1/16 inch to the foot.
Basic parameters for The Illinois are listed below:
Floors, above grade level: 528
Architectural: 5,280 ft (1,609.4 m)
To tip of antenna: 5,706 ft (1739.2 m)
Number of elevators: 76
Gross floor area (GFA): 18,460,106 ft² (1,715,000 m²)
Number of occupants: 100,000
Number of parking spaces: 15,000
Core: Reinforced concrete
Cantilevered floors: Steel
Tensioned tripod: Steel
The Illinois was intended as a mixed-use structure designed to spread urbanization upwards rather than outwards. The Illinois offered nearly three times the gross floor area (GFA) of the Pentagon, and more than seven times the GFA of the Empire State Building for use as office, hotel, residential and parking space. Wright said the building could consolidate all government offices then scattered around Chicago.
The single super-tall skyscraper was intended to free up the ground plane by eliminating the need for other large skyscrapers in its vicinity. This was consistent with Wright’s distributed urban planning concept known as Broadacre City, which he introduced in the mid-1930s and continued to advocate until his death in 1959.
2. Tenuity, continuity and evolution of Wright’s concept for an organic high-rise building
Two aspects of Wright’s concept of organic architecture are the structural principles he termed “tenuity” and “continuity,” both of which he applied in the context of cantilevered and cable-supported structures, such as slender buildings and bridges. Author Richard Cleary reported that Wright first used the term tenuity in his 1932 book Autobiography, and offered his most succinct explanation in his 1957 book Testament.
“The cantilever is essentially steel at its most economical level of use. The principle of the cantilever in architecture develops tenuity as a wholly new human expression, a means, too, of placing all loads over central supports, thereby balancing extended load against opposite extended load.”
“This brought into architecture for the first time another principle in construction – I call it continuity – a property which may be seen as a new, elastic, cohesive, stability. The creative architect finds here a marvelous new inspiration in design. A new freedom involving far wider spacing of more slender supports.”
“Thus architecture arrived at construction from within outward rather than from outside inward; much heightening and lightening of proportions throughout all building is now economical and natural, space extended and utilized in a more liberal planning than the ancients could ever have dreamed of. This is now the prime characteristic of the new architecture called organic.”
“Construction lightened by means of cantilevered steel in tension makes continuity a most valuable characteristic of architectural enlightenment.”
The structural principles of tenuity and continuity are manifest in Wright’s high-rise building designs that are characterized by a deep “taproot” foundation that supports a central load bearing core structure from which the individual floors are cantilevered. A cross-section of the resulting building structure has the appearance of a tree deeply rooted in the Earth with many horizontal branches.
Before looking further at the Mile-High Skyscraper, we’ll take a look at three of its high-rise predecessors and one later design, all of which shared Wright’s characteristic organic architectural features derived from the application of tenuity and continuity: taproot foundation, load-bearing core structure and cantilevered floors:
St. Mark’s Tower project
SC Johnson Research Tower
The Golden Beacon
St. Mark’s Tower project (St. Mark’s-in-the-Bouwerie, 1927 – 1931, not built)
Wright first proposed application of the taproot foundation, load-bearing concrete and steel core structure and cantilevered floors was in 1927 for the 15-floor St. Mark’s Tower project in New York City.
The New York Metropolitan Museum of Modern Art (MoMA) provides this description of the St. Mark’s Tower project.
“The design of these apartment towers for St. Mark’s-in-the-Bouwerie in New York City stemmed from Wright’s vision for Usonia, a new American culture based on the synthesis of architecture and landscape. The organic “tap-root” structural system resembles a tree, with a central concrete and steel load-bearing core rooted in the earth, from which floor plates are cantilevered like branches.”
“This system frees the building of load-bearing interior partitions and supports a modulated glass curtain wall for increased natural illumination. Floor plates are rotated axially to generate variation from one level to the next and to distinguish between living and sleeping spaces in the duplex apartments.”
While the St. Mark’s Tower project was not built, this basic high-rise building design reappeared from the mid-1930s to the mid-1960s as a “city dweller’s unit” in Wright’s Broadacre City plan and was the basis for the Price Tower built in the 1950s.
SC Johnson Research Tower, Racine, WI (1943 – 1950)
The 15-floor, 153 foot (46.6 m) tall SC Johnson Research Laboratory Tower, built between 1943 and 1950 in Racine, WI, was the first high-rise building to actually apply Wright’s organic design with a taproot foundation, load-bearing concrete and steel core structure and cantilevered floors. On their website, SC Johnson describes the structural design of this building as follows:
“One of Frank Lloyd Wright’s famous buildings, the tower rises more than 150 feet into the air and is 40 feet square. Yet at ground level, it’s supported by a base only 13 feet across at its narrowest point. As a result, the tower almost seems to hang in the air – a testament to creativity and an inspiration for the innovative products that would be developed inside.”
“Alternating square floors and round mezzanine levels make up the interior, and are supported by the “taproot” core, which also contains the building’s elevator, stairway and restrooms. The core extends 54 feet into the ground, providing stability like the roots of a tall tree.”
Because of the change in fire safety codes, and the impracticality of retrofitting the building to meet current code requirements, SC Johnson has not used the Research Tower since 1982. However, they restored the building in 2013 and now the public can visit as part of the SC Johnson Campus Tour.
The 19-floor, 221 foot (67.4 m) tall Price Tower, completed in 1956 in Bartlesville, OK, is an evolution of Wright’s 1927 design for the St. Mark’s Tower project. Wright nicknamed the Price Tower, “the tree that escaped the crowded forest,” referring to the building’s cantilever construction and the origin of its design in a project for New York City. Price Tower also has been called the “Prairie Skyscraper.”
H.C. Price commissioned Frank Lloyd Wright to design Price Tower, which served as his corporate headquarters until 1981 when it was sold to Phillips Petroleum. Philips deemed the exterior exit staircase a safety risk and only used the building for storage until 2000, when the building was donated to the Price Tower Arts Center. Since then, Price Tower has been returned to its multi-use origins and public tours are offered, including a visit to the restored 19th floor executive office of H.C. Price and the H.C. Price Company corporate apartment with the original Wright interiors. You can arrange your tour here: https://www.pricetower.org/tour/
The Golden Beacon was a concept for a 50-floor mixed-use office and residential apartment building in Chicago, IL.
As shown in the cross-section diagram, the building design followed Wright’s practice with a deep taproot foundation, a central load-bearing core and cantilevered floors. This design is very similar to the foundation structure proposed for the earlier Mile-High Skyscraper.
3. Extrapolating to the Mile-High Skyscraper
By 1956, Wright’s characteristic organic architectural features for high-rise buildings, derived from the application of tenuity and continuity, had only appeared in two completed high-rise buildings, the 15-floor SC Johnson Laboratory Tower and the 19-floor Price Tower. These two important buildings demonstrated the practicality of the taproot foundation, load-bearing concrete and steel core structure and cantilevered floors for tall, slender buildings. With the unveiling of The Illinois, Wright made a remarkable extrapolation of these architectural principles in his conceptual design of this breathtaking 528 floor, 5,280 feet (1,609 meters) tall skyscraper.
Blaire Kamin, writing for the Chicago Tribune in 2017, reported: “The Mile-High didn’t simply aim to be tall. It was the ultimate expression of Wright’s “taproot” structural system, which sank a central concrete mast deep into the ground and cantilevered floors from the mast. In contrast to a typical skyscraper, in which same-size floors are piled atop one another like so many pancakes, the taproot system lets floors vary in size, opening a high-rise’s interior and letting space flow between floors.”
In addition to the central core to support the building’s dead loads, The Illinois also incorporated an external tensioned steel tripod structure to resist external wind loads and other flexing loads (i.e., earthquakes), distributing those loads through the integral steel structure of the tripod, and resisting oscillations. In his book, “Testament,” Wright stated:
“Finally – throughout this lightweight tensilized structure, because of the integral character of all members, loads are at equilibrium at all points, doing away with oscillations. There would be no sway at the peak of The Illinois.”
Tuned mass dampers (TMD) for reducing the amplitude of mechanical vibrations in tall buildings had not been invented when Wright unveiled his design for The Illinois in 1956. The first use of a TMD in a skyscraper did not occur until the mid-1970s, first as a retrofit to the troubled, 790 foot (241 m) tall, John Hancock building completed in 1976 in Boston, and then as original equipment in the 915 foot (279 m) tall Citicorp Tower completed in 1977 in New York City. While tenuity and continuity may have given The Illinois unparalleled structural stability, I wouldn’t be surprised if TMD technology would have been needed for the comfort of the occupants on the upper floors, three-quarters of a mile above their counterparts in the next tallest building in the world.
To handle its 100,000 occupants, The Illinois had 76 elevators that were divided into five groups, each serving a 100-floor segment of the building, with a single elevator serving only the top floors. Each elevator was a five-story unit that moved on rails and served five floors simultaneously. With the tapering, pyramidal shape of the skyscraper, the vertical elevator shaft structures eventually extended beyond the sloping exterior walls, forming protruding parapets on the sides of the building. In his 1957 book, “A Testament,” Wright said the elevators were designed to enable building evacuation within one hour, in combination with the escalators that serve the lowest five floors.
Wright alluded to the building (and the elevators) being “atomic powered,” but there were no provisions for a self-contained power plant as part of the building. The much smaller Empire State Building currently has a peak electrical demand of almost 10 megawatts (MW) in July and August after implementing energy conservation measures. Scaling on the basis of gross floor area, The Illinois could have had a peak electrical demand of about 70 MW. You’ll find more information on current Empire State Building energy usage here: https://www.esbnyc.com/sites/default/files/esb_overall_retrofit_fact_sheet_final.pdf
The 2012 short video by Charles Muench, “A Peaceful Day in BroadAcre City – One Mile High – Frank Lloyd Wright” (1:31 minutes), depicts The Illinois skyscraper in the spacious setting of Broadacre City and shows an animated construction sequence of the tower. Two screenshots from the video are reproduced below. You’ll find this video at the following link: https://www.dailymotion.com/video/xp86uo
You can see more architectural details in the 2009 video, “Mile High Final Movie – Frank Lloyd Wright” (3:42 minutes), produced for the Guggenheim Museum, New York. Two screenshots are reproduced below. You’ll find the video here: https://vimeo.com/4937909
In his 1957 book, Testament, Wright provided the following two architectural drawings showing typical details of the cantilever construction of The Illinois.
The Illinois was intended for construction in a spacious setting like Broadacre City, rather than in a congested big-city downtown immediately adjacent to other skyscrapers. Two views of The Illinois in these starkly different settings are shown below.
4. Wright’s Mile-High Skyscraper on Exhibit at MoMA
Since Wright’s death in 1959, his archives have been in the care of the Frank Lloyd Wright Foundation (https://franklloydwright.org/frank-lloyd-wright/) and stored at Wright’s homes / architectural schools at Taliesin in Spring Green, WI and Taliesin West, near Scottsdale, AZ.
In September 2012, Mary Louise Schumacher, writing for the Milwaukee Sentinel Journal, reported that Columbia University and the Museum of Modern Art (MoMA) in Manhattan had jointly acquired the Frank Lloyd Wright archives, which consist of architectural drawings, large-scale models, historical photographs, manuscripts, letters and other documents. You’ll find her report here: http://archive.jsonline.com/newswatch/168457936.html
The Frank Lloyd Wright Foundation will retain all copyright and intellectual property responsibilities for the archives, and all three organizations hope to see the archives placed online at some point in the future.
On 12 June 2017, MoMA opened its exhibit, “Frank Lloyd Wright at 150: Unpacking the Archive,” which ran thru 1 October 2017. You can take an online tour of this exhibit, which included Wright’s plans for The Illinois, here: https://www.moma.org/calendar/exhibitions/1660
MoMA’s curator of the Wright collection, Barry Bergdoll, provided an introduction to the trove of recently acquired documentation on The Illinois in a short 2017 video (4:32 minutes) at the following link: https://www.youtube.com/watch?v=VhUDu0Q08UA
Professor Allen Sayegh with Justin Chen & John Pugh, “Mile High Final Movie – Frank Lloyd Wright” (3:42), Harvard University Graduate School of Design for the Guggenheim Museum, New York, 2009: https://vimeo.com/4937909
My 11 December 2018 post, “Lots of Land Speed Record (LSR) Action in 2018,” provides background information on land speed record governance and a look at the fastest cars competing in the 2018 LSR season. 2018 highlights included:
The North American Eagle team, with driver Jessi Combs, continued to extend the performance of their jet-powered LSR car on a track in the Alvord Desert in Oregon.
The Bloodhound team in the UK was saved from insolvency, literally at the last moment, when the business and assets were bought by Yorkshire-based entrepreneur Ian Warhurst.
Salt conditions at the Bonneville salt flats in Utah were very good and many speed records were broken.
The North American Eagle LSR car crashed during a high-speed run in the Alvord Desert in August, killing driver Jessi Combs.
The salt conditions at the Bonneville salt flats were poor, resulting in rough driving conditions and generally lower speeds during Bonneville Speed Week (August) and the Utah Salt Flats Racing Association (USFRA) World of Speed (September). The Bonneville World Finals (October) were cancelled because of wet conditions.
The Carbinite LSR car, the Carbiliner, crashed during a high-speed run at the World of Speed 2019 in September, severely injuring driver Rob Freyvogel.
The 29th Annual Speed Week at Lake Gairdner, Australia in March had only one run over 300 mph (483 kph) in hot, dry conditions.
Now with proper financing, the Bloodhound LSR team transitioned to the next phase of the project, arriving at the Hakskeen Pan track in South Africa in October and conducting high-speed testing, which concluded successfully in November.
Let’s take a look at the 2019 LSR season in more detail.
1. North American Eagle
In August 2019, the North American Eagle team, with driver Jessi Combs, returned to the Alvord Desert in Oregon to attempt to break the official Women’s Land Speed Record set by Kitty O’Neil in 1976 with a two-way average speed of 512.710 mph (825.127 kph) in the rocket-powered SMI Motivator at the same venue. The North American Eagle team website is here: https://www.landspeed.com
An investigation into the cause of the crash revealed that the front wheel assembly of the car collapsed, possibly due to collision damage from hitting something on the track at high speed.
North American Eagle Crew Chief Les Holm reported Jessi Combs’ second run was measured at a speed of 548.342 mph (882.471 kph), yielding a two-way average speed of 531.889 mph (855.992 kph). Hemmings news reported that the North American Eagle team has submitted Jessi Combs’s two-way average speed results to the Guinness Book of World Records to claim the title of fastest woman on the planet.
It is not yet known if Jessi Combs’ two-way average speed will qualify as an official FIA world land speed record.
The Petersen Automotive Museum in Los Angeles held an exhibition entitled “Jessi Combs: Life at Full Speed” to commemorate the life and accomplishments of this extraordinary person.
In June 2020, the Guinness World Record was posthumously awarded to Jessi Combs, declaring: “The fastest land speed record (female) is 841.338 kph (522.783 mph), and was achieved by Jessi Combs (USA) in the Alvord Desert, Oregon, USA, on 27 August 2019. Jessi is the first person to break this record in more than 40 years.” This record is posted on the Guinness World Records website here: https://www.guinnessworldrecords.com/world-records/fastest-land-speed-record-(female)
2. Bonneville Speed Week 2019: 13 – 15 August 2019
Now let’s look at a few of the top challengers at Speed Week 2019.
At the Bonneville World Finals in 2018, Team Vesco’s gas turbine powered Turbinator II, with Dave Spangler driving, made a one-way run through the measured mile of 493.996 mph (795.009 kph), with an exit speed of 503.332 mph (810.034 kph). Turbinator II became the world’s first wheel-driven vehicle to exceed 500 mph and 800 kph.
In 2019, Dave Spangler was unable to complete a single run with Turbinator II during Bonneville Speed Week 2019. Three runs on the 2-mile “short” course were attempted on 14 – 15 August, but none were completed, for a variety of issues. You can watch a short video about Team Vesco at Speed Week 2019 here:
After Speed Week 2019, Team Vesco reported, “In the interest of safety and to correct our course while navigating toward our goal to become the first wheel driven car to set an official National or World record over 500 MPH, we must discontinue racing for the remainder of 2019. To improve our team, we have already begun a search for a company with turbine control engineering capabilities to partner with us.” You’ll find more information on the Team Vesco website here: https://www.teamvesco.com
George Poteet’s Speed Demon is a blown (supercharged or turbocharged) fuel (not gasoline) streamliner (BFS) that currently holds two-way land-speed records in five out of seven of Bonneville’s BFS classes: A, B, C, D and F. The two remaining classes are AA/BFS and E/BFS. The team’s goals for 2019 were to achieve records in these remaining classes and to raise its fastest two-way speed record to over 480 mph (772 kph). The teams current record, set in 2013, stands 437.183 mph (703.578). You can read more about these plans in the following Motor Tend article: https://www.hotrod.com/articles/pottet-speed-demon-aims-480-mph-bonneville/
To compete in several different classes, Speed Demon is designed to accommodate several different displacement engines that have been configured to fit inside the car’s svelte fuselage. At Speed Week 2019, the team had four different Duttweiler engines to challenge BFS records in Classes A, AA, C and E.
A “big block” 555 cubic inch Chevy engine for class AA/BFS, rated at around 3,200 hp at 8,000 rpm and 34 pounds of boost.
An intermediate size 368 cubic inch Chevy engine for class C/BFS.
A “small block,” 256 cubic inch Chevy engine for class E/BFS: dyno tested to 2,632 hp at 9,640 rpm and 51 pounds of boost.
Here’s a photo of the Class A Duttweiler 443 CID LS Bonneville engine configured for Speed Demon.
Speed Demonwas the only car that made runs over 300 mph (483 kph) during Speed Week 2019. On the “long” course, which was shortened to two miles because of poor salt conditions, Speed Demon achieved the following speeds:
13 Aug 2019: 300.648 mph (483.846 kph) and 332.815 mph (535.614 kph) with the E “small block” engine
15 Aug 2019: 369.533 mph (594.706 kph) with the AA “big block” engine
None of these runs broke an existing class speed record. However, Speed Demon and George Poteet were honored with the Hot Rod Magazine trophy for fastest run during Speed Week 2019.
Tom Flattery’s Salt Shark, a Class B blown gas (gasoline) streamliner (B/BGS), made its first appearance at Bonneville Speed Week 2019. The Salt Shark is powered by a twin-turbo, 427 cubic inch, fuel injected LSX engine from Golen Engine Service in New Hampshire. Salt Shark reached a maximum speed of 290.568 mph (467.624 kph) on 15 August 2019, making it the second fastest car at Speed Week 2019 after Speed Demon. You’ll find more information on the Salt Shark Facebook page here: https://www.facebook.com/Bonneville-Salt-Shark-226594851348688/
The Treit and Davenport Target 550 is a Class AA blown fuel streamliner (AA/BFS). At Bonneville Speed Week 2019, new driver Valerie Thompson took the car to a maximum speed of 270.762 mph (435.749 kph) on 15 August 2019. Rough salt conditions prevented a return run.
At the Utah Salt Flats Racing Association’s (USFRA) World of Speed event in October 2019, rough salt conditions persisted. The team reported, “On its first run, the car was bouncing up and down and bottoming almost from the start line. Valerie clocked at 291 mph (468 kph), but the car went airborne due to the rough course. Parts broke, damaging both engines. The drag chutes deployed properly and the car came to a safe stop. Thankfully no one was hurt.”
In January 2020, the Treit and Davenport team plans to ship Target 550 to Australia. With Valerie Thompson driving, the team will challenge the world speed record for its class in March 2020 during Speed Week at Australia’s Lake Gairdner.
3. Utah Salt Flats Racing Association (USFRA) World of Speed 2019: 16 – 16 September 2019
Like Bonneville Speed Week 2019, the USFRA World of Speed 2019 was affected by wet salt conditions. Results are posted on the USFRA website here: https://saltflats.com
Only three cars reached speeds greater than 300 mph (483 kph) on runs during World of Speed 2019. One of them, the Carbinite LSR car, the Carbiliner, was destroyed in a high-speed crash and the driver was seriously injured.
Let’s take a look at the three fastest LSR cars at this meet.
Carbinite LSR – Carbiliner
The Carbiliner is a Class AA blown fuel streamliner (AA/BFS). In 2018, it was one of five LSR vehicles to exceed 400 mph (644 kph) during Bonneville Speed Week, making runs of 406.750 mph (654.601 kph) and 413.542 mph (665.531 kph).
At World of Speed 2019, the Carbiliner, driven by Rob Freyvogel, crashed during a high-speed run on 15 September 2019. The car had been measured at an average speed of 392 mph (631 kph) and was still accelerating heading into the final mile of the long course when the crash occurred. While the rugged structure of the cockpit provided some protection, Rob Freyvogel was seriously injured.
The Strasburg family’s LSR car is a Class C blown fuel lakester (C/BFL). With almost perfect salt conditions at Bonneville in 2018, the Strasburg family set a new world land speed record for a lakester (an open-wheeled car) with an average speed of 373 mph (600 kph).
At World of Speed 2019, this lakester, driven by Anita Strasburg, exceeded 300 mph (483 kph) on several runs. On the best run, Anita Strasburg recorded 347.484 mph (559.221 kph) in the last (3rd) mile with an exit speed of 350.493 mph (564.064 kph).
The Beamco is a Class D unblown gas streamliner (D/GS) owned by Team Vesco and driven by Bob Blakely.
In the following video, you can take a ride aboard the Beamco streamliner as Bob Blakely raised the D/GS 2-way average speed record to 312.664 mph (503.184 kph) during the World of Speed 2019 in rough course conditions.
Blakely also became a new 300 mph Club member.
4. Bonneville World Finals 2019
On 28 September 2019, Bill Lattin, SCTA President, reported: “Unfortunately Mother Nature is at again. We were able to drag a good course and now there is standing water on it. Due to the weather forecast coming we have decided to cancel World Finals.”
5. Bloodhound LSR
After being rescued from insolvency in December 2018 by Ian Warhurst, a new company called Grafton LSR Ltd. was formed in March 2019 to be the car’s legal owner. The team was renamed “Bloodhound LSR” and the team headquarters were moved to the UK Land Speed Record Center in Berkeley, Gloucestershire, UK. The Bloodhound LSR website is here: https://www.bloodhoundlsr.com
The configuration of the jet + rocket-propelled Bloodhound LSR is shown in the following diagram.
The team’s goal for 2019 was to conduct high-speed testing of the Bloodhound LSR at the intended land speed record venue, the Hakskeen Pan in South Africa. The Bloodhound LSR team states that high-speed testing is “needed to allow the team to test many aspects of the car and all operational procedures in advance of the world land speed record runs, currently planned for late 2020.”Hakskeen Pan is a very flat dry lake bed with the world’s largest “unworked” saltpan. A test track measuring 20 km (12.4 miles) long and 1,100 meters (0.68 mile) wide has been established on the saltpan for use by Bloodhound LSR. The layout of the test track on Hakskeen Pan is show in the following diagram. For more information on this test track, see my 8 September 2015 post, “Just How Flat is Hakskeen Pan?” here: https://lynceans.org/all-posts/just-how-flat-is-hakskeen-pan/
For the high-speed test phase, the Bloodhound LSR was propelled only by its EJ200 jet engine, which is rated at 90 kN (20,230 pounds) of thrust. This engine is based on Rolls-Royce gas turbine engine technology and is built by the EuroJet Turbo GmbH consortium. The Nammo hybrid rocket engine was not installed for the 2019 high-speed tests.
High-speed testing was completed on 17 November 2019 with a 628 mph (1,010 kph) run. The team was pleased to report, “Mission accomplished.” You can watch a short video of this final high-speed test run here.
BBC reported, “The car’s costs are currently being underwritten by wealthy Yorkshire businessman Ian Warhurst. He says the next phase of the project will have to be funded by others, most likely corporate sponsors….. ‘With the high-speed testing phase concluded, we will now move our focus to identifying new sponsors and the investment needed to bring Bloodhound back out to Hakskeen Pan in the next 12 to 18 months’ time.’”
Development continues on the hybrid rocket engine that will be added to the Bloodhound LSR for the next set of high-speed runs at Hakskeen Pan.
You’ll find my previous posts on the Bloodhound LSR team and car here:
6. 29th Annual Speed Week at Lake Gairdner, Australia
Speed Week at Lake Gairdner was held from 4 to 8 March 2019 in hot, dry weather with fair salt conditions. There was only one run over 300 mph (483 kph) at this meet. Jim Knapp’s #1584, the Knappsters Streamliner, which is a Class AA blown fuel streamliner (AA/BFS), made the top speed run of the meet at 309.438 mph (497.994 kph).
The record for the top speed run at the Annual Speed Week at Lake Gairdner was set in 2018 by Les Davenport driving the Treit and Davenport Target 550, another AA/BFS, at 345.125 mph (555.425 kph). Track conditions and weather were excellent in 2018. The Treit and Davenport team is planning to be back in 2020.
7. The world’s fastest piston-powered car, Challenger 2, is for sale
Challenger 2 is a Class AA unblown fuel streamliner (AA/FS). Danny Thompson’s record-setting 448.757 mph (722.204 kph) average runs in Challenger 2 during Bonneville Speed Week 2018 set a new official world land speed record for piston-powered cars.
8. 1959 Mooneyes Moonliner on display at Speed Week 2019
At Bonneville Speed Week 2019, the beautiful 1959 Mooneyes Moonliner, built by Jocko Johnson for Dean Moon, was on display. This streamliner originally was powered by an Allison V-12 aircraft engine; later replaced by a fuel-injected, big-block Chevrolet engine. You can follow the Moonliner on Facebook here: https://www.facebook.com/Mooneyes/
The Moonliner was only run for exhibitions and car shows, and never competed at any speed trials. Nonetheless, the Moonliner is an exotic piece of rolling automotive art that could have been an exciting Class AA unblown gas streamliner (AA/GS).
In 1974, the Moonliner, powered by the big-block Chevrolet engine, driven by Gary Gabelich, and painted red and black (Budweiser colors) was at the Bonneville salt flats for a publicity run for Budweiser. The Moonliner is reported to have reached 285 mph (458 kph) during this event.
You’ll find many historic photos of the Moonliner at Bonneville in 1974 on the Getty Images website at the following link. Be sure to check out the photos of the unusual exhaust system.
“Modern Airships” is a three-part document that contains an overview of modern airship technology in Part 1 and links in Parts 1, 2 and 3 to more than 120 individual articles on historic and advanced airship designs. This is Part 1. Here are the links to the other two parts:
Modern Airships – Part 1 begins with an overview of modern airship technology, continues with a summary table identifying the airships addressed in this part, and concludes by providing links to 38 individual articles on these airships. A downloadable copy of Part 1 is available here:
If you have any comments or wish to identify errors in this document, please send me an e-mail to: PL31416@cox.net.
I hope you’ll find the Modern Airships series to be informative, useful, and different from any other single document on this subject.
21 December 2020
2. Well-established benefits and opportunities, but a risk-averse market
For more than two decades, there has been significant interest in the use of modern lighter-than-air craft and hybrid airships in a variety of military, commercial and other roles, including:
Heavy cargo carriers operating point-to-point between manufacturer and end-user, eliminating inter-modal load transfers enroute
Heavy cargo carriers serving remote and/or unimproved sites not adequately served by other modes of transportation
Disaster relief, particularly in areas not easily accessible by other means
Persistent optionally-manned surveillance platforms for maritime surveillance / border patrol / search and rescue
Commercial flying cruise liner / flying hotel
High altitude regional communications node
One of the very significant factors driving interest in modern airships is that they offer the potential to link isolated regions with the rest of the world while doing so in a way that should have lower environmental impacts than other transportation alternatives for those regions. This target market for airships exists in more than two-thirds of the world’s land area where more than half the world’s population live without direct access to paved roads and reliable ground transportation.
This matter is described well in a 21 February 2016 article by Jeanne Marie Laskas, “Helium Dreams – A new generation of airships is born,” which is posted on The New Yorker website at the following link:
In spite of the significant interest and the development of many promising airship designs, an actual worldwide airship cargo and passenger transportation industry has been very slow in developing. To give you an example of how slow:
As of December 2020, the Zeppelin NT 07 is the only advanced airship that has been certified and is flying regularly in commercial passenger service.
At the March 2019 Aviation Innovations Conference – Cargo Airshipsin Toronto, Canada, Solar Ship CEO Jay Godsall proposed an industry-wide challenge to actually demonstrate by July 2021 airships that can move a 3 metric ton (6,614 lb) standard 20 foot intermodal container configured as a mobile medical lab 300 km (186 mi) to a remote location. Godsall noted that this capability would be of great value if it did exist, for example, in support of relief efforts in Africa and other regions of the world.
So in spite of the airship industry having developed many designs capable of transporting 10 to 100 tons of cargo thousands of miles, today there is not a single airship that can transport a 3 metric ton (6,614 lb) payload 300 km (186 mi).
Why has the airship industry been so slow to develop? The bottom line has been a persistent lack of funding. With many manufacturers having invested in developing advanced, detailed designs, the first to secure adequate funding will be able to take the next steps to build a manufacturing facility and a full-scale prototype airship, complete the airship certification process, and start offering a certified airship for sale.
There are a some significant roadblocks in the way:
No full-scale prototypes are flying: The airship firms currently have little more than slide presentations to show to potential investors and customers. There are few sub-scale airship demonstrators, but no full-scale prototypes. The airship firms are depending on potential investors and customers making a “leap of faith” that the “paper” airship actually can be delivered.
Immature manufacturing capability: While the airship industry has been good at developing many advanced designs, some existing as construction-ready plans, few airship firms are in the process of building an airship factory. The industrial scale-up factor for an airship firm to go from the design and engineering facilities existing today to the facilities needed for series production of full-scale airships is huge. Several years ago, Russian airship manufacturer Augur RosAeroSystems proposed building a new factory to manufacture up to 10 ATLANT airships per year. The funding requirement for that factory was estimated at $157 million. The exact amount isn’t important. No matter how you look at it, it’s a big number. Large investments are needed for any airship firm to become a viable manufacturer.
Significant financial risk:The amount of funding needed by airship firms to make the next steps toward becoming a viable manufacturer exceeds the amount available from venture capitalists who are willing to accept significant risk. Private equity sources typically are risk averse. Public sources, or public-private partnerships, have been slow to develop an interest in the airship industry. The French airship firm Flying Whales appears to be the first to have gained access to significant funding from public institutions.
Significant regulatory risk:Current US, Canadian and European airship regulations were developed for non-rigid blimps and they fail to address how to certify most of the advanced airships currently under development. This means that the first airship manufacturers seeking type certificates for advanced airships will face uphill battles as they have to deal with aviation regulatory authorities struggling to fill in the big gaps in their regulatory framework and set precedents for later applicants. It is incumbent on the aviation regulatory authorities to get updated regulations in place in a timely manner and make the regulatory process predictable for existing and future applicants.
No airship operational infrastructure: There is nothing existing today that is intended to support the operation of new commercial airships tomorrow. The early airship operators will need to develop operating bases, hanger facilities, maintenance facilities, airship routes, and commercial arrangements for cargo and passengers. While many airship manufacturers boast that their designs can operate from unimproved sites without most or all of the traditional ground infrastructure required by zeppelins and blimps, the fact of the matter is that not all advanced airships will be operating from dirt fields and parked outside when not flying. There is real infrastructure to be built, and this will require a significant investment by the airship operators.
Steep learning curve for potential customers: Only the operators of the Zeppelin NT have experience in operating a modern airship today. The process for integrating airship operations and maintenance into a customer’s business work flow has more than a few unknowns. With the lack of modern airship operational experience, there are no testimonials or help lines to support a new customer. They’ll have to work out the details with only limited support. Ten years from now, the situation should be vastly improved, but for the first operators, it will be a challenge.
Few qualified pilots and crew: The airship manufacturers will need to work with the aviation regulatory authorities and develop programs for training and licensing new pilots and crew. The British airship manufacturer Varialift has stated that one of the roles of their ARH-PT prototype will be to train future pilots.
This uncertain business climate for airships seems likely to change in the early 2020s, when several different heavy-lift airships are expected to be certified by airworthiness authorities and ready for series production and sale to interested customers. If customers step up and place significant orders, we may be able to realize the promise of airship travel and its potential to change our world in many positive ways.
3. Status of current aviation regulations for airships
As noted previously, current aviation regulations have not kept pace with the development of modern airship technology. In this section, we’ll take a look at the current regulations.
In the US, the Federal Aviation Administration’s (FAA) current requirements for airships are defined in the document FAA-P-8110-2, Change 2, “Airship Design Criteria (ADC),” dated 6 February 1995, which is available here:
The ADC applies to non-rigid, near-equilibrium, conventional airships with seating for nine passengers or less, excluding the pilot, and it serves as the basis for issuing the type certificate required before a particular airship type can enter commercial service in the US. The limited scope of this current regulation is highlighted by the following definitions contained in the ADC:
Airship: an engine-driven, lighter-than-air aircraft, than can be steered.
Non-rigid: an airship whose structural integrity and shape is maintained by the pressure of the gas contained within the envelope.
Near-equilibrium: an airship that is capable of achieving zero static heaviness during normal flight operations.
Supplementary guidance for non-rigid, near-equilibrium, conventional airships is provided in FAA Advisory Circular (AC) No. 21.17-1A, “Type Certification – Airships,” dated 25 September 1992, which is available here:
The FAA’s ADC and the associated AC were written for blimps, not for the range of modern airships under development today. For example, aerostatic lift is only one component of lift in modern hybrid airships, which also depend on powered lift from engines and aerodynamic lift during forward flight. Hybrid airships are not “lighter-than-air” and cannot achieve zero static heaviness during normal operations, yet they are an important class of airships being developed in several countries. In addition, almost all modern airships, except blimps, have rigid or semi-rigid structures that enable them to carry heavy loads and mount powerful engines that cannot possibly be handled by a non-rigid airship.
Recognizing the absence of an adequate regulatory framework for modern airships, civil aviation authorities of Germany and Netherlands developed supplementary guidance to the European Joint Aviation Requirements (JAR-25) and the FAA’s ADC for a category of airships called “Transport Airships,” which they define as follows:
“The transport category is defined for multi-engined propeller driven airships that have a capacity of 20 or more passengers (excluding crew), or a maximum take-off mass of 15,000 kg or more, or a design lifting gas volume of 20,000 m3or more, whichever is greater.”
These supplementary requirements are contained in the document “Transport Airship Requirements” (TAR), dated March 2000, which you will find at the following link:
So, this is the status of US and European airship regulations today.
In the US, Lockheed-Martin currently is in the process of working with the FAA to get a type certificate for their semi-buoyant, hybrid airship, the LMH-1. Clearly, they are dealing with great regulatory uncertainty. Hopefully, the LMH-1 type certification effort will be successful and serve as a precedent for later applicants.
4. Lifting gas
In the US, Canada and Europe, aviation regulations only allow the use of non-flammable lifting gas:
FAA ADC: “The lifting gas must be non-flammable.” (4.48)
TAR: “The lifting gas must be non-flammable, non-toxic and non-irritant” (TAR 893)
Canadian Air Regulations: “Hydrogen is not an acceptable lifting gas for use in airships.” (541.7)
Without hydrogen, the remaining practical choices for lifting gas are helium and hot air. A given volume of hot air can lift only about one-third as much as the same volume of helium, making helium the near-universal choice, with hot air being relegated to a few, small thermal airships.
The current high price of helium is a factor in the renewed interest in hydrogen as a lifting gas. It’s also a key selling point for thermal airships. Most helium is produced as a byproduct from natural gas production. Helium is not “rare.” Only a very small fraction of helium available in natural gas currently is recovered, on the order of 1.25%. The remainder is released to the atmosphere. The helium recovery rate could be higher, but is not warranted by the current market for helium. Helium is difficult to store. The cost of transportation to end-users is a big fraction of the market price of helium.
Hydrogen provides 10% more lift than helium. It can be manufactured easily at low cost and can be stored. If needed, hydrogen can be produced with simple equipment in the field. This could be an important capability for recovering an airship damaged and grounded in a remote region. One airship concept described in Modern Airships – Part 3, the Aeromodeller II, is designed for using hydrogen as the lifting gas and as a clean fuel (zero greenhouse gases produced) for its propulsion engines. A unique feature of this airship concept is an on-board system to generate more hydrogen when needed from the electrolysis of water ballast.
A technique for preventing hydrogen flammability is described in Russian patent RU2441685C2, “Gas compound used to prevent inflammation and explosion of hydrogen-air mixtures,” which was submitted in 2010 and posted in 2012. This technique appears to be applicable to an airship using hydrogen as its lifting gas. You can read the patent at the following link: https://patents.google.com/patent/RU2441685C2/en
The Canadian airship firm Buoyant Aircraft Systems International (BASI) is a proponent of using hydrogen lifting gas. Anticipating a future opportunity to use hydrogen, they have designed their lifting gas cells to be able to operate with either helium or hydrogen. BASI claims that lifting gas cells designed originally for helium lifting gas cannot later be used with hydrogen lifting gas.
Regulatory changes will be required to permit the general use of hydrogen lifting gas in commercial airships. Time will tell if that change ever occurs.
Even with the needed regulatory changes, the insurance industry will have to deal with the matter of insuring a hydrogen-filled airship.
5. Types of modern airships
The term “aerostat” broadly includes all lighter than air vehicles that gain lift through the use of a buoyant gas. Aerostats include unpowered balloons (tethered or free-flying) and powered airships.
The following types of powered airships are described in this section:
Semi-buoyant airships and aircraft
Variable buoyancy airships
Variable buoyancy propulsion airships / aircraft
Helistats (airship – helicopter hybrid)
Thermal (hot air) airships
5.1 Conventional airships
Conventional airships are lighter-than-air (LTA) vehicles that operate at or near neutral buoyancy. The lifting gas (helium) generates approximately 100% of the lift at low speed, thereby permitting vertical takeoff and landing (VTOL) operations and hovering with little or no lift contribution from the propulsion / maneuvering system. Various types of propulsors may be used for cruise flight propulsion and for low-speed maneuvering and station keeping.
Airships of this type include non-rigid blimps, rigid zeppelins, and semi-rigid airships.
Non-rigid airships (blimps): These airships have a flexible envelope that defines the shape of the airship, contains the lifting gas cells and ballonets for buoyancy management, and supports the load of a gondola, engines and payload.
Rigid airships (zeppelins):These airships have a lightweight, rigid airframe that defines their exterior shape. The rigid airframe supports the gondola, engines and payload. Lifting gas cells and ballonets are located within the rigid airframe.
Semi-rigid airships: These airships have a rigid internal spine or structural framework that supports loads. A flexible envelope is installed over the structural framework and contains the lifting gas cells and ballonets.
The Euro Airship DGPAtt and the Flying Whales LCA60T are examples of rigid conventional airships.
The Zeppelin NT and the SkyLifter are examples of semi-rigid conventional airships.
After being loaded and ballasted before flight, conventional airships have various means to control the in-flight buoyancy of the airship. Control can be exercised over ballast, lifting gas and the ballonets as described below.
Controlling buoyancy with ballast:
Many conventional airships require adjustable ballast (i.e., typically water or sand) that can be added or removed as needed to establish a desired net buoyancy before flight. Load exchanges (i.e., taking on / discharging cargo or passengers) can change the overall mass of an airship and may require a corresponding ballast adjustment. If an airship is heavy and the desired buoyancy can’t be restored with the ballonets or other means, ballast can be removed on the ground or may need to be dumped in flight to increase buoyancy.
Controlling buoyancy with lifting gas:
However, temperature differentials between the lifting gas and the ambient air will affect the aerostatic lift produced by the lifting gas. To exploit this behavior, some airships can control buoyancy using lifting gas heaters / coolers to manage gas temperature.
The lifting gas inside an airship’s gas cells is at atmospheric pressure. Normally, there is no significant loss (leakage) of lifting gas to the environment. A given mass of lifting gas will create a constant lift force, regardless of pressure or altitude, when the lifting gas is at equal pressure and temperature with the surrounding air. Therefore, a change in altitude will not change the aerostatic lift.
The lifting gas heaters are important for operation in the Arctic, where a cold-soak in nighttime temperatures may result in the lifting gas temperature lagging behind daytime ambient air temperature. This temperature differential would result in a loss of lift until lifting gas and ambient air temperatures were equal.
Conversely, operating an airship in hot regions can result in the lifting gas temperature rising above ambient air temperature (the lifting gas becomes “superheated”), thereby increasing buoyancy. To restore buoyancy in this case, some airships have coolers (i.e., helium-to-air heat exchangers) in the lifting gas cells to remove heat from the lifting gas.
As described by Boyle’s Law, pressure (P) and gas volume (V) are inversely proportional at a constant temperature according to the following relationship: PV = K, where K is a constant. As an airship ascends, atmospheric pressure decreases. This means that a fixed mass of lifting gas will expand within the lifting gas cells during ascent, and will contract within the lifting gas cells during descent. As described previously, this lifting gas expansion and contraction does not affect the magnitude of the aerostatic lift as long as the lifting gas is at equal pressure and temperature with the surrounding air.
If an airship is light and the desired buoyancy cannot be restored with the ballonets or lifting gas coolers, it is possible to vent some lifting gas to the atmosphere to decrease aerostatic lift.
Controlling buoyancy with ballonets:
The airship hull / envelope is divided into sealed lifting gas volumes and separate gas volumes called “ballonets” that contain ambient air. The ballonets are used to compensate for modest changes in buoyancy by inflating them with small fans or venting them to the atmosphere to change the gross weight of the airship. Fore and aft ballonets can be operated individually to adjust the trim (pitch angle) of the airship.
As the airship gains altitude, external air pressure decreases, allowing the helium gas volume to expand within the gas envelope, into space previously occupied by the air in the ballonets, which vent a portion of their air content overboard. The airship reaches its maximum altitude, known as its “pressure height,” when the helium gas volume has expanded to fill the gas envelope and the ballonets are empty. At this point, the airship’s mass is at a minimum and the helium lifting gas can expand no further.
On the ground, the ballonets may be inflated with air to make the airship negatively buoyant (heavier-than-air) to simplify ground handling. To takeoff, the ballonets would be vented to the atmosphere, reducing the mass of air carried by the airship.
To descend, a low-pressure fan is used to inflate the ballonets with outside air, adding mass. As the airship continues to descend into the denser atmosphere, the helium gas volume continues to contract and the ballonets become proportionately larger, carrying a larger mass of air. Ballonet inflation / venting is controlled to manage buoyancy as the airship approaches the ground for a landing.
In flight, inflating only the fore or aft ballonet, and allowing the opposite ballonet to deflate, will make the bow or stern of the airship heavier and change the pitch of the airship. These operating principles are shown in the following diagrams of a blimp with two ballonets, which are shown in blue.
5.2 Semi-buoyant hybrid airships
Hybrid airships are heavier-than-air (HTA) vehicles. The term “semi-buoyant” means that the lifting gas provides only a fraction of the needed lift (typically 60 – 80%) and the balance of the lift needed for flight is generated by other means, such as vectored thrust engines and aerodynamic lift from the fuselage and wings during forward flight.
Basic characteristics of hybrid airships include the following:
This type of airship requires some airspeed to generate aerodynamic lift. Therefore, it typically makes a short takeoff and landing (STOL).
Some hybrid airships may be capable of limited VTOL operations (i.e., when lightly loaded, or when equipped with powerful vectored thrust engines).
Like conventional airships, the gas envelope in hybrid airship is divided into lifting gas volumes and separate ballonet volumes containing ambient air.
Hybrid airships are heavier-than-air and are easier to control on the ground than conventional airships.
There are two types of hybrid airships: semi-rigid and rigid.
Semi-rigid hybrid airships: These airships have a structural keel or spine to carry loads, and a large, lifting-body shaped inflated fuselage containing the lifting gas cells and ballonets. Operation of the ballonets to adjust net buoyancy and pitch angle is similar to their use on conventional airships. These wide hybrid airships may have separate ballonets on each side of the inflated envelope that can be used to adjust the roll angle. While these airships are heavier-than-air, they generally require adjustable ballast to handle a load exchange involving a heavy load.
Rigid hybrid airships: These airships have a more substantial structure that defines the shape of the exterior aeroshell. The “hard” skin of the airship may be better suited for operation in Arctic conditions, where snow loads and high winds might challenge the integrity of an inflated fuselage of a semi-rigid airship. Otherwise, the rigid hybrid airship behavior is similar to a semi-rigid airship.
The Lockheed-Martin LMH-1 is an example of a semi-rigid hybrid airship. The AeroTruck being developed by Russian firm Airship GP is an example of a rigid hybrid airship.
5.3 Semi-buoyant aircraft
Semi-buoyant aircraft are heavier-than-air, rigid, winged aircraft that carry a large helium volume to significantly reduce the weight of the aircraft and improve its load-carrying capability. Aerostatic lift provides a smaller fraction of total lift for a semi-buoyant aircraft, like a Dynalifter, than it does for a semi-buoyant, hybrid airship.
A semi-buoyant aircraft behaves much like a conventional aircraft in the air and on the ground, and is less affected by wind gusts and changing wind direction on the ground than a hybrid airship.
The semi-buoyant aircraft has some flexibility for loading and discharging cargo without having to be immediately concerned about exchanging ballast, except in windy conditions.
The Aereon Corporation’s Dynairship and the Ohio Airships Dynalifter are examples of semi-buoyant aircraft.
5.4 Variable buoyancy airships
Variable buoyancy airships are rigid airships that can change their net lift, or “static heaviness,” to become LTA or HTA as the circumstances require. Basic characteristics of variable buoyancy airships include the following:
Variable buoyancy airships are capable of VTOL operations and hovering, usually with a full load.
The buoyancy control system may enable in-flight load exchanges from a hovering airship without the need for external ballast.
On the ground, variable buoyancy airships can make themselves heavier-than-air to facilitate load exchanges without the need for external infrastructure or ballast.
It is not necessary for a “light” airship to vent the lifting gas to the atmosphere.
Variable buoyancy / fixed volume airships
Variable buoyancy commonly is implemented by adjusting the net lift of a fixed volume airship. For example, a variable buoyancy / fixed volume airship can become heavier by compressing the helium lifting gas or ambient air:
Compressing some of the helium lifting gas into smaller volume tanks aboard the airship reduces the total mass of helium available to generate aerostatic lift.
Compressing ambient air into pressurized tanks aboard the airship adds mass (ballast) to the airship and thus decreases the net lift.
The airship becomes lighter by venting the pressurized tanks:
Compressed helium lifting gas is vented back into the helium lift cells, increasing the mass of helium available to generate aerostatic lift.
Compressed air is vented to the atmosphere, reducing the mass of the airship and thus increasing net lift.
The Aeros Aeroscraft Dragon Dream and the Varilift ARH-50 are examples of variable buoyancy / fixed volume airships.
Variable buoyancy / variable volume airships
Variable buoyancy also can be implemented by adjusting the total volume of the helium envelope without changing the mass of helium in the envelope.
As the size of the helium envelope increases, the airship displaces more air and the buoyant force of the atmosphere acting on the airship increases. Static heaviness decreases.
Likewise, as the size of the helium envelope decreases, the airship displaces less air and the buoyant force of the atmosphere acting on the airship decreases. Static heaviness increases.
The concept for a variable buoyancy / variable volume airship seems to have originated in the mid-1970s with inventor Arthur Clyde Davenport and the firm Dynapods, Inc. The EADS Tropospheric Airship is a modern example of a variable buoyancy / variable volume airship.
Back in the 1860s, Dr. Solomon Andrews invented the directionally maneuverable, hydrogen-filled airship named Aereon that used variable buoyancy (VB) and airflow around the airship’s gas envelope to provide propulsion without an engine.
VB propulsion airships / aircraft fly a repeating sinusoidal flight profile in which they gain altitude as positively buoyant hybrid airships, then decrease their buoyancy at some maximum altitude and continue to fly under the influence of gravity as a semi-buoyant glider. After gradually losing altitude during a long glide, the pilot increases buoyancy and starts the climb back to higher altitude in the next cycle.
The UK’s Phoenix and Michael Walden’s HY-SOAR BAT concept are two examples of variable buoyancy propulsion airships / aircraft.
5.6 Helistats (airship / helicopter hybrid)
There have been many different designs of airship / helicopter hybrid aircraft (a helistat) in which the airship part of the hybrid aircraft carries the weight of the aircraft itself and helicopter rotors deployed around the base of the airship work in concert to propel the aircraft and to lift and deliver heavy payloads without the need for an exchange of ballast.
The Piasecki PA-97 and the Boeing / Skyhook International SkyHook JLH-40 are examples of helistats.
5.7 Stratospheric airships
Stratospheric airships are designed to operate at very high altitudes, well above the jet stream and in a region of relatively low prevailing winds typically found at altitudes of 60,000 to 75,000 feet (11.4 to 14.2 miles / 18.3 to 22.9 km). This is a harsh environment where airship materials are exposed to the damaging effects of ultraviolet radiation and corrosive ozone. These airships are designed as unmanned vehicles.
Applications for stratospheric airships include military intelligence, surveillance and reconnaissance (ISR) missions, civil environmental monitoring / resource management missions, military / civil telecommunications / data relay functions, and research missions such as high-altitude astronomy. All of these can be long term missions that can last weeks, months or even years.
Typically, the stratospheric airship will operate as a “pseudo-satellite” from an assigned geo-stationary position. Station keeping 24/7 is a unique challenge. Using a hybrid electric power system, these airships can be solar-powered during the day and then operate from an energy storage source (i.e., a battery or regenerative fuel cell) at night. Some propulsion systems, such as propellers that work well at lower altitudes, may have difficulty providing the needed propulsion for station keeping or transit in the very low atmospheric pressure at operating altitude.
The DARPA ISIS airship and the ATG StratSat are two examples for stratospheric airships.
5.8 Thermal (hot air) airships
Thermal airships use hot air as the lifting gas in place of helium or hydrogen. A given volume of hot air can lift only about one-third as much as the same volume of helium. Therefore, the gas envelope on a thermal airship is proportionally larger than it would be on a comparable airship using helium as the lifting gas.
The non-rigid GEFA-Flug four-seat AS-105GD/4 and six-seat AS-105GD/6 and the semi-rigid, two-seat Skyacht Personal Blimp are examples of current thermal airships that use propane burners to produce the hot air for lift. Pitch can be controlled with fore and aft burners. There are no ballonets.
6. How does an airship pick up and deliver a heavy load?
The term “load exchange” refers to the pickup and delivery of cargo by an airship, with or without an exchange of external ballast to compensate for the mass of cargo being moved on or off the airship. This isn’t a simple problem to solve.
The problem of buoyancy control
In Jeanne Marie Laskas’ article, Igor Pasternak, CEO of airship manufacturer Worldwide Aeros Corp. (Aeros), commented on the common problem facing all airships when a heavy load is delivered:
“The biggest challenge in using lighter-than-air technology to lift hundreds of tons of cargo is not with the lifting itself—the larger the envelope of gas, the more you can lift—but with what occurs after you let the stuff go. ‘When I drop the cargo, what happens to the airship?’ Pasternak said. ‘It’s flying to the moon.’ An airship must take on ballast to compensate for the lost weight of the unloaded cargo, or a ground crew must hold it down with ropes.”
Among the many current designers and manufacturers of large airships, the matter of maintaining the airship’s net buoyancy within certain limits while loading and unloading cargo and passengers is handled in several different ways depending on the type of airship involved. Some load exchange solutions require ground infrastructure at fixed bases and/or temporary field sites for external ballast handling, while others require no external ballasting infrastructure and instead use systems aboard the airship to adjust buoyancy to match current needs or provide vectored thrust (or suction) to temporarily counteract the excess buoyancy. The solution chosen for managing airship buoyancy during a load exchange strongly influences how an airship can be operationally employed and where it can pickup and deliver its payload.
Additional problems for airborne load exchanges
Several current designers and manufacturers of large airships report that their airships will have the ability to conduct airborne load exchanges of cargo from a hovering airship. Jeremy Fitton, the Director of SkyLifter, Ltd., described the key issues affecting a precision load exchange executed by a hovering airship as follows:
“The buoyancy management element of (an airborne) load-exchange is not the main control problem for airships. Keeping the aircraft in a geo-stationary position – in relation to the payload on the ground – is the main problem, of which buoyancy is a component.”
The matters of precisely maintaining the airship’s geo-stationary position throughout an airborne load exchange and controlling the heading of the airship and the suspended load are handled in different ways depending on the type of airship involved. The time required to accomplish the airborne load exchange can be many minutes or much longer, depending on the weight of the cargo being picked up or delivered and the time it takes for the airship to adjust its buoyancy for its new loaded or unloaded condition. Most of the airships offering an airborne load exchange capability are asymmetrical (i.e., conventional “cigar shaped” or hybrid aerobody-shaped) and must point their nose into the wind during an airborne load exchange. Their asymmetrical shape makes these airships vulnerable to wind shifts during the load exchange. The changing cross-sectional area exposed to the wind complicates the matter of maintaining a precise geo-position with an array of vectoring thrusters.
During such a delivery in variable winds, even with precise geo-positioning over the destination, the variable wind direction may require the hovering airship to change its heading slightly to point into the wind. This can create a significant hazard on the ground, especially when long items, such as a wind turbine blade or long pipe segment are being delivered. For example, the longest wind turbine blade currently in production is the GE Haliade-X intended for off-shore wind turbine installations. This one-piece blade is 107 meter (351 ft) long. A two degree change in airship heading could sweep the long end of the blade more than three meters (10 feet), which could be hazardous to people and structures on the ground.
Regulatory requirements pertaining to load exchanges
The German / Netherlands “Transport Airship Requirements” (TAR), includes the following requirement for load exchanges in TAR 80, “Loading / Unloading”:
(c) During any cargo exchange…the airship must be capable of achieving a safe free flight condition within a time period short enough to recover from a potentially hazardous condition.”
This requirement will be a particular challenge for airships designed to execute an airborne load exchange from a hovering airship.
The CargoLifter approach to an airborne load exchange
“The airship hovers at about 100 m above the ground and a special loading frame, which is fixed during flight to the keel of the airship, is then rigged with four cable winches to the ground, a procedure which is to assure that the airship’s lifting gear stays exactly above the desired position. Ballast water is then pumped into tanks on the frame and the payload can be unloaded. The anchor lines are released and the frame is pulled back into the payload bay of the airship.”In a 2002 test using a heavy-lift CargoLifter CL75 aerostat as an airship surrogate, a 55 metric ton German mine-clearing tank was loaded, lifted and discharged from the loading frame as water ballast was unloaded and later reloaded in approximately the same time it took to secure the tank in the carriage (several minutes). In this test, the 55 metric tons cargo was exchanged with about 55 cubic meters (1,766 cubic feet, 14,530 US gallons) of water ballast.
The SkyLifter approach to an airborne load exchange
One airship design, the SkyLifter, addresses the airborne load exchange issues with a symmetrical, disc-shaped hull that presents the same effective cross-sectional area to a wind coming from any direction. This airship is designed to move equally well in any direction (omni-directional), simplifying airship controls in changing wind conditions, and likely giving the SkyLifter an advantage over other designs in conducting a precision airborne load exchange.
You’ll find more information on airship load exchange issues in a December 2017 paper by Charles Luffman, entitled, “A Dissertation on Buoyancy and Load Exchange for Heavy Airships (Rev. B)”, which is available at the following link:
Some of the advanced airship concepts being developed, especially for future heavy-lift cargo carriers, will result in extremely large air vehicles on a scale not seen since the heyday of the giant zeppelins in the 1930s. Consider the following semi-rigid hybrid airships shown to scale with contemporary fixed-wing cargo aircraft.
8. Specific airships in Part 1
The wide variety of airships reviewed in Modern Airships – Part 1 are summarized in the following set of tables. Links to the individual articles on these airships are provided at the end of this document.
The Aerofloat HL, CargoLifter CL160, helistats, Megalifter, Aereon Dynairship, Project Walrus and the HULA program are included because they are of historical interest as early, though largely unsuccessful, attempts to develop heavy-lift cargo airships. Concepts and technologies developed on these airship projects have contributed to the development of modern airships.
Among the airships in the above tables, the following have flown:
Cargolifter Joey airship & CL75 AC aerostat
Zeppelin NT 07
Variable buoyancy, fixed volume airships:
Aeros Aeroscraft Dragon Dream
Helistats (airship / helicopter hybrid):
Hybrid, semi-buoyant aircraft:
Aereon 26 (only as a heavier-than-air craft)
Hybrid, semi-buoyant airships:
Lockheed Martin P-791
Hybrid Air Vehicles HAV-3 & HAV-304
Hybrid Air Vehicles Airlander 10
Voliris 901 & 902
Lockheed Martin HALE-D
Thermal (hot air) airships:
GEFA-Flug AS-105GD/4 & AS-105GD/6
Skyacht Personal Blimp
As of December 2020, the Zeppelin NT 07 is the only advanced airship that has been certified and is flying regularly in commercial passenger service. The simpler GEFA-Flug and Skyacht thermal (hot air) airships also are flying regularly. Among the others that have flown, most have been retired and a few were damaged or destroyed. The remaining airships in the Part 1 tables are under development or remain as concepts only.
Among the airships in the above tables, the following cargo airships seem likely to receive their airworthiness certification in the next several years. The leading candidates identified in Part 1 are:
Lockheed Martin: LMH-1 hybrid airship
Hybrid Air Vehicles (HAV): Airlander 10 hybrid airship
These airships will be competing in the worldwide airship market with the leading candidates identified in Part 2, which may enter the market in the same time frame:
Flying Whales: LCA60T rigid airship
Varialift: ARH-PT variable buoyancy airship prototype and the larger ARH 50
Euro Airship: Corsair & DGPAtt variable buoyancy airships
Solar Ship: 24-meter Caracal light cargo semi-buoyant airship and the Wolverine medium cargo semi-buoyant aircraft
Egan Airships: The PLIMP drone and Model J plane / blimp hybrids
All of these candidates depend on a source of funding to bring their advanced designs to market.
This next decade will be an exciting time for the airship industry. We’ll finally get to see if the availability of several different heavy-lift airships with commercial airworthiness certificates will be enough to open a new era in airship transportation. Aviation regulatory agencies need to help reduce risk by eliminating regulatory uncertainty and putting in place an adequate regulatory framework for the wide variety of advanced airships being developed. Customers with business cases for airship applications need to step up, place firm orders, and then begin the pioneering task of employing their airships and building a worldwide airship transportation network with associated ground infrastructure.
9. Links to the individual articles
The following links will take you to the 38 individual Modern Airships – Part 1 articles.
“Modern Airships” is a three-part document that contains an overview of modern airship technology in Part 1 and links in Parts 1, 2 and 3 to 95 individual articles on historic and advanced airship designs. This is Part 3. Here are the links to the other two parts:
Modern Airships – Part 3 begins with a summary table identifying the airship concepts addressed in this part, and concludes by providing links to 32 individual articles on these airship concepts. A downloadable copy of Part 3 is available here:
If you have any comments or wish to identify errors in this document, please send me an e-mail to: PL31416@cox.net.
I hope you’ll find the Modern Airships series to be informative, useful, and different from any other single document on this subject.
2. Specific airship concepts in Part 3
The airships described in Part 3 are relatively exotic concepts in comparison to the heavy-lift cargo airships that dominate Parts 1 and 2. Many of the airship concepts in Part 3 are designed for operation with very low or no carbon emissions. I’ve grouped these airship concepts based on their applications rather than on their design / type because sometimes those details are difficult to determine when few graphics and limited descriptions are available. A few of these airships look good as concepts, but may be impossible to build. Nonetheless, all of these relatively exotic concepts point toward an airship future that will benefit from the great creativity expressed by these designers.
The airship design concepts reviewed in Part 3 are summarized in the following set of tables. Except for a few sub-scale models, none of these airship concepts have flown. Links to individual articles on these airships are provided at the end of this document.
3. Links to the individual articles
The following links will take you to 32 individual articles. Note that the Avalon Airships article addresses all three of their airship design concepts, which are listed separately in the above tables and in the following index.
“Modern Airships” is a three-part document that contains an overview of modern airship technology in Part 1 and links in Parts 1, 2 and 3 to 95 individual articles on historic and advanced airship designs. This is Part 2. Here are the links to the other two parts:
Modern Airships – Part 2 begins with a summary table identifying the airship concepts addressed in this part, and concludes by providing links to 25 individual articles on these airship concepts. A downloadable copy of Part 2 is available here:
The links to the individual articles are at the end of this document.
If you have any comments or wish to identify errors in this document, please send me an e-mail to: PL31416@cox.net.
I hope you’ll find the Modern Airships series to be informative, useful, and different from any other single document on this subject.
2. Specific airships in Part 2
The airships reviewed in Part 2 are summarized in the following set of tables. There are many heavy-lift cargo airships in these tables. In addition, there are several solar-powered airships and sub-scale airships that demonstrated novel means of airship propulsion. Links to the individual articles on these airships are provided at the end of this document.
Among the airships in the above tables, the following full-scale airships have flown:
Project Sol’R Nephelios solar-powered airship
Solar Ship 20-meter Caracal prototype
Solomon Andrews’ Aereon I and II variable buoyancy propulsion airships (in the 1860s)
In addition, the following sub-scale demonstrators have flown:
Festo b-IONIC Airfish (demonstration of ionic propulsion)
Phoenix and AHAB (demonstrations of variable buoyancy propulsion)
Among the airships in the above tables, several airships are likely to receive their airworthiness certification in the next several years. The leading candidates identified in Part 2 are:
Flying Whales: The LCA60T prototype maiden flight is expected to take place in 2021, and the firm appears to have the funding needed to enter full-scale production.
Varialift: The ARH-PT prototype’s first “float test” is expected in 2019. The first ARH 50 roll out is expected in 2021, with a 24-month certification process before commercial deliveries begin.
Euro Airship: Production-ready drawings exist for the Corsair and the larger DGPAtt. When funding becomes available, they’re ready to go.
Solar Ship: The 24-meter Caracal semi-buoyant, inflated wing airship and the larger Wolverine semi-buoyant aircraft are expected to receive Canadian certification, possibly by 2020 – 2021.
Egan Airships: The PLIMP drone and Model J plane / blimp hybrids that have started their FAA certification processes.
These airships will be competing in the worldwide airship market with the leading candidates identified in Part 1, which may enter the market in the same time frame:
Lockheed Martin: LMH-1 hybrid airship
Hybrid Air Vehicles (HAV): Airlander 10 hybrid airship
Aeros Aeroscraft ML866 / Aeroscraft Gen 2: variable buoyancy airship
The early 2020s will be an exciting time for the airship industry. We’ll finally get to see if the availability of several different heavy-lift airships with commercial airworthiness certificates will be enough to open a new era in airship transportation. Aviation regulatory agencies need to help reduce risk by eliminating regulatory uncertainty and putting in place an adequate regulatory framework for the wide variety of advanced airships being developed. Customers with business cases for airship applications need to step up, place firm orders, and then begin the pioneering task of employing their airships and building a worldwide airship transportation network with associated ground infrastructure.
3. Links to the individual articles
The following links will take you to the 25 individual articles. Note that the Atlas / Augur RosAeroSystems, Solar Ship, Egan Airships, and variable buoyancy propulsion articles addressed all of the related airship designs, some of which were listed separately in the preceding tables.
On July 16th, 1969, 13:32:00 UTC, the Saturn V launch vehicle, SA-506, lifted off from Launch Pad 39-A at Kennedy Space Center, Florida on the Apollo 11 mission with astronauts Neil Armstrong (Mission commander), Michael Collins (Command Module pilot) and Edwin (Buzz) Aldrin (Lunar Module pilot).
The Apollo spacecraft consisted of three modules:
The three-person Command Module (CM), named Columbia, was the living quarters for the three-person crew during most of the lunar landing mission.
The Service Module (SM) contained the propulsion system, electrical fuel cells, consumables storage tanks (oxygen, hydrogen) and various service / support systems.
The two-person, two-stage Lunar Module (LM), named Eagle, would make the Moon landing with two astronauts and return them to the CM.
The LM’s descent stage (bottom part of the LM with the landing legs) remained on the lunar surface and served as the launch pad for the ascent stage (upper part of the LM with the crew compartment). Only the 4.9 ton CM was designed to withstand Earth reentry conditions and return the astronauts safely to Earth.
From its initial low Earth parking orbit, Apollo 11 flew a direct trans-lunar trajectory to the Moon, inserting into lunar orbit about 76 hours after liftoff. The Apollo 11 mission profile to and from the Moon is shown in the following diagram, and is described in detail here: https://www.mpoweruk.com/Apollo_Moon_Shot.htm
Neil Armstrong and Buzz Aldrin landed the Eagle LM in the Sea of Tranquility on 20 July 1969, at 20:17 UTC (about 103 hours elapsed time since launch), while Michael Collins remained in a near-circular lunar orbit aboard the CSM. Neil Armstrong characterized the lunar surface at the Tranquility Base landing site with the observation, “it has a stark beauty all its own.”
In the two and a half hours they spent on the lunar surface, Armstrong and Aldrin collected 21.55 kg (47.51 lb) of rock samples, took photographs and set up the Passive Seismic Experiment Package (PSEP) and the Laser Ranging RetroReflector (LRRR), which would be left behind on the Moon. The PSEP provided the first lunar seismic data, returning data for three weeks after the astronauts left, and the LRRR allows precise distance measurements to be collected to this day. Neil Armstrong made an unscheduled jaunt to Little West crater, about 50 m (164 feet) east of the LM, and provided the first view into a lunar crater.
Armstrong and Aldrin departed the Moon on 21 July 1969 at 17:54 UTC in the ascent stage of the Eagle LM and then rendezvoused and docked with Collins in the CSM about 3-1/2 hours later.
After discarding the ascent stage, the CSM main engine was fired and Apollo 11 left lunar orbit on 22 July 1969 at 04:55:42 UTC and began its trans-Earth trajectory. As the Apollo spacecraft approached Earth, the SM was jettisoned.
The CM reentered the Earth’s atmosphere and landed in the North Pacific on 24 July 1969 at 16:50:35 UTC. The astronauts and the Apollo 11 spacecraft were recovered by the aircraft carrier USS Hornet. President Nixon personally visited and congratulated the astronauts while they were still in quarantine aboard the USS Hornet. You can watch a video of this meeting here:
Mankind’s first lunar landing mission was a great success.
Postscript to the first Moon landing
A month after returning to Earth, the Apollo 11 astronauts were given a ticker tape parade in New York City, then termed as the largest such parade in the city’s history.
There were a total of six Apollo lunar landings (Apollo 11, 12, 14, 15, 16, and 17), with the last mission, Apollo 17, returning to Earth on 19 December 1972. Their landing sites are shown in the following graphic.
In the past 46+ years since Apollo 17, there have been no manned missions to the Moon by the U.S. or any other nation.
Along with astronaut John Glenn, the first American to fly in Earth orbit, the three Apollo 11 astronauts were awarded the New Frontier Congressional Gold Medal in the Capitol Rotunda on 16 November 2011. This is the Congress’ highest civilian award and expression of national appreciation for distinguished achievements and contributions.
Neil Armstrong died on 25 August 2012 at the age of 82.
The Apollo 11 command module Columbia was physically transferred to the Smithsonian Institution in 1971 and has been on display for decades at the National Air and Space Museum on the mall in Washington D.C. For the 50th anniversary of the Apollo 11 mission, Columbia will be on display at The Museum of Flight in Seattle, as the star of the Smithsonian Institution’s traveling exhibition, “Destination Moon: The Apollo 11 Mission.” You can get a look at this exhibit at the following link: http://www.collectspace.com/news/news-041319a-destination-moon-seattle-apollo.html
After years of changing priorities under the Bush and Obama administrations, NASA’s current vision for the next U.S. manned lunar landing mission is named Artemis, after the Greek goddess of hunting and twin sister of Apollo. NASA currently is developing the following spaceflight systems for the Artemis mission:
The Space Launch System (SLS) heavy launch vehicle.
A manned “Gateway” station that will be placed in lunar orbit, where it will serve as a transportation node for lunar landing vehicles and manned spacecraft for deep space missions.
The Orion multi-purpose manned spacecraft, which will deliver astronauts from Earth to the Gateway, and also can be configured for deep space missions.
Lunar landing vehicles, which will shuttle between the Gateway and destinations on the lunar surface.
While NASA has a tentative goal of returning humans to the Moon by 2024, the development schedules for the necessary Artemis systems may not be able to meet this ambitious schedule. The landing site for the Artemis mission will be in the Moon’s south polar region. NASA administrator Jim Bridenstine has stated that Artemis will deliver the first woman to the Moon.
After the failure of Israel’s Beresheet spacecraft to execute a soft landing on the Moon in April 2019, India is the next new contender for lunar soft landing honors with their Chandrayaan-2 spacecraft. We’ll take a look at the Chandrayaan-2 mission in this post.
1. Background: India’s Chandrayaan-1 mission to the Moon
India’s first mission to the Moon, Chandrayaan-1, was a mapping mission designed to operate in a circular (selenocentric) polar orbit at an altitude of 100 km (62 mi). The Chandrayaan-1 spacecraft, which had an initial mass of 1,380 kg (3,040 lb), consisted of two modules, an orbiter and a Moon Impact Probe (MIP). Chandrayaan-1 carried 11 scientific instruments for chemical, mineralogical and photo-geologic mapping of the Moon. The spacecraft was built in India by the Indian Space Research Organization (ISRO), and included instruments from the USA, UK, Germany, Sweden and Bulgaria.
Chandrayaan-1 was launched on 22 October 2008 from the Satish Dhawan Space Center (SDSC) in Sriharikota on an “extended” version of the indigenous Polar Satellite Launch Vehicle designated PSLV-XL. Initially, the spacecraft was placed into a highly elliptical geostationary transfer orbit (GTO), and was sent to the Moon in a series of orbit-increasing maneuvers around the Earth over a period of 21 days. A lunar transfer maneuver enabled the Chandrayaan-1 spacecraft to be captured by lunar gravity and then maneuvered to the intended lunar mapping orbit. This is similar to the five-week orbital transfer process used by Israel’s Bersheet lunar spacecraft to move from an initial GTO to a lunar circular orbit.
The goal of MIP was to make detailed measurements during descent using three instruments: a radar altimeter, a visible imaging camera, and a mass spectrometer known as Chandra’s Altitudinal Composition Explorer (CHACE), which directly sampled the Moon’s tenuous gaseous atmosphere throughout the descent. On 14 November 2008, the 34 kg (75 lb) MIP separated from the orbiter and descended for 25 minutes while transmitting data back to the orbiter. MIP’s mission ended with the expected hard landing in the South Pole region near Shackelton crater at 85 degrees south latitude.
In May 2009, controllers raised the orbit to 200 km (124 miles) and the orbiter mission continued until 28 August 2009, when communications with Earth ground stations were lost. The spacecraft was “found” in 2017 by NASA ground-based radar, still in its 200 km orbit.
Numerous reports have been published describing the detection by the Chandrayaan-1 mission of water in the top layers of the lunar regolith. The data from CHACE produced a lunar atmosphere profile from orbit down to the surface, and may have detected trace quantities of water in the atmosphere. You’ll find more information on the Chandrayaan-1 mission at the following links:
2. India’s upcoming Chandrayaan-2 mission to the Moon
Chandrayaan-2 was launched on 22 July 2019. After achieving a 100 km (62 mile) circular polar orbit around the Moon, a lander module will separate from the orbiting spacecraft and descend to the lunar surface for a soft landing, which currently is expected to occur in September 2019, after a seven-week journey to the Moon. The target landing area is in the Moon’s southern polar region, where no lunar lander has operated before. A small rover vehicle will be deployed from the lander to conduct a 14-day mission on the lunar surface. The orbiting spacecraft is designed to conduct a one-year mapping mission.
The launch vehicle
India will launch Chandrayaan-2 using the medium-lift Geosynchronous Satellite Launch Vehicle Mark III (GSLV Mk III) developed and manufactured by ISRO. As its name implies, GSLV Mk III was developed primarily to launch communication satellites into geostationary orbit. Variants of this launch vehicle also are used for science missions and a human-rated version is being developed to serve as the launch vehicle for the Indian Human Spaceflight Program.
The GSLV III launch vehicle will place the Chandrayaan-2 spacecraft into an elliptical parking orbit (EPO) from which the spacecraft will execute orbital transfer maneuvers comparable to those successfully executed by Chandrayaan-1 on its way to lunar orbit in 2008. The Chandrayaan-2 mission profile is shown in the following graphic. You’ll find more information on the GSLV Mk III on the ISRO website at the following link: https://www.isro.gov.in/launchers/gslv-mk-iii
Chandrayaan-2 builds on the design and operating experience from the previous Chandrayaan-1 mission. The new spacecraft developed by ISRO has an initial mass of 3,877 kg (8,547 lb). It consists of three modules: an Orbiter Craft (OC) module, the Vikram Lander Craft (LC) module, and the small Pragyan rover vehicle, which is carried by the LC. The three modules are shown in the following diagram.
Chandrayaan-2 carries 13 Indian payloads — eight on the orbiter, three on the lander and two on the rover. In addition, the lander carries a passive Laser Retroreflector Array (LRA) provided by NASA.
The OC and the LC are stacked together within the payload fairing of the launch vehicle and remain stacked until the LC separates in lunar orbit and starts its descent to the lunar surface.
The solar-powered orbiter is designed for a one-year mission to map lunar surface characteristics (chemical, mineralogical, topographical), probe the lunar surface for water ice, and map the lunar exosphere using the CHACE-2 mass spectrometer. The orbiter also will relay communication between Earth and Vikram lander.
The solar-powered Vikram lander weighs 1,471 kg (3,243 lb). The scientific instruments on the lander will measure lunar seismicity, measure thermal properties of the lunar regolith in the polar region, and measure near-surface plasma density and its changes with time.
The 27 kg (59.5 lb) six-wheeled Pragyan rover, whose name means “wisdom” in Sanskrit, is solar-powered and capable of traveling up to 500 meters (1,640 feet) on the lunar surface. The rover can communicate only with the Vikram lander. It is designed for a 14-day mission on the lunar surface. It is equipped with cameras and two spectroscopes to study the elemental composition of lunar soil.
You’ll find more information on the spacecraft in the 2018 article by V. Sundararajan, “Overview and Technical Architecture of India’s Chandrayaan-2 Mission to the Moon,” at the following link:
The firm Northrop Grumman Innovation Systems (formerly Orbital ATK, and before that, Orbital Sciences Corporation) was the first to develop a commercial, air-launched rocket capable of placing payloads into Earth orbit. Initial tests of their modest-size Pegasus launch vehicle were made in 1990 from the NASA B-52 that previously had been used as the “mothership” for the X-15 experimental manned space plane and many other experimental vehicles.
Since 1994, Orbital ATK has been using a specially modified civilian Lockheed L-1011 TriStar, a former airliner renamed Stargazer, as a mothership to carry a Pegasus launch vehicle to high altitude, where the rocket is released to fly a variety of missions, including carrying satellites into orbit. With a Pegasus XL as its payload (launch vehicle + satellite), Stargazer is lifting up to 23,130 kg (50,990 pounds) to a launch point at an altitude of about 12.2 km (40,000 feet).
Paul Allen’s firm Stratolaunch Systems Corporation (https://www.stratolaunch.com) was founded in 2011 to take this air-launch concept to a new level with their giant, twin-fuselage, six-engine Stratolaunch carrier aircraft. The aircraft has a wingspan of 385 feet (117 m), which is the greatest of any aircraft ever built, a length of 238 feet (72.5 m), and a height of 50 feet (15.2 m) to the top of the vertical tails. The empty weight of the aircraft is about 500,000 pounds (226,796 kg). It is designed for a maximum takeoff weight of 1,300,000 pounds (589,670 kg), leaving about 550,000 pounds (249,486 kg) for its payload and the balance for fuel and crew. It will be able to carry multiple launch vehicles on a single mission to a launch point at an altitude of about 35,000 feet (10,700 m). A mission profile for the Stratolaunch aircraft is shown in the following diagram.
Stratolaunch rollout – 2017
Built by Scaled Composites, the Stratolaunch aircraft was unveiled on 31 May 2017 when it was rolled out at the Mojave Air and Space Port in Mojave, CA. Following is a series of photos from Stratolaunch Systems showing the rollout.
Stratolaunch ground tests – 2017 to 2019
Ground testing of the aircraft systems started after rollout. By mid-September 2017, the first phase of engine testing was completed, with all six Pratt & Whitney PW4000 turbofan engines operating for the first time. The first low-speed ground tests conducted in December 2017 reached a modest speed of 25 knot (46 kph). By January 2019, the high-speed taxi tests had reached a speed of about 119 knots (220 kph) with the nose wheel was off the runway, almost ready for lift off. Following is a series of photos from Stratolaunch Systems showing the taxi tests.
Stratolaunch first flight
The Stratolaunch aircraft, named Roc, made an unannounced first flight from the Mojave Air & Space Port on 13 April 2019. The aircraft stayed aloft for 2.5 hours, reached a peak altitude of 17,000 feet (5,180 m) and a top speed of 189 mph (304 kph). The following series of photos show the Stratolaunch aircraft during its first flight.
Stratolaunch posted an impressive short video of the first flight, which you can view here:
Stratolaunch family of launch vehicles: ambitious plans, but subject to change
In August 2018, Stratolaunch announced its ambitious launch vehicle development plans, which included the family of launch vehicles shown in the following graphic:
Up to three Pegasus XL launch vehicles from Northrop Grumman Innovation Systems (formerly Orbital ATK) can be carried on a single Stratolaunch flight. Each Pegasus XL is capable of placing up to 370 kg (816 lb) into a low Earth orbit (LEO, 400 km / 249 mile circular orbit).
Medium Launch Vehicle (MLV) capable of placing up to 3,400 kg (7,496 lb) into LEO and intended for short satellite integration timelines, affordable launch and flexible launch profiles. MLV was under development and first flight was planned for 2022.
Medium Launch Vehicle – Heavy, which uses three MLV cores in its first stage. That vehicle would be able to place 6,000 kg (13,228 lb) into LEO. MLV-Heavy was in the early development stage.
A fully reusable space plane named Black Ice, initially intended for orbital cargo delivery and return, with a possible follow-on variant for transporting astronauts to and from orbit. The space plane was a design study.
Stratolaunch was developing a 200,000 pound thrust, high-performance, liquid fuel hydrogen-oxygen rocket engine, known as the “PGA engine”, for use in their family of launch vehicles. Additive manufacturing was being widely used to enable rapid prototyping, development and manufacturing. Successful tests of a 100% additive manufactured major subsystem called the hydrogen preburner were conducted in November 2018.
After Paul Allen’s death on 15 October 2018, the focus of Stratolaunch Corp was greatly revised. On 18 January 2019, the company announced that it was ending work on its own family of launch vehicles and the PGA rocket engine. The firm announced, “We are streamlining operations, focusing on the aircraft and our ability to support a demonstration launch of the Northrop Grumman Pegasus XL air-launch vehicle.”
You’ll find an article describing Stratolaunch Systems’ frequently changing launch vehicle plans in an article on the SpaceNews website here:
Air launch offers a great deal of flexibility for launching a range of small-to-medium sized satellites and other aerospace vehicles. With only the Pegasus XL as a launch vehicle, and with Northrop Grumman having their own Stargazer carrier aircraft for launching the Pegasus XL, the business case for the Stratolaunch aircraft has been greatly weakened.
Additional competition in the airborne launch services business will come in 2020 from Richard Branson’s firm Virgin Orbit, with its airborne launch platform Cosmic Girl, a highly-modified Boeing 747, and its own launch vehicle, known as LauncherOne. Successful drop tests of LauncherOne were conducted in 2019. The first launch to orbit is expected to occur in 2020. You’ll find more information on the Virgin Orbit website here: https://virginorbit.com
Additional competition for small satellite launch services comes from the newest generation of small orbital launch vehicles, like Electron (Rocket Lab, New Zealand) and Prime (Orbix, UK), which are expected to offer low price launch services from fixed land-based launch sites. Electron is operational now, and achieved six successful launches in six attempts in 2019. Prime is expected to enter service in 2021.
In the cost competitive launch services market, Stratolaunch does not seem to have an advantage with only the Pegasus XL in its launch vehicle inventory. Hopefully, they have something else up their sleeve that will take advantage of the remarkable capabilities of the Stratolaunch carrier aircraft.
19 March 2020 Update: Stratolaunch change of ownership
Several sources reported on 11 October 2019 that Stratolaunch Systems had been sold by its original holding company, Vulcan Inc., to an undisclosed new owner. Two months later, Mark Harris, writing for GeekWire, broke the news that the private equity firm Cerberus Capital Management was the new owner. It appears that Jean Floyd, Stratolaunch’s president and CEO since 2015, remains in his roles for now. Michael Palmer, Cerberus’ managing director, was named Stratolaunch’s executive vice president. You can read Mark Harris’ report here: https://www.geekwire.com/2019/exclusive-buyer-paul-allens-stratolaunch-space-venture-secretive-trump-ally/
It will be interesting to watch as the new owners reinvent Stratolaunch Systems for the increasingly competitive market for airborne launch services.