NASA’s DART spacecraft impact measurably redirected the asteroid Dimorphos

Peter Lobner, updated 28 July 2023

NASA’s Double Asteroid Redirection Test (DART), which was launched on 24 November 2021, was the first test of a technology for defending Earth against potential asteroid or comet hazards. DART’s target was the small “moonlet” named Dimorphos orbiting the larger near-Earth asteroid Didymos, which itself is only a half mile in diameter.  You can explore at the Didymos – Dimorphos binary system on NASA’s Solar System Exploration webpage here: https://solarsystem.nasa.gov/asteroids-comets-and-meteors/asteroids/didymos/in-depth/

Simulation of the Didymos – Dimorphos binary system. 
Source: NASA’s Solar System Exploration
Actual view of the Didymos – Dimorphos binary system as 
DART approached impact with Dimorphos (background). 
Source: NASA / JHAPL

The goal is for the DART spacecraft was to strike the moonlet Dimorphos at high speed while being trailed by another small spacecraft, the Italian Space Agency’s (ASI) cubesat, dubbed LICIACube, that would directly observe the encounter and report back to NASA and ASI. 

By comparing pre- and post-impact measurements made with powerful Earth-based and orbiting telescopes, the NASA / Johns Hopkins Applied Physics Lab (JHAPL) team could determine what changes occurred to Dimorphos’ orbit around Didymos. These results will help assess the feasibility of using a high-energy impactor as a tool for deflecting the trajectory of an asteroid, particularly one that represents a significant risk to Earth.  Learn more about the DART spacecraft and its mission objectives on NASA’s Planetary Defense Coordination Office website here: https://www.nasa.gov/planetarydefense/dart/dart-news

NASA successfully guided DART to a collision with Dimorphos on 26 September 2022.   You can watch the final five minutes of DART’s approach to the Didymos – Dimorphos binary system up to the final image before impact here: https://www.nasa.gov/feature/dart-s-final-images-prior-to-impact

DART closeup image of Dimorphos moments before impact.
Source: NASA / JHAPL
ASI’s LICIACube image just before its closest approach to Dimorphos (background). The debris plume cast off from Dimorphos after DART’s impact is clearly visible. Didymos is in the foreground. Source: ASI / NASA

The Hubble Space Telescope was used to capture images of the impact.  The NASA/ESA Hubble Space Telescope team reported:

“The Hubble movie starts at 1.3 hours before impact. The first post-impact snapshot is 20 minutes after the event. Debris flies away from the asteroid in straight lines, moving faster than four miles per hour (fast enough to escape the asteroid’s gravitational pull, so it does not fall back onto the asteroid). The ejecta forms a largely hollow cone with long, stringy filaments.

At about 17 hours after the impact the debris pattern entered a second stage. The dynamic interaction within the binary system started to distort the cone shape of the ejecta pattern. The most prominent structures are rotating, pinwheel-shaped features. The pinwheel is tied to the gravitational pull of the companion asteroid, Didymos. 

Hubble next captures the debris being swept back into a comet-like tail by the pressure of sunlight on the tiny dust particles. This stretches out into a debris train where the lightest particles travel the fastest and farthest from the asteroid. The mystery is compounded later when Hubble records the tail splitting in two for a few days.”

8 October 2022 photo by the Hubble Space Telescope shows Dimorphos with its debris tail. Source: NASA/ESA/STScI/Hubble

The results are in, and on 1 March 2023, the NASA / JHAPL team reported a much greater change to Dimorphos’ orbit than originally expected.

“…the investigation team, led by Cristina Thomas of Northern Arizona University, arrived at two consistent measurements of the period change from the kinetic impact: 33 minutes, plus or minus one minute. This large change indicates the recoil from material excavated from the asteroid and ejected into space by the impact (known as ejecta) contributed significant momentum change to the asteroid, beyond that of the DART spacecraft itself.”

Source: NASA/JHAPL

After the success of the DART mission, maybe the U.S. Planetary Defense Officer will have fewer sleepless nights, but this is only the first small, but successful step toward an operational planetary defense system.

28 June 2023 update: Hubble sees bolder swarm surrounding Dimorphos

In June 2023, NASA reported that the Hubble Space Telescope had observed a swarm of 37 boulders that appears to have been knocked loose from Dimorphos upon impact. 

An image of the impacted asteroid, Dimorphos, with drawn-in circles around the areas where boulders have been detected. Note that the relationship between north and east on the sky (as seen from below) is flipped relative to direction arrows on a map of the ground (as seen from above). Source: NASA, ESA, David Jewitt (UCLA); Alyssa Pagan (STScI)

NASA reported: 

“The 37 free-flung boulders range in size from three feet to 22 feet across, based on Hubble photometry. They are drifting away from the asteroid at little more than a half-mile per hour – roughly the walking speed of a giant tortoise. The total mass in these detected boulders is about 0.1% the mass of Dimorphos…… The boulders are most likely not shattered pieces of the diminutive asteroid caused by the impact. They were already scattered across the asteroid’s surface, as evident in the last close-up picture taken by the DART spacecraft just two seconds before collision, when it was only seven miles above the surface.”

The loose composition of the surface of Dimorphos can be seen in this last complete image just prior to DART impact. Source: NASA, APL

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A UAE Rover Carried by a Japanese Lander Attempted a Moon Landing in April 2023

Peter Lobner, updated 13 September 2023

1. Introduction

To date, only Russia, the U.S. and China have accomplished soft landings on the Moon, with each nation using a launch vehicle and spacecraft developed within their own national space programs. 

On 8 October 2020, Sheikh Mohammed bin Rashid announced the formation of the UAE’s lunar rover program, which intends to accomplish the first moon landing for the Arab world using the commercial services of a U.S. SpaceX Falcon 9 launch vehicle and a Japanese ispace lunar landing vehicle named HAKUTO-R. Once on the lunar surface, the UAE’s Rashid rover will be deployed to perform a variety of science and exploration tasks. This mission was launched from Cape Canaveral on 11 December 2022.

Emirates Lunar Mission (ELM) patch. 
Source: MBRSpaceCenter tweet

2. Japan’s ispace HAKUTO-R lunar lander

The Japanese firm ispace, inc. was founded in September 2010, with headquarters in Tokyo, a U.S. office in Denver, CO, and a European office in Luxembourg.  Their website is here: https://ispace-inc.com

ispace’s HAKUTO team was one of six finalist teams competing for the Google Lunar XPRIZE. On 15 December 2017, XPRIZE reported,” Congratulations to Google Lunar XPRIZE Team HAKUTO for raising $90.2 million in Series A funding toward the development of a lunar lander and future lunar missions! This is the biggest investment to date for an XPRIZE team, and sends a strong signal that commercial lunar exploration is on the trajectory to success. One of the main goals of the Google Lunar XPRIZE is to revolutionize lunar exploration by spurring innovation in the private space sector, and this announcement demonstrates that there is strong market interest in innovative robotic solutions for sustainable exploration and development of the Moon. The XPRIZE Foundation looks forward to following Team HAKUTO as they progress toward their lunar mission!”

The Google Lunar XPRIZE was cancelled when it became clear that none of the finalist teams could meet the schedule for a lunar landing in 2018 and other constraints set for the competition.  Consequently, Team HAKUTO’s lander was not  flown on a mission to the Moon.

In April 2021, the Mohammed Bin Rashid Space Center (MBRSC) of the United Arab Emirates (UAE) signed a contract with ispace, under which ispace agreed to provide commercial payload delivery services for the Emirates Lunar Mission. After final testing in Germany, the ispace SERIES-1 (S1) lunar lander was ready in 2022 for the company’s ‘Mission 1,’ as part of its commercial lunar landing services program known as ‘HAKUTO-R’.

HAKUTO-R, aka SERIES-1 (S1), lunar lander general arrangement. 
It is more than 7 feet (2.3 meters) tall. Source: ispace

After its launch on 11 December 2022, the lunar spacecraft has been flying a “low energy” trajectory to the Moon in order to minimize fuel use during the transit and, hence, maximizes the available mission payload. It will take nearly five months for the combined lander / rover spacecraft to reach the Moon in April 2023.

The low-energy trajectory being flown for the Emirates Lunar Mission shows spacecraft position (end of blue line, at top) as of 4 March 2023. The spacecraft will enter lunar orbit (yellow circle) in April 2023, before landing on the Moon.
Source: ispace

The primary landing site is the  Atlas crater in Lacus Somniorum (Lake of Dreams), which is a basaltic plain formed by flows of basaltic lava, located in the northeastern quadrant of the moon’s near side.

Lake of Dreams is highlighted in the yellow square.
Source: The Lunar Registry
Hakuto-R Mission 1 Moon landing milestones. Source: ispace

If successful, HAKUTO-R will also become the first commercial spacecraft ever to make a controlled landing on the moon.

After landing, the UAE’s Rashid rover will be deployed from the HAKUTO-R lander. In addition, the lander will deploy an orange-sized sphere from the Japanese Space Agency that will transform into a small wheeled robot that will move about on the lunar surface. 

3. UAE’s Rashid lunar rover

The Emirates Lunar Mission (ELM) team at the Mohammed bin Rashid Space Centre (MBRSC) is responsible for designing, manufacturing and developing the rover, which is named Rashid after Dubai’s royal family.  The ELM website is here: https://www.mbrsc.ae/service/emirates-lunar-mission/

The Rashid rover weighs just 22 pounds (10 kilograms) and, with four-wheel drive, can traverse a smooth surface at a maximum speed of 10 cm/sec (0.36 kph) and climb over an obstacle up to 10 cm (3.9 inches) tall and descend a 20-degree slope. 

Rashid rover general arrangement. Source: MBRSC

The Rashid rover is designed to operate on the Moon’s surface for one full lunar day (29.5 Earth days), during which time it will conduct studies of the lunar soil in a previously unexplored area. In addition, the rover will conduct engineering studies of mobility on the lunar surface and susceptibility of different materials to adhesion of lunar particles. The outer rims of this rover’s four wheels incorporate small sample panels to test how different materials cope with the abrasive lunar surface, including four samples contributed by the European Space Agency (ESA).

The diminutive rover carries the following scientific instruments:

  • Two high-resolution optical cameras (Cam-1 & Cam-2) are expected to take more than 1,000 still images of the Moon’s surface to assess the how lunar dust and rocks are distributed on the surface.
  • A “microscope” camera
  • A thermal imaging camera (Cam-T) will provide data for determining the thermal properties of lunar surface material.
  • Langmuir probes will analyze electric charge and electric fields at the lunar surface.
  • An inertial measurement unit to track the motion of the rover.

Mobility and communications tests of the completed rover were conducted in March 2022 in the Dubai desert.

Rashid rover during desert tests. Source: Gulf News (March 2022)

The Ottawa, Ontario company Mission Control Space Services has provided a deep-learning artificial intelligence (AI) system named MoonNet that will be used for identifying geologic features seen by the rover’s cameras. Mission Control Services reports, “Rashid will capture images of geological features on the lunar terrain and transmit them to the lander and into MoonNet. The output of MoonNet will be transmitted back to Earth and then distributed to science team members….Learning how effectively MoonNet can identify geological features, inform operators of potential hazards and support path planning activities will be key to validating the benefits of AI to support future robotic missions.”

This color-coded image is an example of the type of output the MoonNet AI system is expected to produce.
 Source: Mission Control Space Services

4. Landing attempt failed

The Hakuto-R lander crashed into the Moon on 25 April 2023 during its landing attempt.

In May 2023, the results of an ispace analysis of the landing failure were reported by Space.com:

“The private Japanese moon lander Hakuto-R crashed in late April during its milestone landing attempt because its onboard altitude sensor got confused by the rim of a lunar crater. the unexpected terrain feature led the lander’s onboard computer to decide that its altitude measurement was wrong and rely instead on a calculation based on its expected altitude at that point in the mission. As a result, the computer was convinced the probe was lower than it actually was, which led to the crash on April 25.”

“While the lander estimated its own altitude to be zero, or on the lunar surface, it was later determined to be at an altitude of approximately 5 kms [3.1 miles] above the lunar surface,” ispace said in a statement released on Friday (May 26). “After reaching the scheduled landing time, the lander continued to descend at a low speed until the propulsion system ran out of fuel. At that time, the controlled descent of the lander ceased, and it is believed to have free-fallen to the moon’s surface.”

On 23 May 2023, NASA reported that the its Lunar Reconnaissance Orbiter spacecraft had located the crash site of the UAE’s lunar spacecraft. The before and after views are shown in the following images.

Hakuto-R crash site, before (left) and after (right) the crash. Source: NASA/GSFC/Arizona State University

5. The future

ispace future lunar plans

ispace reported, “ispace’s SERIES-2 (S2) lander is designed, manufactured, and will be launched from the United States. While the S2 lander leverages lessons learned from the company’s SERIES-1 (S1) lander, it is an evolved platform representing our next generation lander series with increased payload capacity, enhanced capabilities and featuring a modular design to accommodate orbital, stationary or rover payloads.”

Ispace was selected through the Commercial Lunar Payload Services (CLPS) initiative to deliver NASA payloads to the far side of the Moon using the SERIES-2 (S2) lander, starting in 2025.

UAE future lunar plans

In October 2022, the UAE announced that it was collaborating with China on a second lunar rover mission, which would be part of China’s planned 2026 Chang’e 7 lunar mission that will be targeted to land near the Moon’s south pole. These plans may be cancelled after the U.S. applied export restrictions in March 2023 on the Rashid 2 rover, which contains some US-built components. The U.S. cited its 1976 International Traffic in Arms Regulations (ITAR), which prohibit even the most common US-built items from being launched aboard Chinese rockets.

6. For more information

Future missions

Video

DoD’s Project Pele microreactor is being developed by BWXT with a target for initial operation at a DoD facility in 2027

Peter Lobner

In 2016 the Defense Science Board (DSB) identified energy as a critical enabler of future military operations. The DoD’s Strategic Capabilities Office (SCO) launched Project Pele with the objective to design, build, and demonstrate a prototype mobile nuclear reactor to provide reliable and resilient electric power, while minimizing risk of nuclear proliferation, environmental damage, or harm to nearby personnel or populations. 

The Pele reactor will be the first electricity-generating Generation IV nuclear reactor built in the United States. Check out the DoD Office of the Under Secretary of Defense, Research and Engineering (OUSD(R&E)) website for the Project Pele Environmental Impact Statement (EIS) here: https://www.cto.mil/pele_eis/

In June 2022, Department of Defense (DoD) selected BWXT to produce a single prototype Pele mobile microreactor, which will be a Brayton-cycle high-temperature gas-cooled reactor (HTGR) capable of generating an electrical output of 1 MWe to 5 MWe. See the story in Power magazine here: https://www.powermag.com/dod-picks-bwxt-to-manufacture-project-pele-prototype-nuclear-microreactor/

The Pele reactor will use High-Assay, Low-Enriched Uranium (HALEU, <20% enriched) fuel in the form of TRstructural ISOtropic (TRISO) coated fuel pellets (each about the size of a poppy seed). 

Cross-section of a TRISO particle, greatly magnified.
Source: DOE

The reactor will be assembled and initially operated at the Idaho National Laboratory (INL), under the safety oversight of the Department of Energy (DOE).  The Pele reactor is expected to be transportable by rail, truck or cargo aircraft.

Pele reactor modes of transportation. Source: GAO

There’s a good status update on Project Pele in a February 2023 article on the Energy Intelligence website, “Interview: Pentagon’s Jeff Waksman on Project Pele Microreactor,” at the following link: https://www.energyintel.com/00000186-7b02-d1cb-a3ee-ffbf32940000

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Kelvin-Helmholtz Clouds Look Like Ocean Waves in the Sky

Peter Lobner

I recently saw the following spectacular photos of Kelvin-Helmholtz clouds that had occurred a few days earlier in Wyoming. The website EarthSky, which posted the first photo, reported, “Kelvin-Helmholtz clouds are named for Lord Kelvin and Hermann von Helmholtz, who studied the physics of the instability that leads to this type of cloud formation.” 

 Kelvin-Helmholtz clouds in Sheridan, Wyoming, 6 December 2022.
Source: Abbie Long, via EarthSky Community Photos: https://earthsky.org/earthsky-community-photos/entry/54020/
Kelvin-Helmholtz clouds in Wyoming, 9 December 2022
Source: Rachel Gordon / Facebook via BBC: https://www.bbc.com/news/world-us-canada-63912257

The Hydrometeorology Group website (https://hydrometeology-group1.weebly.com/kelvinndashhelmholtz-instability.html) reports, “Kelvin-Helmholtz clouds are the product of a strong wind shear. Wind shear refers to the rate of change of wind speed, or wind direction, over a set distance. The formation of Kelvin-Helmholtz clouds requires the presence of two vertical air layers of different densities that travel at different speeds. The upper layer must be the warmer and less dense of the two. Given a great enough wind shear, eddies will develop where the two air layers meet.”This type of process is illustrated in the following diagram.

Formation of Kelvin-Helmholtz clouds. 
Source: SKYbrary (https://www.skybrary.aero/articles/kelvin-helmholtz-waves)

You’ll find more photos and details on Kelvin-Helmholtz clouds in the following March 2022 EarthSky article, which notes that Kelvin-Helmholtz formations also can be observed at the interfaces of some cloud bands encircling Jupiter and Saturn: https://earthsky.org/earth/kelvin-helmholtz-clouds/

Kelvin-Helmholtz clouds pattern formed between two of Saturn’s cloud bands.
Source: Astronomy.com (https://astronomy.com/news/2004/10/turbulent-clouds-and-a-rock-steadied-ring

Could Kelvin-Helm clouds have been the inspiration for Vincent Van Gogh’s post-impressionistic masterpiece, The Starry Night, which he painted while recovering in an asylum in Saint Rémy (Provence) France in June 1889?

Source: MoMA, https://www.moma.org/collection/works/79802

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Webb Space Telescope Provides an Extraordinary View of the Planet Neptune

Peter Lobner

In April 2021, I posted a short article entitled, “Multi-messenger Astronomy Provides Extraordinary Views of Uranus,” which included two composite views of Uranus, created by combining near-infrared images taken by the Keck-1 telescope at an elevation of 4,145 meters (13,599 ft) on Maunakea, Hawaii, with X-ray images taken with the Advanced CCD Imaging Spectrometer (ACIS) aboard the orbiting Chandra X-Ray Observatory.

Now, the Webb Space Telescope has taken stunning near-infrared images of the next, and outermost, planet in our solar system, Neptune (sorry, Pluto). You can read NASA’s 21 September 2022 news release on these images here: https://www.nasa.gov/feature/goddard/2022/new-webb-image-captures-clearest-view-of-neptune-s-rings-in-decades

The Webb images of Neptune, taken on July 12, 2022, are reproduced below.

NASA: “Webb captured seven of Neptune’s 14 known moons: Galatea, Naiad, Thalassa, Despina, Proteus, Larissa, and Triton. Neptune’s large and unusual moon, Triton, dominates this Webb portrait of Neptune as a very bright point of light sporting the signature diffraction spikes seen in many of Webb’s images.”
Source: NASA, ESA, CSA, STScI
NASA: “…image of Neptune……brings the planet’s rings into full focus for the first time in more than three decades. The most prominent features of Neptune’s atmosphere in this image are a series of bright patches in the planet’s southern hemisphere that represent high-altitude methane-ice clouds. More subtly, a thin line of brightness circling the planet’s equator could be a visual signature of global atmospheric circulation that powers Neptune’s winds and storms. Additionally, for the first time, Webb has teased out a continuous band of high-latitude clouds surrounding a previously-known vortex at Neptune’s southern pole.” Source: NASA, ESA, CSA, STScI

The Space Telescope Science Institute (STScI) has created a Resource Gallery of Webb Space Telescope images, which you can browse here: https://webbtelescope.org/resource-gallery/images. Currently there are 280 images in the Webb Resource Gallery.  I think this is a website worth revisiting from time to time.

NASA’s Solar System Exploration website provides views of Neptune from several earlier sources, including the 1989 Voyager 2 deep space probe, the Hubble Space Telescope and the European Southern Observatory’s (ESO) Very Large Telescope (VLT). Check it out here: https://solarsystem.nasa.gov/planets/neptune/galleries/

2018: The following image was taken in July 2018 during the testing of the narrow-field, adaptive optics mode of the optical/infrared MUSE/GALACSI instrument on ESO’s VLT, which is located at an elevation of 2,635 m (8,645 ft) at Cerro Paranal, in the Atacama Desert of northern Chile.

2018 VLT image of Neptune. The corrected image is sharper than a comparable image from the NASA/ESA Hubble Space Telescope. Source: ESO/P. Weilbacher (AIP)

1994: The more recent Webb Space Telescope and VLT images are much better than the Hubble Space Telescope optical-range images of Neptune taken more than two decades earlier, in 1994.

NASA: “The images were taken in 1994 on October 10 (upper left), October 18 (upper right), and November 2 (lower center). Hubble is allowing astronomers to study Neptune’s dynamic atmosphere with a level of detail not possible since the 1989 flyby of the Voyager 2 space probe. Building on Voyager’s initial discoveries, Hubble is revealing that Neptune has a remarkably dynamic atmosphere that changes over just a few days. The temperature difference between Neptune’s strong internal heat source and its frigid cloud tops (-260 degrees Fahrenheit) might trigger instabilities in the atmosphere that drive these large-scale weather changes. In addition to hydrogen and helium, the main constituents, Neptune’s atmosphere is composed of methane and hydrocarbons, like ethane and acetylene.” Source: NASA, JPL, STScI

1989: In October 1989, the following whole planet view of Neptune was produced using images taken through the green and orange filters on the narrow angle camera during the Voyager 2 spacecraft flyby of the planet.

NASA: “This picture of Neptune was taken by Voyager 2 less than five days before the probe’s closest approach of the planet on Aug. 25, 1989. The picture shows the “Great Dark Spot” — a storm in Neptune’s atmosphere — and the bright, light-blue smudge of clouds that accompanies the storm”. 
Source: NASA/JPL-Caltech (1989)
 

In the future, we can hopefully look forward to more detailed multi-messenger images of Neptune, combining the near-infrared images from Webb with images from other observatories that can view the planet in different spectral bands.

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Video

Ulstein’s Nuclear-powered Thor and its All-electric Companion Vessel Are a Zero-Carbon Solution for Marine Tourism

Peter Lobner

1. Introduction

In June 2022, the Norwegian firm Ulstein (https://ulstein.com) announced their conceptual design of a Replenishment, Research and Rescue (3R) vessel named Thor that will be powered by a thorium molten salt reactor (MSR). This vessel can function as a seaborne mobile charging station for a small fleet of electrically-powered expedition / cruise ships that are designed to operate in environmentally sensitive areas such as the Arctic and Antarctic. Other environmentally sensitive areas include the West Norwegian Fjords, which are UNESCO World Heritage sites that will be closed in 2026 to all ships that are not zero-emission. In the future, similar regulations could be in place to protect other environmentally sensitive regions of the world, thereby reinforcing Ulstein’s business case behind Thor and its all-electric companion vessels.

Ulstein’s Thor MSR-powered vessel (left) and 
Sif electrically-powered expedition / cruise vessel (right). 
Source: Ulstein

2. The MSR-powered Thor charging station

Thor is a 149-meter (500-foot) long, zero-emission, nuclear-powered vessel that features Ulstein’s striking, backwards-sloping X-bow, which is claimed to result in a smoother ride, higher speed while using less energy, and less mechanical wear than a ship with a conventional bow. 

For its R3 mission, Thor would be outfitted with work boats, cranes, a helicopter landing pad, unmanned aerial vehicles (UAVs), unmanned surface vessels, firefighting equipment, rescue booms, a lecture hall and laboratories.

As a charging station, Thor would be sized to recharge four all-electric vessels simultaneously.

Thor.  Source: Ulstein

Thor also could serve as a floating power station, replacing diesel power barges in some developing countries or in some disaster areas while the local electric power infrastructure is being repaired.

Ulstein projects that an operational Thor vessel could be launched in “10 to 15 years.” However, the development and licensing of a marine MSR is on the critical path for that schedule.  

Thor, starboard side views.  Source, both graphics: Ulstein

3. The all-electric Sif expedition / cruise ship

Sif, named after the goddess who was Thor’s wife, is a design concept for a 100-meter (330-foot) long, all-electric, zero-emission expedition / cruise ship designed to operate with minimal impact in environmentally sensitive areas. The ship will be powered by a new generation of solid batteries that are expected to offer greater capacity and resistance to fire than lithium-ion batteries used commonly today.  It will be periodically recharged at sea by Thor.

The ship can accommodate 80 passengers and 80 crew. 

Sif, starboard side view.  Source, both graphics: Ulstein

4. A marine MSR power plant

The pressurized water reactor (PWR) is the predominant marine nuclear power plant in use today, primarily in military vessels, but also in Russian icebreakers and a floating nuclear power plant in the Russian Arctic. 

Ulstein reported that it has been exploring MSR technology because of its favorable operating and safety characteristics. For example, an MSR operates at atmospheric pressure (unlike a PWR) and passive features and systems maintain safety in an emergency. If the core overheats, the molten salt fuel/coolant mixture automatically drains out of the reactor and into a containment vessel where it safely solidifies and can be reused.  You’ll find a good overview of MSR technology here: https://whatisnuclear.com/msr.html

While a few experimental MSRs have operated in the past, no MSR has been subject to a commercial nuclear licensing review, even for a land-based application. Ulstein favors a thorium-fueled MSR. The thorium-uranium-233 fuel cycle introduces additional technical and nuclear licensing uncertainties because of the lack of operational and nuclear regulatory precedents.

Several firms are developing MSR concepts. However, the combination of a marine MSR and a thorium fuel cycle remains elusive. Two uranium-fueled marine MSR design concepts are described below.

Seaborg Technologies

The Danish firm Seaborg Technologies (https://www.seaborg.com), founded in 2014, is developing a compact MSR (CMSR) with a rating of about 250 MWt / 100 MWe for use in power barges (floating nuclear power plants) of their own design (see my 16 May 2021 post). The thermal-spectrum CMSR uses uranium-235 fuel in a molten proprietary salt, with a separate sodium hydroxide (NaOH) moderator.  

A Seaborg Technologies CMSR module could generate 100 MWe. Dump tank shown below reactor. Source: Seaborg via NEI (2022)

Seaborg’s development time line calls for a commercial CMSR prototype to be built in 2024, with commercial production of power barges beginning in 2026. 

Source: Seaborg (2022)

In April 2022, Seaborg and the Korean shipbuilding firm Samsung Heavy Industries signed a partnership agreement for manufacturing and selling turnkey CMSR power barges. 

On 10 June 2022, Seaborg was selected by the European Innovation Council to receive a significant (potentially up to €17.5 million) innovation grant to help accelerate their work on the CMSR.

CORE-POWER and the Southern Company consortium

The UK firm CORE-POWER Ltd. (https://corepower.energy), founded in 2018, began with a concept for a compact uranium-235 fueled, molten chloride salt reactor named the m-MSR for marine applications. This modular, inherently safe, 15 MWe micro-reactor system was designed as a zero-carbon replacement power source for the fossil-fueled power plants in many existing commercial marine vessels.  It also was intended for use as the original power source for new vessels, as proposed for the Earth 300 Eco-Yacht design concept unveiled by entrepreneur Aaron Olivera in April 2021 (see my 17 April 2021 post). The power output of a modular CORE-POWER m-MSR installation could be scaled to meet operational needs by adding reactor modules in compact arrangements suitable for shipboard installation. 

A set of six small, compact CORE-POWER m-MSR modules
could generate 90 MWe. Dump tank not shown. Source: CORE-POWER

In November 2020, CORE-POWER announced that it had joined an international consortium to develop MSRs. This team includes the US nuclear utility company Southern Company (https://www.southerncompany.com), US small modular reactor developer TerraPower (https://www.terrapower.com) and nuclear technology company Orano USA (https://www.orano.group/usa/en). In the consortium, TerraPower is responsible for the fast-spectrum Molten Chloride Fast Reactor (MCFR). CORE-POWER is responsible for maritime readiness and regulatory approvals.

This consortium applied to the US Department of Energy (DOE) to participate in cost-share risk reduction awards under the Advanced Reactor Demonstration Program (ARDP), to develop a prototype MCFR as a proof-of-concept for a medium-scale commercial-grade reactor. In December 2020, the consortium was awarded $90.4 million, with the goal of demonstrating the first MCFR in 2024.  DOE reported, “They expect to begin testing in a $20 million integrated effects test facility starting in 2022. The team has successfully scaled up the salt manufacturing process to enable immediate testing. Data generated from the test facility will be used to validate thermal hydraulics and safety analysis codes for licensing of the reactor.”In February 2021, CORE-POWER presented the MCFR development schedule in the following chart, which shows the MCFR becoming available for deployment in marine propulsion in about 2035.  This is within the 10 to 15 year timescale projected by Ulstein for their first Thor vessel.

Source: CORE-POWER (2021)

5. In conclusion

A seaborne nuclear-powered “charging station” supporting a small fleet of all-electric marine vessels provides a zero-carbon solution for operating in protected, environmentally sensitive areas that otherwise would be off limits to visitors. Ulstein’s concept for the MSR-powered Thor R3 vessel and the Sif companion vessel is a clever approach for implementing that strategy.

It appears that a uranium-fueled marine MSR could be commercially available in the 10 to 15 year time frame Ulstein projects for deploying Thor and Sif.  The technical and nuclear regulatory uncertainties associated with a thorium-fueled marine MSR will require a considerably longer time frame. 

6. For additional information 

Ulstein Thor & Sif

Video

Seaborg CMSR

CORE-POWER m-MSR

The Event Horizon Telescope Team has Produced the First Image Showing the Shadow of the Sgr A* Black Hole at the Center of our Milky Way Galaxy

Peter Lobner

Background

The first-ever direct image of a black hole was released on 10 April 2019 by the Event Horizon Telescope (EHT) team and the National Science Foundation (NSF).  The target for their observation was the supermassive M87* black hole at the center of the distant Messier 87 (M87) galaxy, some 54 million light years away. The EHT team estimated that M87* has a mass of about 6.5 billion Solar-masses (6.5 billion times greater than the mass of our Sun), and the black hole consumes the equivalent of about 900 Earth-masses per day. One Solar mass is roughly equivalent to the weight of the Sun and about 333,000 times the mass of Earth. Gases orbiting around the giant M87* black hole take days to weeks to complete an orbit. For more information on the first M87* black hole image, see my 10 April 2019 article here: https://lynceans.org/all-posts/the-event-horizon-telescope-team-has-produced-the-first-image-showing-the-shadow-of-a-black-hole/

For decades, there has been mounting evidence that there is a massive black hole, known as Sagittarius A*, or Sgr A* for short, at the center of our Milky Way galaxy.  Its presence has been inferred from the motions of visible stars that are orbiting under the gravitational influence of the black hole or are in the general vicinity of the black hole.  Using observed data from more than 30 stars in the region around the galactic center, scientists developed high-resolution simulations that helped refine estimates of the location, mass and size of the Sgr A* black hole without having data from direct observations.  For more information on this work, see my 24 January 2017 article here: https://lynceans.org/all-posts/the-black-hole-at-our-galactic-center-is-revealed-through-animations/

First-ever image of Sgr A*

On 12 May 2022, the EHT team and the European Southern Observatory (ESO) held a press conference and released the first-ever image to directly show the ring of glowing gas surrounding the Sgr A* black hole.  You can read their press release here: https://eventhorizontelescope.org/blog/astronomers-reveal-first-image-black-hole-heart-our-galaxy

Initial EHT team and ESO results from their Sgr A* observations have been published and are available on The Astrophysical Journal Letters website here: https://iopscience.iop.org/journal/2041-8205/page/Focus_on_First_Sgr_A_Results

First-ever image looking down into the ring of rotating, glowing gas
surrounding Sgr A*. Source: EHT Collaboration
Composite image showing the location of the Sgr A* black hole (inset) in a composite 
X-ray/infrared NASA image of the heart of our Milky Way galaxy. 
Source: EHT Collaboration & NASA

Even though it was much closer than M87*, getting an image of Sgr A* was much harder because the Sgr A* black hole had to be viewed through the densely populated central plane of our Milky Way.  The Sgr A* radio frequency (millimeter wave) observations were made in 2017 at a wavelength of 1.3 mm (230 GHz), the same as the first image of M87*. 

Details that have emerged so far from the Sgr A* observation include the following.

  • Sgr A* is about 27,000 light years away, at the heart of our own galaxy (about 2 thousand times closer than M87*, which is in a different galaxy). 
  • Sgr A* has a mass is about 4 million times the mass of our Sun, which is just a small fraction (1/1,500th , or 0.07%) of the mass of M87*.
  • The glowing gas ring surrounding the Sgr A* black hole has an outer diameter of about 72 million miles (115 million km) across, which is approximately the diameter of Mercury’s orbit around the Sun in our solar system. The EHT team reported, “We were stunned by how well the size of the ring agreed with predictions from Einstein’s Theory of General Relativity.”  By comparison, M87* is vastly larger, with the inner black hole region measuring about 23.6 billion miles (38 billion km) across (about 330 times the diameter of the entire Sgr A* black hole, including the glowing gas ring), as shown in the following scale diagram.
Comparison of the sizes of M87* (left) and Sgr A* (right). 
Source: EHT Collaboration (acknowledgment: Lia Medeiros)
  • The two black holes subtend approximately the same angle when viewed from Earth. The EHT team reported that the M87* bright emission disk subtends an angle of 42 ± 3 microarcseconds.
  • Gases orbiting around the Sgr A* black hole take mere minutes to an 1 hour to complete an orbit.  The fast moving gases blur the image for an EHT observation typically lasting several hours. The released image of the Sgr A* black hole is an average of many different images the EHT team extracted from the data.
  • Sgr A* is far less active than M87*, and consumes only about 1/1,000th the mass per day (equivalent of about 1 Earth-mass per day).
  • The source of the three bright spots in the glowing gas ring are unknown at this time.  They may be artifacts of the EHT observation process.

Follow-on EHT observations will benefit from additional telescopes joining the EHT network and significant technical improvements being made to the EHT telescopes and network systems.  For example, operating the telescopes in the EHT array at a shorter wavelength of 0.87 mm (frequency of 345 GHz) will improve angular resolution by about 40%. More frequent observations and faster data processing would enable time-lapse movies to be created to show the dynamics of gas motion around the black hole. Details on planned improvements are discussed in my 9 April 2020 article here: https://lynceans.org/all-posts/working-toward-a-more-detailed-view-of-a-black-hole/

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Hey, PG&E! Energy Storage is Not the Same as Energy Generation!!

Peter Lobner, updated 20 February 2022

The two-unit Diablo Canyon nuclear power plant, which is owned and operated by Pacific Gas & Electric (PG&E), is the last operating nuclear power station in California. In the five year period from 2016 – 2020, the average annual load factor performance of these power plants was as follows:

  • Diablo Canyon 1:  1,138 MWe net @ 91.56% = 1.042 Gigawatt-years (GW-years) generated per year
  • Diablo Canyon 2:  1,118 MWe net @ 85.64% = 0.957 GW-years generated per year

Over that five year period, the average annual amount of electricity delivered to the California electrical grid by the two-unit Diablo Canyon nuclear power plant was about 2.0 GW-years (2,000 Megawatt-years or 17,520,000 Megawatt-hours). On a daily basis, that’s an average of about 48,000 MW-hours. This electricity was generated reliably, 24/7 (except during planned outages), with zero carbon emissions.

The Diablo Canyon nuclear plant in Avila Beach, CA. 
Source: Joe Johnston / San Luis Obispo Tribune via LA Times (2018)

In 2016, I reported (https://lynceans.org/all-posts/the-nuclear-renaissance-is-over-in-the-u-s/):

“On 21 June 2016, PG&E issued a press release announcing that they will withdraw their application to the NRC for a 20-year license extension for the Diablo Canyon 1 & 2 nuclear power plants and will close these plants by 2025 when their current operating licenses expire.  PGE will walk away from about 41 GW-years of carbon-free electric power generation.”

The shutdown plan was approved by the California Public Utilities Commission in January 2018.

In 2019, PG&E reported that their mix of generation sources (owned and purchased from a third-party) looked like this:

Source: PG&E (2019)

A few interesting points about this PG&E generation source chart:

  • Nuclear power generation is the biggest piece of the pie chart. Shutdown of Diablo Canyon by 2025 will eliminate this piece.
  • Renewables include wind, solar, small hydro, geothermal and biomass / waste.  Batteries are not included because they are energy storage devices, not energy generation sources.  The energy stored in a grid-scale battery comes from a generator, or simply, from the grid.
  • Large hydro depends on the associated reservoirs having enough water in them. The Edward Hyatt hydroelectric power plant at Lake Oroville (California’s second-largest reservoir) was shut down in August 2021 for the first time since it opened in 1967 because of low water levels during the persistent drought affecting the US West. Power production at Oroville resumed in January 2022 with only a single hydroelectric generator, after heavy winter precipitation increased lake water level. If the drought continues, the large hydro piece of the pie chart will shrink.

Another point is that the PG&E generation source mix is quite different from the California state-wide generation source mix reported by the California Energy Commission in 2020 and shown in the following pie chart.  Not all of the generation sources represented in this chart are physically located in California (more on that later).

Source: Data from California Energy Commission (2020)
 

Diablo Canyon has a disproportionate impact on the PG&E  generation mix because they own the nuclear power plant and they take credit for its entire net generation.  State-wide, nuclear power makes up only 9.33% of the state generation mix in a much larger electric power market.

When Diablo Canyon is shut down in 2025, I would think that the PG&E energy generation mix will look a lot more like the California state-wide generation mix, with most of the nuclear power generation share being replaced, at least in the short term, by fossil fuel-powered generators.

In January 2022, PG&E announced that they have a plan: “PG&E Corp. said it has reached agreements to install nine new battery energy storage projects as part of a push to replace a retiring nuclear power plant and help decarbonize California’s power grid.”

So, let me see if I’ve got this right.  PG&E is going to use grid-scale storage batteries that produces zero carbon emissions during their operation to partially replace a nuclear power generating station that produces zero carbon emissions during 24/7 operation. Where will the power come from to charge those batteries?  It’ll come from the California Independent System Operator (CAISO) grid, which has the California state-wide generation source mix shown above, with almost 40% coming from fossil fuel-powered generators in 2020, and likely to increase after Diablo Canyon’s retirement. So, one charge-discharge cycle of a grid-scale battery isn’t carbon-free.

PG&E further announced, “The proposed projects would have a total capacity of about 1,600 megawatts, which would bring its total battery energy storage capacity to more than 3,300 gigawatts by 2024…”

On the surface, that sounds like an impressive amount of battery capacity, but let’s put it in perspective.

The former Moss Landing fossil power station on Monterey Bay was decommissioned and transformed into a grid-scale energy storage facility. In August 2021, after completing Phase II of the transformation, the facility was operating with a capacity of 400 MW / 1,600 MW-hours, making it the world’s largest grid-storage project. The facility’s owner, Vistra Energy, said the Moss Landing facility could be expanded to a capacity of up to 1,600 MW / 6,000 MWh.

At its current discharge capacity of 400 MW, the Moss Landing batteries could discharge their full energy storage capacity of 1,600 MW-hours in about four hours.  Then the battery is “empty” and needs to be recharged from the CAISO grid (as we discussed, that’s about 40% from fossil-powered generation sources in 2020). Of course, a grid-storage facility wouldn’t be operated regularly on such a stressful cycle. But my point is that the world’s largest grid-storage project is be capable of delivering no more than 3.3% of the 48,000 MW-hours of electricity delivered daily, 24/7, with zero carbon emissions, by the Diablo Canyon nuclear power plant.

California has a huge, and growing, energy problem of its own making. With Diablo Canyon and several fossil-powered generators scheduled for retirement in the next few years, the state needs new generating capacity.  However, the development time scale for a new large generating facility in California, especially considering the state’s challenging regulatory environment, might have to be measured in decades.

One of California’s solutions to its shortfall of electrical generating capacity is to import electric power from other states and nations.  The U.S. Energy Information Administration (EIA) reported that California was the largest net electricity importer, by a wide margin, of any state in 2019. Its net electricity imports were 70.8 million MW-hours, or 25% of the state’s total electricity usage. California utilities partly own and import power from several power plants in Arizona and Utah. In addition, California’s electricity imports include hydroelectric power from the Pacific Northwest and power from fossil and wind generators in Mexico.

Source: EIA

Grid-scale battery storage is not going to solve the state’s shortfall of electrical generating capacity. Rather, the batteries are a means to mitigate short-term demand peaks and help stabilize the grid as generators attempt to match energy supply with demand.

Another mitigating measure used by CAISO is a “flex alert,” which asks consumers to cut back on electricity usage and move their electricity usage to off-peak hours, typically after 9 pm.  CAISO issued five flex alerts in 2020 and eight in 2021. When a grid-scale battery is discharged during a flex alert, recharging it would add a large load on an already strained grid; probably not a good idea.

California is throwing away valuable 24/7 generating capacity and replacing it with intermittent renewable generators, with grid-scale energy storage facilities to provide short-term mitigation that doesn’t address the real underlying problem.  There is no substitute for adequate generating capacity, sized to meet the current and future demands of businesses and individuals as we try to move together into a more electrified future.

Failing that, I can see increasing electric power rates, more flex alerts, and in California, I wouldn’t be surprised to see some form of legislated energy rationing coupled with higher energy use taxation. So much for that vision of a more electrified future.

Don’t sell you gasoline or diesel-powered car yet.  You may need it during the next flex alert.

20 February 2022 update: Moss Landing battery fires

Since becoming operational, Vistra Energy’s Moss Landing battery storage facility on Monterey Bay experienced two damaging fire events in lithium-ion battery packs. A fire on 4 September 2021 set off fire suppression system sprinklers that damaged about 7,000 batteries. Vistra Energy reported corrective actions following this fire on 21 January 2022.  Another fire on 13 February 2022 resulted in 10 melted lithium-ion battery packs. The latest fire event was contained by the facility’s fire suppression system. Vistra reported that it was looking further into the latest incident, while the Moss Landing facility remains offline during the investigation.

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Veteran LSR Car Little Giant Raises the US National Electric Car Speed Record

Peter Lobner, 2 November 2021

In 2016, I wrote about Ohio State University’s Venturi Buckeye Bullet-3 (VBB-3) all-electric, four wheel drive land speed record (LSR) car, which set an FIA (Federation Internationale de l’Automobile) world electric vehicle two-way land-speed record (Category A Group VIII Class 8) at an average speed of 341.4 mph (549 kph) on 19 September 2016. (https://lynceans.org/all-posts/vbb-3-the-worlds-most-powerful-electric-car-will-challenge-the-land-speed-record-in-2016/)

That FIA two-way world speed record still stands, but on 1 October 2021, the Team Vesco 444 reVolt Systems streamliner, Little Giant, set a faster US national electric vehicle Class E3 record at 353.870 mph (569.499 kph) driven by Eric Ritter.  This is a US national record because the team was not able to recharge to Little Giant’s batteries fast enough to enable it to make the return runs within the 60 minute time limit set by the FIA for world records. The highest recorded speed of the Little Giant on the four runs was 357.0 mph (574.5 kph).

Little Giant electric LSR car and the team members at the 
2021 Bonneville Speed Week. 
Source: Team Vesco via WonderfulEngineering

You can watch a short video of the 1 October 2021 speed run from the driver’s perspective here:  https://www.youtube.com/watch?v=cji50zWnxjE

Two views of the narrow, streamlined, all-electric incarnation of the veteran LSR car Little Giant.
Source, both photos: Team Vesco

The Little Giant was powered by two highly modified Tesla electric motors and 1,152 prismatic (not cylindrical) lithium-ion battery cells.  Engine power and battery rating were not revealed.  As a point of comparison, the VBB-3’s battery was rated at 2 MW.

Little Giant electric LSR car with the upper body panel removed. Source: Team Vesco

Little Giant is a veteran streamliner that made its debut at the 1957 Bonneville Speed Week, where it reached a speed of 169 mph and received the “Best Engineered Car of the Year” award.  Over the years, it has been rebuilt several times.  Through 2020, Little Giant was powered by a variety of piston engines. You’ll find more history on this car here: https://www.teamvesco.com/history.html

Well done to the Team Vesco 444 reVolt Systems efforts to raise the electric car land speed record! 

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Video

First-ever Lower Colorado River Basin Water Shortage Declaration

Peter Lobner, updated 17 September 2011

At its maximum capacity, Lake Mead water level is at an elevation of 1,220 feet (372 meters) at the Hoover Dam and holds 9.3 trillion gallons (36 trillion liters) of water. It was last at its maximum capacity in 2000 and has been declining since then as shown in the following graph.

Source: Universe Today, data via US Bureau of Reclamation & NASA

In my 18 June 2021 post, I discussed the Lake Mead water supply for Las Vegas and the alarming trend of decreasing water level in Lake Mead as a result of the persistent drought in the watershed for the Colorado River. 

In July, the Bureau of Reclamation began releasing additional water from reservoirs upstream of Lake Powell (which is upstream of Lake Mead) in an attempt to stabilize the lake level and maintain hydropower generation at the Glen Canyon dam (which forms Lake Powell). 

The following chart shows that the Lake Mead water level was at 1,067.72 feet on 17 August 2021, more than seven feet below the 1,075 foot threshold for triggering a water shortage declaration.  The lake level appears to have temporarily stabilized, possibly benefiting from the increased releases into upstream Lake Powell.

Source: Universe Today, data via US Bureau of Reclamation & NASA

On 16 August 2021, the Bureau of Reclamation issued their much anticipated projection of 2022 operating conditions for Lake Powell and Lake Mead. They reported: 

“Given ongoing historic drought and low runoff conditions in the Colorado River Basin, downstream releases from Glen Canyon Dam and Hoover Dam will be reduced in 2022 due to declining reservoir levels. In the Lower Basin the reductions represent the first “shortage” declaration—demonstrating the severity of the drought and low reservoir conditions.”

The planned actions in response to this first-ever shortage declaration take effect on 1 January 2022, as described in the Bureau’s news release here: https://www.usbr.gov/newsroom/#/news-release/3950

In summary, the following cuts in Colorado River water allocations are expected:

  • Arizona:  Loses 18% of the state’s annual apportionment
  • Nevada:  Loses 7% of the state’s annual apportionment
  • Mexico:  Loses about 5% of the country’s annual allotment

California has more senior water rights than Arizona and Nevada and will be spared immediate cutbacks when they are implemented on 1 January 2022.

Additional cuts in water allocations will be triggered if Lake Mead water level continues to decline to the following thresholds:  1,050 feet, 1,045 feet, and 1,025 feet.

Let’s pray for a lot of wet weather in the US southwest.

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