The Marshall Star for August 21, 2024
The Marshall Star for August 21, 2024
Hundreds Honored at Marshall, NASA Awards Ceremony
NASA Chief Financial Officer Margaret Vo Schaus speaks to audience members and honorees Aug. 15 during the 2023 Agency/Center Honor Awards at NASA’s Marshall Space Flight Center in Activities Building 4316. In all, 332 Marshall team members were awarded this year for their outstanding work and dedication to furthering the NASA mission, along with 97 teams. “As a newcomer to NASA, I am in awe of the work of this agency and the breadth of what we do,” said Vo Schaus, who served as the keynote speaker for the ceremonies. “These awards celebrate those who have gone above and beyond in making NASA what it is, and who have driven NASA forward in ways that demonstrate this agency’s core values of safety, integrity, teamwork, excellence, and inclusion.” View a full list of honorees and watch the ceremonies. (NASA/Charles Beason)
Marshall Center Director Joseph Pelfrey welcomes team members to the Agency/Center Honor Awards program. (NASA/Charles Beason)
FAQ: NASA’s Boeing Crew Flight Test Return Status
Editor’s note: This article was updated Aug. 20 to reflect the latest information from NASA’s Office of Communications.
NASA astronauts Butch Wilmore and Suni Williams arrived at the International Space Station orbiting laboratory on June 6 aboard the Boeing Starliner after lifting off on June 5 from Space Launch Complex-41 at Cape Canaveral Space Force Station.
During Starliner’s flight to the space station, engineers noticed some of the spacecraft’s thrusters did not perform as expected and several leaks in Starliner’s helium system also were observed. Engineering teams at NASA and Boeing have since conducted several thruster tests and in-depth data reviews to better understand the spacecraft. While engineers work to resolve technical issues before Starliner’s return to Earth, the astronaut duo have been working with the Expedition 71 crew, performing scientific research and maintenance activities.
NASA now plans to conduct two reviews – a Program Control Board and an Agency Flight Readiness Review – before deciding how it will safely return Wilmore and Williams from the station. NASA expects to decide on the path forward by the end of August.
Here are some frequently asked questions about their mission.
About the Mission and Delay
What is NASA’s Boeing Crew Flight Test?
NASA’s Boeing Crew Flight Test launched June 5, and is the first flight of the Starliner spacecraft to the International Space Station with astronauts. The flight test aims to prove the system is ready for rotational missions to the space station. NASA wants two American spacecraft, in addition to the Roscosmos Soyuz spacecraft, capable of carrying astronauts to help ensure a permanent crew aboard the orbiting complex.
What are the goals of the Crew Flight Test?
This flight test aims to demonstrate Starliner’s ability to execute a six-month rotational mission to the space station. The flight test objectives were developed to support NASA’s certification process and gather the performance data needed to evaluate readiness ahead of long-duration flights.
Why is the Crew Flight Test staying longer than planned aboard the space station?
During Starliner’s flight to the space station, some of the spacecraft’s thrusters did not perform as expected and several leaks in Starliner’s helium system were observed. While the initial mission duration was planned for about a week, there is no rush to bring crew home, so NASA and Boeing are taking additional time to learn about the spacecraft. This is a lesson learned from the space shuttle Columbia accident. Our NASA and Boeing teams are poring over data from additional in-space and ground testing and analysis, providing mission managers data to make the best, safest decision on how and when to return crew home.
If there’s an emergency on the space station, how will Butch and Suni get home?
Starliner remains the primary option for Butch and Suni if an emergency occurs and they need to rapidly depart the station. There is no urgent need to bring them home, and NASA is using the extra time to understand the spacecraft’s technical issues before deciding on a return plan.
How long could Butch and Suni stay on the space station if they don’t come home on Starliner?
If NASA decides to return Starliner uncrewed, Butch and Suni would remain aboard station until late-February 2025. NASA would replan the agency’s SpaceX Crew-9 mission by launching only two crew members instead of four in late September. Butch and Suni would then return to Earth after the regularly scheduled Crew-9 increment early next year.
Are Butch and Suni staying in space until 2025?
No decisions have been made. NASA continues to evaluate all options as it learns more about Starliner’s propulsion system. Butch and Suni may return home aboard Starliner, or they could come back as part of the agency’s SpaceX Crew-9 mission early next year.
Can Starliner fly without astronauts?
Yes, Starliner can undock and deorbit autonomously, if NASA decides to return the spacecraft uncrewed.
Could NASA send a SpaceX Dragon to bring Butch and Suni back?
If NASA decides to return them aboard a SpaceX Dragon, NASA will replan its SpaceX Crew-9 mission by launching only two crew members in late September instead of four. Butch and Suni would then return to Earth after the regularly scheduled Crew-9 increment early next year.
Why does NASA need two crew transportation systems?
The main goal of the agency’s Commercial Crew Program is two, unique human spaceflight systems. Should any one system encounter an issue, NASA still has the capability to launch and return crew to ensure safety and a continuous human presence aboard the International Space Station.
About the Astronauts
Are Butch and Suni stuck on the space station?
No, Butch and Suni are safe aboard the space station working alongside the Expedition 71 crew. They also have been actively involved in Starliner testing and technical meetings. Butch and Suni could return home aboard Starliner if an emergency arises. The agency also has other return options available, if needed, for both contingency and normal returning planning.
Are Suni and Butch prepared for a longer stay on the station?
Butch and Suni each have previously completed two long-duration stays aboard the station. NASA astronauts embark on missions fully aware of the various scenarios that may become reality. This mission is no different, and they understood the possibilities and unknowns of this test flight, including being aboard station longer than planned.
How long would an extended stay for Butch and Suni compare to other space station mission lengths?
A typical stay aboard the space station is about six months, and NASA astronauts also have remained on the space station for longer duration missions. Previous missions have given NASA volumes of data about long-duration spaceflight and its effects on the human body, which the agency applies to any crew mission.
Do the astronauts have what they need (e.g., food, clothing, oxygen, personal items, etc.)?
Yes. The space station is well-stocked with everything the crew needs, including food, water, clothing, and oxygen. Additionally, NASA and its space station partners frequently launch resupply missions to the orbiting complex carrying additional supplies and cargo.
Recently, a Northrop Grumman Cygnus spacecraft carrying 8,200 pounds of food, fuel, supplies, and science and a Progress resupply spacecraft carrying three tons of cargo arrived at the station. NASA has additional SpaceX resupply missions planned through the end of 2024.
What are they doing aboard the space station?
The crew continues to monitor Starliner’s flight systems and gather performance data for system certification. NASA also is taking advantage of Butch and Suni’s extra time aboard the orbital laboratory, where they have completed various science experiments, maintenance tasks, and assisted with spacewalk preparations. Some of the science they’ve recently completed includes new ways to produce fiber optic cables and growing plants aboard the orbiting complex.
Can they talk to their family and friends?
Butch and Suni enjoy many of the same comforts we have here on Earth. They can email, call, and video conference with their family and friends when they have “free time” aboard the space station.
About the Return Plan
What are the other options for bringing Butch and Suni back?
NASA has two unique American space transportation systems capable of carrying crew to and from station. Although no decisions have been made, NASA is considering several options to return Butch and Suni from the space station, including returning aboard Starliner, if cleared, or as part of agency’s SpaceX Crew-9 mission in February 2025.
Is it safer to bring them home aboard a SpaceX Dragon?
Crewed test flights are inherently risky, and although rotation missions may seem routine, they also are not without risk. It is NASA’s job to evaluate that risk and determine whether it is acceptable for crew ahead of each flight.
What other steps is NASA taking to bring them home?
NASA adjusted SpaceX Crew-9 launch and the agency’s SpaceX Crew-8 return, allowing more time to finalize Starliner return plans. NASA also is looking at crew assignments to ensure Butch and Suni can return with Crew-9, if needed.
For NASA’s blog and more information about the mission, visit here.
NASA Awards $1.25 Million to 3 Teams at Deep Space Food Finale
NASA has awarded a total of $1.25 million to three U.S. teams in the third and final round of the agency’s Deep Space Food Challenge. The teams delivered novel food production technologies that could provide long-duration human space exploration missions with safe, nutritious, and tasty food.
The competitors’ technologies address NASA’s need for sustainable food systems for long-duration habitation in space, including future Artemis missions and eventual journeys to Mars. Advanced food systems also could benefit life on Earth and inspire food production in parts of the world that are prone to natural disasters, food insecurity, and extreme environments.
“The Deep Space Food Challenge could serve as the framework for providing astronauts with healthy and delicious food using sustainable mechanisms,” said Angela Herblet, challenge manager for the Deep Space Food Challenge at NASA’s Marshall Space Flight Center. “The challenge has brought together innovative and driven individuals from around the world who are passionate about creating new solutions that support our agency’s future Moon to Mars missions.”
Since the challenge’s launch in 2021, more than 300 teams from 32 countries have participated by submitting innovative food system designs. The competition, conceived and managed by NASA Centennial Challenges at Marshall, is a first-of-its-kind coordinated effort between NASA and CSA (Canadian Space Agency), which ran its own challenge in parallel.
Four American teams competed in Phase 3, which began in September 2023. The Methuselah Foundation partnered with Ohio State University to facilitate the final phase of the challenge, which included a two-month testing and demonstration period held on the university’s campus in Columbus, Ohio. Each U.S. team in Phase 3 was awarded $50,000 and took their technology to Columbus for testing.
Throughout this phase, the teams constructed full-scale food production systems that were required to pass developmental milestones like safety, sensory testing, palatability, and harvesting volumes. Each team worked with four “Simunauts,” a crew of Ohio State students who managed the testing and demonstrations for Phase 3 over the eight-week period. The data gathered from testing was delivered to a judging panel to determine the winner.
The challenge concluded at the Deep Space Food Symposium, a two-day networking and learning summit Aug. 15-16 at the Nationwide and Ohio Farm Bureau 4-H Center. Throughout the event, attendees met the Phase 3 finalists, witnessed demonstrations of the food production technologies, and attended panels featuring experts from NASA, government, industry, and academia. The winners of the challenge were announced at an awards ceremony at the end of the symposium.
The U.S. winner and recipient of the $750,000 grand prize is Interstellar Lab of Merritt Island, Florida. Led by Barbara Belvisi, the small business combines several autonomous phytotrons and environment-controlled greenhouses to support a growth system involving a self-sustaining food production mechanism that generates fresh vegetables, microgreens, and insects necessary for micronutrients.
Two runners-up each earned $250,000 for their food systems’ successes: Nolux of Riverside, California, and SATED of Boulder, Colorado.
Nolux, a university team led by Robert Jinkerson, constructed an artificial photosynthetic system that can create plant and fungal-based foods without the operation of biological photosynthesis.
Standing for Safe Appliance, Tidy, Efficient & Delicious, SATED is a one-man team of Jim Sears, who developed a variety of customizable food, from pizza to peach cobbler. The product is fire-safe and was developed by long-shelf-life and in-situ grown ingredients.
NASA also selected and recognized one international team as a Phase 3 winner: Solar Foods of Lappeenranta, Finland, developed a food production system through gas fermentation that relies on single-cell protein production.
In April 2024, CSA and Impact Canada awarded the grand prize winner of its parallel challenge to Ecoation, a Vancouver-based small business specializing in greenhouses.
“Congratulations to the winners and all the finalist teams for their many years dedicated to innovating solutions for the Deep Space Food Challenge,” said Amy Kaminski, program executive for NASA’s Prizes, Challenges, and Crowdsourcing at NASA Headquarters. “These food production technologies could change the future of food accessibility on other worlds and our home planet.”
Also present at the symposium was celebrity chef and cookbook author Tyler Florence. After spending time with each finalist team and getting acquainted with their food systems, Florence selected one team to receive the “Tyler Florence Award for Culinary Innovation.” Team SATED of Boulder, Colorado, received the honor for their system that impressed Florence due to its innovative approach to the challenge.
The Deep Space Food Challenge, a NASA Centennial Challenge, is a coordinated effort between NASA and CSA. Subject matter experts at Johnson Space Center and Kennedy Space Center supported the competition. NASA’s Centennial Challenges are part of the Prizes, Challenges, and Crowdsourcing program within NASA’s Space Technology Mission Directorate and managed at Marshall. The Methuselah Foundation, in partnership with NASA, oversees the United States and international competitors.
Roger Baird Named Associate Director of Marshall
Roger Baird has been named to the position of associate director of NASA’s Marshall Space Flight Center, effective Aug. 19.
Baird will lead execution and integration of the center’s business operations, mission support enterprise functions, and budget management. In addition, he will be a senior adviser in advancing the direction of the center’s future. He will also help manage the center’s 7,000 civil service and contract employees and help oversee an annual budget of approximately $5 billion. He will provide executive leadership across Marshall’s mission support areas as well as the center’s diverse portfolio of human spaceflight, science, and technology efforts, which touch nearly every mission NASA pursues.
Prior to this assignment, Baird served as associate director for operations of Marshall’s Engineering Directorate from 2020-2024, after being detailed to the position in 2019. Named to the Senior Executive Service position in March 2020, he provided senior management and leadership expertise for the evaluation of spacecraft, payloads and launch vehicle systems, and the integration of the associated budgets and resources authority for these efforts. He was responsible for planning, directing, and coordinating engineering project management and integration activities in support of Marshall’s programs and projects, and oversaw an annual budget of approximately $550 million, including management of a highly technical workforce of more than 2,500 civil service and contractor employees.
In 2018, Baird was selected as manager of the Engineering Resource Management Office, where he was responsible for advising, coordinating, monitoring, directing, and performing work associated with planning, programming, budgeting, and managing the Engineering Directorate’s financial, human and infrastructure resources.
Baird brings a wealth of expertise to the role, with 34 years of NASA experience in the areas of engineering design, development, testing, facility and budget management, and strategic workforce acquisition and development. He joined NASA in 1990 as an avionics engineer in Marshall’s Astrionics Laboratory and served in multiple technical leadership positions within the Engineering Directorate’s Space Systems Department, Spacecraft and Vehicle Systems Department, and Propulsion Systems Department.
A native of Birmingham, Alabama, Baird earned a bachelor’s degree in electrical engineering from the University of Alabama in Birmingham. He has received numerous NASA awards, including an Outstanding Leadership Medal, Exceptional Achievement Medal, and a Silver Snoopy.
NASA SPoRT Using Science Data to Better Understand Hurricanes
By Paola Pinto
The Short-term Prediction Research and Transition (SPoRT) Center at NASA’s Marshall Space Flight Center is at the forefront of converting advanced research into practical tools to enhance weather forecasting and decision making, particularly for hurricane prediction.
One of SPoRT’s major partners is the National Oceanic and Atmospheric Administration (NOAA). NOAA employs the Geostationary Lightning Mapper (GLM) to gather valuable information on physical lightning properties, such as size and brightness, within storms. These properties can be indicative of storm structure and intensity changes in hurricanes undergoing rapid intensification.
John Mark Mayhall, a research assistant and graduate student at the University of Alabama in Huntsville (UAH), and Kiahna Mollette, a NASA Pathways Intern and UAH graduate student, both contribute significantly to NASA SPoRT’s projects. Their work focuses on utilizing high-resolution data to deepen the understanding of hurricane behavior.
Mollette’s research examines how lightning characteristics evolve during hurricanes’ rapid intensification.
“Lightning data provides insights into the storm’s structure that are not available from other sources,” Mollette said. “For instance, lightning activity around the eye of the hurricane can help determine whether or not the storm will intensify.”
Meanwhile, Mayhall’s research focuses on identifying cloud features within the upper levels of tropical cyclones. His findings have shown promising correlations between specific cloud formations and hurricane intensity and behavior.
Mayhall’s machine-learning model has revealed transverse bands in tropical cyclones are more common during the day than overnight. Transverse bands are regions of upper-level clouds that look like waves and typically occur in regions of strong wind shear. These cloud bands tend to form on the leading edge of thunderstorms that move outward from a hurricane, influenced by changes in solar radiation. Mayhall’s results have quantified these relationships for the first time using an objective algorithm, supporting previous research linking these cloud patterns to changes in a hurricane’s thunderstorm activity throughout the daytime. His endeavors recently earned him the Highest Undergraduate Achievement award from the UAH College of Science.
Another significant focus area of NASA SPoRT research is the development and application of sea surface temperature (SST) products. Mollette said NASA SPoRT’s high spatial resolution SST product has been instrumental in predicting hurricane development and intensification since warm sea surface temperatures provide the energy needed for hurricanes to develop and intensify.
“SST data is used by other government agencies, universities, and the private sector to help stakeholders understand the environmental conditions that favor hurricane formation and growth,” Mollete said. “The data is then assimilated into models to improve hurricane prediction and is used to anticipate the impacts of hurricane landfall.”
The SPoRT SST is available in NOAA National Ocean Service nowCoast portal and the NASA Disaster’s program portal, providing widespread access to emergency management to anticipate coastal risk as hurricanes approach landfall.
Sebastian Harkama, a research scientist at UAH working with SPoRT, has focused on updating the SST product. He said warmer sea surface temperatures fuel hurricanes and notes this year’s significant temperature anomalies due to La Niña could lead to a more intense hurricane season. La Niña, a climate pattern marked by cooler waters in the eastern Pacific, alters atmospheric circulation, potentially increasing hurricane activity in the Atlantic.
The upcoming updated version of the SPoRT SST product is in development and will feature new satellite datasets for greater accuracy. This update will include plots showing short-term temperature trends and anomalies, expected to be highly beneficial during this hurricane season. The datasets will incorporate observations from the Visible Infrared Imaging Radiometer Suite on NOAA-20 and NOAA-21 satellites, as well as the Advanced Very High Resolution Radiometer on MetOp-B and MetOp-C satellites.
Mayhall highlights the significance of the SPoRT Dust RGB (red, green, blue) product on the Geostationary Operational Environmental Satellite-16 (GOES-16) for monitoring dust and its impact on tropical cyclone development and intensity. The Dust RGB product contrasts airborne dust with clouds by using band differencing and measuring thermal energy. These measurements are then represented in various colors to differentiate dust from cloud formations and facilitate precise analysis.
“Saharan dust can significantly impact hurricane formation and strength,” Mayhall explained. “The presence of dust in the atmosphere can weaken tropical cyclones by introducing dry air into the storm, disrupting its structure, and inhibiting its growth.”
NASA SPoRT’s collaborative efforts with researchers and stakeholders extend beyond the tools and data. Regular engagement with experts from various institutions helps identify priorities for data products in the tropical cyclone community and develop solutions to persistent challenges.
NOAA predicts the 2024 season will be particularly active. The products and capabilities derived from SPoRT’s research are more important than ever in helping communities prepare for and respond to these potentially devastating storms.
Patrick Duran is a research scientist at NASA Marshall Space Flight Center and tropical meteorology team lead with the SPoRT mission and advises graduate students like Mollette and Mayhall. He also serves as the mission applications lead for NASA’s TROPICS mission, a constellation of advanced small satellites that measure temperature, humidity, and precipitation with high spatial resolution and an unprecedented 60-minute median revisit time. Duran fosters interaction between the TROPICS Science Team and the community of end users to maximize the mission’s societal benefits.
Duran collaborates with other NASA experts, particularly research scientist Chris Schultz, in understanding how lightning can predict hurricane intensity. Together, they are researching the dynamics of lightning outbreaks to determine those that correspond to storm intensification from those indicating weakening. Using the geostationary lightning mapper, they analyze the size and energy of lightning flashes to gain insights into storm processes. Larger and more energetic flashes often signify intensification, while smaller, less energetic flashes can indicate weakening.
Duran also mentions the development of situational awareness products for aircraft observation, which provide NOAA Hurricane Hunter aircraft with real-time data to enhance their operations. Although these products are not yet publicly available, they signify advancement in utilizing SPoRT’s research for practical applications in hurricane tracking and prediction. For example, these products will include imagery from the GOES and TROPICS satellites, allowing Hurricane Hunters to see their position within the storm relative to key meteorological features observed by the satellites.
The NASA SPoRT Center is advancing the understanding of hurricanes and providing tools to aid forecasters in their decision-making process. During this active hurricane season, NASA SPoRT’s collaborative efforts with stakeholders, other government agencies, and NASA programs like NOAA National Weather Service, National Ocean Service, and the NASA Disasters Program are vital in helping communities prepare for and mitigate the impacts of these powerful storms.
Pinto is a research associate at the University of Alabama in Huntsville, specializing in communications and user engagement for NASA SPoRT.
NASA Telescopes Work Out Black Hole’s Snack Schedule
By using new data from NASA’s Chandra X-ray Observatory and Neil Gehrels Swift Observatory as well as ESA’s XMM-Newton, a team of researchers have made important headway in understanding how – and when – a supermassive black hole obtains and then consumes material, as described in a press release.
This artist’s impression shows a star that has partially been disrupted by such a black hole in the system known as AT2018fyk. The supermassive black hole in AT2018fyk – with about 50 million times more mass than the Sun – is in the center of a galaxy located about 860 million light-years from Earth.
Astronomers have determined that a star is on a highly elliptical orbit around the black hole in AT2018fyk so that its point of farthest approach from the black hole is much larger than its closest. During its closest approach, tidal forces from the black hole pull some material from the star, producing two tidal tails of “stellar debris”.
The illustration shows a point in the orbit soon after the star is partially destroyed, when the tidal tails are still in close proximity to the star. Later in the star’s orbit, the disrupted material returns to the black hole and loses energy, leading to a large increase in X-ray brightness occurring later in the orbit (not shown here). This process repeats each time the star returns to its point of closest approach, which is approximately every 3.5 years. The illustration depicts the star during its second orbit, and the disk of X-ray emitting gas around the black hole that is produced as a byproduct of the first tidal encounter.
Researchers took note of AT2018fyk in 2018 when the optical ground-based survey ASAS-SN detected that the system had become much brighter. After observing it with NASA’s NICER and Chandra, and XMM-Newton, researchers determined that the surge in brightness came from a “tidal disruption event,” or TDE, which signals that a star was completely torn apart and partially ingested after flying too close to a black hole. Chandra data of AT2018fyk is shown in the inset of an optical image of a wider field-of-view.
When material from the destroyed star approached close to the black hole, it got hotter and produced X-ray and ultraviolet (UV) light. These signals then faded, agreeing with the idea that nothing was left of the star for the black hole to digest.
However, about two years later, the X-ray and UV light from the galaxy got much brighter again. This meant, according to astronomers, that the star likely survived the initial gravitational grab by the black hole and then entered a highly elliptical orbit with the black hole. During its second close approach to the black hole, more material was pulled off and produced more X-ray and UV light.
Based on what they had learned about the star and its orbit, a team of astronomers predicted that the black hole’s second meal would end in August 2023 and applied for Chandra observing time to check. Chandra observations on Aug. 14, 2023, indeed showed the telltale sign of the black hole feeding coming to an end with a sudden drop in X-rays. The researchers also obtained a better estimate of how long it takes the star to complete an orbit, and predicted future mealtimes for the black hole.
A paper describing these results appears in the Aug. 14 issue of The Astrophysical Journal and is available online. The authors are Dheeraj Passam (Massachusetts Institute of Technology), Eric Coughlin (Syracuse University), Muryel Guolo (Johns Hopkins University), Thomas Wevers (Space Telescope Science Institute), Chris Nixon (University of Leeds, UK), Jason Hinkle (University of Hawaii at Manoa), and Ananaya Bandopadhyay (Syracuse).
NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science from Cambridge Massachusetts and flight operations from Burlington, Massachusetts.
Europa Clipper Solar Array Alignment, Installation
Technicians move NASA’s Europa Clipper spacecraft inside the Payload Hazardous Servicing Facility to accommodate installation of its five-panel solar array at the agency’s Kennedy Space Center on Aug. 1. After moving the spacecraft, the team had to precisely align the spacecraft in preparation for the installation. The huge arrays – spanning more than 100 feet when fully deployed, or about the length of a basketball court – will collect sunlight to power the spacecraft as it flies multiple times around Jupiter’s icy moon, Europa, conducting science investigations to determine its potential to support life. Europa Clipper is launching Oct. 10. Scientists predict Europa has a salty ocean beneath its icy crust that could hold the building blocks necessary to sustain life. Managed by Caltech in Pasadena, California, JPL leads the development of the Europa Clipper mission in partnership with the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, for NASA’s Science Mission Directorate. APL designed the main spacecraft body in collaboration with JPL and NASA’s Goddard Space Flight Center. The Planetary Missions Program Office at NASA’s Marshall Space Flight Center executes program management of the Europa Clipper mission. (NASA/Frank Michaux)
Danish Instrument Helps NASA’s Juno Spacecraft See Radiation
Scientists with NASA’s Juno mission have developed the first complete 3D radiation map of the Jupiter system. Along with characterizing the intensity of the high-energy particles near the orbit of the icy moon Europa, the map shows how the radiation environment is sculpted by the smaller moons orbiting near Jupiter’s rings.
The work relies on data collected by Juno’s Advanced Stellar Compass (ASC), which was designed and built by the Technical University of Denmark, and the spacecraft’s Stellar Reference Unit (SRU), which was built by Leonardo SpA in Florence, Italy. The two datasets complement each other, helping Juno scientists characterize the radiation environment at different energies.
Both the ASC and SRU are low-light cameras designed to assist with deep-space navigation. These types of instruments are on almost all spacecraft. But to get them to operate as radiation detectors, Juno’s science team had to look at the cameras in a whole new light.
“On Juno we try to innovate new ways to use our sensors to learn about nature, and we have used many of our science instruments in ways they were not designed for,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “This is the first detailed radiation map of the region at these higher energies, which is a major step in understanding how Jupiter’s radiation environment works. This will help planning observations for the next generation of missions to the Jovian system.”
Consisting of four star cameras on the spacecraft’s magnetometer boom, Juno’s ASC takes images of stars to determine the spacecraft’s orientation in space, which is vital to the success of the mission’s magnetic field experiment. But the instrument has also proved to be a valuable detector of high-energy particle fluxes in Jupiter’s magnetosphere. The cameras record “hard radiation,” or ionizing radiation that impacts a spacecraft with sufficient energy to pass through the ASC’s shielding.
“Every quarter-second, the ASC takes an image of the stars,” said Juno scientist John Leif Jørgensen of the Technical University of Denmark. “Very energetic electrons that penetrate its shielding leave a telltale signature in our images that looks like the trail of a firefly. The instrument is programmed to count the number of these fireflies, giving us an accurate calculation of the amount of radiation.”
Because of Juno’s ever-changing orbit, the spacecraft has traversed practically all regions of space near Jupiter.
ASC data suggests that there is more very high-energy radiation relative to lower-energy radiation near Europa’s orbit than previously thought. The data also confirms that there are more high-energy electrons on the side of Europa facing its orbital direction of motion than on the moon’s trailing side. This is because most of the electrons in Jupiter’s magnetosphere overtake Europa from behind due to the planet’s rotation, whereas the very high-energy electrons drift backward, almost like fish swimming upstream, and slam into Europa’s front side.
Jovian radiation data is not the ASC’s first scientific contribution to the mission. Even before arriving at Jupiter, ASC data was used to determine a measurement of interstellar dust impacting Juno. The imager also discovered a previously uncharted comet using the same dust-detection technique, distinguishing small bits of the spacecraft ejected by microscopic dust impacting Juno at a high velocity.
Like Juno’s ASC, the SRU has been used as a radiation detector and a low-light imager. Data from both instruments indicates that, like Europa, the small “shepherd moons” that orbit within or close to the edge of Jupiter’s rings (and help to hold the shape of the rings) also appear to interact with the planet’s radiation environment. When the spacecraft flies on magnetic field lines connected to ring moons or dense dust, the radiation count on both the ASC and SRU drops precipitously. The SRU is also collecting rare low-light images of the rings from Juno’s unique vantage point.
“There is still a lot of mystery about how Jupiter’s rings were formed, and very few images have been collected by prior spacecraft,” said Heidi Becker, lead co-investigator for the SRU and a scientist at NASA’s Jet Propulsion Laboratory, which manages the mission. “Sometimes we’re lucky and one of the small shepherd moons can be captured in the shot. These images allow us to learn more precisely where the ring moons are currently located and see the distribution of dust relative to their distance from Jupiter.”
NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center for the agency’s Science Mission Directorate. The Technical University of Denmark designed and built the Advanced Stellar Compass. The Stellar Reference Unit was built by Leonardo SpA in Florence, Italy. Lockheed Martin Space in Denver built and operates the spacecraft.