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Powerful New US-Indian Satellite Will Track Earth’s Changing Surface
6 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater) The NISAR mission will help researchers get a better understanding of how Earth’s surface changes over time, including in the lead-up to volcanic eruptions like the one pictured, at Mount Redoubt in southern Alaska in April 2009.R.G. McGimsey/AVO/USGS
Data from NISAR will improve our understanding of such phenomena as earthquakes, volcanoes, and landslides, as well as damage to infrastructure.
We don’t always notice it, but much of Earth’s surface is in constant motion. Scientists have used satellites and ground-based instruments to track land movement associated with volcanoes, earthquakes, landslides, and other phenomena. But a new satellite from NASA and the Indian Space Research Organisation (ISRO) aims to improve what we know and, potentially, help us prepare for and recover from natural and human-caused disasters.
The NISAR (NASA-ISRO Synthetic Aperture Radar) mission will measure the motion of nearly all of the planet’s land and ice-covered surfaces twice every 12 days. The pace of NISAR’s data collection will give researchers a fuller picture of how Earth’s surface changes over time. “This kind of regular observation allows us to look at how Earth’s surface moves across nearly the entire planet,” said Cathleen Jones, NISAR applications lead at NASA’s Jet Propulsion Laboratory in Southern California.
Together with complementary measurements from other satellites and instruments, NISAR’s data will provide a more complete picture of how Earth’s surface moves horizontally and vertically. The information will be crucial to better understanding everything from the mechanics of Earth’s crust to which parts of the world are prone to earthquakes and volcanic eruptions. It could even help resolve whether sections of a levee are damaged or if a hillside is starting to move in a landslide.
The NISAR mission will measure the motion of Earth’s surface — data that can be used to monitor critical infrastructure such as airport runways, dams, and levees. NASA/JPL-Caltech What Lies BeneathTargeting an early 2025 launch from India, the mission will be able to detect surface motions down to fractions of an inch. In addition to monitoring changes to Earth’s surface, the satellite will be able to track the motion of ice sheets, glaciers, and sea ice, and map changes to vegetation.
The source of that remarkable detail is a pair of radar instruments that operate at long wavelengths: an L-band system built by JPL and an S-band system built by ISRO. The NISAR satellite is the first to carry both. Each instrument can collect measurements day and night and see through clouds that can obstruct the view of optical instruments. The L-band instrument will also be able to penetrate dense vegetation to measure ground motion. This capability will be especially useful in areas surrounding volcanoes or faults that are obscured by vegetation.
“The NISAR satellite won’t tell us when earthquakes will happen. Instead, it will help us better understand which areas of the world are most susceptible to significant earthquakes,” said Mark Simons, the U.S. solid Earth science lead for the mission at Caltech in Pasadena, California.
Data from the satellite will give researchers insight into which parts of a fault slowly move without producing earthquakes and which sections are locked together and might suddenly slip. In relatively well-monitored areas like California, researchers can use NISAR to focus on specific regions that could produce an earthquake. But in parts of the world that aren’t as well monitored, NISAR measurements could reveal new earthquake-prone areas. And when earthquakes do occur, data from the satellite will help researchers understand what happened on the faults that ruptured.
“From the ISRO perspective, we are particularly interested in the Himalayan plate boundary,” said Sreejith K M, the ISRO solid Earth science lead for NISAR at the Space Applications Center in Ahmedabad, India. “The area has produced great magnitude earthquakes in the past, and NISAR will give us unprecedented information on the seismic hazards of the Himalaya.”
Surface motion is also important for volcano researchers, who need data collected regularly over time to detect land movements that may be precursors to an eruption. As magma shifts below Earth’s surface, the land can bulge or sink. The NISAR satellite will help provide a fuller picture for why a volcano deforms and whether that movement signals an eruption.
Finding NormalWhen it comes to infrastructure such as levees, aqueducts, and dams, NISAR’s ability to provide continuous measurements over years will help to establish the usual state of the structures and surrounding land. Then, if something changes, resource managers may be able to pinpoint specific areas to examine. “Instead of going out and surveying an entire aqueduct every five years, you can target your surveys to problem areas,” said Jones.
The data could be equally valuable for showing that a dam hasn’t changed after a disaster like an earthquake. For instance, if a large earthquake struck San Francisco, liquefaction — where loosely packed or waterlogged sediment loses its stability after severe ground shaking — could pose a problem for dams and levees along the Sacramento-San Joaquin River Delta.
“There’s over a thousand miles of levees,” said Jones. “You’d need an army to go out and look at them all.” The NISAR mission would help authorities survey them from space and identify damaged areas. “Then you can save your time and only go out to inspect areas that have changed. That could save a lot of money on repairs after a disaster.”
More About NISARThe NISAR mission is an equal collaboration between NASA and ISRO and marks the first time the two agencies have cooperated on hardware development for an Earth-observing mission. Managed for the agency by Caltech, JPL leads the U.S. component of the project and is providing the mission’s L-band SAR. NASA is also providing the radar reflector antenna, the deployable boom, a high-rate communication subsystem for science data, GPS receivers, a solid-state recorder, and payload data subsystem. The U R Rao Satellite Centre in Bengaluru, India, which leads the ISRO component of the mission, is providing the spacecraft bus, the launch vehicle, and associated launch services and satellite mission operations. The ISRO Space Applications Centre in Ahmedabad is providing the S-band SAR electronics.
To learn more about NISAR, visit:
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NASA Kennedy’s Applied Chemistry Lab Achieves Agency First
NASA’s Kennedy Space Center in Florida has a long record of achievements in sustainability and recently added another to the list when the spaceport’s Applied Chemistry Lab became the first in the agency to be certified for its environmentally conscious practices.
The My Green Lab Certification recognizes sustainability best practices in research facilities around the world. The certification program run by My Green Lab, a non-profit dedicated to creating a culture of sustainability through science, is considered a key measure of progress towards a zero-carbon future by the United Nations Race to Zero campaign.
“When I heard our lab achieved certification, I was so happy,” said Dr. Annie Meier, one of the laboratory’s chemical engineers. “It meant we could now make a conscious effort to share these green practices with all who work in our lab. We even added them to our training materials for new and incoming members in the lab.”
The lab performs research and technology development for a wide range of chemistry and engineering-related applications to solve the unique operational needs of NASA and outside partners. The lab primarily focuses on in-situ resource utilization and addressing technology gaps related to lunar and Martian sustainability. The lab’s scientists also provide expertise in the fields of logistics reduction, plasma science, hypergolic fuels, analytical instrumentation, and gas analysis.
While sustainability has long been a focus of the lab, the journey to the certification began when Riley Yager, a doctoral student from University of Alabama at Birmingham – where Meier was a technical monitor – shared her knowledge of the program after pursuing green lab practices at her university.
“I work as a sustainability ambassador at my university, so I knew of this program,” Yager said. “Sustainable practices are something woven into my everyday life, so naturally I wanted to bring those practices into my lab environments.”
After learning about the program from Yager and discovering the many other academic institutions and companies certified globally, Meier submitted a proposal to NASA and obtained funding to pursue certification for the Applied Chemistry Lab.
After a kickoff event hosted by My Green Lab in April 2023, the lab’s path to certification began with a self-assessment survey, in which members of the lab answered a series of questions about their practices in areas such as cold storage, green chemistry, infrastructure energy, resource management, waste reduction, and water. My Green Lab collected and analyzed the answers, providing a baseline assessment and recommendations to improve the lab’s sustainable practices.
“We took their initial survey and learned we had lots of room for improvements as a lab,” Meier said. “Then I worked with a few interns over the summer to spearhead the ‘green team’ to implement changes and get momentum from the entire lab.”
The lab began with minimizing purchases by improving efficiencies during the inventory process. The team also performed a waste audit of all seven of its laboratories. They adopted nitrile glove and pipette tip box recycling, reviewed the “12 principles of green chemistry” with the lab members, and installed stickers and signage about what can and cannot be unplugged to save energy. Additionally, they installed low-flow aerators on the lab tap sinks to reduce flow, and the lab now uses a recycling sink to save on water or solvents for cleaning parts.
As luck would have it, Yager ended up working at the Applied Chemistry Lab on a NASA fellowship and became a member of the green team.
“It was really fun to see that come full circle,” Meier said. “Almost all members of the lab, from our fellows to most senior members, used their self-motivation to get on the sustainability train.”
The green team continued to grow as the lab implemented changes to become more sustainable. Just over six months after the kickoff event, they completed another assessment survey. With possible certification levels of bronze, silver, gold, platinum, and green – the level that adheres closest to My Green Lab’s highest standards – the ACL was certified green, marking the first time any NASA center obtained a My Green Lab Certification.
“Our lab is looking to sustain these green practices and achieve the same status when we are reassessed in the future,” Meier said. “This effort could be a wonderful catalyst to inspire other work groups to lean towards more ‘green’ practices at the frontline in our laboratories.”
The NASA Kennedy lab joined over 2,500 labs in a range of sectors that received the My Green Lab certification. Maintaining the distinction will require recertification every two years.
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CODEX Coronagraph Heads to the ISS on Cargo Dragon
A new space-based telescope aims to address a key solar mystery.
A new experiment will explore a region of the Sun that’s tough to see from the surface of the Earth. The solar corona—the elusive, pearly white region of the solar atmosphere seen briefly during a total solar eclipse—is generally swamped out by the dazzling Sun. Now, the Coronal Diagnostic Experiment (CODEX) will use a coronagraph to create an ‘artificial eclipse’ in order to explore the poorly understood middle corona region of the solar atmosphere.
CODEX launched as part of the cargo manifest on SpaceX’s Cargo Dragon this week, on mission CRS-31. CRS-31 arrived at the ISS and docked at the Harmony forward port of the station on November 5th.
CODEX is a partnership between NASA’s Goddard Spaceflight Center, Italy’s National Institute for Astrophysics (INAE) and KASI (Korea Astronomy and Space Science Institute). Technical expertise for the project was provided by the U.S. Naval Research Laboratory (NRL).
CODEX will be mounted on the EXPRESS (Expedite the Processing of Experiments to the Space Station) Logistics Carrier Site 3 (ELC-3) on the ISS.
An animation of CODEX on the ISS. NASA Why Use CoronagraphsCoronagraphs work by blocking out the Sun with an occulting disk. The disk used in CODEX is about as wide as an orange. Though coronagraphs can work on Earth, placing them in space is an easy way to eliminate unwanted light due to atmospheric scattering.
The solar corona, as imaged by the High Altitude Observatory’s coronagraph. UCAR/NCAR.Targeting the middle region of the corona is crucial, as it’s thought to be the source of the solar wind. But what heats this region to temperatures actually hotter than the surface below? This rise is in the order of a million degrees, versus 6000 degrees Celsius for the solar photosphere. The same unknown process accelerates particles to tremendous speeds of over a million kilometers an hour.
CODEX seeks to address this dilemma, and will measure Doppler shifts in charged particles at four filtered wavelengths. The instrument will need to center and track the Sun from its perch on the exterior of the ISS. To this end, this must occur while speeding around the Earth once every 90 minutes. CODEX will be able to see the Sun roughly half of the time, though seasons near either solstice will allow for near-continuous views.
CODEX will work with NASA’s Parker Solar Probe and ESA’s Solar Orbiter (SolO) in studying this coronal heating dilemma. In addition, it will also join the Solar Heliospheric (SOHO’s) LASCO C2 and C3 coronagraph in space. Another new coronagraph instrument in space is the National Oceanic Atmospheric Administration’s CCOR-1 (Compact Coronagraph) aboard the GOES-19 satellite in geosynchronous orbit.
A Solar Wind Riddle“CODEX measures the plasma’s temperature, speed and density around the whole corona between 3 and 10 solar radii, and will measure how those parameters evolve in time, providing new constraints on all theories of coronal heating,” Niicholeen Viall (GFSC-Solar Physics Laboratory) told Universe Today. “Parker Solar Probe measures these plasma parameters in the upper corona (getting as close as 10 solar radii) in great detail, but it makes those measurements in situ (from one one location in space and time) and only briefly that close to the Sun.”
The CODEX team with the instrument, ahead of launch. Credit: CODEX/NASA.The goal of CODEX is to provide a holistic view of solar wind activity. “In contrast, CODEX provides a global view and context of these plasma parameters and their evolution,” says Viall. “Additionally, CODEX extends the measurements much closer to the Sun than Parker Solar Probe (PSP), linking the detailed measurements made at PSP at 10 solar radii through the middle corona, down to ~3 solar radii, closer to their source. This is important because most of the coronal heating has already taken place by 10 solar radii, where PSP measures.”
A Dual MysteryTwo theories vie to explain the solar heating mystery. A first says that tangled magnetic fields are converted into thermal power. These are in turn fed into the corona as bursts of energy. Another says that oscillations known as Alfvén waves inject energy in a sort of feedback loop in the lower corona.
“Solar Orbiter has (an) EUV (Extreme ultraviolet) and white light imager that could be used to connect the CODEX measurements to their sources on the Sun,” says Viall.
Understanding this region and the source of the solar wind is crucial to predicting space weather. This is especially vital when the Sun sends powerful corona mass ejections our way. Not only can these spark low latitude aurorae, but these can also impact communications and pose a hazard to satellites and astronauts in space.
“CODEX is similar to all coronagraphs, in that they block light out from the photosphere to see the much fainter corona.” Says Viall. CODEX’s field of view has overlap with, but is different than SOHO’s coronagraphs and CCOR. The largest difference though, is that CODEX has special filters that can provide the temperature and speed of the solar wind, in addition to the density measurements that white light coronagraphs always make.”
The Past (and Future) of Coronagraphs in SpaceFurthermore, there’s also a history of coronagraphs aboard space stations. This goes all the way back to the white-light coronagraph aboard Skylab in the early 1970s.
Looking to the future, more coronagraphs are headed space-ward. ESA’s solar-observing Proba-3 launches at the end of November. Proba-3 will feature the first free-flying occulting disk as part of the mission. PUNCH (the Polarimeter to UNify the Corona and Heliosphere) will feature four micro-sat orbiters. The mission will rideshare launch with NASA’s SPHEREx mission early next year.
“PUNCH is a white light coronagraph and set of heliospheric imagers that together image from six solar radii out through the inner heliosphere.” Says Viall. PUNCH will be able to watch the structures that CODEX identifies as they as they evolve and are modulated father out in the heliosphere.”
Fianlly, astronomers can also use coronagraph-style instruments to image exoplanets directly. The Nancy Grace Roman Space telescope (set to launch in 2027) will feature one such instrument.
It will be exciting to see CODEX in action, as it probes the mysteries of the solar wind.
The post CODEX Coronagraph Heads to the ISS on Cargo Dragon appeared first on Universe Today.
Let African Communities Manage Their Climate Adaptation Plans
Outside groups often offer their solutions for climate adaptation in Africa. But the best people to manage the climate crisis are the people in those communities themselves. For climate adaptation to succeed in Africa, let communities and local leaders show the way
Beaverlab Finder TW2 AI-enhanced telescope review
40 Years Ago: STS-51A – “The Ace Repo Company”
Successfully deployed from the space shuttle Challenger during the February 1984 STS-41B mission, the Westar 6 and Palapa B2 communications satellites ended up in incorrect orbits due to failures of their upper stage rockets. During STS-51A in November 1984, Discovery’s second trip into space, the crew of Commander Frederick H. “Rick” Hauck, Pilot David M. Walker, and Mission Specialists Joseph P. Allen, Anna L. Fisher, and Dale A. Gardner worked as a team to not only deploy two new satellites but also to retrieve the two wayward but otherwise healthy satellites for return to Earth. Hauck and Walker piloted Discovery to rendezvous with each satellite in turn, Allen and Gardner retrieved them during two spacewalks, and Fisher grappled and placed them in the payload bay for return to Earth. After refurbishment, both satellites returned to space.
Left: The STS-51A crew of Dale A. Gardner, left, David M. Walker, Anna L. Fisher, Frederick “Rick” H. Hauck, and Joseph P. Allen. Right: The STS-51A crew patch.
NASA originally designated Hauck, Walker, Allen, Fisher, and Gardner as a crew in November 1983 and assigned them to STS-41H, a mission aboard Challenger planned for late September 1984 to either deploy the second Tracking and Data Relay Satellite (TDRS) or fly a classified payload for the Department of Defense. Due to ongoing problems with the Inertial Upper Stage that failed to put the first TDRS satellite in its correct orbit during STS-6, NASA canceled STS-41H and shifted Hauck’s crew to STS-51A. In February 1984, an agreement between NASA and the Canadian government added an as-yet unnamed Canadian payload specialist to the STS-51A crew. Managers later named the Canadian as Marc Garneau and reassigned him to STS-41G.
A shuffling of payloads following the STS-41D launch abort resulted in STS-51A now deploying the Anik D2 satellite for Canada and Leasat 1 (also known as Syncom IV-1) for the U.S. Navy. By early August, the launch date had slipped to Nov. 2, with NASA considering the possibility of retrieving the two wayward satellites from STS-41B, officially adding that task on Aug. 13. NASA selected Allen in 1967 as one of 11 scientist-astronauts, while the rest of the crew hail from the Class of 1978. Hauck, on his second mission after serving as pilot on STS-7, has the distinction as the first from his class to command a shuttle mission. Allen and Gardner had each flown one previous mission, STS-5 and STS-8, respectively, while for Walker and Fisher STS-51A represented their first flight. Fisher has the distinction as the first mother in space.
Left: After its arrival from the Orbiter Processing Facility, workers in the Vehicle Assembly Building (VAB) prepare to lift Discovery for mating with an External Tank (ET) and Solid Rocket Boosters (SRBs). Middle: Workers lift Discovery to stack it with the ET and SRBs. Right: The completed stack prepares to leave the VAB for the rollout to Launch Pad 39A.
Discovery arrived back at NASA’s Kennedy Space Center (KSC) in Florida on Sept. 10, returning from Edwards Air Force Base in California following the STS-41D mission. Workers towed it to the Orbiter Processing Facility (OPF) the next day to begin the process of refurbishing it for STS-51A. On Oct. 18, they rolled it over to the Vehicle Assembly Building (VAB), for stacking with an External Tank and twin Solid Rocket Boosters.
At NASA’s Kennedy Space Center in Florida, space shuttle Discovery rolls out to Launch Pad 39A, with the Saturn V rocket on display in the foreground.
The completed stack rolled out to Launch Pad 39A on Oct. 23. Two days later, the five-member STS-51A crew participated in the Terminal Countdown Demonstration Test, essentially a dress rehearsal for the actual countdown to launch. The crew returned to KSC on Nov. 5, the day the countdown began for a planned Nov. 7 launch. High upper-level winds that day forced a one-day delay.
Left: STS-51A astronaut Dale A. Gardner trains for the capture of a satellite using the Apogee Kick Motor Capture Device. Middle: Astronaut Anna L. Fisher trains to use the Canadian-built Remote Manipulator System, or robotic arm. Right: As part of the Terminal Countdown Demonstration Test, the STS-51A astronauts practice rapid evacuation from the launch pad.
Following deployment from Challenger during STS-41B, the upper stages of both the Westar 6 and Palapa B2 satellites malfunctioned, leaving them in non-useable 160-by-600-mile-high orbits instead of the intended 22,300-mile-high geostationary orbits required for their normal operations. While both satellites remained healthy, their own thrusters could not boost them to the proper orbits. NASA devised a plan to have astronauts retrieve the satellites during spacewalks using the jetpack known as the Manned Maneuvering Unit (MMU), after which the shuttle’s Canadian-built Remote Manipulator System (RMS) or robot arm would grapple them and place them into the cargo bay for return to Earth. Astronauts had demonstrated the capability of the MMU during the STS-41C Solar Max satellite repair mission in April 1984 and NASA felt confident of its ability to capture and return Westar and Palapa.
In the weeks prior to STS-51A, ground controllers lowered the orbits of both satellites and reduced their spin rates from 50 to 1 rpm to enable capture by the shuttle astronauts. Engineers at NASA’s Johnson Space Center in Houston developed the Apogee Kick Motor Capture Device (ACD), otherwise known as the stinger due to its appearance, to allow an astronaut to capture the satellites while flying the MMU. Once relocated over the payload bay, a second astronaut would remove the satellite’s omnidirectional antenna with pruning shears and install an Antenna Bridge Structure (ABS) with a grapple fixture over the satellite’s main antenna dish. Allen would fly the MMU to capture Palapa, then he would switch roles with Gardner who would capture Westar. Fisher would use the RMS to grapple the satellites by this second fixture and lower them into specially built cradles to secure them into the payload bay.
Left: The STS-51A crew leaves crew quarters on their way to Launch Pad 39A. Middle: Liftoff of Discovery on the STS-51A mission. Right: View inside Discovery’s payload bay shortly after orbital insertion – the top of Anik D2 is visible, with Leasat 1 hidden behind it.
Space shuttle Discovery roared off KSC’s Launch Pad 39A on Nov. 8, 1984, to begin the STS-51A mission and mark the orbiter’s first return to space. For Gardner, launch day coincided with his 36th birthday. The launch took place just 26 days after the landing of the previous mission, STS-41G, a then record-breaking turnaround time between shuttle flights. Eight and a half minutes after liftoff, Discovery and its five-member crew reached space and shortly thereafter settled into a 182-by-172-mile-high initial orbit. As their first order of business, the crew checked out the RMS to ensure its functionality for the satellite captures later in the mission. They also performed the first rendezvous burn to begin the approach to the Palapa satellite. The crew then settled down for its first night’s sleep in orbit.
Left: Nighttime deploy of the Anik D2 satellite. Middle: Deploy of the Leasat 1 satellite. Right: Leasat 1 as it departs from Discovery.
The primary activity of the second flight day involved Allen deploying the 2,727-pound Anik D2 satellite via a spring ejection mechanism, occurring on time and with no issues. The crew also circularized the shuttle’s orbit at 186 miles. The next day, Gardner deployed the 17,000-pound Leasat 1 using the Frisbee style mechanism used to deploy the first Leasat during STS-41D two months earlier. With the satellite deployments complete, the crew began to focus on the rendezvous maneuvers to bring them close to the Palapa B2 satellite while Allen and Gardner verified the functionality of their spacesuits. On flight day 4, the astronauts reduced the pressure inside the shuttle from 14.7 pounds per square inch (psi) to 10.2 psi in order to prevent the spacewalking astronauts from developing the bends inside the spacesuits that operated at 4.3 psi.
Left: During the first spacewalk, Jospeh P. Allen captures the Palapa B2 satellite. Middle: Anna L. Fisher grasps Allen and Palapa with the Remote Manipulator System, or robotic arm. Right: Allen, left, and Dale A. Gardner prepare to place Palapa in its cradle in the payload bay.
On the fifth mission day, after Hauck and Walker piloted Discovery to within 35 feet of Palapa, Allen and Gardner exited the airlock to begin the spacewalk portion of the satellite capture. Allen donned the MMU mounted on the side wall of the cargo bay, attached the stinger to its arms, and flew out to Palapa. Once there, he inserted the stinger into the satellite’s Apogee Kick Motor bell and using the MMU’s attitude control system stopped Palapa’s spin.
Fisher then steered the RMS to capture a grapple fixture mounted on the stinger between Allen and the satellite. She then maneuvered them over the payload bay where Gardner waited to remove its omnidirectional antenna and install the bridge structure. However, Gardner could not attach the ABS to the satellite due to an unexpected clearance issue on the satellite. Using a backup plan, Allen undocked from the stinger, leaving it attached to the satellite as well as the RMS, and stowed the MMU in the payload bay. With Allen now holding the satellite by its antenna, Gardner attached an adaptor to the bottom end of the satellite to secure it in its cradle in the payload bay. This plan worked and Allen and Gardner completed the spacewalk in exactly six hours.
Left: Dale A. Gardner flies the Manned Maneuvering Unit to capture Westar 6 during the second spacewalk. Middle: Anna L. Fisher operates the Remote Manipulator System from Discovery’s aft flight deck. Right: Gardner, left, and Joseph P. Allen maneuver Westar prior to placing it in its cradle in the payload bay.
Between the two spacewalk days, the crew serviced the spacesuits, conducted routine maintenance on the shuttle, and prepared for the second rendezvous, this time to retrieve Westar. Allen and Gardner switched roles for the second spacewalk on flight day seven, with Gardner flying the MMU to capture Westar. The astronauts repeated the procedure from the first spacewalk, except for not removing the omni antenna so they could use it as a handhold. With Westar secured in the payload bay, Gardner and Allen completed the second spacewalk in 5 hours and 42 minutes.
Left: Dale A. Gardner, left, and Joseph P. Allen pose at the end of the Remote Manipulator System controlled by Anna L. Fisher, holding a For Sale sign above the two retrieved satellites secured in Discovery’s payload bay. Middle: Inflight photo of the STS-51A crew after the successful satellite retrievals. Right: View inside Discovery’s payload bay shortly before the deorbit burn, with Westar 6 in the foreground and Palapa B2 behind it.
During their final full day in space, Discovery’s crew repressurized the shuttle’s cabin to 14.7 psi and tidied the cabin in preparation for reentry. On Nov. 16, the astronauts closed the payload bay doors and fired the Orbital Maneuvering System engines to begin the descent back to Earth. Hauck guided Discovery to a smooth landing at KSC, completing a flight of 7 days, 23 hours, and 45 minutes. The crew had traveled nearly 3.3 million miles and completed 127 orbits around the Earth. The next day, workers towed Discovery to the OPF to begin preparing it for its next flight, STS-51C in January 1985.
Left: Discovery streaks over Houston on its way to land at NASA’s Kennedy Space Center (KSC) in Florida. Middle: Discovery moments before touchdown at KSC. Right: NASA officials greet the STS-51A astronauts as they exit Discovery.
As a postscript, STS-51A marked the last flight to use the MMUs, and the last untethered spacewalks until 1994 when STS-64 astronauts tested the Simplified Aid for EVA Rescue (SAFER). All subsequent spacewalks on the space shuttle and the International Space Station used safety tethers, with the SAFER as a backup in case a crew member disconnects from the vehicle.
Left: In the Orbiter Processing Facility at NASA’s Kennedy Space Center in Florida, workers inspect the Westar 6, left, and Palapa B2 satellites in Discovery’s payload bay. Right: The STS-51A crew, with Lloyd’s of London representative Stephen Merritt, sitting at right, during their visit to London.
On Dec. 7, 1984, in a ceremony at the White House, President Ronald W. Reagan presented the STS-51A crew with the Lloyd’s of London – the company had insured the two satellites they returned to Earth – Silver Medal for Meritorious Salvage Operations. Fisher has the distinction as only the second woman to receive that award. In February 1985, Lloyd’s flew the crew to London on the Concorde for a week of activities, including addressing the Lloyd’s underwriters and tea with Prince Charles at Kensington Palace.
Hong Kong-based AsiaSat purchased the Westar 6 satellite, refurbished it, and relaunched it as AsiaSat 1 on April 7, 1990, on a Chinese CZ-3 rocket. Title to the Palapa B2 satellite returned to Indonesia after its relaunch as Palapa B2R on April 13, 1990, aboard a Delta rocket.
Read recollections of the STS-51A mission by Hauck, Allen, and Fisher in their oral histories with the JSC History Office. Enjoy the crew’s narration of a video about the STS-51A mission.
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Hubble Captures a Galaxy with Many Lights
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Hubble Captures a Galaxy with Many Lights This NASA/ESA Hubble Space Telescope image captures the spiral galaxy NGC 1672 with a supernova.ESA/Hubble & NASA, O. Fox, L. Jenkins, S. Van Dyk, A. Filippenko, J. Lee and the PHANGS-HST Team, D. de Martin (ESA/Hubble), M. Zamani (ESA/Hubble) Download this image
This NASA/ESA Hubble Space Telescope image features NGC 1672, a barred spiral galaxy located 49 million light-years from Earth in the constellation Dorado. This galaxy is a multi-talented light show, showing off an impressive array of different celestial lights. Like any spiral galaxy, shining stars fill its disk, giving the galaxy a beautiful glow. Along its two large arms, bubbles of hydrogen gas shine in a striking red light fueled by radiation from infant stars shrouded within. Near the galaxy’s center are some particularly spectacular stars embedded within a ring of hot gas. These newly formed and extremely hot stars emit powerful X-rays. Closer in, at the galaxy’s very center, sits an even brighter source of X-rays, an active galactic nucleus. This X-ray powerhouse makes NGC 1672 a Seyfert galaxy. It forms as a result of heated matter swirling in the accretion disk around NGC 1672’s supermassive black hole.
Image Before/AfterAlong with its bright young stars and X-ray core, a highlight of this image is the most fleeting and temporary of lights: a supernova, visible in just one of the six Hubble images that make up this composite. Supernova SN 2017GAX was a Type I supernova caused by the core-collapse and subsequent explosion of a giant star that went from invisible to a new light in the sky in just a matter of days. In the image above, the supernova is already fading and is visible as a small green dot just below the crook of the spiral arm on the right side. Astronomers wanted to look for any companion star that the supernova progenitor may have had — something impossible to spot beside a live supernova — so they purposefully captured this image of the fading supernova.
Recently, NGC 1672 was also among a crop of galaxies imaged with the NASA/ESA/CSA James Webb Space Telescope, showing the ring of gas and the structure of dust in its spiral arms. The image below compares the Webb image with Hubble’s image.
Image Before/After Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubbleMedia Contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
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