Members Can Post Anonymously On This Site
A Defining Era: NASA Stennis and Space Shuttle Main Engine Testing
-
Similar Topics
-
By NASA
NASA astronaut and Expedition 65 Flight Engineer Megan McArthur removes Kidney Cells-02 hardware inside the Space Automated Bioproduct Laboratory and swaps media inside the Microgravity Science Glovebox. The human research study seeks to improve treatments for kidney stones and osteoporosis NASA astronaut Megan McArthur has retired, concluding a career spanning more than two decades. A veteran of two spaceflights, McArthur logged 213 days in space, including being the first woman to pilot a SpaceX Dragon spacecraft and the last person to “touch” the Hubble Space Telescope with the space shuttle’s robotic arm.
McArthur launched as pilot of NASA’s SpaceX Crew-2 mission in April 2021, marking her second spaceflight and her first long-duration stay aboard the International Space Station. During the 200-day mission, she served as a flight engineer for Expeditions 65/66, conducting a wide array of scientific experiments in human health, materials sciences, and robotics to advance exploration of the Moon under Artemis and prepare to send American astronauts to Mars.
Her first spaceflight was STS-125 in 2009, aboard the space shuttle Atlantis, the fifth and final servicing mission to Hubble. As a mission specialist, she was responsible for capturing the telescope with the robotic arm, as well as supporting five spacewalks to update and repair Hubble after its first 19 years in space. She also played a key role in supporting shuttle operations during launch, rendezvous with the telescope, and landing.
“Megan’s thoughtful leadership, operational excellence, and deep commitment to science and exploration have made a lasting impact,” said Steve Koerner, acting director of NASA’s Johnson Space Center in Houston. “Her contributions have helped shape the future of human space exploration, and we are incredibly grateful for her service.”
In addition to her flight experience, McArthur has served in various technical and leadership roles within NASA. In 2019, she became the deputy division chief of the Astronaut Office, supporting astronaut training, development, and ongoing spaceflight operations. She also served as the assistant director of flight operations for the International Space Station Program starting in 2017.
Since 2022, McArthur has served as the chief science officer at Space Center Houston, NASA Johnson’s official visitor center. Continuing in this role, she actively promotes public engagement with space exploration themes, aiming to increase understanding of the benefits to humanity and enhance science literacy.
“Megan brought a unique combination of technical skill and compassion to everything she did,” said Joe Acaba, chief of the Astronaut Office at NASA Johnson. “Whether in space or on the ground, she embodied the best of what it means to be an astronaut and a teammate. Her contributions will be felt by the next generation of explorers she helped train.”
McArthur was born in Honolulu and raised as a “Navy kid” in many different locations worldwide. She earned a Bachelor of Science in aerospace engineering from the University of California, Los Angeles, and a doctorate in oceanography from the Scripps Institution of Oceanography at the University of California, San Diego. Before being selected as an astronaut in 2000, she conducted oceanographic research focusing on underwater acoustics, which involved shipboard work and extensive scuba diving.
McArthur is married to former NASA astronaut Robert Behnken, who also flew aboard the Dragon Endeavour spacecraft during the agency’s SpaceX Demo-2 mission in 2020.
“It was an incredible privilege to serve as a NASA astronaut, working with scientists from around the world on cutting-edge research that continues to have a lasting impact here on Earth and prepares humanity for future exploration at the Moon and Mars,” said McArthur. “From NASA’s Hubble Space Telescope to the International Space Station, our research lab in low Earth orbit, humanity has developed incredible tools that help us answer important scientific questions, solve complex engineering challenges, and gain a deeper understanding of our place in the universe. Seeing our beautiful planet from space makes it so clear how fragile and precious our home is, and how vital it is that we protect it. I am grateful I had the opportunity to contribute to this work, and I’m excited to watch our brilliant engineers and scientists at NASA conquer new challenges and pursue further scientific discoveries for the benefit of all.”
To learn more about NASA’s astronauts and their contributions to space exploration, visit:
https://www.nasa.gov/astronauts
-end-
Shaneequa Vereen
Johnson Space Center, Houston
281-483-5111
shaneequa.y.vereen@nasa.gov
View the full article
-
By Space Force
The inaugural class of Guardian officers graduates from the Officer Training Course at Peterson Space Force Base.
View the full article
-
By NASA
This graphic features data from NASA’s Chandra X-ray Observatory of the Cassiopeia A (Cas A) supernova remnant that reveals that the star’s interior violently rearranged itself mere hours before it exploded. The main panel of this graphic is Chandra data that shows the location of different elements in the remains of the explosion: silicon (represented in red), sulfur (yellow), calcium (green) and iron (purple). The blue color reveals the highest-energy X-ray emission detected by Chandra in Cas A and an expanding blast wave. The inset reveals regions with wide ranges of relative abundances of silicon and neon. This data, plus computer modeling, reveal new insight into how massive stars like Cas A end their lives.X-ray: NASA/CXC/Meiji Univ./T. Sato et al.; Image Processing: NASA/CXC/SAO/N. Wolk The inside of a star turned on itself before it spectacularly exploded, according to a new study from NASA’s Chandra X-ray Observatory. Today, this shattered star, known as the Cassiopeia A supernova remnant, is one of the best-known, well-studied objects in the sky.
Over three hundred years ago, however, it was a giant star on the brink of self-destruction. The new Chandra study reveals that just hours before it exploded, the star’s interior violently rearranged itself. This last-minute shuffling of its stellar belly has profound implications for understanding how massive stars explode and how their remains behave afterwards.
Cassiopeia A (Cas A for short) was one of the first objects the telescope looked at after its launch in 1999, and astronomers have repeatedly returned to observe it.
“It seems like each time we closely look at Chandra data of Cas A, we learn something new and exciting,” said Toshiki Sato of Meiji University in Japan who led the study. “Now we’ve taken that invaluable X-ray data, combined it with powerful computer models, and found something extraordinary.”
As massive stars age, increasingly heavy elements form in their interiors by nuclear reactions, creating onion-like layers of different elements. Their outer layer is mostly made of hydrogen, followed by layers of helium, carbon and progressively heavier elements – extending all the way down to the center of the star.
Once iron starts forming in the core of the star, the game changes. As soon as the iron core grows beyond a certain mass (about 1.4 times the mass of the Sun), it can no longer support its own weight and collapses. The outer part of the star falls onto the collapsing core, and rebounds as a core-collapse supernova.
The new research with Chandra data reveals a change that happened deep within the star at the very last moments of its life. After more than a million years, Cas A underwent major changes in its final hours before exploding.
“Our research shows that just before the star in Cas A collapsed, part of an inner layer with large amounts of silicon traveled outwards and broke into a neighboring layer with lots of neon,” said co-author Kai Matsunaga of Kyoto University in Japan. “This is a violent event where the barrier between these two layers disappears.”
This upheaval not only caused material rich in silicon to travel outwards; it also forced material rich in neon to travel inwards. The team found clear traces of these outward silicon flows and inward neon flows in the remains of Cas A’s supernova remnant. Small regions rich in silicon but poor in neon are located near regions rich in neon and poor in silicon.
The survival of these regions not only provides critical evidence for the star’s upheaval, but also shows that complete mixing of the silicon and neon with other elements did not occur immediately before or after the explosion. This lack of mixing is predicted by detailed computer models of massive stars near the ends of their lives.
There are several significant implications for this inner turmoil inside of the doomed star. First, it may directly explain the lopsided rather than symmetrical shape of the Cas A remnant in three dimensions. Second, a lopsided explosion and debris field may have given a powerful kick to the remaining core of the star, now a neutron star, explaining the high observed speed of this object.
Finally, the strong turbulent flows created by the star’s internal changes may have promoted the development of the supernova blast wave, facilitating the star’s explosion.
“Perhaps the most important effect of this change in the star’s structure is that it may have helped trigger the explosion itself,” said co-author Hiroyuki Uchida, also of Kyoto University. “Such final internal activity of a star may change its fate—whether it will shine as a supernova or not.”
These results have been published in the latest issue of The Astrophysical Journal and are available online.
To learn more about Chandra, visit:
https://science.nasa.gov/chandra
Read more from NASA’s Chandra X-ray Observatory Learn more about the Chandra X-ray Observatory and its mission here:
https://www.nasa.gov/chandra
https://chandra.si.edu
Visual Description
This release features a composite image of Cassiopeia A, a donut-shaped supernova remnant located about 11,000 light-years from Earth. Included in the image is an inset closeup, which highlights a region with relative abundances of silicon and neon.
Over three hundred years ago, Cassiopeia A, or Cas A, was a star on the brink of self-destruction. In composition it resembled an onion with layers rich in different elements such as hydrogen, helium, carbon, silicon, sulfur, calcium, and neon, wrapped around an iron core. When that iron core grew beyond a certain mass, the star could no longer support its own weight. The outer layers fell into the collapsing core, then rebounded as a supernova. This explosion created the donut-like shape shown in the composite image. The shape is somewhat irregular, with the thinner quadrant of the donut to the upper left of the off-center hole.
In the body of the donut, the remains of the star’s elements create a mottled cloud of colors, marbled with red and blue veins. Here, sulfur is represented by yellow, calcium by green, and iron by purple. The red veins are silicon, and the blue veins, which also line the outer edge of the donut-shape, are the highest energy X-rays detected by Chandra and show the explosion’s blast wave.
The inset uses a different color code and highlights a colorful, mottled region at the thinner, upper left quadrant of Cas A. Here, rich pockets of silicon and neon are identified in the red and blue veins, respectively. New evidence from Chandra indicates that in the hours before the star’s collapse, part of a silicon-rich layer traveled outwards, and broke into a neighboring neon-rich layer. This violent breakdown of layers created strong turbulent flows and may have promoted the development of the supernova’s blast wave, facilitating the star’s explosion. Additionally, upheaval in the interior of the star may have produced a lopsided explosion, resulting in the irregular shape, with an off-center hole (and a thinner bite of donut!) at our upper left.
News Media Contact
Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu
Corinne Beckinger
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
corinne.m.beckinger@nasa.gov
Share
Details
Last Updated Aug 28, 2025 EditorLee MohonContactCorinne M. Beckingercorinne.m.beckinger@nasa.govLocationMarshall Space Flight Center Related Terms
Chandra X-Ray Observatory General Marshall Astrophysics Marshall Space Flight Center Supernova Remnants Supernovae The Universe Explore More
6 min read Meet NASA’s Artemis II Moon Mission Masterminds
Article 22 hours ago 4 min read Washington State Student Wins 2025 NASA Art Contest
Article 3 days ago 5 min read Astronomers Map Stellar ‘Polka Dots’ Using NASA’s TESS, Kepler
Scientists have devised a new method for mapping the spottiness of distant stars by using…
Article 3 days ago View the full article
-
By European Space Agency
Video: 00:09:30 In Tenerife, Spain, stands a unique duo: ESA’s Izaña-1 and Izaña-2 laser-ranging stations. Together, they form an optical technology testbed of the European Space Agency that takes the monitoring of space debris and satellites to a new level while maturing new technologies for commercialisation.
Space debris is a threat to satellites and is rapidly becoming a daily concern for satellite operators. The Space Safety Programme, part of ESA Operations, managed from ESOC in Germany, helps develop new technologies to detect and track debris, and to prevent collisions in orbit in new and innovative ways.
One of these efforts takes place at the Izaña station in Tenerife. There, ESA and partner companies are testing how to deliver precise orbit data on demand with laser-based technologies. The Izaña-2 station was recently finalised by the German company DiGOS and is now in use.
To perform space debris laser ranging, Izaña-2 operates as a laser transmitter, emitting high-power laser pulses towards objects in space. Izaña-1 then acts as the receiver of the few photons that are reflected back. The precision of the laser technology enables highly accurate data for precise orbit determination, which in turn is crucial for actionable collision avoidance systems and sustainable space traffic management.
With the OMLET (Orbital Maintenance via Laser momEntum Transfer) project, ESA combines different development streams and possibilities for automation to support European industry with getting two innovative services market-ready: on-demand ephemeris provision and laser-based collision avoidance services for end users such as satellite operators.
A future goal is to achieve collision avoidance by laser momentum transfer, where instead of the operational satellite, the piece of debris will be moved out of the way. This involves altering the orbit of a piece of space debris slightly by applying a small force to the object through laser illumination.
The European Space Agency actively supports European industry in capitalising on the business opportunities that not only safeguard our satellites but also pave the way for the sustainable use of space.
View the full article
-
By NASA
Teams at NASA’s Kennedy Space Center in Florida participate in the first joint integrated launch countdown simulation for Artemis I inside Firing Room 1 of the Launch Control Center on July 8, 2021. Seen at the top of the room is Charlie Blackwell-Thompson (right), launch director.Credit: NASA/Ben Smegelsky As four astronauts venture around the Moon on NASA’s Artemis II test flight in 2026, many people will support the journey from here on Earth. Teams directing operations from the ground include the mission management team, launch control team, flight control team, and the landing and recovery team, each with additional support personnel who are experts in every individual system and subsystem. The teams have managed every aspect of the test flight and ensure NASA is prepared to send humans beyond our atmosphere and into a new Golden Age of innovation and exploration.
Mission management team
Reviews of mission status and risk assessments are conducted by the mission management team, a group of 15 core members and additional advisors. Amit Kshatriya, NASA’s deputy associate administrator, Moon to Mars Program, will serve as the mission management team chair for the test flight.
Two days prior to launch, the mission management team will assemble to review mission risks and address any lingering preflight concerns. With more than 20 years of human spaceflight experience, Kshatriya will conduct polls at key decision points, providing direction for the relevant operations team. If circumstances during the flight go beyond established decision criteria or flight rules outlined ahead of the mission, the team will assess the situation based on the information available and decide how to respond.
Matt Ramsey, serving as the Artemis II mission manager, will oversee all elements of mission preparedness prior to the mission management team assembly two days before launch and serve as deputy mission management team chair throughout the mission. With more than two decades of experience at NASA, Ramsey managed the SLS (Space Launch System) Engineering Support Center for Artemis I.
Launch control team
The launch control team coordinates launch operations from NASA’s Kennedy Space Center in Florida. Charlie Blackwell-Thompson serves as the agency’s Artemis launch director, responsible for integrating and coordinating launch operations for the SLS, Orion, and Exploration Ground Systems Programs, including developing and implementing plans for countdown, troubleshooting, and timing.
Two days before liftoff, when the countdown for launch begins, Blackwell-Thompson’s team will begin preparations for launch from their console positions in Firing Room 1 in Kennedy’s Launch Control Center. On the day of launch, Blackwell-Thompson and her team will manage countdown progress, propellent loading, and launch commit criteria. The criteria include standards for systems involved in launch, and the team will monitor the rocket until it lifts off from the launchpad.
Rick Henfling, flight director, monitors systems in the Flight Control Center at NASA’s Johnson Space Center in Houston.Credit: NASA Flight control team
From solid rocket booster ignition until the crew is safety extracted from the Orion capsule following splashdown in the Pacific Ocean at the end of their mission, the flight control team oversees operations from the Mission Control Center at NASA’s Johnson Space Center in Houston. Multiple flight directors will take turns leading the team throughout the 10-day mission to support operations around the clock. Jeff Radigan, bringing more than 20 years of International Space Station experience to Artemis II, will serve as lead flight director for the mission. The work for this role begins well in advance of the mission with building mission timelines; developing flight rules and procedures; leading the flight control team through simulations that prepare them for the flight test; and then helping them carry out the plan.
On launch day, the ascent flight control team will be led by Judd Frieling, an Artemis I flight director who also supported more than 20 shuttle missions as a flight controller. Frieling is responsible for overseeing the crew’s ascent to space, including performance of SLS core stage engines, solid rocket boosters, and propulsion systems from the moment of launch until the separation of Orion from the Interim Cryogenic Propulsion Stage. As Orion is propelled toward the Moon, guidance of operations will pass to the next flight director.
At the opposite end of the mission, Rick Henfling will take the lead for Orion’s return to Earth and splashdown. Orion will reenter Earth’s atmosphere at roughly 25,000 mph to about 20 mph for a parachute-assisted splashdown. Drawing from a background supporting space shuttle ascent, entry, and abort operations and 10 years as a space station flight director, Henfling and the team will monitor weather forecasts for landing, watch over Orion’s systems through the dynamic entry phase, and to ensure the spacecraft is safely shutdown before handing over operations to the recovery team.
At any point during the mission, a single voice will speak to the crew in space on behalf of all members of the flight control team: the capsule communicator, or CapCom. The CapCom ensures the crew in space receives clear and concise communication from the teams supporting them on the ground. NASA astronaut Stan Love will serve as the lead CapCom for Artemis II. Love flew aboard STS-122 mission and has acted as CapCom for more than a dozen space station expeditions. He is also part of the astronaut office’s Rapid Prototyping Lab, which played a key role in development of Orion’s displays and controls.
Landing, recovery team
Retrieval of the crew and Orion crew module will be in the hands of the landing and recovery team, led by Lili Villarreal. The team will depart San Diego on a Department of Defense ship, and head to the vicinity of the landing site several days before splashdown for final preparations alongside the U.S. Navy and DOD.
The recovery team is made up of personnel operating from the ship, land, and air to recover both astronauts and the capsule. Decision-making authority during the recovery phase of mission operations belongs to Villarreal, who served as deputy flow director for Artemis I and worked in the operations division for the space station.
The success of Artemis II will pave the way for the next phase of the agency’s campaign, landing on the lunar South Pole region on Artemis III. These teams, along with the four crew members and countless NASA engineers, scientists, and personnel, are driving humanity’s exploration on the Moon, Mars, and beyond.
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.