In the space of just 3 days, a pair of NASA astronauts conducted an unplanned and rapidly executed contingency space walk on the exterior of the space station on Tuesday, May 23 in order to replace a critical computer unit that failed over the weekend.
The spacewalk was conducted by Expedition 51 Commander Peggy Whitson – NASA’s most experienced astronaut – and Flight Engineer Jack Fischer aboard the International Space Station (ISS).
This marked the 10th spacewalk for Whitson – who already has the most cumulative spacewalk time by a female and the most time in space by a NASA astronaut. This was Fischer’s second spacewalk.
Furthermore Whitson now moves into third place all-time for cumulative spacewalking time totaling 60 hours, 21 minutes. Only Russia’s Anatoly Solovyev and NASA’s Michael Lopez-Alegria have more spacewalking time to their credit.
NASA managers ordered the spacewalk over the weekend when a computer unit known as multiplexer-demultiplexer-1 (MDM-1) unexpectedly failed Saturday morning, May 20 at 1:13 p.m. Central time.
The cause of the MDM failure is not known, says NASA. Multiple attempts by NASA flight controllers to restore power to the MDM-1 relay box were not successful.
The US dynamic duo successfully changed out the MDM computer relay box with a spare unit on board the station. They also installed a pair of antennas on the station on the U.S. Destiny Laboratory module to enhance wireless communication for future spacewalks.
The MDM functions as a data relay box and is located on the S0 truss on the exterior of the US segment of the ISS, thereby necessitating a spacewalk by astronaut crew members.
After NASA engineers thoroughly assessed the situation and reviewed spacewalk procedures on Sunday, May 21, they gave the go ahead for Whitson and Fischer to carry out the hurriedly arranged extravehicular activity (EVA) spacewalk on Tuesday.
Meanwhile, Whitson worked on Sunday to prepare the spare data relay box and test its components to ensure it was ready for Tuesdays swap out of the failed unit.
“The relay box, known as a multiplexer-demultiplexer (MDM), is one of two units that regulate the operation of radiators, solar arrays and cooling loops.” says NASA.
“Because each MDM is capable of performing the critical station functions, the crew on the station was never in danger and station operations have not been affected.”
The two MDM’s housed in the truss are fully redundant systems.
“The other MDM in the truss is functioning perfectly, providing uninterrupted telemetry routing to the station’s systems.”
The spacewalk began Tuesday morning, May 23 at 7:20 a.m. EDT when the two NASA astronauts switched their spacesuits to battery power.
While Whitson focused on the MDM swap, Fischer worked on the antenna installation.
The unplanned spacewalk marks the second this month by Whitson and Fischer. The first was on May 12 and the 200th overall. The Destiny module antenna installation was deferred from the May 12 spacewalk.
The relatively short EVA lasted a total of two hours and 46 minutes. It concluded at 10:06 a.m. EDT.
Overall this was the 201st spacewalk in support of the space station assembly, maintenance and upgrade. Spacewalkers have now spent a total of 1,250 hours and 41 minutes working outside the orbiting lab complex since its inception.
Spacewalk 201 was also the sixth spacewalk conducted from the Quest airlock in 2017 aboard the ISS.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Between them, Foale and Ochoa flew to space a combined total of ten times – 6 for Foale and 4 for Ochoa.
They flew together as crewmates on the STS-56 space shuttle mission aboard Space Shuttle Discovery which launched from the Kennedy Space Center, Florida, on 8 April 1993.
The nine day STS-56 mission was Ochoa’s rookie flight and Foale’s second flight. It was the second of the shuttle’s ATLAS series of Earth science missions – dubbed Atlas-2 – whose purpose was to study the atmosphere and solar interactions.
“I was so happy to hear he and I were going to be inducted together,” Ochoa said during her acceptance speech. “He’d already had one mission and he passed along all kinds of helpful information that helped a rookie like me know where to focus and hopefully not be too surprised when the flight happened. Because being surprised in space is really not a good thing, as Mike found out.”
Ellen Ochoa counts as the first Hispanic woman to travel to space and currently serves as the 11th director of NASA’s Johnson Space Center in Houston.
Michael Foale counts as the only U.S. astronaut to serve on both the International Space Station (ISS) and Russian space station Mir.
Foale was on board Mir in June 1997 during one of the worst disasters in space when an out of control unmanned Russian Progress cargo ship collided with the station’s Spektr module causing its air depressurization and sent Mir tumbling and rolling. He and his two Russian crewmates rapidly went into action to seal the leak, to stabilize and save Mir and themselves. He spent four months on Mir during the Mir 23 and Mir 24 missions.
Ochoa and Foale joined the ranks of 93 prestigious American space heroes who have previously received the same honor over the years since the U. S. Astronaut Hall of Fame was established in its current incarnation more than 30 years ago by the founders of the Astronaut Scholarship Foundation, the six surviving Mercury 7 astronauts.
The new duo comprise the 16th group of space shuttle astronauts to be inducted into the Hall of Fame.
Thus the Astronaut Hall of Fame now numbers 95 heroic and famous space explorers.
Foale and Ochoa unveiled their new ‘Hall of Fame’ commemorative plaques during the ceremony.
The Astronaut Scholarship Foundation has awarded more than $4 million in merit-based scholarships to more than 400 brilliant students since its inception.
Some 21 legendary NASA astronauts were on hand for the induction ceremony, including: Robert Cabana, Dan Brandenstein, Al Worden, Charlie Duke, Karol “Bo” Bobko, Brian Duffy, Scott Altman, Michael Bloomfield, Charles Bolden, Ken Bowersox, Curtis Brown, Michael Coats, Robert Crippen, Sam Durrance, Robert Gibson, Fred Gregory, Rhea Seddon, Brewster Shaw, Loren Shriver, Kathryn Thornton, and James Wetherbee.
Here is a description of their space flight accomplishments from NASA:
“Ochoa joined NASA in 1988 as a research engineer at NASA’s Ames Research Center in California after earning a doctorate in electrical engineering from Stanford University. She joined Johnson in 1990, when she was selected as an astronaut candidate. After completing astronaut training, she served on the nine-day STS-56 mission aboard the space shuttle Discovery in 1993, conducting atmospheric studies to better understand the effect of solar activity on Earth’s climate and environment.
Ochoa has flown in space four times, including the STS-66, STS-96 and STS-110 missions, logging nearly 1,000 hours in orbit. She is Johnson’s first Hispanic director and its second female director. She also has served as the center’s deputy director and director of Flight Crew Operations.”
“Foale, whose hometown is Cambridge, England, earned a doctorate in laboratory astrophysics from the University of Cambridge, Queens’ College. A naturalized U.S. citizen, Foale was selected as an astronaut candidate in June 1987. Before his first spaceflight, he tested shuttle flight software in the Shuttle Avionics Integration Laboratory simulator.
Foale was a crew member on six space missions, including STS-45, STS-56, STS-63, STS-84, STS-103 and Soyuz TMA-3. During STS-84, he helped reestablish the Russian Space Station Mir after it was degraded by a collision and depressurization. Foale logged more than 374 days in space, including four spacewalks totaling 22 hours and 44 minutes.
Foale also served as chief of the Astronaut Office Expedition Corps, assistant director (technical) of Johnson, and deputy associate administrator for exploration operations at NASA Headquarters in Washington. His last assignment at Johnson was as chief of the Soyuz Branch, Astronaut Office, supporting Soyuz and International Space Station operations and space suit development. Foale retired from NASA in 2013.”
Read this description of the U.S. Astronaut Hall of Fame Induction Process and Eligibility:
“Each year, inductees are selected by a committee of Hall of Fame astronauts, former NASA officials, flight directors, historians and journalists. The process is administered by the Astronaut Scholarship Foundation. To be eligible, an astronaut must have made his or her first flight at least 17 years before the induction. Candidates must be a U.S. citizen and a NASA-trained commander, pilot or mission specialist who has orbited the earth at least once.”
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
If you’re a frequent reader of Universe Today you know that, despite the end of the Shuttle program and the constant battle for a piece of the federal budget, NASA has a lot on their plate for future space exploration missions. But there are still a lot of people among the general public who think that the U.S. space administration is “dead,” or, at the very least, in the process of dying. Which is unfortunate because there’s actually a lot going on, both in space and in development on the ground.
The video above, released Monday by Johnson Space Center, shows highlights from 2013 as well as some of the many things NASA has in progress. As anyone can see, rumors of its death have been greatly exaggerated! (By whom I’m still not quite sure.)
NASA’s “lean and green” Morpheus lander crashed and burned during a free flight test at Kennedy Space Center today, August 9, at approximately 12:46 pm EDT.
Watch a video of the failed test after the jump:
Designed in-house at Johnson Space Center, the Morpheus lander is engineered to use a liquid oxygen and methane fuel — relatively cheap materials that can be stored easily and would be available resources on other worlds besides Earth.
New investigations of lunar samples collected during the Apollo missions have revealed origins from beyond the Earth-Moon system, supporting a hypothesis of ancient cataclysmic bombardment for both worlds.
Using scanning electron microscopes, researchers at the Lunar-Planetary Institute and Johnson Space Center have re-examined breccia regolith samples returned from the Moon, chemically mapping the lunar rocks to discern more compositional detail than ever before.
What they discovered was that many of the rocks contain bits of material that is chondritic in origin — that is, it came from asteroids, and not from elsewhere on the Moon or Earth.
Chondrites are meteorites that originate from the oldest asteroids, formed during the development of the Solar System. They are composed of the initial material that made up the stellar disk, compressed into spherical chondrules. Chondrites are some of the rarest types of meteorites found on Earth today but it’s thought that at one time they rained down onto our planet… as well as our moon.
The Lunar Cataclysm Hypothesis suggests that there was a period of extremely active bombardment of the Moon’s surface by meteorite impacts around 3.9 billion years ago. Because very few large impact events — based on melt rock samples — seem to have taken place more than 3.85 billion years ago, scientists suspect such an event heated the Moon’s surface enough prior to that period to eradicate any older impact features — a literal resurfacing of the young Moon.
There’s also evidence that there was a common source for the impactors, based on composition of the chondrites. What event took place in the Solar System that sent so much material hurtling our way? Was there a massive collision between asteroids? Did a slew of comets come streaking into the inner solar system? Were we paid a brief, gravitationally-disruptive visit by some other rogue interstellar object? Whatever it was that occurred, it changed the face of our Moon forever.
Curiously enough, it was at just about that time that we find the first fossil evidence of life on Earth. If there’s indeed a correlation, then whatever happened to wipe out the Moon’s oldest craters may also have cleared the slate for life here — either by removing any initial biological development that may have occurred or by delivering organic materials necessary for life in large amounts… or perhaps a combination of both.
The new findings from the Apollo samples provide unambiguous evidence that a large-scale impact event was taking place during this period on the Moon — and most likely on Earth too. Since the Moon lacks atmospheric weathering or water erosion processes it serves as a sort of “time capsule”, recording the evidence of cosmic events that take place around the Earth-Moon neighborhood. While evidence for any such impacts would have long been erased from Earth’s surface, on the Moon it’s just a matter of locating it.
In fact, due to the difference in surface area, Earth may have received up to ten times more impacts than the Moon during such a cosmic cataclysm. With over 1,700 craters over 20 km identified on the Moon dating to a period around 3.9 billion years ago, Earth should have 17,000 craters over 20 km… with some ranging over 1,000 km! Of course, that’s if the craters could had survived 3.9 billion years of erosion and tectonic activity, which they didn’t. Still, it would have been a major event for our planet and anything that may have managed to start eking out an existence on it. We might never know if life had gained a foothold on Earth prior to such a cataclysmic bombardment, but thanks to the Moon (and the Apollo missions!) we do have some evidence of the events that took place.
The LPI-JSC team’s paper was submitted to the journal Science and accepted for publication on May 2. See the abstract here, and read more on the Lunar Science Institute’s website here.