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50 Years Ago: Skylab 4 Astronauts Begin Record-Breaking Third Month in Space
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By NASA
This artist’s concept shows how the universe might have looked when it was less than a billion years old, about 7 percent of its current age. Star formation voraciously consumed primordial hydrogen, churning out myriad stars at an unprecedented rate. NASA’s Nancy Grace Roman Space Telescope will peer back to the universe’s early stages to understand how it transitioned from being opaque to the brilliant starscape we see today.NASA, ESA, and A. Schaller (for STScI) 0:00 / 0:00
Your browser does not support the audio element. Today, enormous stretches of space are crystal clear, but that wasn’t always the case. During its infancy, the universe was filled with a “fog” that made it opaque, cloaking the first stars and galaxies. NASA’s upcoming Nancy Grace Roman Space Telescope will probe the universe’s subsequent transition to the brilliant starscape we see today –– an era known as cosmic dawn.
“Something very fundamental about the nature of the universe changed during this time,” said Michelle Thaller, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Thanks to Roman’s large, sharp infrared view, we may finally figure out what happened during a critical cosmic turning point.”
Lights Out, Lights On
Shortly after its birth, the cosmos was a blistering sea of particles and radiation. As the universe expanded and cooled, positively charged protons were able to capture negatively charged electrons to form neutral atoms (mostly hydrogen, plus some helium). That was great news for the stars and galaxies the atoms would ultimately become, but bad news for light!
It likely took a long time for the gaseous hydrogen and helium to coalesce into stars, which then gravitated together to form the first galaxies. But even when stars began to shine, their light couldn’t travel very far before striking and being absorbed by neutral atoms. This period, known as the cosmic dark ages, lasted from around 380,000 to 200 million years after the big bang.
Then the fog slowly lifted as more and more neutral atoms broke apart over the next several hundred million years: a period called the cosmic dawn.
“We’re very curious about how the process happened,” said Aaron Yung, a Giacconi Fellow at the Space Telescope Science Institute in Baltimore, who is helping plan Roman’s early universe observations. “Roman’s large, crisp view of deep space will help us weigh different explanations.”
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Your browser does not support the audio element. Prime Suspects
It could be that early galaxies may be largely to blame for the energetic light that broke up the neutral atoms. The first black holes may have played a role, too. Roman will look far and wide to examine both possible culprits.
“Roman will excel at finding the building blocks of cosmic structures like galaxy clusters that later form,” said Takahiro Morishita, an assistant scientist at Caltech/IPAC in Pasadena, California, who has studied cosmic dawn. “It will quickly identify the densest regions, where more ‘fog’ is being cleared, making Roman a key mission to probe early galaxy evolution and the cosmic dawn.”
The earliest stars were likely starkly different from modern ones. When gravity began pulling material together, the universe was very dense. Stars probably grew hundreds or thousands of times more massive than the Sun and emitted lots of high-energy radiation. Gravity huddled up the young stars to form galaxies, and their cumulative blasting may have once again stripped electrons from protons in bubbles of space around them.
“You could call it the party at the beginning of the universe,” Thaller said. “We’ve never seen the birth of the very first stars and galaxies, but it must have been spectacular!”
But these heavyweight stars were short-lived. Scientists think they quickly collapsed, leaving behind black holes –– objects with such extreme gravity that not even light can escape their clutches. Since the young universe was also smaller because it hadn’t been expanding very long, hordes of those black holes could have merged to form even bigger ones –– up to millions or even billions of times the Sun’s mass.
Supermassive black holes may have helped clear the hydrogen fog that permeated the early universe. Hot material swirling around black holes at the bright centers of active galaxies, called quasars, prior to falling in can generate extreme temperatures and send off huge, bright jets of intense radiation. The jets can extend for hundreds of thousands of light-years, ripping the electrons from any atom in their path.
NASA’s James Webb Space Telescope is also exploring cosmic dawn, using its narrower but deeper view to study the early universe. By coupling Webb’s observations with Roman’s, scientists will generate a much more complete picture of this era.
So far, Webb is finding more quasars than anticipated given their expected rarity and Webb’s small field of view. Roman’s zoomed-out view will help astronomers understand what’s going on by seeing how common quasars truly are, likely finding tens of thousands compared to the handful Webb may find.
This view from the James Webb Space Telescope contains more than 20,000 galaxies. Researchers analyzed 117 galaxies that all existed approximately 900 million years after the big bang. They focused on 59 galaxies that lie in front of quasar J0100+2802, an active supermassive black hole that acts like a beacon, located at the center of the image above appearing tiny and pink with six prominent diffraction spikes. The team studied both the galaxies themselves and the illuminated gas surrounding them, which was lit up by the quasar’s bright light. The observation sheds light on how early galaxies cleared the “fog” around them, eventually leading to today’s clear and expansive views.NASA, ESA, CSA, Simon Lilly (ETH Zürich), Daichi Kashino (Nagoya University), Jorryt Matthee (ETH Zürich), Christina Eilers (MIT), Rob Simcoe (MIT), Rongmon Bordoloi (NCSU), Ruari Mackenzie (ETH Zürich); Image Processing: Alyssa Pagan (STScI), Ruari Macken “With a stronger statistical sample, astronomers will be able to test a wide range of theories inspired by Webb observations,” Yung said.
Peering back into the universe’s first few hundred million years with Roman’s wide-eyed view will also help scientists determine whether a certain type of galaxy (such as more massive ones) played a larger role in clearing the fog.
“It could be that young galaxies kicked off the process, and then quasars finished the job,” Yung said. Seeing the size of the bubbles carved out of the fog will give scientists a major clue. “Galaxies would create huge clusters of bubbles around them, while quasars would create large, spherical ones. We need a big field of view like Roman’s to measure their extent, since in either case they’re likely up to millions of light-years wide –– often larger than Webb’s field of view.”
Roman will work hand-in-hand with Webb to offer clues about how galaxies formed from the primordial gas that once filled the universe, and how their central supermassive black holes influenced galaxy and star formation. The observations will help uncover the cosmic daybreakers that illuminated our universe and ultimately made life on Earth possible.
The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA’s Jet Propulsion Laboratory and Caltech/IPAC in Southern California, the Space Telescope Science Institute in Baltimore, and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems, Inc in Boulder, Colorado; L3Harris Technologies in Rochester, New York; and Teledyne Scientific & Imaging in Thousand Oaks, California.
Download high-resolution video and images from NASA’s Scientific Visualization Studio
By Ashley Balzer
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Media contact:
Claire Andreoli
claire.andreoli@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
301-286-1940
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Last Updated Jul 25, 2024 ContactAshley Balzerashley.m.balzer@nasa.govLocationGoddard Space Flight Center Related Terms
Nancy Grace Roman Space Telescope Active Galaxies Astrophysics Black Holes Galaxies Galaxies, Stars, & Black Holes Galaxies, Stars, & Black Holes Research Goddard Space Flight Center James Webb Space Telescope (JWST) Origin & Evolution of the Universe Science & Research Stars Supermassive Black Holes The Big Bang The Universe View the full article
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By NASA
In July 1968, much work still remained to meet the goal President John F. Kennedy set in May 1961, to land a man on the Moon and return him safely to the Earth before the end of the decade. No American astronaut had flown in space since the November 1966 flight of Gemini XII, the delay largely a result of the tragic Apollo 1 fire. Although the Apollo spacecraft had successfully completed several uncrewed test flights, the first crewed mission still lay three months in the future. The delays in getting the Lunar Module (LM) ready for its first flight caused schedule concerns, but also presented an opportunity for a bold step to send the second crewed Apollo mission, the first crewed flight of the Saturn V, on a trip to orbit the Moon. Using an incremental approach, three flights later NASA accomplished President Kennedy’s goal.
Left: The charred remains of the Apollo 1 spacecraft following the tragic fire that claimed the lives of astronauts Virgil I. “Gus” Grissom, Edward H. White, and Roger B. Chaffee. Middle left: The first launch of the Saturn V rocket on the Apollo 4 mission. Middle right: The first Lunar Module in preparation for the Apollo 5 mission. Right: Splashdown of Apollo 6, the final uncrewed Apollo mission.
The American human spaceflight program suffered a jarring setback on Jan. 27, 1967, with the deaths of astronauts Virgil I. Grissom, Edward H. White, and Roger B. Chaffee in the Apollo 1 fire. The fire and subsequent Investigation led to wholesale changes to the spacecraft, such as the use of fireproof materials and redesign of the hatch to make it easy to open. The early Block I spacecraft, such as Apollo 1, would now only be used for uncrewed missions, with crews flying only aboard the more advanced Block II spacecraft. The fire and its aftermath also led to management changes. For example, George M. Low replaced Joseph F. Shea as Apollo Spacecraft Program Manager. The first Apollo mission after the fire, the uncrewed Apollo 4 in November 1967, included the first launch of the Saturn V Moon rocket as well as a 9-hour flight of a Block I Command and Service Module (CSM). Apollo 5 in January 1968 conducted the first uncrewed test of the LM, and despite a few anomalies, managers considered it successful enough that they canceled a second uncrewed flight. The April 1968 flight of Apollo 6, planned as a near-repeat of Apollo 4, encountered several significant anomalies such as first stage POGO, or severe vibrations, and the failure of the third stage to restart, leading to an alternate mission scenario. Engineers devised a solution to the POGO problem and managers decided that the third flight of the Saturn V would carry a crew.
Left: Apollo 7 astronauts R. Walter Cunningham, left, Donn F. Eisele, and Walter M. Schirra participate in water egress training. Middle: Workers stack the Apollo 7 spacecraft on its Saturn IB rocket at Launch Pad 34. Right: Schirra, left, Cunningham, and Eisele stand outside the spacecraft simulator.
As of July 1968, NASA’s plan called for two crewed Apollo flights in 1968 and up to five in 1969 to achieve the first lunar landing to meet President Kennedy’s deadline, with each mission incrementally building on the success of the previous ones. The first mission, Apollo 7, would return American astronauts to space following a 23-month hiatus. Planned for October 1968, the crew of Walter M. Schirra, Donn F. Eisele, and R. Walter Cunningham would launch atop a Saturn IB rocket and conduct a shakedown flight of the Block II CSM in Earth orbit, including testing the Service Propulsion System engine, critical on later lunar missions for getting into and out of lunar orbit. The flight plan remained open-ended, but managers expected to complete a full-duration 11-day mission, ending with a splashdown in the Atlantic Ocean. Preparations for Apollo 7 proceeded well during the summer of 1968. Workers had stacked the two-stage Saturn IB rocket on Launch Pad 34 back in April. In KSC’s Manned Spacecraft Operations Building (MSOB), Schirra, Eisele, and Cunningham completed altitude chamber tests of their spacecraft, CSM-101, on July 26 followed by their backups three days later. Workers trucked the spacecraft to the launch pad on Aug. 9 for mating with the rocket. Among major milestones, Schirra, Eisele, and Cunningham completed water egress training in the Gulf of Mexico on Aug. 5, in addition to spending time in the spacecraft simulators at KSC and at the Manned Spacecraft Center (MSC), now NASA’s Johnson Space Center in Houston.
Left: The original Apollo 8 crew of Russell L. Schweickart, left, David R. Scott, and James A. McDivitt during training in June 1968. Middle: Lunar Module-3 arrives at NASA’s Kennedy Space Center (KSC) in Florida in June 1968. Right: In July 1968, workers in KSC’s Vehicle Assembly Building stack the Saturn V rocket for the Apollo 8 mission.
The second flight, targeting a December 1968 launch, would feature the first crewed launch of the Saturn V rocket. The Apollo 8 crew of James A. McDivitt, David R. Scott, and Russell L. Schweickart would conduct the first crewed test of the LM in the relative safety of low Earth orbit. McDivitt and Schweickart would fly the LM on its independent mission, including separating the ascent stage from the descent stage to simulate a takeoff from the Moon, while Scott remained in the CSM. After redocking, Schweickart would conduct a spacewalk to practice an external transfer between the two vehicles. Workers completed stacking the three-stage Saturn V rocket (SA-503) in KSC’s Vehicle Assembly Building (VAB) on Aug. 14. The first component of the spacecraft, LM-3, arrived at KSC on June 9, while CSM-103, arrived on Aug. 12. Workers in the MSOB began to prepare both spacecraft for flight.
Left: The original Apollo 9 crew of William A. Anders, left, Michael Collins, and Frank Borman during training in March 1968. Middle: Lunar Module-3 during preflight processing at NASA’s Kennedy Space Center (KSC) in Florida in August 1968. Right: Following the revision of the mission plans for Apollo 8 and 9 and crew changes, the Apollo 8 crew of James A. Lovell, Anders, and Borman stand before their Saturn V rocket as it rolls out of KSC’s Vehicle Assembly Building in October 1968.
The third flight, planned for early 1969, and flown by Frank Borman, Michael Collins, and William A. Anders, would essentially repeat the Apollo 8 mission, but at the end would fire the SPS engine to raise the high point of their orbit to 4,600 miles and then simulate a reentry at lunar return velocity to test the spacecraft’s heat shield. On July 23, Collins underwent surgery for a bone spur in his neck, and on August 8, NASA announced that James A. Lovell from the backup crew would take his place. Later missions in 1969 would progress to sending the CSM and LM combination to lunar orbit, leading to the first landing before the end of the year. Construction of the rocket and spacecraft components for these future missions continued at various contractor facilities around the country.
Left: In Mission Control during the Apollo 6 mission, Director of Flight Crew Operations Christopher C. Kraft, left, Director of the Manned Spacecraft Center, now NASA’s Johnson Space Center in Houston Robert R. Gilruth, and Apollo Spacecraft Program Manager George M. Low. Middle left: Chief of Flight Crew Operations Donald K. “Deke” Slayton. Middle right: Director of NASA’s Kennedy Space Center in Florida Kurt H. Debus. Right: Director of NASA’s Marshall Space Flight Center in Huntsville, Alabama.
Challenges to this plan began to arise in June 1968. Managers’ biggest concern centered around the readiness of LM-3. After its delivery to KSC on June 9, managers realized the vehicle needed much more work than anticipated and it would not meet the planned December Apollo 8 launch date. Best estimates put its flight readiness no earlier than February 1969. That kind of delay would jeopardize meeting President Kennedy’s fast-approaching deadline. To complicate matters, intelligence reports indicated that the Soviets were close to sending cosmonauts on a trip around the Moon, possibly before the end of the year, and also preparing to test a Saturn V-class rocket for a Moon landing mission.
Apollo Spacecraft Program Manager Low formulated a plan both audacious and risky. Without a LM, an Earth orbital Apollo 8 mission would simply repeat Apollo 7’s and not advance the program very much. By sending the CSM on a mission around the Moon, or even to orbit the Moon, NASA would gain valuable experience in navigation and communications at lunar distances. To seek management support for his plan, on Aug. 9 Low met with MSC Director Robert R. Gilruth, who supported the proposal. They called in Christopher C. Kraft, director of flight operations, for his opinion. Two days earlier, Low had asked Kraft to assess the feasibility of a lunar orbit mission for Apollo 8, and Kraft deemed it achievable from a ground control and spacecraft computer standpoint. Chief of Flight Crew Operations Donald K. “Deke” Slayton joined the discussion, and all agreed to seek support for the plan from the directors of KSC and of NASA’s Marshall Space Flight Center (MSFC) in Huntsville, Alabama, as well as NASA Headquarters (HQ) in Washington, D.C. That afternoon, the four flew to Huntsville and met with MSFC Director Wernher von Braun, KSC Director Kurt H. Debus, and HQ Apollo Program Director Samuel C. Phillips. By the end of the meeting, the group identified no insurmountable technical obstacles to the lunar mission plan, with the qualification that the Apollo 7 mission in October concluded successfully. Von Braun had confidence that the Saturn V would perform safely, and Debus believed KSC could support a December launch.
Slayton called Borman, who was with Lovell and Anders conducting tests with their spacecraft in Downey, California. He ordered Borman to immediately fly to Houston, where he offered him command of the new circumlunar Apollo 8 mission, which Borman accepted. His crew would swap missions with McDivitt’s, who agreed to fly an Earth orbital test of the LM in February 1969, putting that crew’s greater experience with the LM to good use. The training challenge fell on Borman’s crew, who now had just four months to train for a flight around the Moon.
Left: Apollo Program Director Samuel C. Phillips. Middle left: Associate Administrator for Manned Space Flight George E. Mueller. Middle right: Deputy Administrator Thomas O. Paine. Right: Administrator James E. Webb.
On Aug. 14, representatives from MSC, MSFC, and KSC attended a meeting in Washington with NASA Deputy Administrator Thomas O. Paine and Apollo Program Director Phillips, the senior Headquarters officials present as NASA Administrator James E. Webb and Associate Administrator for Manned Space Flight George E. Mueller attended a conference in Vienna. The group discussed Low’s proposal and agreed on the technical feasibility of accomplishing a circumlunar flight with Apollo 8 in December. During the discussion, Mueller happened to call from Vienna and when they presented him with the proposal, he was at first reticent, especially since NASA had yet to fly Apollo 7. He requested more information and more time to consider the proposal so he could properly brief Webb. Paine then polled each center director for his overall assessment. Von Braun, who designed the Saturn V rocket, stated that whether it went to the Moon or stayed in Earth orbit didn’t matter too much. Debus stated that KSC could support a Saturn V launch in December – as noted above, his team was already processing both the rocket and the spacecraft. Gilruth agreed that the proposal represented a key step in achieving President Kennedy’s goal, and emphasized that the mission should not just loop around the Moon but actually enter orbit. Following additional discussions after Webb’s return from Vienna, he agreed to the plan, but would not make a formal decision until after a successful Apollo 7 flight in October. NASA kept the lunar orbit plan quiet even as the crews began training for their respective new missions. An announcement on Aug. 19 merely stated that Apollo 8 would not carry a LM, as the agency continued to assess various mission objectives. Ultimately, the plan required President Lyndon B. Johnson’s approval.
Left: Astronaut Neil A. Armstrong ejects just moments before his Lunar Landing Research Vehicle crashed. Middle left: Pilot Gerald P. Gibbons, left, and astronaut James B. Irwin prepare to enter an altitude chamber for one of the Lunar Module Test Article-8 (LTA-8) vacuum tests. Middle right: Astronauts Joe H. Engle, left, Vance D. Brand, and Joseph P. Kerwin preparing for the 2TV-1 altitude test. Right: One of the final Apollo parachute tests.
As those discussions took place, work around the country continued to prepare for the first lunar landing, not without some setbacks. On May 8, astronaut Neil A. Armstrongejected just in the nick of time as the Lunar Landing Research Vehicle (LLRV) he was piloting went out of control and crashed. Managers suspended flights of the LLRV and its successor, the Lunar Landing Training Vehicle (LLTV), until Oct. 3. Astronauts used the LLRV and LLTV to train for the final few hundred feet of the descent to the Moon’s surface. On May 27, astronaut James B. Irwin and pilot Gerald P. Gibbons began a series of altitude tests in Chamber B of the Space Environment Simulation Laboratory (SESL) at MSC. The tests, using the LM Test Article-8 (LTA-8), evaluated the pressure integrity of the LM as well as the new spacesuits designed for the Apollo program. The first series of LTA-8 tests supported the Earth-orbital flight of LM-3 on Apollo 9 while a second series in October and November supported the LM-5 flight of Apollo 11, the first lunar landing mission. In June, using SESL’s Chamber A, astronauts Joseph P. Kerwin, Vance D. Brand, and Joe H. Engle completed an eight-day thermal vacuum test using the Apollo 2TV-1 spacecraft to certify the vehicle for Apollo 7. A second test in September certified the vehicle for lunar missions. July 3 marked the final qualification drop test of the Apollo parachute system, a series begun five years earlier. The tests qualified the parachutes for Apollo 7.
History records that Apollo 11 accomplished the first human landing on the Moon in July 1969. It is remarkable to think that just one year earlier, with the agency still recovering from the Apollo 1 fire, NASA had not yet flown any astronauts aboard an Apollo spacecraft. And further, the agency took the bold step to plan for a lunar orbital mission on just the second crewed mission. With a cadence of a crewed Apollo flight every two months between October 1968 and July 1969, NASA accomplished President Kennedy’s goal of landing a man on the Moon and returning him safely to the Earth.
John Uri
NASA Johnson Space Center
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By NASA
On July 23, 1999, space shuttle Columbia took to the skies on its 26th trip into space, to deliver its heaviest payload ever – the Chandra X-ray Observatory. The STS-93 crew included Commander Eileen M. Collins, the first woman to command a space shuttle mission, Pilot Jeffrey S. Ashby, and Mission Specialists Catherine “Cady” G. Coleman, Steven A. Hawley, and Michel A. Tognini of the French Space Agency (CNES). On the mission’s first day, they deployed Chandra, the most powerful X-ray telescope. With a planned five-year lifetime, Chandra continues its observations after a quarter century. For the next four days, the astronauts worked on twenty secondary middeck payloads and conducted Earth observations. The successful five-day mission ended with a night landing.
Left: The STS-93 crew patch. Middle: Official photo of the STS-93 crew of Eileen M. Collins, left, Steven A. Hawley, Jeffrey S. Ashby, Michel A. Tognini of France, and Catherine “Cady” G. Coleman. Right: The patch for the Chandra X-ray Observatory.
Tognini, selected by CNES in 1985 and a member of NASA’s class of 1995, received the first assignment to STS-93 in November 1997. He previously flew aboard Mir as a cosmonaut researcher, spending 14 days aboard the station in 1992. On March 5, 1998, First Lady Hilary R. Clinton announced Collins’ assignment as the first woman space shuttle commander in a ceremony at the White House together with President William J. “Bill” Clinton. NASA announced the rest of the crew the same day. For Collins, selected in the class of 1990, STS-93 represented her third space mission, having previously served as pilot on STS-63 and STS-84. Ashby, a member of the class of 1994, made his first flight aboard STS-93, while Coleman, selected in 1992, made her second flight, having flown before on STS-73. Hawley made his fifth flight, having previously served as a mission specialist on STS-41D, STS-61C, STS-31, and STS-82. He has the distinction of making the last flight by any member of his class of 1978, more than 21 years after his selection.
Left: Schematic of the Chandra X-ray Observatory showing its major components. Right: Diagram of the trajectory Chandra took to achieve its final operational 64-hour orbit around the Earth – IUS refers to the two burns of the Inertial Upper Stage and IPS to the five burns of Chandra’s Integral Propulsion System.
Because the Earth’s atmosphere absorbs X-ray radiation emitted by cosmic sources, scientists first came up with the idea of a space-based X-ray telescope in the 1970s. NASA launched its first X-ray telescope called Einstein in 1978, but scientists needed a more powerful instrument, and they proposed the Advanced X-ray Astrophysics Facility (AXAF). After a major redesign of the telescope in 1992, in 1998 NASA renamed AXAF the Chandra X-ray Observatory after Indian American Nobel Prize-winning theoretical physicist Subrahmanyan Chandrasekhar who made significant contributions to our knowledge about stars, stellar evolution, and black holes. Chandra, the third of NASA’s four Great Observatories, can detect X-ray sources 100 times fainter than any previous X-ray telescope. At 50,162 pounds including the Inertial Upper Stage (IUS) it used to achieve its operational orbit, Chandra remains the heaviest payload ever launched by the space shuttle, and at 57 feet long, it took up nearly the entire length of the payload bay. It has far exceeded its expected five-year lifetime, still returning valuable science after 25 years.
Left: The STS-93 crew during the Terminal Countdown Demonstration Test. Middle: The Chandra X-ray Observatory loaded into Columbia’s payload bay. Right: Liftoff of Columbia on the STS-93 mission carrying the Chandra X-ray Observatory and the first woman shuttle commander.
Columbia returned to KSC following its previous flight, the STS-90 Neurolab mission, in May 1998. Workers in KSC’s Orbiter Processing Facility (OPF) serviced the orbiter and removed the previous payload. With all four orbiters at KSC at the same time, workers temporarily stowed Columbia in the Vehicle Assembly Building (VAB), returning it to the OPF for final preflight processing on April 15, 1999. Rollover of Columbia from the OPF to the VAB took place on June 2, where workers mated it with an external tank and two solid rocket boosters. Following integrated testing, the stack rolled out to Launch Pad 39B on June 7. The crew participated in the Terminal Countdown Demonstration Test on June 24. Workers placed Chandra in Columbia’s payload bay three days later.
On July 23, 1994, Columbia thundered into the night sky from KSC’s Launch Pad 39B to begin the STS-93 mission. Two previous launch attempts on July 20 and 22 resulted in scrubs due to a faulty sensor and bad weather, respectively. As Columbia rose into the sky, for the first time in shuttle history a woman sat in the commander’s seat. Far below, problems arose that could have led to a catastrophic abort scenario. During the engine ignition sequence, a gold pin in Columbia’s right engine came loose, ejected with great force by the rapid flow of hot gases, and struck the engine’s nozzle, punching holes in three of its hydrogen cooling tubes. Although small, the hydrogen leak caused the engine’s controller to increase the flow of oxidizer, making the engine run hotter than normal. Meanwhile, a short-circuit knocked out the center engine’s digital control unit (DCU) and the right engine’s backup DCU. Both engines continued powered flight without a redundant DCU, with a failure in either causing a catastrophic abort. Although this did not occur, the higher than expected oxidizer usage led to main engine cutoff occurring 1.5 seconds early, leaving Columbia in a lower than planned orbit. The shuttle’s Orbiter Maneuvering System engines made up for the deficit. The harrowing events of the powered flight prompted Ascent Flight Director John P. Shannon to comment, “Yikes! We don’t need any more of these.”
Left: Eileen M. Collins, the first woman shuttle commander, shortly after reaching orbit. Right: First time space flyer STS-93 Pilot Jeffrey S. Ashby, shortly after reaching space.
After reaching orbit, the crew opened the payload bay doors and deployed the shuttle’s radiators, and removed their bulky launch and entry suits, stowing them for the remainder of the flight. The astronauts prepared for the mission’s primary objective, deployment of Chandra, and also began activating some of the middeck experiments.
Left: The Chandra X-ray Observatory in Columbia’s payload bay shortly after reaching orbit. Middle: Chandra raised to the deployment angle. Right: Chandra departs Columbia.
Coleman had prime responsibility for deploying Chandra. After initial checkout of the telescope by ground teams, the astronauts tilted Chandra and the IUS to an angle of 29 degrees. After additional checks, they tilted it up to the release angle of 58 degrees. A little over seven hours after launch, Coleman deployed the Chandra/IUS stack. Collins and Ashby flew Columbia to a safe distance, and about an hour after deployment, the IUS fired its first stage engine for about two minutes, followed by a two-minute burn of the second stage. This placed Chandra in a temporary elliptical Earth orbit with a high point of 37,200 miles. After separation of the IUS, Chandra used its own propulsion system over the next 10 days to raise its altitude to 6,214 miles by 86,992 miles, its operational orbit, circling the Earth every 64 hours. For the next four days of the mission, the astronauts operated about 20 middeck experiments, including a technology demonstration of a treadmill vibration isolation system planned for the International Space Station.
Left: Michel A. Tognini works with the Commercial Generic Bioprocessing Apparatus. Middle: Jeffrey S. Ashby checks the status of the Space Tissue Lab experiment. Right: Catherine G. Coleman harvests plants from the Plant Growth in Microgravity experiment.
Left: Catherine G. Coleman, left, and Michel A. Tognini pose near the Lightweight Flexible Solar Array Hinge technology demonstration experiment. Middle: Stephen A. Hawley checks the status of the Micro Electromechanical Systems experiment. Right: Tognini places samples of the Biological Research in Canisters experiment into a gaseous nitrogen freezer.
Left: Eileen M. Collins runs on the Treadmill Vibration Isolation System. Middle: Stephen A. Hawley, left, and Michel A. Tognini operate the Southwest Ultraviolet Imaging System instrument. Right: Inflight photograph of the STS-93 crew.
A selection of the STS-93 crew Earth observation photographs. Left: Laguna Verde in Chile. Middle left: Sunrise over the Mozambique Channel. Middle right: Darling River and lakes in Australia. Right: The Society Islands of Bora Bora, Tahaa, and Raiatea.
Left: Eileen M. Collins prepares to bring Columbia home. Middle: Columbia streaks through the skies over NASA’s Johnson Space Center in Houston during reentry. Right: Collins guides Columbia to a smooth touchdown on the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida.
Left: Three holes visible in the hydrogen cooling tubes of Columbia’s right main engine, seen after landing. Middle: The STS-93 crew pose in front of Columbia on the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida. Right: Eileen M. Collins addresses the crowd at Houston’s Ellington Field during the welcome home ceremony for the STS-93 crew, as Vice President Albert “Al” A. Gore and other dignitaries listen.
At the end of five days, the astronauts finished the last of the experiments and prepared for the return to Earth. On July 28, they closed Columbia’s payload bay doors, donned their launch and entry suits, and strapped themselves into their seats for entry and landing. Collins piloted Columbia to a smooth landing on KSC’s Shuttle Landing Facility, completing the 12th night landing of the shuttle program. The crew had flown 80 orbits around the Earth in 4 days, 22 hours, and 50 minutes. Columbia wouldn’t fly again until March 2002, the STS-109 Hubble Servicing Mission-3B. A postflight investigation into the cause of the short on ascent that led to two DCUs failing revealed a wire with frayed insulation, likely caused by workers inadvertently stepping on it, that rubbed against a burred screw head that had likely been there since Columbia’s manufacture. The incident resulted in significant changes to ground processes during shuttle inspections and repairs. With regard to the pin ejected during engine ignition that damaged the hydrogen cooling tubes, investigators found that those pins never passed any acceptance testing. Since STS-93 marked the last flight of that generation of main engines, newer engines incorporated a different configuration, requiring no design or other changes.
Enjoy the crew narrate a video about the STS-93 mission. Read Hawley’s recollections of the STS-93 mission in his oral history with the JSC History Office.
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By European Space Agency
An international team of astronomers using the NASA/ESA/CSA James Webb Space Telescope have directly imaged an exoplanet roughly 12 light-years from Earth. While there were hints that the planet existed, it had not been confirmed until Webb imaged it. The planet is one of the coldest exoplanets observed to date.
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