Records are there to be broken, and in March 1995—20 years ago, this week—the crew of Endeavour was midway through what turned out to be the longest flight in shuttle program history at that time. As described in yesterday’s AmericaSpace history article, Commander Steve Oswald, Pilot Bill Gregory, Mission Specialists Tammy Jernigan, Wendy Lawrence, and John Grunsfeld, and Payload Specialists Sam Durrance and Ron Parise were launched in the small hours of 2 March, for what was already expected to be a record-breaking 15-day mission for the shuttle fleet. By the time the STS-67 crew landed at Edwards Air Force Base, Calif., on 18 March, no less than 16 days, 15 hours, and eight minutes would have elapsed since their liftoff, a total of 262 Earth orbits would have been completed, and an astonishing 6.9 million miles (11.1 million km) would have been traveled.
Aboard Endeavour for STS-67 was ASTRO-2, a payload of three ultraviolet instruments—the Hopkins Ultraviolet Telescope (HUT), the Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photopolarimeter Experiment (WUPPE, which had drawn the rather questionable nickname of “Whoopie”)—for observations of celestial sources within our Solar System and beyond, far deeper into the cosmos. The inclusion of professional astronomers Jernigan, Grunsfeld, Durrance, and Parise on the crew enhanced the scientific importance of the mission.
For Grunsfeld, making his first spaceflight, his arrival in orbit quickly convinced that he did not want to return to Earth. “I had this real feeling of peace,” he said later, “that I never had here on Planet Earth.” There was little time to acclimatize, for STS-67 was an around-the-clock operation, involving “red” and “blue” shifts. Oswald, Gregory, Grunsfeld, and Parise formed the red team, with Jernigan, Lawrence, and Durrance on the blue team. And for Steve Oswald, the first few hours of the flight afforded him precious little time to check on Gregory, Lawrence, and Grunsfeld, the three “rookie” members of his crew.
“It never ceases to amaze me,” he told an interviewer from the Smithsonian, years later, “the fire drill that goes on down in the middeck in those first couple of hours after we reach orbit.” Seven bodies floated hither and thither, removing pressure suits, watching as someone’s sock comically floated past, grabbing a vomit bag to cope with an unexpected attack of motion sickness. “As the commander, you try to figure out how much extra time you need to add to the schedule, based on how many rookies you’ve got,” Oswald continued. “Sometimes guys are semi-Velcroed to the wall, throwing up, while the folks you least expected to be heroes are just chugging along, executing the plan.” That plan was enormous and complex in its scope; so enormous, in fact, that all seven astronauts would receive two half-days of free time at various points during the long mission.
Outside, in Endeavour’s cavernous payload bay, sat 17,380 pounds (7,885 kg) of telescopes and supporting instrumentation from Johns Hopkins University in Baltimore, Md., from NASA’s Goddard Space Flight Center in Greenbelt, Md., and from the University of Wisconsin at Madison. This hardware was mounted atop an Instrument Pointing System (IPS), which itself was fastened to a pair of Spacelab pallets. Attached to the forward pallet was a cylindrical “igloo,” containing electronics, whilst at the aft end of the shuttle’s payload bay was the large Extended Duration Orbiter (EDO) pallet, which provided additional cryogenic oxygen and hydrogen reserves to support the long mission.
Within four hours of reaching orbit, under the supervision of Tammy Jernigan, the IPS had been rotated into its upright orientation, whereupon Sam Durrance applied power to the three telescopes, preparatory to the first ASTRO-2 observations. Early activities proceeded normally, despite a Reaction Control System (RCS) thruster leak, which twice forced the closure of the telescopes’ aperture doors to safeguard their optics from contamination. The mission suffered from none of the IPS pointing troubles which had plagued its predecessor, ASTRO-1, in December 1990. According to NASA’s STS-67 press kit, a special test team was assembled at the Marshall Space Flight Center in Huntsville, Ala., and this “extensively modified and tested the IPS software and made other improvements to ensure the IPS works properly for ASTRO-2.” Specifically, an image motion compensation system—designed to eliminate the effects of “jitter,” induced by crew movements and thrusters firings—helped to refine instrument pointing and stability for the telescopes.
This was particularly vital in the case of UIT, whose images were recorded on film with the individual exposures lasting as long as 30 minutes. WUPPE experienced a somewhat slow start, however, since the activation and verification of its detector was delayed by problems keeping it aligned with a test target. Twelve hours into the mission, controllers at the Johnson Space Center (JSC) in Houston, Texas, declared the IPS fully operational and transferred control of its equipment to the ASTRO-2 payload team at Marshall. With this transfer, John Grunsfeld and Ron Parise began a lengthy procedure known as “Joint Focus and Alignment,” to ensure that all three instruments were capable of pointing in precisely the same direction.
Despite the day-long process of calibration, astronomical observations of the ultraviolet sky got underway with pace and gusto. Early on 3 March, the HUT and UIT science teams had locked their instruments onto the Cygnus Loop, an ancient supernova remnant, with the former instrument gathering temperature, density, and chemical data and the latter imaging “filaments” of excited gas and energizing shockwaves. WUPPE demonstrated that its optics were in perfect working order by observing a calibration star, Beta Cassiopeiae, followed by a study of the hypergiant luminous blue variable star P Cygni. Meanwhile, HUT examined EG Andromedae, a “symbiotic” system of a relatively cool, orange giant star and a tiny, exceptionally hot blue star.
White dwarfs, globular clusters—some of which appeared to be more than 16 billion years old, far older than the Hubble Space Telescope (HST) data suggested the Universe itself to be, according to UIT astronomer Steve Maran—and “Wolf-Rayet” stars formed the center of attention over the following days. The latter include EZ Canis Majoris and are thought to represent one of the final phases in the evolution of supermassive stars, whose luminosities vary between 100,000 and a million times as bright as our Sun. Their powerful ionized-gas emissions, or “stellar winds,” were believed to accelerate their aging process.
Extremely bright-centered Seyfert galaxies, distant quasars, and interactive binary star systems also received attention. In the latter case, WUPPE was directed to observe an X-ray binary, known as Vela X-1, with astronomers speculating that a neutron star was gravitationally “stripping” material from its companion star, causing a large oval disk to form in orbit. Polarisation measurements by WUPPE enabled measurements to be made of the size and shape of this disk, as well as calculations as to the quantities of mass transferred between the two companions.
Closer to home—and illustrated on the STS-67 crew’s mission patch, which was chiefly designed by the rookies, Gregory, Grunsfeld, and Lawrence—the largest planet in the Solar System, Jupiter, also came under ASTRO-2 scrutiny. HUT investigators paid particular attention to its immense magnetosphere, as well as the planet’s volcanically active moon, Io. A recent eruption on Io had deposited material onto the surface and into its tenuous atmosphere, prompting HUT co-investigator Paul Feldman to seek evidence of changes in the number of sulphur and oxygen ions in its environment. “As Io orbits Jupiter once every 42 hours,” noted one of NASA’s news summaries, early in the mission, “some of this material is left behind, forming a doughnut-shaped torus of sulphur and oxygen plasma around Io’s orbit.”
The sheer “strangeness” of the Universe was illustrated by the peculiarities of so many ASTRO-2 targets. Phi Persei, a hot, rapidly spinning star, exhibited an unusual ultraviolet spectrum, possibly due to a “shell” of gas which may have been an outer layer shed by its fast rotation. Two active Seyfert galaxies, both strong emitters of very bright ultraviolet radiation and thought to have supermassive black holes at their hearts, were studied; one of them, NGC 4151, was five times brighter in March 1995 than it had been when ASTRO-1 observed it, more than four years earlier. Indeed, the galaxy exhibited a 10 percent luminosity increase in a matter of days during ASTRO-2.
Ancient stars and young stars, stellar graveyards, and stellar nurseries came under the observatory’s ultraviolet gaze, including an open cluster, called N4, whose youthful occupants were believed to be less than 10 million years old. Elsewhere, M104—a distinctive spiral galaxy, nicknamed “The Sombrero Galaxy,” due to its likeness to the wide-brimmed Mexican hat—was observed, with star-forming regions thought to reside within its “brim” and older stars (and maybe a black hole) within its “crown.”
Periodically, the professional astronomer in Tammy Jernigan was overtaken by a sense of childlike wonder at the environment in which she found herself. “There was a lot of time when the cockpit was darkened,” she remembered, in an interview with the Smithsonian, years later. “You would monitor observation of an object for maybe 20 minutes before you had to regroup, repoint the Instrument Pointing System and set up the instruments again. There were whole blocks of time where you could just look out and reflect, talk to the other crew members who were awake on your shift and really have a sense of what a beautiful Universe we inhabit.”
One crew member who proved particularly valuable—“a tremendous source of knowledge,” according to Steve Oswald—was Ron Parise. Both he and Sam Durrance were non-professional astronauts, but both had served as payload specialists on ASTRO-1 and had trained extensively with the instruments, as well as having been intimately involved in their design and development. On-orbit, Durrance and Parise were assigned to assist the other crew members to don and doff their suits at the beginning and end of the mission, but during ASTRO-2 science operations their support was indispensible. There was room for much fun and ribbing, too, with Oswald describing Parise’s age and experience. “When we got back to Ellington, I said he had been assigned to ASTRO since the Earth cooled,” joked Oswald, “and that’s not really completely accurate. However, he has been working ASTRO since he graduated from college … which was shortly after the Earth cooled!” Ironically, Oswald and Parise were separated in age only by about five weeks. …
If the scientific wonders of the mission were a thing of beauty on STS-67, then so too was the overall experience of flying in space. “How many people,” Wendy Lawrence rhetorically asked, “can say they’re living their dream?” With a 24-hour operation underway, the presence of four phone-booth-sized sleep stations in Endeavour’s middeck provided a welcome area to rest. “Keep in mind that while half of the crew is up and working, the other half of the crew needs to be asleep,” said Lawrence. “The sleep stations really provided you with a great way to get a good, quiet night’s sleep. Personally, I never used earplugs and I slept great on-orbit.” Each day, the teams would try to gather for dinner, with the red shift kicking off with a shrimp cocktail. On one occasion, their blue shift counterpart, Sam Durrance—“who probably didn’t have enough breakfast,” Steve Oswald quipped at the post-flight press conference—even snuck in to partake.
In a sharp contrast with the technical difficulties experienced by its predecessor, the ASTRO-2 observatory was also a beautiful payload, from the standpoint of systems performance, with the IPS and its Image Motion Compensation System (IMCS) performing “in an outstanding manner,” according to NASA’s official post-mission report. “The IPS and IMCS for the first time achieved operational capacity,” exulted ASTRO-2 Mission Manager Robert Jayroe, then quipped: “In my estimation, the IMCS and IPS teams have done everything but make the hardware stand up and do a tap dance!” The WUPPE team gathered more than three times as much data as had been gathered during ASTRO-1, whilst the UIT investigators reported that all planned celestial targets had been acquired and the HUT scientists announced more than 100 successful observations.
Already scheduled for more than 15 days aloft, the crew quietly eclipsed the previous shuttle duration record on the evening of 16 March, with the expectation that Endeavour would make landfall at the Kennedy Space Center (KSC) at 3:09 p.m. EST on the 17th. However, it was not to be. Unacceptable weather conditions in Florida forced the Mission Management Team (MMT) to scrub the attempt and reschedule it for the 18th. With the situation on the East Coast showing little evidence of improvement, it was decided to divert to Edwards Air Force Base, Calif., instead. Already, STS-67 had passed the 16-day mark, which was the maximum “standard” length for an EDO mission, and managers were anxious not to press Endeavour’s consumables any further. Sweeping across the Pacific Ocean, the orbiter entered U.S. airspace at the California coastline and alighted on Runway 22 at Edwards at 1:47 p.m. PST (4:47 p.m. EST), concluding a remarkable mission, which had lasted just a few hours shy of 17 full days.
For Steve Oswald, it was a nice record on which to end his astronaut career. Yet the length of the mission, and the months of preparation for it, had taken their toll. “The training is structured such that it trains to the lowest common denominator,” he explained in a NASA Tacit Knowledge Capture interview, “and it just takes forever. You’re going through all the stuff again for those that haven’t flown before. It got to be kind of a long, drawn-out deal. It was a great flight, great crew; I had a great time, but afterwards, I was just done.”
An interesting side note for STS-67 was that, for the first time, an orbiter other than the queen of the fleet, Columbia, had secured the shuttle program’s longest mission. Since the maiden voyage of the reusable spacecraft in April 1981, Columbia had maintained a crown for herself in terms of the longevity of her missions. Kicking off the shuttle era for two days on STS-1, she steadily increased her endurance to eight days on STS-3 in March 1982, 10 days on STS-9 in the late fall of 1983, almost 11 days on STS-32 in January 1990, 14 days on STS-50 in mid-1992, and—on STS-65 in July 1994—just a few hours shy of 15 full days in orbit. These expanded durations were enabled by her greater provision for cryogenic consumables and, from 1992 onward, by the presence of the Extended Duration Orbiter (EDO) infrastructure, which provided for missions of 16 days and beyond.
STS-67 thus knocked Columbia off the endurance top spot, but not for long. In July 1996, she once more secured the record, by flying a mission of 16 days and 22 hours, an achievement pressed yet further by one of her later crews in December of that year, who spent 17 days and 15 hours in orbit. This latter record stood until the very end of the shuttle’s 30-year career in July 2011. It is therefore a matter of pride for the STS-67 crew that their mission retains its place as the third-longest in shuttle history and—excluding long-duration expeditions by NASA astronauts to Skylab, to Russia’s Mir space station, and to the International Space Station (ISS)—also ranks third on the list of the longest U.S. “solo” space missions of all time.
This is part of a series of history articles, which will appear each weekend, barring any major news stories. Next week’s article will focus on the 20th anniversary of the launch of Norm Thagard to Mir, in which he became the first U.S. astronaut to occupy a Russian space station and finally broke a 21-year Skylab endurance record.