A quarter-century ago, this week, one of the most complex scientific research missions ever undertaken rocketed into orbit aboard Space Shuttle Columbia. The first Spacelab Life Sciences (SLS-1) flight—utilizing the bus-sized Spacelab module in the shuttle’s payload bay—was the first mission totally dedicated to the life sciences. And the STS-40 crew, including a pair of physicians, a cardiologist, and a biochemist, also marked the first time in history that three women had flown together on the same mission.
As outlined in yesterday’s AmericaSpace history article, the flight had a long history. Originally scheduled to take place in early 1986, prior to the Challenger tragedy, it was extensively postponed in the aftermath of the disaster and wound up flying in June 1991. By then, its crew complement had changed markedly. Physiologist Bob Phillips, who should have been one of the two Payload Specialists on SLS-1, was grounded by a medical issue and replaced, whilst the tragic death of another astronaut led to the replacement of STS-40’s original pilot, John Blaha, with Sid Gutierrez.
The “science team” of physicians Jim Bagian and Rhea Seddon, cardiologist Drew Gaffney, and biochemist Millie Hughes-Fulford would be largely responsible for the research work during the nine-day mission. However, the “orbiter team” of Commander Bryan O’Connor and crewmates Gutierrez—the first and only Hispanic-born shuttle pilot—and Tammy Jernigan had shown willingness to participate as “guinea pigs” for blood draws and other experiments. “Tammy Jernigan had already signed up for everything,” O’Connor recalled in his NASA oral history. “She was a scientist herself and certainly was interested and very engaged in the training.” For O’Connor and Gutierrez, as STS-40’s pilots, it was more difficult. Much of their training revolved around landing the shuttle and, although they accepted some experiment duties, they rejected those which posed a risk to their flying abilities, such as those which focused on the eyes or the vestibular system.
When the crew came together in mid-1989, they anticipated a launch in June 1990, but delays to the shuttle program—including a plague of hydrogen leaks which grounded the entire fleet throughout the second half of 1990—pushed them inexorably into the early summer of the following year. Efforts to get Columbia into space began after she returned from her previous mission, STS-35, in December 1990. However, the gremlins were still not done with NASA’s oldest shuttle. STS-40’s pair of Solid Rocket Boosters (SRBs) revealed spurious gauge readings and both were destacked into their individual segments, checked for misalignments, and restacked. By mid-May 1991, the crew arrived at the Kennedy Space Center (KSC) in Florida, with the expectation of a launch on the 22nd. “We’re all ready to go,” an excited Jernigan told journalists. “Light ’em!”
The excitement proved premature. Over the next couple of weeks, Columbia succumbed firstly to a leaking liquid hydrogen transducer in her aft compartment, then to a failed General Purpose Computer (GPC) and Multiplexer-Demultiplexer (MDM), and, finally, a calibration problem with an Inertial Measurement Unit (IMU). The latter caused the launch attempt on 1 June to be scrubbed at T-20 minutes, and NASA subsequently announced that it would try again to get Columbia into orbit on the morning of the 5th.
The seven astronauts awoke early and began suiting-up in the Operations & Checkout (O&C) Building. As part of one of the medical investigations, a catheter was inserted into Drew Gaffney’s arm to monitor cardiovascular changes and fluid shifts during ascent. “That was the first time that had ever happened,” said Bryan O’Connor of the situation. “There was a lot of engineering to do with that, because we’re supposed to be wearing a pressure suit that you can escape with. How do you sit in your chair during ascent, with a catheter in your heart, hooked up to some electronics that goes into the orbiter’s recording systems and then be able to bail out or egress from the cabin on the launch pad if you have to, very quickly? You wouldn’t have believed the effort and the training and the planning that went into that simple question and the modifications they made to the hardware the quick-disconnect, so you don’t bleed to death and all of that stuff.”
Weather forced a 90-minute delay, but Columbia roared into orbit at 9:24 a.m. EDT, quickly establishing herself into a 39-degree-inclination orbit. “A solid E-ticket” was Gutierrez’s description of his first shuttle launch. Gaffney’s catheter had been inserted on 4 June, the day before launch, and was removed by Bagian about four hours after reaching orbit. Its data indicated the degree of body fluid redistribution and the rate at which this redistribution occurred. It revealed a blood pressure rise on the launch pad, which increased sharply and peaked during ascent, then steadily returned to normal after a few minutes in space. This appeared to refute earlier suggestions that a rise in blood pressure resulted from fluid shifting into the upper body as a result of weightlessness.
Unlike most Spacelab flights, whose crews broke into two halves to work around the clock, STS-40 operated on a “single-shift” timeline. That said, the seven astronauts typically worked 14-hour days, with close measurements of their circadian rhythms to provide uniformity of biomedical data points. The 18 experiments aboard SLS-1 explored the fundamental problems affecting the biology of humans—including the heart, blood vessels, lungs, kidneys, and hormone-secreting glands—as well as animals and fish in microgravity. Ten experiments used the astronauts, whilst seven others focused on 28 rats and another utilized almost 2,500 jellyfish. Researchers from France, Russia, Germany, and Canada participated in SLS-1, through a biospecimen-sharing project.
During the mission, several rats were transferred between a Research Animal Holding Facility (RAHF) to a General Purpose Workstation (GPWS), marking the first time that animals had floated freely outside their cages. “He didn’t want to get stuck out in the middle of nowhere with nothing to hold on to,” Seddon recalled of one rat’s experience outside the cage. “He would just hold onto your hand and then once we got him turned loose, we didn’t want to throw him; we just wanted to get him off our hand. He floated around until he could grab onto the cage.”
The 28 rats aboard Columbia were part of a much larger group of 74, of which 45 were kept on the ground as “control” specimens and another had been dropped from the flight, just hours before launch, when a clogged water line failed in his cage. Nine other rats were carried in a pair of Animal Enclosure Modules (AEMs) in the shuttle’s middeck. These provided food, water, waste-management, air, and lighting, but did not enable the astronauts to actually handle the rats. These nine rats flew in the middeck because they were loaded aboard so late in the countdown—only 15 hours before launch—that technicians could not gain easy access to the Spacelab module. At first, in orbit, the rats clung to the sides of their cages, but upon realising that they would not fall, they became more relaxed and floated freely around.
As they worked, the science crew of Bagian, Seddon, Gaffney, and Hughes-Fulford literally regarded SLS-1 as their “home” for most of the flight … for they elected to sleep aboard the Spacelab module, too. “They all thought it was a great place to sleep,” O’Connor told Mission Control on one occasion. “It was nice and dark and quiet back there,” agreed Seddon. “We were doing single shifts, so the lab was essentially buttoned up for the night. It was dark and we could cool it down, so we just hung our hammocks back there.” Every so often, the quiet would be disturbed. The Spacelab was situated near the end of the payload bay, so the science crew could hear the boom boom boom of Columbia’s thrusters, as well as the mice in their cages and the refrigerators switching on and off. However, Seddon regarded it as a far more peaceful place to relax than the flight deck or middeck.
Moreover, all seven astronauts devoted everything to the science, typically beginning their duties ahead of time, working through meals and continuing well past bedtime. The result was a substantial increase in the overall scientific yield from SLS-1, whose effects would be amply illustrated in the analysis of results. So delicate was the need to keep to the timeline that it had even been thrown into some disarray by the 90-minute launch delay on 5 June, which meant the astronauts followed an “off-nominal” timeline for the first day of their mission. As a consequence, they were frequently kept up late, troubleshooting or working an experiment which had earlier experienced difficulties. Every so often, O’Connor had to call them over the Spacelab intercom, calling them back to the flight deck for lunch.
In addition to humans and rodents, SLS-1 marked the first-ever flight of jellyfish aboard the shuttle. All told, 2,478 Moon jellyfish—one of the simplest organisms known to possess a nervous system—were housed in Columbia’s middeck and were being flown to examine their reproductive abilities and swimming behavior in microgravity. The jellyfish polyps, which developed into sexually reproductive ephyrae in space, proved “normal” in most respects, despite hormonal changes and swimming abnormalities after landing.
The success of STS-40 was marred in its final days, however, by a problem with the shuttle’s Thermal Protection System (TPS). Several thermal blankets on the aft bulkhead had become detached and part of the payload bay door seal was displaced. NASA asserted that the problem should not impede the closure of the doors at the mission’s end. “The latches on these doors are very strong,” explained Lead Flight Director Randy Stone, “and we believe that even if the seal was in the way, we could collapse the seal and close the doors safely with no problem.” After lengthy analysis, a contingency EVA by Bagian and Jernigan—which might have seen the first spacewalk ever performed through the Spacelab tunnel adapter—was deemed unnecessary.
On her final evening in orbit, Millie Hughes-Fulford floated alone in the darkened Spacelab module, working out to the haunting sound of Irish singer Enya on her Walkman. At length, she stopped and paused by the window to look out. “The Earth was in darkness,” she recalled, “and I saw great lightning storms below. The storm cells were almost a hundred miles across! When the lightning struck, the entire cloud canopy would light up underneath, like giant hot air balloons.” Startled, she looked around for a camera to capture this amazing scene. There were none within reach, and Hughes-Fulford knew that by the time she had returned to the flight deck to get one, the view would be gone. It summed up a comment from another astronaut, Bob Cabana. Photography never did the scene justice and “planting a memory in your brain” was oftentimes the best and only thing to do.
Early on 14 June, after nine remarkable days aloft, Bagian positioned himself inside the Spacelab module with a video camera, whilst Jernigan floated at the aft flight deck windows, in order that both could capture the closure of the payload bay doors. The seal posed no difficulty and the doors closed without incident. At 7:29 a.m. PDT, O’Connor and Gutierrez guided their ship to a safe landing on Runway 22 at Edwards Air Force Base, Calif., wrapping up the third longest shuttle mission at that time, after STS-32 and STS-9. Interestingly, both of these other missions were also flown by Columbia.
For the first time, an airport-style “people mover,” known as the Crew Transport Vehicle (CTV), was employed to remove the seven astronauts from the shuttle. It allowed them to doff their bulky pressure suits, regain their “land legs,” and subject themselves to the doctors for medical checks. For Millie Hughes-Fulford, the landing produced peculiar sensations. The position of the shuttle’s nose on the runway meant that the entire cabin was angled slightly downward, and she found it hard to get out of her seat and stand up. After removing her suit in the CTV, she finally had the chance to walk down the steps to see her husband and daughter. “Because my equilibrium was totally gone,” she told an interviewer from the Smithsonian, years later, “I was holding onto the rail, trying to move as quickly as possible and not walk like a little old lady.”
When her daughter arrived, Hughes-Fulford gave her a hug and whispered in her ear: “Help hold me up!”
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 STS-78, a “stop-gap” science mission to bridge the twilight of the Spacelab era and the dawn of the International Space Station (ISS) era.