International Year, International Mission: The Changing Fortunes of STS-42

STS-42 mission brochure, personally signed to me by Commander Ron Grabe. I received this brochure in January 1992 – only days before the mission was launched – and for a 15-year-old space enthusiast it was a priceless treasure. Image Credit: Ben Evans personal collection

One summer evening, early in August 1492 three ships – the carrack Santa María and a pair of smaller caravels, the Pinta and the Santa Clara – put to sea from Palos de la Frontera, in southern Spain, to begin one of the most remarkable voyages in human history. Ever since the fall of the Mongol Empire, and, later, the final collapse of Byzantine hegemony in the eastern Mediterranean, it had become increasingly difficult and dangerous for European traders to pursue overland silk and spice routes to India and China. In response to this difficulty, Spain and Portugal had long vied with one another to search out seafaring routes to the ‘East Indies’. In 1488, an eastward possibility had opened when the Portuguese explorer Bartolemeu Dias reached the Cape of Good Hope, but it was Christopher Columbus’ expedition westwards, in 1492, which garnered the most excitement. In the first of four epic voyages, Columbus – born in Portugal, but serving the Spanish crown – sailed via the Canaries, in the expectation of reaching Japan…but after many weeks at sea, he dropped anchor instead in the Bahamas.

The discoveries in those years would have profound implications for the ‘Old World’ and although Columbus never admitted it in his lifetime, his expeditions did uncover a ‘New World’ of which Europeans were hitherto unaware. Fast forward to 1992 and a proposal by Hawaii Senator Spark Matsunaga to designate the year of the 500th anniversary of Columbus’ pioneering expedition as the ‘International Space Year’. In total, 29 national space agencies and ten international organisations supported the theme of the year as a Mission to Planet Earth, with a focus on space exploration and sustainable technology. It was embraced by the United Nations, whose Secretary General, Boutros Boutros-Ghali, declared on 28 August 1992 that the year would “highlight the importance of understanding the Earth as a single, complex, inter-dependent system” and “stress the unique role that space science and technology can play in promoting that understanding”. That year, several key voyages of scientific exploration contributed enormously to humanity’s understanding of the Home Planet and the cosmos. Research was conducted into the life and microgravity sciences, the atmospheric and solar physics and the geosciences and plasma physics and representatives of nine discrete nations journeyed into orbit during the International Space Year.

At the beginning of 1992, NASA readied itself for its most challenging year since before the loss of Challenger. That challenge had been amplified in the case of the first Shuttle flight of the year, STS-42, whose crew composition had changed several times since the first assignment of astronauts in June 1989. The mission was particularly important, for it carried the first International Microgravity Laboratory (IML-1), inaugurating a series of – it was hoped – at least three Spacelab flights dedicated to the life and microgravity sciences, featuring co-operation from more than 200 scientists in over a dozen nations. It was also several years overdue, having been postponed from its original launch date of May 1987 by the Challenger disaster. In particular, NASA, the European Space Agency (ESA), the Deutsche Agentur für Raumfahrtangelegenheiten (DARA, the German space agency), the Canadian Space Agency (CSA), the French Centre National d’Études Spatiales (CNES) and the National Space Development Agency of Japan (NASDA) sponsored significant research aboard IML-1.

The tunnel adaptor for the IML-1 Spacelab module is prepared for installation in the Orbiter Processing Facility. STS-42 was the first human launch of International Space Year 1992. Photo Credit: NASA

The sensitive microgravity requirements of many of the experiments required STS-42 to operate in a so-called ‘pseudo gravity gradient’ orientation, whereby the Shuttle would operate in a 160-mile, 57-degree-inclination orbit, with its tail directed Earthward. This would allow positioning to be effected and maintained primarily by natural forces, thus reducing the number of disruptive thrusters firings on the experiments. Many of these experiments were located inside the Spacelab long module and would be operated around the clock in two, 12-hour shifts. To facilitate planning for what was envisaged to be an early demonstration of how research would be conducted aboard Space Station Freedom, members of the IML-1 ‘science’ crew were announced in advance of the ‘orbiter’ crew…and a new astronaut designation was born. In June 1989, a pair of veteran astronauts, physician Norm Thagard and engineer Mary Cleave were named as IML-1 mission specialists and a cadre of four international scientists – physiologist Ken Money and physician Roberta Bondar, both from Canada, were joined by US physicist Roger Crouch and German physicist Ulf Merbold – were selected to train for two payload specialist positions. The remainder of the seven-member crew (known as the ‘orbiter’ crew, since they would be responsible for managing the Shuttle’s systems throughout the mission) would be named at a later date. Scheduled for launch in December 1990, aboard Columbia, IML-1 would last nine days, with a possibility of a tenth day being added, making it one of the longest Shuttle missions to date.

Within a matter of months, however, the first changes to STS-42 took place. In late January 1990, NASA revealed that Cleave had resigned her position on the crew “for personal reasons” and she was replaced by another veteran astronaut, Navy flight surgeon Manley ‘Sonny’ Carter. In her NASA oral history, many years later, Cleave explained some of her reasoning for the change. She had flown two previous Shuttle missions, separated by almost four years, and with a PhD in environmental engineering she was shocked by the rate at which the Home Planet had changed during that interval. “Cities were grey smudges,” she remembered of the often depressing views from space of human devastation. “The air looked dirtier, less trees, more roads.” She opted to relocate out of the astronaut office in Houston to work at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, on robotic environmental projects. Many of her colleagues thought she was crazy and others advised her to remain in Houston, working in an engineering role for a year, in the hope that she would change her mind. “It was standard military practice,” Cleave said. “Don’t do any traumatic decisions until you think about it for a year.” She did not change her mind. In May 1991, she was named as deputy project manager for a Goddard mission known as ‘SeaWiFS’, dedicated to studying the biological mass of the world’s oceans through analysis of chlorophyll content and plankton production.

By the time Carter replaced Cleave on STS-42, two other major crew additions had been made. Firstly, on 2 January 1990, astronauts Ron Grabe, Steve Oswald and Bill Readdy were assigned as the orbiter crew, followed, three weeks later, by a surprising announcement from NASA that a new mission specialist designation had been created: the ‘Payload Commander’. The agency retroactively named four astronauts, already in training for major Shuttle science missions, as payload commanders…and the first would be Norm Thagard on IML-1. In its news release, NASA acquiesced that the role was “expected to serve as a foundation for the development of a Space Station mission commander concept” and that its purpose was “to provide long-range leadership in the development and planning of payload crew science activities”. This responsibility encapsulated the development and co-ordination of training plans for the science crew, liaison with the mission’s Payload Operations Control Center and principal investigators, attendance at relevant meetings and oversight of pertinent hardware and software changes. Thagard would thus be in charge of IML-1 and the organisation of its science crew and would be responsible for the conduct and accomplishment of its scientific objectives; the mission commander (in this case, Ron Grabe) would maintain overall authority for the safety and success of the flight.

As the Shuttle’s first ‘payload commander’, the role of Norm Thagard on IML-1 was to co-ordinate the mission’s payload science operations and provide an early benchmark for a future Space Station Freedom commander. Photo Credit: NASA

One of Thagard’s biggest challenges as payload commander came relatively late in the IML-1 training process. A series of hydrogen leaks endured by Columbia and Atlantis in the summer of 1990 forced several missions, further downstream, to be unavoidably delayed, and STS-42 was amongst them. By the time Columbia finally flew STS-35, NASA was keenly aware that the veteran orbiter was scheduled for a year-long overhaul, beginning in mid-1991, to add capabilities for extended duration missions. This meant two of Columbia’s flights, STS-42 and STS-45, had to be shifted onto her sisters, Discovery and Atlantis. By the time the space agency issued its December 1990 manifest, STS-42 was listed to fly aboard Atlantis in December 1991, but the problems with Discovery a few weeks later threw another spanner into the works. Ultimately, by mid-1991, the mission had been reshuffled again and was now scheduled to launch aboard Discovery, no earlier than 22 January 1992.This change posed a fundamental problem. One of the reasons that Columbia had been assigned virtually all of the longer-duration Spacelab science flights, lasting around ten days or so, was because she was alone in the fleet in having the capability to house as many as five cryogenic oxygen and hydrogen reactant tanks underneath her payload bay floor to supply the electricity-generating fuel cells. (At the time, her sisters, Discovery and Atlantis, carried four tanks apiece.) Prior to the Extended Duration Orbiter modifications, Columbia was thus capable of supporting a maximum mission length of between nine and 14 days. As shown in NASA’s manifests from December 1990 onwards, the decision to transfer STS-42 to Atlantis and, subsequently, Discovery, prompted a reduction in the length of the mission, down to just seven days. According to Roberta Bondar, who was selected in January 1990, with Ulf Merbold, as a prime payload specialist for IML-1, this change to duration, but not mission content, made the workload of the astronauts extremely frenetic.

With the presence of Bondar and Merbold, the flight truly earned its moniker of an ‘International’ Microgravity Laboratory. Bondar would become Canada’s first female astronaut and the first qualified neurologist to enter space. An accomplished scuba diver and parachutist, Bondar was selected as one of Canada’s first six astronauts – alongside Ken Money – in December 1983. At the time, she was serving as an assistant professor of medicine, with a neurology specialism. The second IML-1 payload specialist, Merbold became one of only a handful of these non-career scientists to undertake more than one space mission. In fact, when Merbold flew aboard the Spacelab-1 mission in November 1983, he was considered ‘West’ German by nationality and political status; by the time of STS-42, the two disparate halves of his country had reunified and he thus became the first ‘German’ astronaut. In his subsequent career, Merbold would also fly aboard the Russian Mir space station and, in so doing, he became the first European to complete three missions.

The sheer complexity of IML-1’s scientific objectives had certainly made the contributions of Norm Thagard as the first payload commander virtually indispensable. Yet there was considerable misfortune still to come. On the calm afternoon of 5 April 1991, Atlantic Southeast Airlines Flight 2311 was approaching Glynco Jetport (today’s Brunswick Golden Isles Airport) in Brunswick, Georgia, after a short, hour-long flight from Atlanta. As the jet approached the runway, in clear weather conditions, eyewitnesses reported that it was flying at much lower altitude than normal – less than a couple of hundred feet – after which it suddenly rolled sharply to the left and descended, nose-down, to crash into a patch of trees. All 20 passengers and three crew were killed. Amongst the dead were two small children, together with Texas Senator John Tower…and IML-1 astronaut Sonny Carter. Initial investigations pointed to severe asymmetric thrust condition with the left-hand engine’s propeller control unit, which led to a rapid loss of control. The pilots were unaware of the problem, until it was too late, and did not even have time to declare an emergency.

With a prominent gold star shining brightly for Sonny Carter, the patch of the STS-42 masked several twists and changes of fortune for the crew of this mission. Mary Cleave had resigned her post, Sonny Carter had lost his life and Dave Hilmers was pulled in as a late replacement member. Image Credit: NASA

For the astronaut corps, Carter’s death was devastating. “He was never without a smile,” wrote Mike Mullane in his memoir, Riding Rockets, “and a positive word.” In Mullane’s mind, Carter’s death was “a gross violation of the natural order” – for it was to be expected that an astronaut dying in an aircraft would do so as a pilot, not a passenger. Two weeks later, veteran astronaut Dave Hilmers was assigned to replace Carter on STS-42. It was, said Don Puddy, the head of Flight Crew Operations, a difficult decision and one which he made with “regret”. When the STS-42 astronauts released their official patch, later that year, it included a single gold star, hanging over Earth’s horizon…in memory, they said, of “our crewmate, colleague and friend”.

The choice of Hilmers was a logical one. Although he was not a scientist – he was an active-duty Marine Corps officer, with an engineering background – Hilmers had long exhibited a fascination with medicine and intended to pursue it after his astronaut career. The IML-1 mission featured life sciences as one of its two primary research aims. By the time of IML-1 Hilmers had already flown three Shuttle missions. “He just never missed a beat,” recalled STS-42 crewmate Bill Readdy in admiration. “You couldn’t throw too much information at him. The guy’s just a sponge and able to absorb it all and then somehow figure out how to process it and spit it back to you.”

Aside from his military background, Hilmers was very religiously conservative – in fact, his devout faith was remarked upon by Mike Mullane – and he had cultivated a long-standing interest in medicine. At one stage he intended to take an Advanced Cardiac Life Support Course. “He wanted to be a doctor,” remembered Rhea Seddon. “It was like he never got a chance to be a doctor. He would come and ask me medical questions. I know he had a lot of fun with the medical training, because it was something he wanted to know more about.” Upon his departure from NASA, Hilmers entered Baylor College, in Houston, and today works as a paediatrician and nutritionist. Adjectives such as “outstanding” have been used to describe him, but the words of Don Puddy, then-head of Flight Crew Operations, sum up Hilmers the best: “A totally unselfish person.”

Despite the trauma of Sonny Carter’s death, the new addition to the crew must have come as a great pleasure for STS-42 commander Ron Grabe…for both he and Hilmers had flown their first space mission together in October 1985. Now, Grabe would be flying his third Shuttle mission overall and, accompanied by ‘orbiter team’ members Steve Oswald and Bill Readdy, would be in charge of the flight deck for 24-hour payload operations.

“Human space flight,” Oswald once said, “is flying airplanes on steroids. It’s just really unforgiving of neglect.” The thick-set naval aviator knew from first-hand experience at NASA the intrinsic dangers of both: for within months of his selection as an astronaut in June 1985, he lost classmate Steve Thorne in an aircraft accident and seven other friends – the crew of Challenger – as they headed for orbit. In the case of the latter, the pain experienced by Oswald and fellow newcomers Carl Meade, Jay Apt and Rick Hieb was even closer, for they were in attendance in Florida, supporting the 51L families. Barely six months after selection, the eleventh class of astronauts were on a ‘fast track’ to space and were already being shifted into their first technical assignments. “We were going to fly in two years,” Oswald remembered, “and needed to hurry up. We had about five months of generic stuff, touring around and learning to fly the T-38s, and then they put us in our jobs.” On the night before Challenger’s fateful launch, Oswald and Hieb had been inside the orbiter’s cockpit, attending to a few final tasks.

Pictured during a visual acuity test with Ulf Merbold, astronaut Dave Hilmers (right) was added to the STS-42 crew only nine months before launch. His interest in medicine would pre-date the IML-1 mission and would form his subsequent career. After obtaining his medical degree from Baylor College, he became a paediatrician and nutritionist and has been described as one of the most selfless individuals ever to walk the halls of the Astronaut Office. Photo Credit: NASA

As STS-42’s pilot, Oswald would work on the same team as Grabe, Thagard and Bondar. They dubbed themselves ‘The Blue Team’. On the opposite shift, the ‘Reds’, were Hilmers, Merbold and team leader Readdy. “They were 24-hour flights,” Readdy said of the IML Spacelab missions, “two-shift flights, and you needed to have a pilot on the other shift. They tended to keep the pilot and the commander on the same shift, so that meant that you had to have somebody else that was schooled in all the orbiter systems and piloting tasks on the other shift.” In effect, Readdy was classed as STS-42’s ‘third’ pilot.

Weather concerns and a hydrogen pump anomaly with one of the fuel cells delayed the launch of STS-42 by an hour on the morning of 22 January 1992, but Discovery finally ascended majestically into space at 9:52 am EST. By the beginning of the International Space Year, as Steve Oswald prepared to become one of the newest members of the unique fraternity of spacefarers, it seemed that few ‘records’ remained to be broken. He was not the oldest or youngest astronaut, nor the first from a particular engineering school or military arena. Instead, by his own admission, he was the first astronaut to “use the bathroom” on the crew access level of the launch pad. Ordinarily, crew members wore modified diapers during launch, to alleviate the pressure of fluid movement whilst lying on their backs for several hours. During the standard pre-launch countdown dress rehearsal – despite having consumed only coffee and orange juice at breakfast – the incessant blood flow from his legs into his torso took its toll and Oswald knew he needed to relieve himself. “Of course, you’re out for two and a half to three hours,” he told a Smithsonian interviewer. “About the time I was going to start to use the diaper, somebody would always talk on the intercom and it would break the spell. Like most of us, after 40 years of being to not pee while you’re lying on your back, it’s a hard thing to do.” When the dress rehearsal ended, Oswald had been the first to rush out of the orbiter’s side hatch…and straight into the little boys’ room. “I was in that bathroom in a heartbeat,” he said, “and that’s how I made history!”

Due to the heavier return weight of the orbiter, with the Spacelab module in the payload bay, STS-42 was always scheduled to return to Edwards Air Force Base in California, despite NASA’s 1991 decision to place the Kennedy Space Center’s Shuttle Landing Facility on an equal footing in terms of priority. The IML-1 experiments were devoted entirely to materials and life science in the microgravity environment and featured significant collaboration from US, European, Canadian and Japanese researchers. Of the life sciences complement, the European-built Biorack sought to understand the fundamental functions of organisms in the microgravity environment, including cell proliferation and differentiation, genetics, gravity sensing and membrane behaviour. To further this research, Biorack carried three incubators, a glovebox and a cooler/freezer to grow, handle and store hundreds of biological samples. Embryonic mouse limb cells were studied in an effort to characterise the similarities observed between skeletal malformations in rodents and human children, with a focus on helping to clarify the processes by which bones heal in microgravity. Previous Soviet long-duration experience had already suggested that bone damage during extended space flights – particularly as far afield as Mars – would be difficult to heal and a contributory factor in the breaking of weakened bones is the loss of calcium through prolonged microgravity exposure. Other experiments utilised the eggs of African clawed frogs and fruit flies, together with yeast, bacteria, lentil roots and plant shoots and the Physarum polycephalum slime mould, to understand the role of gravity in embryonic and cell development. The effect of radiation on soil samples and the eggs of stick insects was also closely studied and Germany’s Biostack facility analysed the influence of cosmic rays on bacteria and fungus spores, together with thale cress seeds and shrimp eggs.

Elsewhere, housed inside a Spacelab Double Rack, was the Gravitational Plant Physiology Facility, which provided nothing less than a small space-based botanical laboratory, equipped with centrifuge chambers, floodlights, videotape recorders and plant compartments. It supported investigations into the gravity-sensing mechanisms of oat seeds and the reactions of wheat specimens to the effect of light stimulation.

Discovery thunders into space on 22 January 1992. Photo Credit: NASA

With Canadian astronauts Roberta Bondar and Ken Money having trained extensively for IML-1 payload science activities, the contribution of their nation to the mission was correspondingly important. Canada’s Space Physiology Experiments focused on the adaptation of the human organism to the weightless environment, including the vestibular apparatus, the body’s sense of position, energy expenditure, cardiovascular adaptation, eye-motion oscillations and back pain. The latter was devised in response to a typical incidence of spinal lengthening by 2.5 inches and back pain in over two-thirds of all astronauts.In support of these experiments, members of IML-1’s payload crew utilised ‘The Sled’, in the centre aisle of the Spacelab module, and wore a helmet instrumented with accelerometers to measure head motions and visors to provide visual stimuli. The sled could be moved backwards and forwards predictably, at a constant speed over the same distance, or at varying distances or at varying speeds with sudden stops and starts. As crew members underwent the test, their response was monitored to gauge their ability to visually track moving objects. Studies of the adaptation of the ‘otolith’ – the gravity-sensing part of the inner ear – and its effect upon the nervous system, together with head and eye movements, were also performed in the sled and in a swivelling chair, part of NASA’s Microgravity Vestibular Investigations. Despite a tripped circuit breaker, which caused the chair to stop working a few seconds into its first run, the experiment produced pleasing results which “quantified the human vestibular function in the microgravity environment”. Additional experiments required the crew to drink water, specially enriched with stable, non-radioactive isotopes of oxygen and hydrogen, to enable researchers to determine energy expenditure through post-flight urinalysis.

In the microgravity science arena, NASA experiments in vapour-driven protein crystal growth were undertaken, together with German Cryostat investigations which employed ‘liquid-diffusion’ and offered researchers the flexibility of a temperature-controlled facility. Specifically involved in the experiments were Beta-galactosidase, a key enzyme found in the intestines of human and animal infants, which assists in the digestion of milk products. (This enzyme was the first protein ever crystallised in space in November 1983.) Also under study was the satellite tobacco mosaic virus.

NASA’s Fluids Experiment System and Vapour Crystal Growth System carried a range of investigations which grew crystals of triglycine sulphate and mercury iodide and performed laser diagnostic recording and created more than 300 three-dimensional structural holograms for post-mission analysis. Several of the mercury iodide experiments were supported by CNES, the French national space organisation, and record-sized crystals were yielded. The Japanese Organic Crystal Growth Facility sought to produce semiconducting crystals of tetrathiafulvalene (TTF, a compound with applications in molecular electronics) and nickel, whilst demonstrating the effectiveness of an epoxy cushioning material to damp accelerations otherwise known to disrupt the growth process, and the European Critical Point Facility explored the behaviour of fluids when they reached the precise temperature-pressure stage at which the difference between vapour and liquid became indistinguishable. Samples of sulphur hexafluoride – primarily used on Earth in the electronics industry – as part of a number of experiments were processed for as long as 60 hours during IML-1. Radiation and acceleration measurements were performed to determine the influence of Shuttle motions upon sensitive experiments.

Beyond the Spacelab module, at the rear end of Discovery’s payload bay, was a ‘bridge’ of Getaway Special canisters. On STS-42, the bridge was originally manifested to carry a maximum load of 12 canisters, but two were dropped due to technical difficulties and only ten eventually flew. (To satisfy the centre-of-gravity constraints, a pair of ‘ballast’ canisters made up the full dozen.) The experiments came from various nations, including and China. The latter was a debris motion study and materials experiment and marked the first time that a Chinese payload had even flown on the Shuttle. Elsewhere were US investigations into the growth of brine shrimp, a German convection study, a Swedish alloy experiment, a Japanese study of gas bubbles in liquids and Australia’s Endeavour ultraviolet telescope.

Despite the decision, late in 1990, to reduce the length of STS-42 from ten to seven days, an option was preserved to extend the mission by up to 24 hours if on-board consumables remained acceptable. As circumstances transpired, the crew’s consumables usage remained below planned levels and an additional day was scheduled to complete the collection of scientific data in the IML-1 module. Touchdown eventually took place on Edwards’ concrete Runway 22 at 8:07 am PST (11:07 am in Florida) on 30 January, completing a voyage of a little over eight full days. Returning with representatives of three nations aboard, STS-42 had accomplished a spectacular start to an ‘International’ Space Year.


Tomorrow’s article will focus on STS-45, an Earth-science mission in International Space Year.


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