Complex Mission

By the time Columbia finally lifted off at precisely 4:00 pm on 28 November, kicking off the ninth Shuttle mission and her own sixth trip into space, her Mission and Payload Specialists had been training for the best part of five years and the entire crew had become a close-knit team. ''When we were training the science crew,'' said Parker, ''we had prime and backups for the American Payload Specialist and for the European Payload Specialist, and then Owen and myself. The six of us almost always travelled together and did the training together. At the very end, in the last year or so, when it became obvious this is going to be on 'your' shift and this is going to be on their shift, we separated a bit in that sense, but still you could do an experiment on both shifts. The Payload Specialists might have felt separated from the orbiter crew [Young and Shaw], because they weren't participating in these trips. I served as the flight engineer, so at the same time as we were training on the experiments, I was training with Brewster and John on ascents and entries. For a good last six months or so, I'd be training on Mondays with them, fly to Huntsville for experiment training, fly back and do ascents and entries on Wednesday, and back and forth. So I got to keep in touch with them a lot better than the others.''

Flight engineers had become an increasingly familiar member of Shuttle crews since STS-5: they were chosen from among the Mission Specialists and called 'MS2'. They sat behind the centre console in between the Commander and Pilot and provided assistance during both ascent and re-entry, helping to monitor the Shuttle's instruments. In fact, one up-and-coming astronaut was looking to the new flight engineer's seat as the next challenge in his career. Carl Walz, who joined the astronaut corps in 1990 and served as Columbia's flight engineer in July 1994, described the role as ''one of the most important jobs that a Mission Specialist can have on a Shuttle flight. During launch and landing, the MS2 [makes] sure that all the checklist steps for normal and emergency procedures are performed flawlessly by the Commander and Pilot [and] keeps a log, recording all the systems that have had problems during launch and landing. Afterwards, he or she then figures out how those problems affect future Shuttle procedures. The training for MS2 is very similar to the training for the Commander and Pilot. In orbit [he or she] is the 'traffic cop' who makes up the plans [to get the vehicle ready for operations] and makes sure [these are] executed properly.'' No mean feat, it seemed, especially on a particularly complex mission like Spacelab-1, which would involve not only a vast number of scientific experiments but also a large number of engineering demonstrations and tests. ^hfct

Spacelab-1 was one of two so-called 'Verification Flight Tests' of the new system: it would evaluate the £

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Spacelab-2 mission would put the pallet-train-and-igloo version through its paces. Only when these two pathfinding missions had been successfully accomplished would the Spacelab system be declared fully operational. For STS-9, more than 200 sensors were installed throughout the Shuttle and Spacelab, providing data on their combined performance during launch, ascent, orbital flight, re-entry and landing.

This equipment verified that Spacelab-l's passive thermal control ^^^^P^^i^^UH system kept temperatures within the module and on the pallet within ■

required limits and prevented con- ^^^^^^ densation or heat leaks. The thermal, acoustic and structural responses of The Life Sciences Minilab f°r ^a^kW the entire payload during the most arrives in Florida for processing-

critical and dynamic portions of the mission were closely monitored, and the astronauts checked the satisfactory operation of the SAL and the tunnel, evaluated their ability to communicate and transmit data through NASA's first Tracking and Data Relay Satellite (TDRS) and confirmed that the Spacelab module was indeed habitable and comfortable to work in.

In general, the system performed admirably and the crew even demonstrated the optical-quality of a small window in the rear end-cone of the module by shooting television pictures through it of the experiments on the pallet. The two-team, 'Red and Blue' system also worked extremely well: the astronauts' sleep cycles had been deliberately adjusted a fortnight before launch to better support their separate 12hour shifts. Although shifts would not be necessary on all Spacelab missions, they were an important demonstration of how to maximise the crew's valuable time in orbit.

After reaching orbit, the crew unstrapped and set about activating their payload. It was during this time that Shaw, who was making his first spaceflight, remembers a minor scare: ''We couldn't get the [Spacelab] hatch open, so we couldn't get into the [module] at all! Looking at Owen and Bob's faces, I remember thinking, 'Boy, these guys are seeing their lives pass in front of their face, if we can't get in there and do the stuff they've been training to do'.'' Fortunately, the problem proved temporary and by the evening of 28 November Spacelab-1 was up and running.

Typically, during shift operations one of the pilots - Young or Shaw - would spend their time on Columbia's flight deck monitoring her systems and communicating with the science crew in Spacelab-1 by means of an intercom. Although undoubtedly awestruck by his first space experience, Shaw recalled the monotony of this job: ''We had a few manoeuvres to do once in a while with the vehicle, and then the rest of the time you were monitoring systems. After a few days of that, boy, it got pretty boring. You spent a lot of time looking out the window and taking pictures and all that. But there was nobody to talk to, because the other guys were back in the Spacelab working away and you just [thought] 'Gosh, I wish I had something to do.' But the flight went fine and we did a great bunch of science.'' The manoeuvres that Shaw was referring to were a number of so-called 'thermal attitudes' to expose the Spacelab hardware to 24 hours of extreme cold and 12 hours of fierce solar heating to test its performance.

The only real problem of note that emerged from Spacelab-1 was a temperature glitch in the Remote Acquisition Unit (RAU)-21, which served all of NASA's instruments on the pallet. Subsequent analysis by ground-based engineers found that the temperature of the Shuttle's freon coolant was partially to blame and subsequent use of the unit at 22 Celsius apparently solved the problem. However, as part of these efforts to work around the RAU-21 problem, a 'patch' inserted into Spacelab-1's software caused the module's experiment computer to crash and temporarily affect data-gathering from the pallet-mounted instruments.

Otherwise, as Shaw commented, the mission gathered a great deal of scientific data. Its experiments were divided into five disciplines: (1) astronomy and solar physics, (2) space plasma physics, (3) atmospheric physics and Earth observations, (4) life sciences and (5) materials sciences and technology. These were jointly sponsored by NASA and ESA, although they featured cooperation from Canadian and Japanese scientists. NASA's part was run by its Marshall Space Flight Center, while ESA's portion was controlled by a team called SPICE: the Spacelab Payload Integration and Coordination in Europe, based at Cologne in West Germany.

In recognition of ESA's immense contribution, Garriott and Parker spent a great deal of their training with the two Payload Specialists working in continental Europe. ''[It was the] first European mission,'' recalled Parker, ''so we had to go to every European country that had a piece of it in ESA. We went to Denmark to look at this experiment, [then] two or three places in France, but they were centralised in Germany, so we spent most of our time [there].'' The genesis of these experiments went back to 1976, when 400 proposals were jointly solicited by NASA and ESA.

After each of the 70-plus experiments had been carefully selected, its Principal Investigator formed a working group and, together with a NASA Mission Scientist, guided it through tricky waters from initial design and manufacture to ensuring that it met each of the stringent demands needed for integration into the Spacelab-1 payload. During the course of the mission, science operations were coordinated in real time from the POCC at JSC and it was possible - for the first time - for ground-based scientists to communicate directly with the crew, rather than indirectly via the Capcom in Houston.

Six experiments were dedicated to Astronomy and Solar Physics. These included a NASA-provided far-ultraviolet telescope on the pallet, which acquired spectra of high-temperature celestial sources as part of efforts to gain clearer insights into the life-cycles of stars and galaxies. Unfortunately, a fogged film ruined many of its images and a post-mission investigation recommended that on its next flight it should record photons electronically, rather than on film as time exposures, to better pinpoint the cause of the fogging. It did, however, achieve 95% of its objectives and took the first far-ultraviolet picture of the Cygnus Loop, a relatively nearby supernova remnant.

The module's roof-mounted SAL was used to support ESA's Wide Field Camera, which took a series of photographs of 10 astronomical objects on 3 December. Among its notable results were impressive ultraviolet images of a 'bridge' of hot gas linking the Large and Small Magellanic Clouds, suggestive of an interaction between them. Sadly, the month-long delay to Columbia's launch from late October until late November resulted in shorter-than-expected orbital 'nights', which reduced the camera's viewing opportunities by about 60%. The third astronomical instrument was a highly successful ESA-built X-ray spectrometer on the pallet.

The other three experiments - the Active Cavity Radiometer (ACR), Measurement of Solar Constant (SOLCON) and Measurement of Solar Spectrum (SOLSPEC) - tracked with extreme precision the total amount of solar energy received by Earth's atmosphere and its impact upon our planet's environment to further the study of the solar-terrestrial relationship. Modified versions of each of these instruments would fly throughout the 1990s on a series of Shuttle research missions in order to calibrate similar instruments on a variety of spacecraft and NASA's Upper Atmosphere Research Satellite (UARS) which were to investigate environmental changes over time on a global scale.

Five experiments came under the Space Plasma Physics banner, all of them mounted on the Spacelab pallet at the rear of Columbia's payload bay. Of these, the most noticeable was the Space Experiments with Particle Accelerators (SEPAC), designed by Japan's Tokyo-based Institute of Space and Astronautical Science (ISAS). SEPAC consisted of an 'electron gun' to investigate the dynamics of Earth's ionosphere. During the mission, it fired streams of gas and high-intensity electrons into the ionosphere to better understand the production of aurorae, the nature of Earth's magnetic and electric fields, and the effects of plasma on the Shuttle's structure. Despite the failure of its electron-beam assembly to run in a high-power mode, the device was highly successful and achieved almost all of its planned objectives. A similar electron-gun experiment, provided by France, was the Phenomena Induced by Charged Particle Beams (PICPAB), which contained an 'active' unit attached to the pallet and a 'passive' recorder inserted into the SAL. Like SEPAC, its electron gun was capable of producing and examining artificial aurorae. Some data was lost when one of its gas bottles failed, but it nevertheless achieved a 60% success rate.

Two other experiments worked in conjunction with SEPAC and PICPAB by measuring atmospheric constituents using emissions from their particle-beam firings, as well as examining real aurorae under ultraviolet and visible light. They also measured particulate contamination in the vicinity of Columbia herself and observed the effects of the Shuttle's emissions - from water dumps, outgassing and thruster firings - on the artificial aurorae generated by the electron guns. Several of these investigations required Young and Shaw to orient Columbia to acquire the necessary data. A cosmic-ray detector was also carried to measure their abundances in low-Earth orbit.

Six experiments were covered by the Atmospheric Physics and Earth Observation category: five provided by ESA and one - the Imaging Spectrometric Observatory (ISO) - from NASA. This latter device, consisting of five spectrometers housed in a single unit, examined the presence and relative abundances of oxygen, nitrogen and sodium in the 'middle atmosphere' (or 'mesosphere') between 80 and 100 km above the Earth's surface. It was part of a project to build the first comprehensive database of the vertical structure of the atmosphere. During the mission, ISO also aided studies of the emissions produced by Columbia, which were of concern to potential future customers.

The European experiments included a Metric Camera, attached to the roof-mounted SWAA optical-quality window in the forward section of the Spacelab-1 module. Loaded with black-and-white, colour and infrared films, it achieved an 80% success rate and took a wide range of high-resolution Earth-mapping photographs. Three experiments mounted on the pallet examined oxygen and hydrogen emissions from the atmosphere and tested equipment which, it was hoped, might lead to the development of advanced, all-weather remote-sensing systems.

The only Atmospheric Physics experiment that did not perform as advertised was the Grille Spectrometer, so-called because it employed a specially designed 'grille' as a window for one part of its optical system and as a mirror for the other. This was supposed to measure atmospheric constituents in the stratosphere, mesosphere and thermosphere, as part of efforts to understand their dynamic behaviour. Although it achieved some promising results, the month-long delay to STS-9 meant that observing conditions were unfavourable and it only completed 16% of its objectives. Nevertheless, it was reflown with greater success on a dedicated Earth-observation mission in March 1992 and later installed on the Mir space station to make long-term observations.

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