STS 45

A Meeting of Minds: The Earth-Centred Voyage of STS-45 By Ben Evans Surrounded by the black spheres of the SEPAC experiment, ATLAS-1 represented the first Shuttle payload fully dedicated to exploring the relationship between the Earth’s atmosphere and its interaction with the Sun. Photo Credit: NASA Two remarkable men met on the morning of 2 April 1992, three months into International Space Year. One of them was on his second day as NASA Administrator, whilst the other was an astronaut, newly returned from space. Today, Daniel Saul Goldin – NASA’s longest-tenured Administrator, who served until December 2001 – is remembered both positively and negatively; positively for having transformed the troubled Space Station Freedom from a project on the brink of cancellation to a fruitful, revitalised endeavour which saw the Russians courted as full partners, and negatively in that the United States’ aspirations to explore beyond Earth orbit with humans were indefinitely set back in favour of faster, better and cheaper robotic craft. The other man, Charlie Bolden, had already made history as one of the United States’ first black spacefarers and today serves as NASA’s first African-American Administrator. Yet the first exchange between the two men was not quite the meeting of minds that Goldin had anticipated. “I’m Dan Goldin,” he began. “I’m the new NASA Administrator and I want you to come and work for me.” The pair shook hands, but Bolden had no desire to leave his job at the Johnson Space Center in Houston for one at NASA Headquarters in Washington. Goldin thought for a moment. “Well, when you get finished with your debriefs, come and talk.” Shortly therafter, Bolden went to Washington and was impressed by the space agency’s new chief – “The guy was a visionary,” he reflected – to such an extent that he accepted Goldin’s offer to become Assistant Deputy Administrator. Within six months, however, Bolden would be informed of his selection to command another Shuttle mission, scheduled for November 1993. When he learned of the mission’s content, Bolden did not want it…for STS-60 would be the first flight in the new co-operative enterprise with Russia and its crew would include a cosmonaut. As an active-duty colonel in the Marine Corps, Bolden had spent his entire adult life hating Russia and all it stood for. He was partially appeased by the offer to at least meet the two cosmonaut candidates – Vladimir Titov and Sergei Krikalev – and immediately liked them both. Titov spoke no English and, recalled Bolden, “couldn’t even ask for water”, although his resilience in the face of this struggle and throughout a year of arduous training was admirable. Years later, Bolden would remember this period of his life as the most memorable, for he made unlikely friends and forged the early bonds of an international partnership between two former foes which endures to this day. Twenty years ago, at the beginning of 1992, Bolden prepared to lead STS-45, his first Shuttle mission in the commander’s seat. Originally, the flight had a science crew of NASA mission specialists Kathy Sullivan and British-born Mike Foale, together with two career scientists as payload specialists: biomedical engineer Byron Lichtenberg and physicist Mike Lampton. Both Lichtenberg and Lampton had a long association with NASA, having been selected in 1978 as payload specialist candidates for Spacelab-1. Lichtenberg went on to fly on Spacelab-1, with Lampton as his backup, and in May 1984 the two men were assigned to support a future Shuttle flight, carrying the first in a series of Earth Observation Missions (EOM-1), then scheduled for launch in the summer of the following year. As early as February 1985, however, Flight International noted that NASA had cancelled EOM-1, reassigned a number of its NASA ‘core’ crew members to other missions and had merged it with the second mission in the series, EOM-2. In December 1985, Belgian physicist Dirk Frimout and US physicist Charles ‘Rick’ Chappell were named as Lichtenberg and Lampton’s backups. By this time, the renamed ‘EOM-1/2’ mission had slipped until the middle of August 1986. A summertime launch would have benefitted one of the EOM-1/2 experiments – the European Space Agency’s Metric Camera, mounted in the roof of a Spacelab short module – by offering a better chance of good weather over primary land masses in the Northern Hemisphere. All hope for EOM-1/2 was lost on the cold morning of 28 January 1986 when Challenger exploded and the Shuttle fleet was grounded. In the year after Challenger, former astronaut Sally Ride chaired a task force to formulate a new strategy for NASA. One of its four key recommendations was for the implementation of a ‘Mission to Planet Earth’, designed to foster new technologies for the study of our home world, its atmosphere and climate. It was at around the same time that EOM-1/2 underwent a figurative and literal metamorphosis, changing both its configuration and its name. Instead of the short pressurised module, single Spacelab pallet and Mission-Peculiar Equipment Support Structure (MPESS), it would fly on a pair of pallets and its control and command systems would be housed in a pressurised ‘igloo’. Of course, EOM-1/2 had been planned as long ago as 1983, and was not originally conceived to be part of Mission to Planet Earth, “but the nature of its scientific work,” said Kathy Sullivan, “really genuinely did align with the purposes of that new programme, which was gaining momentum and clarity”. The mission received an impressive new name: the Atmospheric Laboratory for Applications and Science (ATLAS). Early plans called for a series of up to ten ATLAS flights, launched every 12-18 months, to undertake research in atmospheric chemistry, solar and space plasma physics and ultraviolet astronomy. As part of NASA’s Mission to Planet Earth, ATLAS sought to characterise solar energy inputs across an entire 11-year activity ‘cycle’ of the Sun, recording seasonal elements of atmospheric change over the long term. Of additional importance was assessing the extent of human impact upon the atmosphere, through agriculture, forestry and heavy industrial processes. It had already become clear by the late 1980s that chlorofluorocarbons, together with halons and naturally occurring chemicals, such as methane and nitrous oxide, and increasing concentrations of carbon dioxide, were playing a significant role in the depletion of Earth’s stratospheric ozone layer and impacting global atmospheric temperatures. The ATLAS-1 experiments were designed to explore the features, gaseous constituents and solar effects upon the troposphere (which extends from the surface to an altitude of about 12 miles), the stratosphere (12-30 miles), the mesosphere (30-50 miles) and the thermosphere (50-430 miles). Mounted on the two pallets were 12 scientific instruments to support 14 experiments from the United States, France, Germany, Belgium, Switzerland, the Netherlands and Japan. Several were scheduled to be reflown on subsequent ATLAS missions. “Reuse of these facilities,” noted NASA’s ATLAS-1 press kit, issued in March 1992, “also will allow scientists to expand their base of knowledge to provide a more accurate, long-term picture of Planet Earth and its environment.” Of these experiments, NASA’s Far Ultraviolet Space Telescope (FAUST) sought to acquire spectra of high-temperature celestial objects at far ultraviolet wavelengths, as part of efforts to gain a clearer insight into the life cycles of distant hot stars, faint diffuse galactic features, large nearby galaxies, quasars and stellar nebulae. Unfortunately, on its previous flight, Spacelab-1 in November 1983, a fogged film ruined many images and an investigation recommended that, when it flew next, the telescope should record photons electronically, rather than on film as time exposures, to better pinpoint the cause. It did, however, achieve 95 percent of its scientific objectives and took the first far ultraviolet image of the Cygnus Loop, a relatively close supernova remnant. Its activities on ATLAS-1 were unfortunately hampered by a blown fuse which left it without power and its aperture door stuck open. This prevented it from being reactivated in flight. Elsewhere on the ATLAS-1 pallets, the Active Cavity Radiometer (ACR), the Measurement of Solar Constant (SOLCON) and Measurement of Solar Spectrum (SOLSPEC) were also veterans of Spacelab-1 and were designed to precisely track 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. Of particular note, ACR had a direct counterpart aboard NASA’s Upper Atmosphere Research Satellite (UARS), launched in September 1991. Through intercomparison with SOLCON data, its role on the ATLAS missions was to support extended solar irradiance experiments, calibrating UARS’ instruments over the long term, and establish radiation scales at the solar total flux level. Meanwhile, SOLCON itself was a self-calibrating radiometer, tasked with measuring the absolute value of the solar ‘constant’ and monitor its long-term variation. Working in close conjunction was SOLSPEC, whose trio of spectrometers observed the variabilities of solar irradiance with an accuracy of better than 0.1 percent. Girdled by the names of the seven STS-45 astronauts – including British-born Mike Foale and Belgium’s Dirk Frimout – the patch for ATLAS-1 paid homage to the two central tenets of the mission: study of the Earth and study of the Sun. Image Credit: NASA Other former Spacelab-1 experiments carried over onto ATLAS-1 included NASA’s Imaging Spectrometric Observatory (ISO), which comprised five spectrometers, housed in a single unit, and examined the presence and relative abundances of oxygen, nitrogen and sodium in the mesosphere. ISO formed part of an extensive project to build a comprehensive database of the atmosphere’s vertical structure and its energy-transfer processes. Meanwhile, the European Grille Spectrometer studied the dynamic behaviour of the gaseous constituents of the stratosphere, mesosphere and thermosphere. Unfortunately, this device – so-called because it employed a special ‘grille’ as a window for part of its optical system and as a mirror for the other – had been only partially successful on Spacelab-1, due to lengthy launch delays and unfavourable observing conditions, but would more than prove its worth on ATLAS-1. Among other achievements, it would detect far higher quantities of chlorine in the upper atmosphere than scientists had previously anticipated. One of its key sets of measurements was the Energetic Neutral Atom Precipitation (ENAP), which observed very faint emissions arising from fluxes of energetic neutral atoms in the thermosphere.Particularly visible on the ATLAS-1 pallets were the black spheres of the Space Experiments with Particle Accelerators (SEPAC), designed by Japan’s Institute of Space and Astronautical Science, based in Tokyo. It comprised an ‘electron gun’ to investigate the charged-particle dynamics of the ionosphere and during the mission was used to emit a stream of xenon plasma to ‘clamp’ the electrical potential of the Shuttle to the plasma potential of the upper atmosphere, as part of efforts to gain a clearer understanding of aurorae, the nature of the planet’s magnetic and electric fields and the effects on the orbiter itself. During Spacelab-1, SEPAC’s electron beam assembly – capable of operating at voltages of between 500 volts and 7.5 kilovolts at 1.6 amps – failed to function in a high-power mode, although it returned pleasing results. “We were all pretty jazzed up about this,” said Kathy Sullivan of SEPAC. “The idea was to have the orbiter oriented so that the aperture of the instrument would inject these electrons roughly along the magnetic field line down towards the atmosphere, near the polar regions.” It was, in her words, a ‘dose-response’ experiment; just like in medicine, it injected a known dose of energy into the atmosphere and measured the brightness of the resultant aurora-type glow. “If I know I put in this many kilowatts of energy and I measured that luminosity,” she reasoned, “maybe I can start to get a clearer understanding of how the energy of the incoming solar particles couples into the atmosphere and creates auroral luminescence.” To Sullivan, SEPAC was “the biggie”. Working in conjunction with the electron-gun investigation were experiments which sought to measure atmospheric constituents, ‘trace’ molecules – including carbon dioxide and ozone – and other gaseous emissions, together with the impact of solar inputs on the chemistry of the upper atmosphere. The Atmospheric Trace Molecule Spectroscopy (ATMOS) was designed to determine compositional structures between the altitudes of 12-60 miles – from the base of the stratosphere to the low thermosphere – and examine the ‘partitioning’ of solar energy within those various gaseous levels. During ATLAS-1, data from both ATMOS and Grille revealed clear evidence of aerosol bands resulting from the Mount Pinatubo eruption. The Atmospheric Emissions Photometric Imager (AEPI) investigated transport processes within the ionosphere (a region embedded in the mesosphere) and worked in conjunction with ISO and SEPAC by observing the optical properties of artificially-induced electron beams, naturally-occurring aurorae and atmospheric ‘airglow’ and Shuttle-generated emissions. The Millimetre Wave Atmospheric Sounder (MAS) focused on temperature and ozone distribution in the stratosphere, mesosphere and lower thermosphere and provided critical correlative measurements with UARS’ Microwave Limb Sounder experiment. Also closely linked with UARS was the Solar Ultraviolet Spectral Irradiance Monitor (SUSIM), which operated concurrently with a similar experiment aboard the satellite to improve the absolute accuracy of solar irradiance measurements. Finally, the Atmospheric Lyman-Alpha Emissions (ALAE) measured the relative abundances of hydrogen and deuterium in the atmosphere. Flying again as part of efforts to calibrate ozone-monitoring sensors aboard the National Oceanic and Atmospheric Administration’s NOAA-9 and NOAA-11 satellites, together with NASA’s Nimbus-7, the Shuttle Solar Backscatter Ultraviolet (SSBUV) instrument was also aboard ATLAS-1. Although it had flown on three previous occasions, STS-45 represented the first SSBUV mission in the wake of the September 1991 eruption of Mount Pinatubo in the Philippines. Its results from ATLAS-1 onwards enabled scientists to confirm an approximately ten-percent depletion of ozone in the northern hemisphere and at mid-latitudes, probably triggered by the presence of residual aerosols in the upper atmosphere after the eruption. Moreover, the effects of cold stratospheric temperatures in the winter of 1992-93 would also be seen in subsequent SSBUV data. Led by Charlie Bolden (seated, front right) – NASA’s incumbent Administrator – STS-45 was a remarkable mission in support of the advancement of Earth science. Photo Credit: NASA Sullivan, Foale, Lichtenberg and Lampton were assigned as the ATLAS-1 science crew in September 1989, with launch anticipated in March 1991. Backing up the two payload specialists were Dirk Frimout and Rick Chappell. A few months later, in May 1990, the other members of the crew were named, with Bolden in command, joined by pilot Brian Duffy and a third mission specialist, Dave Leestma. Like IML-1 before them, the ATLAS-1 crew would operate two 12-hour shifts, around the clock, with Bolden, Duffy, Sullivan and Lampton on the ‘Blue Team’ and Leestma, Foale and Lichtenberg on the ‘Red Team’. The shift planning was logical, reasoned Sullivan, because it enabled a proper spreading of expertise across both teams. (She, Bolden, Leestma and Lichtenberg had all flown before, whereas Duffy, Foale and Lampton were ‘rookies’.) Although not restrained to a single shift, Bolden aligned his schedule with that of the Blues, since it worked well into the mission’s planned re-entry and landing timelines. As a first-time Shuttle commander, Bolden took up an option from the NASA operational psychologists to have his crew participate in a personality evaluation, based along the lines of the Myers-Briggs psychometric questionnaire, to ensure that the team would function at their peak in terms of performance and cohesion. “We were going to fly two out of four guys who’d been sitting around for a decade, waiting,” said Sullivan. “Quite a different mix of folks. I think Charlie knew he wanted to look at everybody to have a sense of how best to move them and drive them, support, encourage and propel them.” The tests revolved around six personality types, two of which described focused, goal-oriented individuals, which Sullivan noted was a trait representative of about 15 percent of the general population…but around 98 percent of the astronaut population. Such personality characteristics for astronauts are hardly surprising, but Sullivan and Bolden considered the psychometric tests enlightening in that they uncovered each crew member’s strategies for handling periods of calm and extreme stress. The Shuttle’s hydrogen leaks in the summer of 1990, and the inevitable impact on future missions, meant that STS-45 was moved off Columbia and reassigned to Atlantis, with launch shifted from March 1991 until March 1992. Unperturbed, the seven astronauts, together with Frimout and Chappell, continued their training. Then, with just six months to go, in early September 1991, Mike Lampton was abruptly removed from the flight, due to a medical issue, and was replaced by Frimout. In her NASA oral history, Sullivan recalled that Lampton’s ailment began around Christmas 1990, but as he “got life-threateningly ill” over the following months, a decision was made by Lennard Fisk, NASA’s Associate Administrator for Space Science and Applications, to replace him. It hit the rest of the STS-45 crew particularly hard. As the payload commander, Sullivan remembered the cross-evaluation process which led to the formal announcement of Frimout as Lampton’s replacement. “Both very competent,” she said of the two men. “There wasn’t really any high-level distinguishing factor there.” Ennobled as a viscount in the wake of his Shuttle mission, Dirk Dries David Damiaan Frimout came from Poperinge, Belgium, where he was born on 21 March 1941. He received elementary schooling in his home town and studied electrical engineering at the University of Ghent, gaining his degree there in 1963 and his doctorate in applied physics in 1970. He subsequently undertook post-doctoral research in atmospheric science at the University of Colorado. Frimout’s early career was spent at the Belgian Institute for Space Aeronomy, working on stratospheric balloon and sounding rocket projects, before joining ESA in 1978 as the Experiment Co-ordinator for Spacelab-1. As Belgium’s first astronaut, Frimout earned overnight fame on STS-45. Launch was originally scheduled for 23 March 1992, but was halted when higher than acceptable concentrations of liquid hydrogen and oxygen – 860 parts per million, far higher than the maximum allowable 500 ppm – were detected in the orbiter’s aft compartment during operations to slow-fill the External Tank. Efforts to troubleshoot the problem failed to reproduce the cause and this led engineers to the conclusion that it was the result of plumbing in the main propulsion system being improperly conditioned to the propellants. Launch was postponed by 24 hours and although liquid oxygen concentrations peaked above the maximum allowable limit, they rapidly recovered in what NASA later described as “anticipated and acceptable”. Atlantis set off at 8:13 am EST on the 24th. Atlantis rises atop a pillar of golden flame to kick off the ATLAS-1 mission, dedicated to investigating the interactions between our planet’s atmosphere and the awesome power of the Sun. Photo Credit: NASA For the first-time fliers, it was an awesome experience. “I was really impressed with just how much raw power there is in that vehicle,” Brian Duffy told the NASA oral historian. “You can think about what it might be like, but you don’t actually physically feel it until you go do it. The simulator is great in that it can give you vibration and some little sense of motion, but it doesn’t give you that acceleration. I had flown Mach 2 in an F-15 in my career, many times, and had thought that had been pretty fast…and we blew through Mach 2 in nothing flat and we still had a long way to go to accelerate!” After the separation of the boosters, Atlantis continued to climb, under the thrust of her main engines, and although there were few ‘good’ visual references it was obvious to Duffy that their velocity was immense. Every few seconds, he would glance at the acceleration tapes on his instrument panel and would register momentary astonishment as it zinged its way higher and higher up the scale. This cacophony of controlled violence seemed to end when the main engines shut down, as planned, some eight minutes into the mission, and the entire cockpit fell deathly quiet. “You go from the most violent place you’ve ever been in your life,” Duffy said, “to the most peaceful place you’ve ever been in your life…in a couple of seconds.”Within minutes of reaching orbit, the seven astronauts divided themselves into their two teams to begin the activation of the ATLAS-1 experiments. Inclined at 57 degrees to the equator, Atlantis’ orbit carried her approximately as far north at Juneau in Alaska and a little further south than Tierra del Fuego in Argentina, enabling atmospheric scientists to gather data from the tropics to the auroral regions and over diverse geographical areas, from rainforests to deserts and oceans to landmasses. ATLAS-1 activation was completed within three hours, although a 13-minute delay to the launch shifted ‘shadow times’ by approximately one degree and 34 minutes, which required the adjustment of experiment observation timings. Neither of the two 12-hour teams saw themselves to be in ‘competition’ with the other. “Charlie didn’t ever really use such a device like that to drive performance,” remembered Sullivan. “Commitment to each other, commitment to the mission [were] the intrinsic factors that he exemplified and reinforced. He wouldn’t have needed to set up some fake game for me to make me do anything better.” Dave Leestma, who was in charge of the Red Team, broadly agreed, although he admitted to some light-hearted competition during training. “Maybe one day,” he told the NASA oral historian, “the Red Team has their sim and the Blue Team has it the next day. When you’re done, you ask your training team: ‘Well, how did we do compared to those guys?’ There’s always that natural competitiveness.” As a mission specialist, Leestma was effectively in charge of the flight deck during each of his team’s 12-hour shifts and therefore was responsible for executing a number of manoeuvres, flying the vehicle in order to direct the ATLAS-1 instruments. Primary responsibility for the instruments themselves, and the science, fell to the members of the payload crew: Foale and Lichtenberg on Leestma’s shift, Sullivan and Frimout on Bolden and Duffy’s Blue Team. The rear of the flight deck was a hive of activity during both shifts, with the relatively small space packed with hand-held cameras, photomultipliers and filters. Twenty-four hours into the mission, the first firing from the coffee-can-like SEPAC electron beam generator was scheduled to occur in the early stages of a Red shift. “Us Blue guys were all down below” in the middeck, recalled Sullivan, “mucking around with dinner and starting to get changed for sleep. We knew it was coming and we were eager to see it, but we thought we should get out of their way, let them get set up for this and get into this.” Although much of the ATLAS-1 hardware was housed in Atlantis’ payload bay, the orbiter’s aft flight deck was a hive of activity for manoeuvres and scientific investigations. It also played host to the first person of Belgian nationality to enter space: Dirk Frimout. Photo Credit: NASA All at once came a cry from upstairs: “Oh my God, look at THAT!” “There’s a cardinal rule on spaceflights,” said Sullivan, “or at least on all my crews, which is ‘There shall be no sentences from the flight deck ending in that’, as in ‘What the hell was that?’, because you’ll terrify the guys down below, who can’t see anything.” As a consequence, the Blues floated up to Atlantis’ flight deck to witness the first firing. It was one of few successful demonstrations of the experiment. The spectacle reminded Sullivan of something from a sci-fi movie, as an oscillating blue blob of energy – looking like “some luminescent blue creature…about to ooze out” – lingered atop the SEPAC canister and abruptly shot into the upper atmosphere. “It goes by quickly,” she recalled. “It was starting to curve away. You could see the curvature of the magnetic field line. You could just see it begin to spiral along. All this material you drilled into your head in college physics…and now you’re seeing, in front of your eyes, the curvature of the magnetic field lines, the electron gyro-radius as this thing spirals around it.” The Red Team’s exclamation was surely understandable when faced with such a captivating sight. SEPAC reminded Leestma of a phaser or some futuristic space gun from ‘Star Wars’. Interestingly, the STS-45 crew participated in the presentation of the Irving G. Thalberg Memorial Award to Star Wars creator George Lucas whilst in orbit. They also carried a real Oscar statuette aboard Atlantis. For Sullivan, although she admitted to being a fan of Lucas’ films, “our photon torpedoes”, from SEPAC, “were much better!” Yet they were not quite as long-lived. Without warning, on only its second or third firing, SEPAC’s electron beam assembly abruptly arced and shorted out. “The fuse died,” Sullivan concluded, grimly. “They got two or three doses off. We were distraught.” However, the SEPAC team announced that the data already gained was more than sufficient for their research needs. Despite the disappointing loss of SEPAC, the remainder of the ATLAS-1 mission proceeded without incident and produced spectacular results. Atmospheric science stations as far afield as India, Indonesia, Japan and New Zealand made joint observations with the Shuttle. Already, in the days before launch, Mike Foale had been assigned to the ATLAS-2 flight, scheduled for the spring of 1993. Kathy Sullivan, for whom STS-45 was her final mission, found time during her last days in orbit to marvel at the view of the aurora, a brilliant red and purple mass, extending all the way from Africa to Australia. It reminded Sullivan of “a huge, richly brocaded theatre curtain”, albeit that on this occasion the ‘curtain’ hung upwards from Earth into space. The scientific part of her brain was momentarily overtaken by one of childlike wonder. Auroral displays and auroral ‘arcs’ were a frequent sight of majestic splendour for the STS-45 crew…and a target for several ATLAS-1 experiments. Photo Credit: NASA Today, two decades after STS-45, Sullivan’s involvement with atmospheric research and environmental protection continues; since May 2011 she has been Assistant Secretary of Commerce for environmental observation and prediction and Deputy Administrator of the National Oceanic and Atmospheric Administration. Her career with NOAA stretches back to the end of her astronaut career. Her friend Sylvia Earle had been the administration’s chief scientist from 1990-92 and proposed Sullivan as her potential successor. Sullivan had considered leaving NASA for some time and in August 1992 she succeeded Earle and received formal Senate confirmation in March of the following year. Aside from the scientific rigours of their mission, the crew of STS-45 also carried the Shuttle Amateur Radio Experiment (SAREX), enabling ground-based ‘hams’ around the world to speak directly to the astronauts. Leestma, Sullivan, Brian Duffy and Dirk Frimout were licenced amateur radio operators and the mission’s 57-degree inclination permitted worldwide contact possibilities, including high-latitude areas not normally accessible to the Shuttle. At various stages when the SAREX equipment was running – whilst flying over China or New Zealand, for example, or central Africa or Tierra del Fuego – the astronauts would be inundated with amateur calls. It was impossible to speak for very long, admittedly, because the Shuttle might lose signal or another ham might break in, but Sullivan remembered speaking to an Australian man and his seven-year-old daughter on one occasion. On another, Dave Leestma woke her up to speak to someone at Palmer Station, on Antarctica’s Anvers Island, and the pair succeeded in speaking to hams on all seven terrestrial continents. On yet another, Brian Duffy was unexpectedly patched through to an amateur radio shack at JSC and from thence to his wife, Jan, sitting at the kitchen table of thei home in El Lago. At one stage, Duffy had contacted at least one ham from almost every continent, save Asia. “We had a night pass coming up right along, just offshore, parallel  to the islands of Japan,” recalled Kathy Sullivan. “As Duffy began his communications session, it seemed that a hundred thousand voices came back!” Duffy grabbed one call sign. “Roger, got you,” he said…and promptly turned off the radio and pulled the antenna. He had achieved his final continental contact. Job done. “Duffy, you are cruel,” Sullivan scolded. “There are 99,999 really disappointed people on the ground there!” To be fair, Duffy’s responsibilities on STS-45 were heavy; as the pilot of the Blue Team, he helped to run the flight deck for his shift and with Bolden was charged with bringing Atlantis safely back to Earth. Exceptionally economical use of cryogenic consumables meant that on 29 March the Mission Management Team opted to add an extra day in orbit. The mission was therefore extended from eight to nine days, with return to Earth rescheduled for 2 April. The hour-long re-entry back to the Kennedy Space Center in Florida on that day came as a surprise to Duffy. “Coming back in, pretty much all at night,” he told the NASA oral historian, “because we were going to land just after dawn in Florida, so the whole thing was in the dark.” This fact alone generated a spectacular return to Earth. Periodically, Duffy’s gaze would flicker from his instruments and over to the dramatic fire show underway outside his window: the nose glowed carnation-pink and it seemed that Atlantis was surrounded with a yellow and orange blaze. Every so often, he would look over at Charlie Bolden, in the commander’s seat, watching his gauges, and would realise how different the real thing was from the simulator. “The biggest surprise, however, was physically,” Duffy said, “and part of it was because…it was the first time in which I’d gone to extended weightlessness to now back into the G-field, into gravity, and it’s not just to 1 G – it’s to 1.4 or 1.5 G and it’s sustained for a long period of time, and you’re coming in at a 40-degree angle. I actually had to put my hand on the glare shield and hold my torso up to keep it from slumping down and forward during the entry.” It has often been remarked that the pilot’s key role at the end of a mission was to deploy the landing gear. “I’m calling altitudes and airspeeds to [Bolden] as we’re coming in for the final approach,” Duffy said, “because a lot of things are happening very quickly.” At 6:23 am EST, a little under nine full days since leaving the Cape, Atlantis’ tyres kissed Runway 33 of the Shuttle Landing Facility to conclude STS-45. The weeks which followed were consumed by traditional post-flight tours and, having transported Frimout into space, one notable focus was a journey to the Kingdom of Belgium. Kathy Sullivan was unable to attend, because she was already beginning confirmation hearings for her appointment to NOAA, but for the rest of the crew it was both a pleasure and a privilege. They had spoken to Prince Philippe whilst aloft and Duffy remembered the post-flight trip very well. “We were just treated like royalty,” he reflected. “It was nice for the spouses, too, because they don’t get the rewards that we get when we fly.”