When Columbia’s payload bay doors opened at around midday EST on 16 January 2003, they exposed a cargo unlike anything which had flown into space for almost five years. Most shuttle missions in the interim had been exclusively dedicated to the construction of the International Space Station and only four—a radar-mapping flight, two Hubble Space Telescope servicing calls, and the deployment of the Chandra X-ray Observatory—had been dedicated to non-ISS tasks. This caused concern to both the scientific community and Congress, who feared that such paucity of “science” missions threatened to harm the United States’ lead in the microgravity arena. “We can’t expect the scientific community to remain engaged,” Congressman Dana Rohrabacher told a March 2000 hearing, “if researchers do not see hope that there will be research flight opportunities on a regular basis.” Columbia’s mission, STS-107, was set to address that issue.
There were other benefits of carrying experiments on a two-week shuttle flight, before committing them to long-term ISS missions. John Charles, NASA’s mission scientist for biological and physical research at the time, had long referred to STS-107 as doing “simulated space station science … although the science itself stands on its own right.” Moreover, many of the life and physical science experiments to be performed by Columbia’s crew—Rick Husband, Willie McCool, Dave Brown, Kalpana Chawla, Mike Anderson, Laurel Clark, and Israeli astronaut Ilan Ramon—carried an overwhelming emphasis on improving astronaut health and safety in readiness for extended ISS missions.
Congressman Dave Weldon, a Republican from the shuttle’s home state of Florida and a colleague of Rohrabacher, agreed that research missions like STS-107 were critical for demonstrating experiments before committing them to the space station. Unfortunately, for a time, this backing was crippled by a mission known as “Triana,” which, bizarrely, had been conceived in a dream by then-Vice President Al Gore. Named after the lookout on Christopher Columbus’ first voyage to the New World, Triana was billed as a 21st-century Earth-watching lookout with questionable scientific value. Gore’s challenge to NASA was to build a relatively inexpensive—between $25-50 million—satellite to broadcast real-time images of the Home Planet, 24 hours per day, over the internet. It received generally negative reviews from NASA’s Inspector General and an angry Congressional panel slammed its scientific worth. At an early stage in its development, Triana was manifested onto STS-107, but it soon became clear that it could not be completed in time, and by the summer of 2001 it was pulled from the mission. In its place was a bridge-like facility at the rear end of the payload bay, known as the Fast Reaction Experiments Enabling Science, Technology, Applications, and Research (FREESTAR), which would house six high-priority instruments, including an Israeli dust-monitoring camera.
As for the experiments which demanded a pressurized environment, there was a problem. The two European-built Spacelab modules had been retired following the Neurolab mission in early 1998. In their place, NASA paid $47 million to Spacehab, Inc., a provider of commercial augmentation modules to expand the Shuttle’s pressurized envelope. In its original incarnation, first flown in June 1993, Spacehab increased the working volume of the reusable orbiter by almost a thousand cubic feet, but with STS-107 a new “Research Double Module” would take the stage for the first time. Although a Logistics Double Module had already flown on several earlier missions, the RDM included additional environmental controls for humidity removal, electrical power, and experiment data-handling … and provided in excess of 2,100 cubic feet to support over 8,500 pounds of payloads. On STS-107, Spacehab, Inc., marketed 18 percent of the module’s capacity, netting $22 million in revenue, whilst the rest was reserved for NASA experiments.
Those experiments were roughly divided into life and physical sciences. The former included studies of pulmonary and cardiovascular changes during rest and exercise and investigated bone cell activity. Before launch, Dave Brown—a physician and former Navy flight surgeon—hoped that the Canadian-provided bone cell experiments could yield insights into future treatments for osteoporosis, since the loss of calcium from astronauts’ bones in space flight offered “a very accelerated model” of what happens to people on Earth over many years. During STS-107, the science crew members gulped down pills and injected fluids, laden with “tracer” chemicals, to indicate the rate at which calcium was being lost from their bones. Elsewhere, Michael Delp of Texas A&M University provided an experiment to investigate the effect of microgravity on blood vessels, which featured a contingent of rats being flown to assess how their hind limbs grew thinner and weaker in space. Rats’ bones react much more rapidly than human ones, and previous missions had shown that 16 days in orbit was roughly comparable to several months in orbit for humans. It was hoped that the blood vessels in the rats’ hind limb skeletal muscles would be examined after Columbia’s landing to track structural and genetic changes. Still other experiments included studies of the astronauts’ sleep patterns, with watch-like “actigraphs” monitoring disturbances in their sleep-wake cycles as they passed through 16 “sunrises” and “sunsets” in each 24-hour period.
As well as combining several scientific disciplines, STS-107 combined several nations, with the European, Canadian, German, and Japanese space agencies sponsoring a variety of payloads. Students from Australia, China, Israel, Japan, Liechtenstein, and the United States observed the impact of microgravity exposure on fish, spiders, ants, silkworms, bees, and inorganic crystals. To Rick Husband, who oversaw the whole mission, it was “a humbling experience” to carry such immense responsibility for so many experiments. As the payload commander, Mike Anderson held in his hands the task of deciding who to train for which experiments and how to finely choreograph the research work in orbit.
None of these experiments could have been accomplished without a superbly organized payload crew … and this necessitated a dual-shift system, operating around the clock, 24 hours per day. The “Red Team” consisted of Husband, Clark, Ramon, and Chawla, while the “Blue Team” comprised McCool, Anderson, and Brown. Their division of labor was far more intricate than a simple divvying-up of tasks. “The issue is that, on our orbiter, there are lots of attitude requirements,” Kalpana Chawla remarked in one of her last interviews. “The orbiter should be in a certain attitude to do the ozone measurements; in a different attitude to do the dust measurements; in a ‘free-drift’ attitude … to do some of our very microgravity-sensitive experiments.” One series of experiments, featuring the Combustion Module, demanded a particularly quiescent environment, with virtually no thrusters disturbances, and this demanded almost a full dedicated day. “It really helps to use the crew more efficiently,” continued Chawla, “by doing that.”
That efficiency began within minutes of achieving orbit, when Dave Brown bailed out of his seat on the flight deck and moved crisply into position to photograph the just-jettisoned External Tank. With Mike Anderson acting as what Rick Husband called “the post-insertion guru,” supervising the activation of STS-107’s many payloads, astronauts Ilan Ramon and Laurel Clark busied themselves with setting up the Spacehab Research Double Module for an intensive 16 days of research. Elsewhere, Brown and Willie McCool started up the FREESTAR pallet and the laptops to support the Shuttle Ozone Limb Sounding Experiment. The latter utilized a visible and ultraviolet spectrograph to measure the distribution of ozone in the atmosphere using limb-viewing geometry. It was calibrated as Columbia flew above Hawaii, coinciding with a ground-based balloon launch. Other experiments included Israel’s high-profile dust study, which brought joy on 19 January when it detected an “elf”—a type of electrical phenomena which materialize above thunderstorms in time spans of a tenth of a millisecond—in one of its earliest data-takes. Overall, FREESTAR performed admirably and Mission Manager Tom Dixon described STS-107 as “one of the smoothest missions I’ve ever had a payload on … and the closest we’ve ever stuck to the pre-mission timeline.”
Only the most minor of glitches troubled Columbia herself. One of two dehumidifiers to collect and distribute water inside the Spacehab module produced an electrical “spike”; an identical system had earlier sprung a leak and had been shut down. Following the reconfiguration of a valve to allow cool air from the orbiter’s cabin to flow into the Spacehab, the temperature stabilized and was brought down to comfortable levels of around 22 degrees Celsius. In fact, the warm temperature inside the module had brought envious comments from staff at NASA’s Goddard Space Flight Center: for overnight forecasts in Maryland predicted lows of just 8 degrees Celsius and a wind chill of -5 degrees Celsius, and even Cape Canaveral had endured snow flurries on 17 January. In spite of the temperature, the work inside Spacehab continued at a rapid clip. Europe’s Advanced Respiratory Monitoring System required extensive breathing exercises to measure cardiac output, with the first data taken a few hours into the 16-day mission. All four members of the science crew—Anderson, Clark, Brown, and Ramon—participated in the experiment, gathering data both at rest and whilst undertaking moderate and medium-high exercise on a stationary bicycle ergometer. Ten days into the mission, on 26 January, the investigators were lauding a 100-percent success rate for the device, but noted that the most critical data would be acquired in the hours after touchdown on 1 February.
Elsewhere, cell cultures were being grown to understand genetic characteristics and a German study observed the development of gravity-sensing organs in fish. Students from around the world explored the effects of the strange environment of space on a variety of insects. Proteins were crystallized, mammal cells were cultivated, and the effect of cosmic radiation upon biological processes was examined. One experiment, “Astroculture,” actually nurtured a rose and an African rice flower, being flown as part of a commercial attempt to produce new, space-grown fragrances.
Kalpana Chawla took charge of several combustion science experiments, including SOFBALL, which explored the behavior of flame balls in microgravity, and the Laminar Soot Processes, which analyzed the formation of soot. The SOFBALL work yielded new records for the weakest flame ever burned on Earth or in orbit, the least amount of fuel mixed with air, and—at more than 81 minutes—the longest-lived flame ever burned in space. (The latter flame ball, nicknamed “Kelly,” came close to completing an entire orbit of Earth.) Fifteen different fuel mixtures produced 39 tests and triggered no fewer than 55 flame balls for a grand total of 6.5 hours. With expectations for a fully-fledged combustion facility aboard the International Space Station, this work was expected to ultimately lead to cleaner and more efficient car engines and better fire safety equipment. The Mechanics of Granular Materials sought to test “sand columns” in microgravity to enable better models for soil movement under stress, with possible applications in strengthening the building foundations, managing undeveloped land, and handling powdered and granular industrial materials.
For the “rookie” members of the STS-107 crew, their first experience of weightlessness was a magical time. Laurel Clark remembered the noises. Since everything was in a perpetual state of free-fall, she found it beautiful that belts and D-rings tinkled against each other, producing a gentle background “music.” Willie McCool spent much of his time on Columbia’s flight deck and reflected upon the glorious splendor of sunrises and sunsets. Panoramic views of Australia and the grandeur of the Himalayas took his breath away. Former circus gymnast Dave Brown spent his free time doing weightless backflips in the Spacehab. And Ilan Ramon could do little but marvel upon the fragility of the Home Planet’s gaseous veil, “so thin and fragile,” which both gave life and saved it.
A week and a half after launch, on 27 January, the crew had the chance to speak to the three-man Expedition Six team aboard the International Space Station, codenamed “Alpha.” Commander Ken Bowersox and Flight Engineers Nikolai Budarin and Don Pettit had been in orbit for two months, and their communications session with Columbia occurred as the station passed over eastern Ukraine and as the Shuttle was over northern Brazil.
“Hey, Alpha, this is Columbia,” called Rick Husband. “How you doing over there?”
“We’re doing great. We’re so glad to see you guys made it into orbit,” replied Bowersox.
“We’re glad to be here, too,” said Husband. “We’re really excited to be able to talk to you guys, one space lab to another big old space lab on that beautiful station of yours.”
The conversation lasted just a handful of minutes, before the two crews bade each other farewell and drifted out of radio range. Next day, the 28th, they both joined with people on Earth in reflecting upon the loss of the Challenger Seven in 1986. As Rick Husband spoke of his profound sadness at the loss of those seven brave lives, he could hardly have imagined that his own crew would follow them in barely four days’ time.
Video footage, acquired during Columbia’s ascent, had already shown a briefcase-sized chunk of insulating foam fall from the External Tank about 81 seconds after launch and hit the left wing. Debris of this kind had been falling from every tank since the dawn of the shuttle era and few NASA managers were unduly concerned. Nonetheless, the media latched on to the foam strike, to such an extent that an email was sent to Husband a week after launch to advise him of the incident, lest he be caught off-guard by a journalist’s question. The email assured Husband that painstaking analysis on the ground had cleared Columbia as safe to fly. Any damage was superficial, said Flight Director Steve Stich, and there was “absolutely no concern for entry.”
Today, a decade later, those haunting words send a chill down every spine.
On 30 January, as Anderson, Brown, Clark, and Ramon wrapped up the final few Spacehab experiments, a quick check of the troublesome dehumidifier was made and no moisture was found. Next day, the FREESTAR payload was deactivated, as was Spacehab itself, and Husband, McCool, and Chawla set to work on the standard test of Columbia’s thrusters, hydraulics, and other systems, ahead of re-entry and landing. Speaking to journalists that day, Entry Flight Director LeRoy Cain remarked that weather conditions at the Kennedy Space Center on 1 February were predicted to be excellent and that the re-entry “will be a very good visual sighting for folks, particularly on the West Coast, as well as in mid-Arizona, New Mexico area.” He added that “it should be a pretty spectacular event for folks that have never seen a shuttle sighting, particularly at night.”
It was going to be “spectacular,” though not as Cain intended.
For the STS-107 crew, their impending return to Earth closed a chapter on a job well done. “Science-wise, this flight’s been absolutely fantastic,” said Mike Anderson on the 31st. “I think a lot of our experiments have exceeded our expectations by 100 percent. We’ve seen things we never expected to see.”
Early on 1 February, the astronauts donned their pumpkin-orange pressure suits and took their seats for the hour-long hypersonic glide back to Earth. At 8:15 am EST, as Columbia hurtled over the Indian Ocean at five miles per second, Capcom Charlie Hobaugh gave Rick Husband a “Go” to execute the irreversible de-orbit burn, committing the ship to a landing in Florida at 9:16 am. For the first 30 minutes, the orbiter fell like a metaphorical stone, through darkness, toward its date with the Shuttle Landing Facility on the opposite side of the planet. The second 30 minutes were expected to be far more interesting, as compression of the steadily thickening air at hypersonic velocities produced a brilliant light show outside the windows.
“That might be some plasma now,” Willie McCool noted at one stage. The pitch blackness of space had been replaced by a steadily brightening pinkish glow, a little like salmon in color.
“Think so? Already?” queried Laurel Clark, seated behind him on the flight deck. She aimed a handheld video camera through the window above her head to capture the flashes.
“That’s some plasma,” confirmed Husband.
“Copy, and there’s some good stuff outside,” continued Clark. “I’m filming overhead right now.”
“It’s kinda dull,” said McCool.
“Oh, it’ll be obvious when the time comes,” replied Husband.
A few minutes later, as the glow brightened further, McCool was able to tell Dave Brown, Mike Anderson, and Ilan Ramon on the middeck that he could now see orange and yellow waves washing across Columbia’s nose. In the chatter that followed, Husband referred to it as “a blast furnace.” The time was now 8:44 am EST and the Shuttle had reached an altitude of around 75 miles as it hurtled across the eastern Pacific, just nine minutes from the California coastline. Flying with her nose angled “upwards” to subject her reinforced carbon-carbon nosecap and the leading edges of her wings to the most extreme re-entry temperatures of close to 3,000 degrees Celsius, Columbia was still dropping at more than 24 times the speed of sound. Aerodynamic pressures upon her airframe doubled, tripled, quadrupled. For the STS-107 crew, as they calmly donned their gloves and pressurized their suits and conducted communications checks, it was a chance to ride out the greatest light show on—or off—the Earth.
At 8:50 am, with the computers still flying the vehicle, Columbia’s right-hand Reaction Control System (RCS) jets automatically fired to adjust the position of her nose. Three minutes later, precisely on time, she crossed the California coastline and ground-based observers were able to see her streaking, like a meteor, across the darkened sky. It was at this point that freelance photographer Gene Blevins and his colleague Bill Hartenstein saw what they later described as “a big red flare” coming off the Shuttle and disappearing beneath it. To them, the first uneasy sense that something acutely wrong had taken hold.
Hundreds of miles away, in Florida, NASA and Israeli dignitaries and the astronauts’ families had gathered at the Shuttle Landing Facility to await Columbia’s arrival. NASA Administrator Sean O’Keefe was there, as was his new Associate Administrator for Space Flight, former astronaut Bill Readdy. The landing of STS-107 would kick off an ambitious series of missions in 2003; missions which would see the construction of the International Space Station pushed several steps closer to completion. Almost its entire electricity-generating solar array network and trusses were expected to be in place by the end of the year and Columbia herself was scheduled to fly one of those missions, STS-118, in mid-November. She was also pencilled-in to fly a servicing mission to the Hubble Space Telescope in 2004 or 2005.
All of those plans changed a few minutes before 9:00 am EST on 1 February 2003, when Columbia’s otherwise normal re-entry profile began to go hideously wrong.
The fourth part of this article will appear tomorrow.