‘Comm Check’: Remembering Columbia, OTD in 2003

As evidenced by the clock on the main screen at 14:15:05 GMT (9:15:05 am EST), this view of a tense Mission Control was acquired a quarter of an hour after the first sign of trouble…and a minute ahead of Columbia’s expected landing. By now, everyone was aware that all hope was gone and contingency procedures were in effect. Photo Credit: NASA

For 16 days in January 2003, the seven men and women of shuttle Columbia’s STS-107 crew—Commander Rick Husband, Pilot Willie McCool, Mission Specialists Dave Brown, Mike Anderson, Laurel Clark and Kalpana Chawla and Payload Specialist Ilan Ramon of Israel—worked around-the-clock to complete 80 scientific experiments spanning a variety of disciplines from life sciences to fluid physics and from materials research to Earth observations. Eighty-seven missions after Challenger, they had serviced the Hubble Space Telescope (HST) four times, docked nine times with Russia’s Mir orbital complex and begun building the sprawling International Space Station (ISS) in low-Earth orbit.

After multiple delays, STS-107 finally got underway on the morning of 16 January 2003. Photo Credit: NASA

The shuttle remained an inherently dangerous vehicle, although the robustness of the four surviving orbiters—Discovery, Atlantis, Columbia herself and the “baby” of the fleet, Endeavour—had been amply demonstrated and their shortcomings were well-understood. Or so it seemed. Those shortcomings came home to roost with horrifying suddenness on the morning of 1 February 2003.

In over two decades of operational services, the fleet had weathered last-second shutdowns on the launch pad, main engine problems during ascent and severe Thermal Protection System (TPS) damage during re-entry.

Severe damage to the shuttle’s Thermal Protection System (TPS) had been seen on several previous missions, notably STS-27 in December 1988. Photo Credit: NASA

And when a briefcase-sized chunk of insulating foam was spotted on the STS-107 launch video falling from the External Tank (ET) at T+82 seconds and hitting Columbia’s left wing—at precisely the spot where Reinforced Carbon Carbon (RCC) would later guard the ship against the most severe re-entry temperatures—concern was elevated, but ultimately dismissed. It would prove to be a dismissal as ill-judged as declaring the Titanic to be unsinkable.

The video footage from STS-107’s launch on 16 January offered little indication of what, if any, damage the foam strike had caused, save for a huge shower of particles. It was unclear if these particles originated from the impact of the foam itself or from shattered pieces of the RCC panels. If it was the latter, this did not bode well for Columbia’s re-entry, for the panels helped to guard the vehicle against the brunt of 3,000-degree-Celsius (5,400-degree-Fahrenheit) extremes during the hypersonic return to Earth.

Two ground-based views of Columbia, before (left) and after (right) the debris strike. Photo Credit: NASA

Senior managers doubted that a foam strike—an event which had occurred on earlier missions—could possibly be a “safety of flight” issue. This did not, however, prevent an analysis of a possible scenario in which the RCC had been breached.

On 31 January, the day before Columbia was due to land, engineer Kevin McCluney offered a hypothetical description to his colleagues at the Johnson Space Center’s (JSC) flight control team of the kind of data “signature” they could expect to receive in the event that the worst should happen.

STS-107 roars to orbit on 16 January 2003. Photo Credit: NASA

Let us suppose, said McCluney—outlined in depth by Michael Cabbage and William Harwood in their harrowing account of the tragedy, Comm Check—that a large hole had been punched through one of the shuttle’s RCC panels, enabling super-heated plasma to enter the airframe.

“Let’s surmise,” he told them, “what sort of signature we’d see if a limited stream of plasma did get into the wheel well [of Columbia’s main landing gear], roughly from entry interface until about 200,000 feet (60 km); in other words, a 10–15-minute window.” Little could McCluney possibly have guessed that his “signature” would almost exactly mirror the dreadful events which befell Columbia on the morning of Saturday, 1 February 2003.

The beauty of Earth was a sight that none of the STS-107 crew ever grew tired. Photographed through Columbia’s overhead flight deck windows, this astonishing vista was captured on 22 January, six days after launch. Photo Credit: NASA

“First would be a temperature rise for the tires, brakes, strut actuator, and the uplock actuator return…”

At 8:52:17 a.m. EST, nine minutes after entry interface—the point at which the shuttle began to encounter the tenuous upper traces of the “sensible” atmosphere—Entry Flight Director LeRoy Cain and his team saw the first unusual data on their monitors. Cain had begun his shift on console earlier that morning, with an up-tempo “Let’s go get ’em, guys,” before giving STS-107 Commander Rick Husband the go-ahead to perform the irreversible de-orbit burn to drop Columbia out of orbit and onto an hour-long path to land at the Kennedy Space Center’s (KSC) Shuttle Landing Facility (SLF) at 9:16 a.m. EST.

Pictured from Columbia’s aft flight deck, this view shows the payload bay and Spacehab research double module. The grey-colored Reinforced Carbon Carbon (RCC) panels lining the leading edges of the wings can clearly be seen, but the impact location is out of sight. Investigators would later conclude that a hole, six to ten inches across, had been punched through the RCC during ascent. Photo Credit: NASA

Much of the entry profile was controlled by the shuttle’s General Purpose Computers (GPCs), as was normal protocol, but with 23 minutes remaining before touchdown, Maintenance, Mechanical Arm and Crew Systems (MMACS) Officer Jeff Kling saw something peculiar in his data. It was what flight controllers termed an “off-nominal event”.

As later described by Cabbage and Harwood, Kling noticed that two downward-pointing arrows appeared next to readings from a pair of sensors deep within Columbia’s left wing. They were designed to measure hydraulic fluid temperatures in lines leading to the elevons. A few seconds later, two more sensors also failed. The attention of Kling and his team was instantly captivated; it looked for all the world that the wiring to all four sensors had been cut.

The STS-107 astronauts head to the T-38 flight line at Ellington Air Force Base, near the Johnson Space Center (JSC) in Houston, Texas, in July 2002. From left to right are Kalpana Chawla, Laurel Clark, Rick Husband, Dave Brown, Ilan Ramon, Willie McCool and Mike Anderson. Photo Credit: NASA

They tried to fathom a common “thread” to explain the fault, but none was forthcoming.

Kling spoke directly to Cain. “FYI, I’ve just lost four separate temperature transducers on the left side of the vehicle,” he began, cautiously. “Hydraulic return temperatures. Two of them on System One and one in each of Systems Two and Three.”

“Four hyd return temps?” queried Cain.

“To the left outboard and left inboard elevon.”

Commander Rick Husband occupies his seat in Columbia’s forward flight deck during STS-107. Photo Credit: NASA

Cain’s thoughts mirrored those of Kling: was there a common root cause for all four sensors to have failed in such close physical and temporal proximity to one another? When Kling asserted that there was “no commonality” between the failures, Cain was perplexed, but instantly thought back to the foam strike. In subsequent interviews, he would admit that his immediate fear was that hot gas had worked its way through a breach in Columbia’s left wing and was somehow affecting the interior systems.

However, Guidance, Navigation and Control Officer (GNC) Mike Sarafin assured him that overall vehicle performance as it crossed the California-Nevada state line at 22.5 times the speed of sound remained nominal. Was Kling happy with all other hydraulic systems? Kling replied that, yes, everything else was functioning normally.

The Sun peeks from behind the Earth’s limb in this spectacular nighttime view from STS-107. Photo Credit: NASA

“Tire pressures would rise, given enough time, and assuming the tires don’t get holed,” continued Kevin McCluney’s chilling prediction of what might happen. “The data would start dropping out as the electrical wiring is severed…”

Suddenly, at 8:58 a.m. EST, Commander Husband made his first radio communication since entry interface a quarter of an hour earlier. He started to call Houston, but his words were abruptly cut off. A few seconds later came a loss of temperature and pressure data from both the inboard and outboard tires of Columbia’s landing gear in the left well.

Kalpana Chawla is pictured at work in Spacehab, as seen through the connecting tunnel which linked the double module to the shuttle’s middeck. Photo Credit: NASA

If the tires were holed or losing pressure, it was very bad news, for STS-107 was a “heavyweight” mission with the fully-loaded Spacehab module and experiment pallet. A “wheels-up” belly landing was not expected to be survivable. The astronauts would need to perform a never-before-tried bailout, utilizing an escape pole system implemented after Challenger, but this could not be attempted until Columbia was at much lower altitude and at much lower relative airspeed.

“Data loss would include that for tire pressures and temperatures, brake pressures and temperatures,” concluded McCluney.

Dave Brown works out on a cycle ergometer as Ilan Ramon enters data on a laptop computer on Columbia’s flight deck. Photo Credit: NASA

After hearing Jeff Kling’s report, astronaut Charlie Hobaugh—the lead Capcom on duty that morning and the man responsible for talking directly to the STS-107 crew—called Husband to inform him of the anomalous tire pressure messages. Hobaugh also asked Husband to repeat his last comment. There was no reply from the rapidly-descending Columbia. By now, LeRoy Cain was pressing Kling for answers on whether the messages were due to faulty instrumentation, but was advised that all associated sensors were reading “off-scale-low”—they had simply stopped working.

Seconds later, at 8:59:32 a.m., Husband tried again to contact Mission Control. These were to be the last words ever received from Space Shuttle Columbia.

The dual-shift nature of STS-107 required the inclusion of sleep stations in Columbia’s middeck. In this image, Red Team members Laurel Clark, Rick Husband and Kalpana Chawla peek out of their bunks. Photo Credit: NASA

“Roger,” he said, presumably acknowledging Hobaugh’s earlier pressure call, “uh, buh…” At that point, abruptly, his words were cut off in mid-sentence, together with the flow of data from the orbiter. Communications were never restored. Thirty-two seconds after Husband’s partial transmission, a ground-based observer with a camcorder shot video footage of multiple debris contrails streaking like tears across the Texas sky.

With the telemetry thus broken, the atmosphere in Mission Control was becoming increasingly uncomfortable. Kling told Cain that there was no common thread between the tire pressure messages and the earlier hydraulic sensor failures; moreover, other instrumentation for monitoring the positions of the orbiter’s nose and main landing gear had also been lost.

Kalpana Chawla, Ilan Ramon, Dave Brown and Mike Anderson gather around Combustion Module (CM)-2, one of the major research payloads aboard the Spacehab. Photo Credit: NASA

As the seconds of radio silence stretched longer, Cain asked Instrumentation and Communications Officer (INCO) Laura Hoppe how long she expected the intermittent “comm” to last. She admitted that she expected some ratty comm, but was surprised and puzzled by how protracted and “solid” it was.

“Columbia, Houston, comm check,” radioed Charlie Hobaugh at 9:03 a.m. His words were greeted only by static and by the echo of his own voice in the deathly-silent Mission Control. A minute later, he repeated the call. Again, there was no reply.

The STS-107 crew adopts a “flying” pose for their in-flight portrait. In red shirts (from left) are Kalpana Chawla, Rick Husband, Laurel Clark and Ilan Ramon. In blue shirts (from left) are Dave Brown, Willie McCool and Mike Anderson. Photo Credit: NASA

Half a continent away, at KSC, astronauts Jerry Ross and Bob Cabana were chatting outside the convoy commander’s van at the SLF, when they heard that communications with Columbia had been lost. At first, they were unconcerned—that is, until they were informed that powerful long-range radars at the Cape, which were supposed to lock onto the incoming orbiter at 9:04 a.m. and track its final approach, saw nothing coming over the horizon.

In Cain’s words, that offered the final punch-in-the-stomach confirmation that all hope was lost. Columbia was gone. “That was the absolute black-and-white end,” he said later. “If the radar is looking and there’s nothing coming over the horizon, the vehicle is not there.”

A mesmerized Ilan Ramon watches the Earth’s sunlit limb from the shuttle. Photo Credit: NASA

Unlike an aircraft, which can adjust its flight profile to make secondary approaches, the shuttle had only one shot to make a pinpoint landing. Its trajectory through the atmosphere could be timed to the second and touchdown was expected at 9:16 a.m. Weather data also made it possible to predict how far down the runway—about 1,500 feet (460 meters)—the shuttle would land.

At the Cape, the assembled crowds saw the countdown clock tick to zero…and then begin ticking upwards again as 9:16 came and went, with no sign of Columbia. No trademark sonic booms had been heard. No sign of the tiny black-and-white dot of the orbiter had been seen. Veteran shuttle commander Steve Lindsey—later to become Chief of the Astronaut Office—was one of the escorts for the STS-107 families and his blood ran cold. Something was terribly wrong.

Video Credit: NASA, via Matthew Travis/YouTube

Standing next to NASA Administrator Sean O’Keefe was former astronaut Bill Readdy, now serving as the agency’s Associate Administrator for Space Flight. O’Keefe would describe the former fighter pilot and veteran shuttle commander as ashen-faced and visibly trembling. Jerry Ross was a few months into his new job as head of the Cape’s Vehicle Integration Test Team (VITT) and his first act was to say a brief prayer.

In Texas, police were being inundated with 911 calls, reporting strange lights in the sky, loud explosions, and instances of falling debris. CNN quickly picked up on the stories and began reporting them. In Mission Control, however, televisions were not tuned to outside broadcasts. It was an off-duty NASA engineer, Michael Garske, who watched the shuttle pass overhead from the roadside, south of Houston, and called colleague Don McCormack in Mission Control with the news.

View of Columbia in orbit, acquired on 28 January 2003 by the U.S. Air Force’s ground-based Maui Optical and Supercomputing Site (AMOS). Photo Credit: NASA

“Don, Don, I saw it,” Garske cried, paraphrased by Cabbage and Harwood in Comm Check. “It broke up!”

“Slow down,” McCormack replied. “What are you telling me?”

“I saw the orbiter. It broke up!”

Sitting behind LeRoy Cain at the same time, veteran flight director Phil Engelauf received a call from off-duty flight director Bryan Austin, who provided his own first-hand testimony of Columbia’s death throes. By this time, although no one in Mission Control had physically seen the evidence of the disaster, they had resigned themselves to it. At 9:05 a.m., Cain had asked Flight Dynamics Officer (FDO) Richard Jones when he could expect tracking data from the long-range radars in Florida. One minute ago, came the reply.

Ground-based view of Columbia during re-entry, acquired from the Starfire Optical Range, Directed Energy Directorate, Air Force Research Laboratory, Kirtland Air Force Base, N.M. This image was acquired at approximately 8:57 a.m. EST. Photo Credit: NASA

Now, as Engelauf relayed Austin’s emotional report to Cain, the flight director slowly shook his head, composed himself and turned to the silent control room to declare an emergency. At 9:12 a.m., he instructed Ground Control (GC) Officer Bill Foster to “lock the doors”—a de facto admission that all hope was gone—and ordered flight controllers not to leave the building, but to begin preserving their data and writing up their logbook notes for use in the subsequent investigation. After checking with Jones that no further tracking had been acquired, Cain referred his team to their contingency plans; the plans that they and the STS-107 crew had worked in training, but which they hoped fervently would never be needed.

“OK,” Cain began, “all flight controllers on the Flight loop, we need to kick off the FCOH [Flight Control Operations Handbook] contingency plan procedure, FCOH checklist, page 2.8-5.” He then proceeded to talk them through the required actions: preserving logbook entries and display printouts, communicating only on the Flight loop and restricting outside telephone calls and transmissions. “No phone calls, no data, in or out,” he told them.

Pictured during pre-flight training, STS-107 astronauts (from left) Ilan Ramon, Laurel Clark and Mike Anderson occupy the seats on the shuttle’s middeck that they would use during re-entry and landing. Photo Credit: NASA

Nine hundred miles (1,500 km) to the east, in Florida, the STS-107 families were shepherded from the landing site to the crew quarters by 9:30 a.m. It was left to Bob Cabana to break the terrible news—one of his worst jobs in his astronaut career.

Mission Control, he explained, had not picked up any radio beacon signals which would have been activated if the crew had managed to bail out of Columbia. Regardless, the orbiter was at an altitude of around 40 miles (64 km) and traveling at nearly 15,000 mph (24,000 km/h) when it disintegrated. That alone offered not even the faintest hope of being survivable.

Hundreds of balloons and floral tributes are laid outside the gates of the Johnson Space Center (JSC) in Houston, Texas, in the days after the tragedy. Photo Credit: NASA

Later that morning, near Hemphill, Texas, Roger Coday found some human remains. He said a brief prayer and built a tiny wooden cross by the roadside.

It would be only the first of many memorials to be laid over the coming hours, days, weeks, months, and years, to reflect upon the United States’ second shuttle disaster, to understand what had gone wrong and to rebuild shattered dreams and look again to the future.

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