Remembrance: Columbia (Part 2)

by Stephanie Osborn

http://www.stephanie-osborn.com

It is perhaps best if I simply let the timeline of the catastrophe speak for itself. Due to my familiarity with the subject, one of the crewmembers, and the bird itself, perhaps my readers will forgive me if I pull from the Wikipedia article on the matter [http://en.wikipedia.org/wiki/Columbia_disaster]. Having read the CAIB (Columbia Accident Investigation Board) Report in some detail, I find it to be accurate in the essentials.

~~~

“The following is a timeline of Columbia's re-entry. The shuttle was scheduled to land at 9:16 a.m. EST.

2:30 a.m. EST, February 1, 2003 – The Entry Flight Control Team began duty in the Mission Control Center.

The Flight Control Team had not been working on any issues or problems related to the planned de-orbit and re-entry of Columbia. In particular, the team had indicated no concerns about the debris impact to the left wing during ascent, and treated the re-entry like any other. The team worked through the de-orbit preparation checklist and re-entry checklist procedures. Weather forecasters, with the help of pilots in the Shuttle Training Aircraft, evaluated landing-site weather conditions at the Kennedy Space Center.

8:00 – Mission Control Center Entry Flight Director LeRoy Cain polled the Mission Control room for a GO/NO-GO decision for the de-orbit burn.

All weather observations and forecasts were within guidelines set by the flight rules, and all systems were normal.

8:10 – The Capsule Communicator (CAPCOM) notified the crew that they were GO for de-orbit burn.

8:15:30 (EI-1719) – Husband and McCool executed the de-orbit burn using Columbia’s two Orbital Maneuvering System engines.

The Orbiter was upside down and tail-first over the Indian Ocean at an altitude of 175 miles (282 km) when the burn was executed. The de-orbit maneuver was performed on the 255th orbit, and the 2-minute, 38-second burn slowed the Orbiter from 17,500 miles per hour (7.8 km/s) to begin her re-entry into the atmosphere. During the de-orbit burn, the crew felt about 10% of the effects of gravity. There were no problems during the burn, after which Husband maneuvered Columbia into a right-side-up, forward-facing position, with the Orbiter's nose pitched up.

8:44:09 (EI+000) – Entry Interface (EI), arbitrarily defined as the point at which the Orbiter enters the discernible atmosphere at 400,000 feet (120 km; 76 mi), occurred over the Pacific Ocean.

As Columbia descended from outer space into the atmosphere, the heat produced by air molecules colliding with the Orbiter typically caused wing leading-edge temperatures to rise steadily, reaching an estimated 2,500 °F (1,370 °C) during the next six minutes. (As former Space Shuttle Program Manager Wayne Hale stated in a press briefing, about 90% of this heating is the result of compression of the atmospheric gas caused by the orbiter's supersonic flight, rather than the result of friction.)

Columbia at approximately 8:57. Debris is visible coming from the left wing (bottom).

8:48:39 (EI+270) – A sensor on the left wing leading edge spar showed strains higher than those seen on previous Columbia re-entries.

This was recorded only on the Modular Auxiliary Data System, which is similar in concept to a flight data recorder, and was not telemetered to ground controllers or displayed to the crew.

8:49:32 (EI+323) – Columbia executed a planned roll to the right. Speed: Mach 24.5.

Columbia began a banking turn to manage lift and therefore limit the Orbiter's rate of descent and heating.

8:50:53 (EI+404) – Columbia entered a 10-minute period of peak heating, during which the thermal stresses were at their maximum. Speed: Mach 24.1; altitude: 243,000 feet (74 km; 46 mi).

8:52:00 (EI+471) – Columbia was approximately 300 miles (480 km) west of the California coastline. The wing leading-edge temperatures usually reached 2,650 °F (1,450 °C) at this point.

8:53:26 (EI+557) – Columbia crossed the California coast west of Sacramento. Speed: Mach 23; altitude: 231,600 feet (70.6 km; 43.9 mi).

8:53:46 (EI+577) – Signs of debris being shed were sighted by people out to watch the re-entry. Speed: Mach 22.8; altitude: 230,200 feet (70.2 km; 43.6 mi).

The superheated air surrounding the Orbiter suddenly brightened, causing a streak in the Orbiter's luminescent trail that was quite noticeable in the pre-dawn skies over the West Coast. Observers witnessed another four similar events during the following 23 seconds. Dialogue on some of the amateur footage indicates the observers were aware of the abnormality of what they were filming.

8:54:24 (EI+615) – The Maintenance, Mechanical, and Crew Systems (MMACS) officer informed the Flight Director that four hydraulic sensors in the left wing were indicating "off-scale low." In Mission Control, re-entry had been proceeding normally up to this point.

"Off-scale low" is a reading that falls below the minimum capability of the sensor, and it usually indicates that the sensor has failed (stopped functioning, due to internal or external factors), rather than that the quantity it measures is actually below the sensor's minimum response value. The Entry Team continued to discuss the failed indicators.

8:54:25 (EI+616) – Columbia crossed from California into Nevada airspace. Speed: Mach 22.5; altitude: 227,400 feet (69.3 km; 43.1 mi).

Witnesses observed a bright flash at this point and 18 similar events in the next four minutes.

8:55:00 (EI+651) – Nearly 11 minutes after Columbia re-entered the atmosphere, wing leading-edge temperatures normally reached nearly 3,000 °F (1,650 °C).

8:55:32 (EI+683) – Columbia crossed from Nevada into Utah. Speed: Mach 21.8; altitude: 223,400 feet (68.1 km; 42.3 mi).

8:55:52 (EI+703) – Columbia crossed from Utah into Arizona.

8:56:30 (EI+741) – Columbia initiated a roll reversal, turning from right to left over Arizona.

8:56:45 (EI+756) – Columbia crossed from Arizona to New Mexico. Speed: Mach 20.9; altitude: 219,000 feet (67 km; 41 mi).

8:57:24 (EI+795) – Columbia passed just north of Albuquerque.

8:58:00 (EI+831) – At this point, wing leading-edge temperatures typically decreased to 2,880 °F (1,580 °C).

8:58:20 (EI+851) – Columbia crossed from New Mexico into Texas. Speed: Mach 19.5; altitude: 209,800 feet (63.9 km; 39.7 mi).

At about this time, the Orbiter shed a Thermal Protection System tile, the most westerly piece of debris that has been recovered. Searchers found the tile in a field in Littlefield, Texas, just northwest of Lubbock.

8:59:15 (EI+906) – MMACS informed the Flight Director that pressure readings had been lost on both left main landing-gear tires. The Flight Director then told the Capsule Communicator (CAPCOM) to let the crew know that Mission Control saw the messages and was evaluating the indications, and added that the Flight Control Team did not understand the crew's last transmission. [I believe that it was around this point that the pressurized landing-gear tires likely exploded from the heat. At the very least it would have torn a huge hole in the underbelly of the wing, if not outright sheared off a substantial portion thereof. Note that the next several entries occur in fractions of a second. --Osborn]

8:59:32 (EI+923) – A broken response from the mission commander was recorded: "Roger, uh, bu – [cut off in mid-word] ..." It was the last communication from the crew and the last telemetry signal received in Mission Control.

8:59:37 (EI+928) – Hydraulic pressure, which is required to move the flight control surfaces, was lost at approximately

8:59:37. At that time, the Master Alarm would have sounded for the loss of hydraulics, and the shuttle began to lose control, beginning to roll and yaw uncontrollably, and the crew would have become aware of the serious problem.

9:00:18 (EI+969) – Videos and eyewitness reports by observers on the ground in and near Dallas revealed that the Orbiter had disintegrated overhead, continuing to break up into more and smaller pieces, and leaving multiple contrails, as it continued eastward. In Mission Control, while the loss of signal was a cause for concern, there was no sign of any serious problem. Prior to orbiter breakup at 9:00:18, the Columbia cabin pressure was nominal and the crew was capable of conscious actions. The crew module remained mostly intact through the breakup, though it had lost enough structural integrity that it lost pressure, and was completely depressurized no later than 9:00:53.

9:00:57 (EI+1008) - The still intact crew module was seen breaking into small subcomponents. It disappeared from view at 9:01:10. The crew, if not already dead, were dead no later than this point. [I will take issue with this statement later. -Osborn]

9:05 – Residents of north central Texas, particularly near Tyler, reported a loud boom, a small concussion wave, smoke trails and debris in the clear skies above the counties east of Dallas.

9:12:39 (EI+1710) – After hearing of reports of the shuttle being seen to break apart, the NASA flight director declared a contingency (events leading to loss of the vehicle) and alerted search and rescue teams in the debris area. He made a call to the Ground Controller: "GC; flight, GC; flight. Lock the doors." Two minutes later Mission Control put contingency procedures into effect. Nobody was permitted to enter or leave the room, and flight controllers had to preserve all the mission data for later investigation.

~~~

The morning of the disaster was about 3 months after my husband had had emergency heart bypass surgery. It had been a grueling recovery for both of us, and I clearly recall that it was the weekend (I believe it was Saturday) and we had slept in. I got up, wandered into the den, grabbed the remote, and hit the power. The television came on to the last channel we'd watched – the Weather Channel – and even they were reporting that “...Space Shuttle Columbia is twelve minutes late exiting the re-entry comm blackout.” I knew what that meant; I worked too long on those birds – on THAT bird – not to. Twelve seconds...maybe. Twelve minutes, there was no doubt. I turned and yelled down the hall, “HONEY! Get in here! We've lost a Shuttle!”

In retrospect, probably not the wisest thing to do to a recovering heart patient.

But he survived. They didn't.

It was so very surreal for me, and still is. I worked with Columbia more than any other shuttle in the fleet. I had a friend on board her – I helped train Kalpana Chawla for her first mission, back in '97. I'd kept up with her, popping into the Astronaut Office to look for her whenever I was in Houston. We'd have a cup of coffee, sit down and catch up, laughing and chatting. But I was doing DOD work at that point, and had lost track of who was scheduled for which flights. It wasn't until my husband asked me if I'd known any of the crew that I thought to check. And I was horrified. KC had one of the widest smiles, the most cheerful demeanors, of anyone I have known, before or since. To think she went through that...it was, and is, hard for me to accept.

I'd written a book, entitled Burnout:The mystery of Space Shuttle STS-281. It was fiction, every bit of it. It was in the hands of my writing mentor, and later sometime co-author, Travis S. Taylor, to read and critique. He was going to help me polish it, then help me find a publisher. I'd researched using the information from the Challenger disaster, but decided to make it very obviously NOT that incident; I'd chosen a re-entry scenario instead. The disaster which now played out before my eyes was precisely what I'd written into the book. Travis had to talk me out of trashing it instead.

In the end, life went on for some of us. My book, and numerous more, have been published. In January 2012, I was invited to return to my undergraduate alma mater, Austin Peay State University, to help support the library and to give a talk and a book-signing. It was a messy, cold, stormy night with torrents of rain falling when I arrived at the location and began setting up. The Friends of the Library were setting up around me for a reception before the talk, when a gentleman showed up. In all honesty I cannot recall his name because what came next was very...I'm not sure the English language has the word for what I felt in those ensuing minutes.

Because he told me he had been one of the 3 field coroners for the Columbia disaster. He had come, partly to answer the questions I had about it that I'd never been able to answer, and partly to hear my perspective on it. He had copies of the autopsy reports which I was allowed to flip through – though I can't recall a word on any page. And he gave me the answer I didn't want to hear: my friend KC had been alive through the breakup – they all had. In fact, he told me, at least one crewman was found on the ground, body intact, death due to multiple blunt force traumas. He didn't say so outright, but I can interpret that – he died when he hit the ground.

A recent presentation I made on scientific and engineering work done since then included a summation of that chat. I was later gently challenged on the matter of the crew's deaths. This upset me because, unable to remember the man's name, I hadn't a way to verify his credentials. (If you're out there, mystery man, please contact me through this blog.) But today, as I refreshed my memory on the details of the catastrophe, I found a newspaper report that took its information from the final version of the CAIB report, and I quote:

“The Working Group found no irregularities in its extensive review of all applicable medical records and crew health data. The Armed Forces Institute of Pathology and the Federal Bureau of Investigation conducted forensic analyses on the remains of the crew of Columbia after they were recovered. It was determined that the acceleration levels the crew module experienced prior to its catastrophic failure were not lethal. The death of the crew members was due to blunt trauma and hypoxia. The exact time of death - sometime after 9:00:19 a.m. Eastern Standard Time - cannot be determined because of the lack of direct physical or recorded evidence.” [http://www.spaceflightnow.com/columbia/report/030826crew/]

As a result of all this, some colleagues and I from SIGMA, the science fiction think tank [www.sigmaforum.org], are in process of developing a new system called SPEARED – Single Person Emergency Atmospheric Re-Entry Device. (This is the “scientific and engineering work” I mentioned earlier.) We have patents pending and hope that someday soon this new system will prevent deaths such as those aboard Columbia, and maybe even Challenger.

I'll keep you posted.

-Stephanie Osborn

http://www.stephanie-osborn.com