243,000 feet Here is the Colombia's final moments: Destruction during re-entry
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, Saturday, 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 notified the crew that they are GO for de-orbit burn.
8:15:30 (EI-1719) – Commander Husband and Pilot 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 statute 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 mph (7.8 km/s) to begin its 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 or 76 mi), occurred over the Pacific Ocean.
As Columbia descended from 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 degrees Fahrenheit (1,400 °C) during the next six minutes.
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, and was not telemetered to ground controllers or displayed to the crew.
8:49:32 (EI+323) – Columbia executed a pre-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).
Columbia at approximately 0857. Debris is visible coming off from the left wing (bottom).8:52:00 (EI+471) – Columbia was approximately 300 miles (500 km) west of the California coastline.
The wing leading-edge temperatures usually reached 2,650 degrees Fahrenheit (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).
Columbia debris (in red, orange, and yellow) detected by National Weather Service radar over Texas and Louisiana.
A makeshift memorial at the main entrance to the Johnson Space Center in Houston, Texas
The Orbiter's wing leading edge typically reached more than 2,800 degrees Fahrenheit (1,540 °C) at this point.
8:53:46 (EI+597) – Signs of debris being shed were sighted. Speed: Mach 22.8; altitude: 230,200 feet (70.2 km).
The superheated air surrounding the Orbiter suddenly brightened, causing a noticeable streak in the Orbiter's luminescent trail. Observers witnessed another four similar events during the following 23 seconds.
8:54:24 (EI+613) – 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.
The Entry Team continued to discuss the failed indicators.
8:54:25 (EI+614) – Columbia crossed from California into Nevada airspace. Speed: Mach 22.5; altitude: 227,400 feet (69.3 km).
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 degrees Fahrenheit (1,650 °C).
8:55:32 (EI+683) – Columbia crossed from Nevada into Utah. Speed: Mach 21.8; altitude: 223,400 ft (68 km).
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 (67,000 m).
8:57:24 (EI+795) – Columbia crossed just north of Albuquerque.
8:58:00 (EI+831) – At this point, wing leading-edge temperatures typically decreased to 2,880 degrees Fahrenheit (1,580 °C).
8:58:20 (EI+851) – Columbia crossed from New Mexico into Texas. Speed: Mach 19.5; altitude: 209,800 feet (64 km).
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.
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.
9:00:18 (EI+969) – Videos made by observers on the ground revealed that the Orbiter was disintegrating. In Mission Control, while the loss of signal was a cause for concern, there was no sign of any serious problem.
9:05 – Residents of north central Texas reported a loud boom, a small concussion wave, smoke trails and debris in the clear skies above the counties southeast 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 told the Ground Controller to "lock the doors", and two minutes later put Mission Control 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