Houston (TX) – A new 400-page report written by the Spacecraft Crew Survival Integrated Investigation Team (SCSIIT) formed by NASA details the circumstances of the explosion of space shuttle Columbia. The report concludes that the crew had no chance of survival and died quickly. However, the report also suggests 30 improvements to make future spaceflight safer.
According to the report the 2003 explosion of Columbia saw a chain of five critical events, each of which was fatal for the crew members.
First, a rapid depressurization of the crew module at or shortly after orbiter breakup is likely to have incapacitated crew members “within seconds”, well before they could have configured their advanced crew escape suit (ACES) to protect the astronauts from loss of cabin pressure. “Although circulatory systems functioned for a brief time, the effects of the depressurization were severe enough that the crew could not have regained consciousness,” the report states.
“Unconscious or deceased” crew members were then exposed “to a dynamic rotating load environment with nonconformal helmets and a lack of upper body restraint.” The seat inertial reel mechanisms are believed to have failed to lock despite the off-nominal motion. Combined with helmets that did not conform to the head and the lack of upper body restraint during the rotation of the shuttle resulted in injuries and lethal trauma.
The third event “with lethal potential was separation from the crew module and the seats with associated forces, material interactions, and thermal consequences,” the report states. The authors of the document believe that all crew were deceased before, or by the end of, this event, which caused “traumatic injury related to seat restraints, high loads associated with deceleration due to a change in ballistic number, aerodynamic loads, and thermal events.” Those thermal events, which refer to increased heat and fire, are least understood as the ACES “has no performance requirements for occupant protection from thermal events and may not provide adequate protection even for egress scenarios involving heat and flames.” In fact, the report states that “there is no known complete protection from the breakup event except to prevent its occurrence” and that the “actual maximum survivable altitude for the crew module following a breakup of the orbiter is too complex to compute because it depends on the altitude and velocity at release as well as rotational dynamics, which are understood only in a general way.”
The two final lethal events were “exposure to near vacuum, aerodynamic accelerations, and cold temperatures” as well as the ground impact. Again the ACES system appeared to lack testing as the operating envelope exceeds the certification of the suit of a maximum altitude of 100,000 feet, and a “certified survive exposure to a maximum velocity of 560 knots equivalent air speed.” Also, while the current spacesuits integrate a parachute, a manual activation is required, which was impossible in this case.
The report states that Mission commander Air Force Col. Rick Husband, shuttle pilot Navy Cmdr. William C. McCool, Kalpana Chawla, Navy Capt. David M. Brown, Navy Cmdr. Laurel Clark, Air Force Lt. Col. Michael P. Anderson and Israeli Air Force Col. Ilan Ramon had about 45 seconds from the time they realized they were in trouble until they lost consciousness. Apparently, Husband attempted to save Columbia, but there was not enough time until the space shuttle burst into flames. It was concluded that there was nothing the crew could have done to save themselves in that timeframe.
Following the Columbia disaster, NASA formed SCSIIT and asked the group to investigate all elements of crew survival, including the design features, equipment, training, and procedures intended to protect the crew. Besides providing detailed insight in the accident, the report includes a list of 30 recommendations to make future space flights safer, even if key questions remain and potentially fatal events remain a risk for astronauts. In the case of Columbia, the shuttle’s wing was damaged by debris that had fallen from its external fuel tank. The damage was serious enough to create hot gases that put Columbia on a fatal path.
Most of the SCSIIT recommendations relate to suit and seat improvements, changes to the loss of control training during shuttle training, as well as a “crashworthy” data recorder and a “graceful degradation”. The report noted that spaceflight is still in its infancy and that improvements to safety are made on a continuous basis. For example, “after the Apollo 1 fire, sweeping changes were made to spacecraft design and to the way crew rescue equipment was positioned and available at the launch pad. After the Challenger accident, a jettisonable hatch, personal oxygen systems, parachutes, rafts, and pressure suits were added to ascent and entry operations of the space shuttle.”
While it was said that the “Columbia accident was not survivable,” the investigation regarding the cause of the accident produced a question of whether there were lessons to be learned about how to improve crew survival in the future. Some improvements apparently can be made, reaching the goal of the SCSIIT “to add meaning to the sacrifice of the crew’s lives by making space flight safer for all future generations.”