Another post-Challenger upgrade, the pumpkin-orange suits are equipped with a parachute pack, a built-in life preserver, their own air supply, survival gear and a backpack with a small collapsible life raft.
The idea would be to inflate the raft, climb aboard it, and then shoot off flares until search-and-rescue forces arrived on the scene. The rescuers would be combing a widely scattered area off the coast of
Cape Canaveral for any survivors.
The inescapable problem, however, is this: Most credible launch failure scenarios would make it difficult, if not impossible, to level the ship’s wings and fly a controlled glide.
So NASA is studying three potential alternatives:
Ejection seats
Shuttle Columbia was equipped with ejection seats for its first few flights. But only a commander and a pilot -- both of whom could be seated on the upper level of the ship’s crew cabin -- were aboard for those flights.
The system was removed from Columbia when NASA began flying larger crews on shuttle missions. The reason: NASA could not accommodate astronauts seated on the cabin’s lower level during launch.
Agency engineers, however, have found a way around that problem -- albeit a rather complicated one.
As part of a preliminary study delivered to managers last week, engineers outlined plans for an ejection seat system that could accommodate four astronauts on the flight deck and two on the lower mid deck.
Significant structural changes would have to be made to the crew cabin to clear the way for the mid-deck astronauts, but the general idea is to install a rail system that would guide their rocket-powered ejection seats out an overhead hatch.
The four flight deck astronauts then would follow:
An extraction system
The same study outlined a rail-guided system that would employ small rocket motors to pull harnessed astronauts out an overhead hatch.
"There would be a small rocket motor that would be fired to pull the crew along that rail and jerk them away from the vehicle, and away from the plume if there was an explosion going on," McHenry said.
"It would basically jerk them out of the vehicle and they would be parachuting [to safety]."
Only five astronauts could be accommodated by this system, though, and all would have to be seated on the shuttle’s flight deck.
A detachable crew module
A modified crew cabin that could be jettisoned away from the shuttle is the only apparent alternative for saving an entire seven-member crew.
Attached rocket packs would blast the cabin out away from an explosion, and then parachutes would be deployed to float the astronauts to a safe landing.
"That’s the most intuitive solution," McHenry said. "But it’s also the most technically intrusive."
Such a system would require major structural modifications to the forward end of the shuttle, weighing down the nose of the orbiter. The shuttle’s wings, consequently, also would have to be modified "to make it more flyable with all that extra mass in the front," McHenry said.
Thermal shielding also would be a requirement in case a failure cropped up late in flight, exposing the module to the intense heat experienced during atmospheric reentry.
None of the alternatives would be inexpensive to implement.
A separable crew cabin would cost about $1 billion to design and develop. The other options would cost several hundred million dollars.
The investment, however, would give future astronaut crews a fighting chance to survive even a Challenger-like explosion, and if the shuttle fleet is going
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