NASA Seeks Crew Escape System

C A P E   C A N A V E R A L, Fla., Jan. 26, 2001 -- Fifteen years after Challengerdisintegrated in the sky, NASA is considering a variety of escapesystems — ejection seats, flyaway capsules — that could save thecrew in another space shuttle accident.

It is the most extensive and expensive look at shuttle crewescape systems ever conducted by NASA. Engineers expect to wrap upthe yearlong, $5 million study by spring. But ultimately, the spaceagency may decide not to add any such features.

NASA puts the odds of a catastrophic accident during launch —the most dangerous part of any shuttle mission — at 1-in-438.Shuttle flight No. 102 is coming up in a week and a half.

Ejection Seats a Favorite

The leading contender among the safety features underconsideration is the ejection seat — the same system used for theGemini program and the first four shuttle flights. The Mercury andApollo spacecraft had rocket-powered towers to fling the capsulesaway in an emergency. None of these was ever used, but in theSoviet Union, an escape rocket safely pulled two cosmonauts from aburning booster in 1983.

Ejection seats were no longer considered necessary once NASAdeclared the space shuttle operational, beginning with flight No. 5in 1982.

"It was the Titanic syndrome: 'Not even God can sink thisship,"' recalls former astronaut Bryan O'Connor, director ofengineering at Futron Corp.

NASA's attitude changed with flight No. 25 — the doomed launchof Challenger, which took place 15 years ago this Sunday, on Jan.28, 1986. All seven crew members were killed, including teacherChrista McAuliffe. The cause: a gas leak in the right boosterrocket.

In the explosion, the crew module separated from the fireballand plunged into the sea. But the crew members had no parachutesand no way to jettison the hatch. They were wearing flimsy bluejumpsuits.

O'Connor headed a panel that looked at crew escape systems afterthe disaster. When shuttle flights resumed in 1988, he and otherastronauts ended up with parachutes; partially pressurized, brightorange suits with emergency oxygen and survival gear; a hatch thatblows open; and a pole for sliding out of the spacecraft.

Protection Minutes Into Liftoff

The Challenger explosion happened 73 seconds after liftoff. Theescape systems now under consideration could be used during thefirst three minutes of flight at an altitude of 150,000 feet ormore, as well as during landing and even on the launch pad.

Any one of these systems might have saved the Challenger crew,says Kevin Templin, a project manager in the shuttle engineeringoffice. Challenger's crew module separated intact and went into a2½-minute free fall from 50,000 feet.

Military-style ejection seats probably would be the easiestsystem to implement. More extreme would be a crewcabin-turned-escape capsule that would be capable of parachutingonto either land or water.

There is also the extraction method, in which miniature rocketswould pull astronauts from their seats. Although the lightestoption, it could accommodate only five astronauts rather than thedesired seven. The capsule could fit in everyone but would add8,400 pounds to the shuttle and cut into payload weight. Ejectionseats could accommodate six astronauts but would take up preciouscabin space.

No Guarantees

"Yes, I would feel better if I had some sort of escape system,but to do so at this stage in the design would make it worse, itwould make life so much worse," says Kenneth Cockrell, commanderof the next shuttle flight. "The concepts that I've seen just takethe crew compartment down to nothing."

Each method requires explosives for blasting out of the shuttle,which introduces the danger of something backfiring.

Then there is the cost. Elric McHenry, manager of space shuttleprogram development, estimates an ejection or extraction systemwould cost hundreds of millions of dollars. A crew module capableof separating from the shuttle could cost $1 billion or more.

The conclusion may well be that none of these systems is cheapenough, light enough, practical enough and easy enough toimplement.

A major factor is the international space station. If NASA hopesto finish building it in five years, then space shuttles cannot begrounded for major overhauls.

Another factor is the longevity of NASA's four space shuttles.It wouldn't make much sense, McHenry and others point out, toinstall expensive escape systems if the shuttles are not going tobe around for long once the space station is built.

Besides, NASA concedes even the most elaborate escape systemcannot guarantee crew survival.

In the end, the findings may be left for the designers offollow-on spaceships.

Retired NASA engineer Don Nelson says that would beunconscionable.

"They're taking a very big gamble — when they don't need to,"says Nelson, who has a book coming out titled NASA … You Have aProblem.

He proposes replacing shuttle pilots and flight displays with anautomated launch and landing system, thereby saving enough weightto put a pop-out crew module in the payload bay.

Otherwise, he says, "you're going to have to live with thisvehicle and lose another crew someday. And we will. The warningsigns are all there."