Amid reports that the crew cabin of the Challenger space shuttle may have remained resonably intact after Tuesday`s explosion, then fallen into the ocean, NASA spokesmen refused to speculate whether the crew could have survived any portion of the plummet.
At the time that the massive blast occurred–74 seconds after liftoff
–the seven crew members were locked in the cabin with no possibility of escape, and prevented by the shuttle`s design from safely aborting the doomed mission.
If the shuttle is separated from its fuel tank or booster rockets during the first 127 seconds of a mission, it will plunge powerlessly back to Earth. Not until the booster rockets have been ejected can the shuttle hope to roll into a glide that would allow it to safely land on the runway at the Kennedy Space Center.
Given the suddenness and the extent of the explosion that ended the mission and stunned the nation, experts agreed that the Challenger crew members were probably doomed under any circumstances.
But even a less-catastrophic failure, such as the shutdown of an engine, would put the lives of the occupants in danger if it occurred before the boosters were detached.
Some built-in vulnerabilities such as that are inevitable in any spacecraft, but they may be even more so in the shuttle that, from the very first, has been a compromise among competing interests and plagued by underfunding.
At many stages of the shuttle`s development, safety considerations took a back seat to other considerations, including cost and the payload capacity of a craft that at some point was expected to pay for itself.
The decision about a decade ago to build a craft that is a hybrid between a rocket and an airplane virtually guaranteed that there would be this period at the outset of a flight when occupants are totally hostage to the machine and its ability to function as intended.
When a reusable space vehicle was first proposed, one proposal was for a self-contained rocket ship with an internal fuel supply that could take off and land like an airplane. Such a craft, if it could have been developed, would have been less unwieldy and safer than the existing shuttle. But this idea was dismissed as far too expensive.
What finally was built was a shuttle with three external-fuel components attached to the spaceship–the two boosters filled with solid fuel and the huge aluminum tank that carries liquid hydrogen and liquid oxygen, two of the most volatile subtances known to man.
Challenger`s liquid-fuel tank exploded, for reasons not yet determined. One theory advanced by some aerospace experts is that a leak in one of the booster rockets might have touched off the blast.
On Friday, two remote-control submarines photographed the site of a large submerged object off the coast of Florida after NASA films reportedly showed Challenger`s crew cabin hitting the ocean reasonably intact.
Based on the size of fuselage pieces that have been retrieved, the Associated Press reported, NASA officials have privately discussed the possibility that the cabin could have survived, despite the explosion and nine-mile plunge after its Tuesday launch.
NASA films show what appears to be the cabin, trailing a long stream of smoke as it plummeted out of the fireball into the ocean, striking the water with tremendous impact, the wire service said.
Officials refused to discuss the reports or whether bodies of Challenger`s seven-member crew might be found if the cabin were intact.
As President Reagan led a memorial service for the crew in Houston, a press release regarding Friday`s ocean search stated, ”No comment will be made by NASA officials today on anything concerning personal effects or human remains out of respect for the astronauts` families.”
Although dramatic televised footage of liftoff seemed to show Challenger vaporizing in a fireball, large pieces have been found. On Friday, the Coast Guard cutter Dallas returned from the area of the mysterious submerged object with five large tiled sections from the Challenger`s fuselage.
Such findings had stirred speculation that all or much of the crew cabin, which is part of the fuselage, also fell.
The pressurized crew cabin is ”a double-walled vehicle, like a thermos jug. It is very, very strong,” said Jim Mizell, a spokesman and former engineer with the National Aeronautics and Space Administration. ”It is much stronger than the rest of the vessel.”
Asked if it could survive the explosion or impact in the water, he said,
”I wouldn`t want to speculate on that.”
The question of the cabin surviving intact involves whether the seals on about 300 tiny holes for pipes and wiring could withstand the explosion and ocean impact, NASA spokesman Charles Redmond said.
Coast Guard spokesman James Simpson, a lieutenant commander, cautioned that the large object might not be the cabin. ”It could be a shrimp boat from 20 years ago or a Spanish galleon from 300 years ago,” he told the Associated Press.
Among the five shuttle fragments recovered was a 25-foot-long section with tiles and a porthole-door, painted with a yellow arrow and the word
”Rescue.”
The section was an escape hatch, Mizell said. Its location was at the base of the mid-deck, where three of the crew members sat, and 8 feet below the flight deck where the others were.
After strong currents deterred divers from trying to observe the submerged object, the two NASA recovery ships lowered unmanned submarines with television and still cameras at the sonar-indicated site, described as 140-foot-deep water 20 to 40 miles off Daytona Beach.
Aboard Challenger were Cmdr. Francis ”Dick” Scobee, 46; pilot Michael Smith, 40; Ronald McNair, 35; Judith Resnik, 36; Ellison Onizuka, 39; Gregory Jarvis, 41; and Christa McAuliffe, 37. McAuliffe, a high school teacher in Concord, N.H., was to be the first private citizen in space.
Asked about equipment in the crew cabin, Redmond said space shuttles had been equipped with ejection seats only on the first four missions, in which two-man crews wore pressurized suits. Later flights carried larger crews wearing nonpressurized suits in pressurized cabins. On the Challenger, only the commander and pilot were provided with emergency oxygen bottles, he said. Redmond said there was no automatic signal device in the cabin that would lead searchers to it if the shuttle crashed.
The search for debris covered a 6,800-square-mile area Friday, increased by 500 square miles from Thursday.
A fragment of bone, tissue and cloth found by a civilian on nearby Indiatlantic beach had not yet been identified at Patrick Air Force Base Hospital, NASA spokesman Hugh Harris said.
If the crew cabin did indeed survive the explosion and make it back to Earth, this will undoubtedly stir new debate about the design compromises that were made as the shuttle evolved and their impact on the safety of the occupants.
The very first flight of the shuttle was such a compromise.
In an interview on the eve of the shuttle Columbia`s first launch in 1981, Max Faget, director of engineering and development at NASA`s Johnson Space Center in Houston, acknowledged at that a shortage of funds had forced some safety shortcuts.
John Young and Robert Crippen were to fly the Columbia for its maiden voyage, the first time an American spacecraft wouldn`t be tested in unmanned flights before taking humans into space.
”It`s obviously more hazardous for the crew,” Faget said. ”There`s no hazard at all if the crew stays on the ground, but there is another consideration–the safety of the vehicle. Being very cold-blooded about it, the orbiter costs in the neighborhood of $1 billion, a big chunk of money.
”So one can say one is willing to risk, to put the crew to a certain amount of hazard, to protect our investment in that vehicle.”
One member of the original committee that designed the shuttle, Hans Mark, a former NASA deputy administrator and now the chancellor of the University of Texas system, said Friday that he doubts any design flaws played a role in the Challenger explosion.
”Those people never had a chance,” Mark said. ”I don`t think this is a design problem. It can happen because there is a flaw, a leak . . . God knows. The design is sound. I think something wasn`t put together right or tightened down or some electrical system malfunctioned.”
Mark acknowledged that funding shortages did have an effect on the shuttle`s design.
”Obviously if you spend more money, you can always make things better,” he said. ”Within the alloted funds we had, it is the best spaceship we could make. It is the best in the world.”
Some safety items, such as escape rockets for occupants of the shuttle to use in case of trouble during liftoff were scrapped for financial reasons and to save on weight when the craft was designed.
The capacity of 65,000 pounds designed for the shuttle was also a compromise. Several engineers favored a smaller reusable craft, one that could carry about 50,000 pounds into space and take off and land from regular airports.
Capacity was increased and has been boosted since the first Columbia flight at the insistence of the military, which wants to put bigger payloads into space. It was only after Air Force officials convinced Congress and President Jimmy Carter to beef up NASA`s shuttle budget because of military aspects that the agency got enough money to complete the craft`s development.
