Columbia hits minor snags, but so far flight is a breeze

Space shuttle Columbia has again shown earth orbit to be a good place for a scientific laboratory.

As with all previous shuttle missions, astronauts Thomas K. Mattingly and Henry W. Hartsfield have run into problems. Balky equipment kept them up past their bedtime Sunday night, and a costly hardware failure sent the shuttle's normally recoverable external rocket fuel tanks to the ocean bottom. The bill for loss of the fuel tanks: $36 million - $50 million for the canisters, minus the $14 million normally spent to refurbish the recovered equipment.

Due to hail and rain denting and soaking the shuttle's protective tiles before liftoff, the crew took special measures to dry out the tiles Sunday with sunshine. This was to prevent ice formation in the tiles, which could have caused the tiles to pop off the ship during reentry.

In addition, a thruster leak caused a slight shift of plan, lowering the orbit altitude from 189 to 185 statute miles (or from 165 to 161 nautical miles). This will cause only a 19-minute earlier landing July 4.

For the Space Transportation System (STS), however, the unexpected is not only expected - it is anticipated by a meticulously preprogramed network of flight-simulation computers.

Two STS mission specialists, ''flying'' a shuttle mockup as this reporter watched recently, had the tricky task of controlling the shuttle after complete engine failure.

As far as this particular shuttle's computers knew, the emergency was absolutely real. The only difference was that the data about such things as engine failure, altitude, and velocity came from other computers rather than from actual in-flight conditions.

NASA officials here at the Johnson Space Center in Houston say simulated mission activities on the ground and in flight are essential parts of a continual process of scientific experimentation.

So far, the experiments have ranged from testing microscopic changes in plant tissue in space to testing the shuttle's ability to withstand extreme temperature and the shuttle crew's ability to correct equipment malfunctions. For the first time, STS-4 is also testing a package of military sensors being developed to track missiles.

As part of the ''Shuttle Student Involvement Project'' which sends high-school experiments into space, the STS-4 crew has been filling out forms to evaluate ''the effects of diet, exercise, and zero gravity on lipoprotein profiles'' for Amy Kusske of Wilson High School in Long Beach, Calif.

Along with two high-school-generated experiments, Columbia carries the STS program's first commercial payload,the privately funded ''Getaway Special.'' Shuttle contractor Gilbert Moore paid the $10,000 shuttle-fare for this five-cubic-foot, 200-pound canister packed with nine experiments designed by Utah State University students. These test various metals and chemicals as well as plant and animal growth.

One early problem for the STS-4 crew was that the Utah University canister failed to start. (The astronauts were attempting to repair the canister as of this writing.) But such glitches in this fourth space mission are minor compared with the computer and power-unit problems that delayed all three previous shuttle liftoffs and cut the second flight from 157 to 54 hours.

Another advantage of the shuttle system over one-shot space vehicles is to make it possible to repeat experiments relatively easily after failures occur. If a ''getaway special'' or other package doesn't perform properly on one mission, it can be sent aloft again on a subsequent shuttle flight. Once STS flights become routine, high-school students will no longer be likely to graduate before their experiments go into orbit.

The shuttle's ability to allow scientists to try-and-try-again has already paid off for NASA's ''Nightime/Daytime Optical Survey of Lightning.'' Conceived by State University of New York Prof. Bernard Vonnegut to increase understanding of severe storms, this experiment first flew on STS-2 but revealed little due to that mission's shortened flight time. NASA expects a more successful experiment on STS-4.

Also being tested is STS-4's suitability as a space-mounted scientific laboratory. A liner was installed in the payload bay to prevent contamination of scientific experiments.

In addition, the shuttle crew is using the Canadian-built manipulator arm to sweep the shuttle surface with an 800-pound sensor package designed to measure possible contamination.

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