Columbia: ingenuity versus glitches
For astronaut Richard Truly, the successful second launching of the space shuttle Columbia was ''the biggest birthday candle I ever had!'' Lifting off at 10:10 a.m. EST, Nov. 12, Columbia became the first spacecraft to go into orbit more than once. This opens a new era of reusable space transportation.Skip to next paragraph
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The fact that it happened on Captain Truly's birthday was compensation for the frustration he and Columbia commander Joe Engle felt when their first launch attempt was scrubbed a week earlier. Oil contamination in the units that power the spacecraft's hydraulic systems had forced the postponement. Now, with clean lubricating oil and oil filters, there were few problems to mar the launch countdown this time.
The timing of the launch was delayed 21/2 hours because a faulty data relay unit had to be located and replaced the previous day. There was a further slight delay that morning to sort out minor problems and, as launch director George Page put it, allow some of the tense members of the launching team to relax a little.
''Take your time and do it right,'' Mr. Page told his team. Then, explaining the short delay to the astronauts, he said he wanted to make certain ''we're going to give you a good one.'' Columbia entered orbit with no hitches.
But the mission could be shortened. At this writing there was a strong possibility that a malfunctioning fuel cell would be taken permanently off-line. Mission rules would the require curtailing the mission to 54 hours. Before the launch, astronaut Donald Slayton, in charge of operations, had said it was possible to achieve all important mission objectives within two days. One of the shuttle's three fuel cells, which supply electric power, was shut down because of suspected seepage between the hydrogen and oxygen sections of the cell.
But the uncovering of such troubles is the whole purpose of Columbia's first four missions. Taken together, they are intended to qualify for routine operation of what the National Aeronautics and Space Administration (NASA) calls the Space Transportation System.
A key element is the capacity to refurbish a shuttle between flights and get it ready for relaunch. A quick turnaround is crucial for commercial or military operations.
NASA had thought hopefully of refining this to as little as 14 days. However, this now is considered unrealistic. Mike Weeks, NASA acting associate administrator for the Space Transportation System (STS), says, ''I think that we can probably get 10 launches per year out of each orbiter.'' With a projected fleet of four orbiters and with the possibility of a fifth joining them later, that still would allow quite a few missions per year.
Mr. Weeks adds that ''we're working at the (turnaround) problem very hard.'' He explains there are problems in each of the STS subsystems, especially the reusable solid rocket boosters, which are recovered at sea, refurbished, and recharged each time.
Indeed, this process of detailed testing and refining of STS systems management is a main objective of the test flights.
From this viewpoint, the lubrication problems that postponed Columbia's launch has helped meet that objective. The auxiliary power units (APUs), as they are called, are gas turbines that drive the pumps that pressurize the shuttle's hydraulic systems. These are the systems that lower landing gear and move flight control surfaces. The turbines are spun by jets of gas produced by the decomposition of hydrazine. If that chemical leaks past the seals in excessive amounts to contaminate the APUs' lubricating oil, it can cause crystals to form.
This happened when the original launch was scrubbed. Subsequent ground tests showed the crystals dissolve as the oil heats up. Thus, were such a problem to develop in orbit, it probably would not be critical.
As Weeks explains, the shuttle team now feels ''quite confident this is nothing to be concerned about. . . . It's a very forgiving system.''
That is the kind of information NASA welcomes from this shuttle flight test program.