Research aboard space shuttle - equipment costs less
America's space shuttle Columbia has opened a new kind of research opportunity for space scientists. Because the shuttle itself is reusable, so, potentially, are any instruments or scientific experiments it carries. No longer must equipment be built to the rigorous, and expensive, standards required when it has to function unattended for long periods in orbit. This cost-cutting advantage, plus the fact that astronauts can help operate instruments, means that more investigators now can do a wider range of science than ever before in space.Skip to next paragraph
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If instruments lose accuracy in orbit, they can be recalibrated when returned to Earth. Scientists then can often compensate for the inaccuracies. If an experiment fails, it can be reflown on a subsequent shuttle mission. Also, long-term studies can be made over a number of years with instruments being sent up from time to time as needed.
All of these advantages were demonstrated with the scientific payload carried by Columbia on its second test flight in November. Having made preliminary studies of their results, the investigators now say they generally are delighted with the research possibilities of the shuttle.
The thunderstorm study is typical. For this, astronauts Richard Truly and Joe Engle used a standard movie camera and photocells to photograph thunderheads and record lightning flashes. Because failure of one of their fuel cell electric generators forced them to cut their time in orbit from five days to 54 hours, the astronauts got only a little film footage and recorded only one lightning flash. However, principal investigator Bernard Vonnegut of the State University of New York at Albany says the potential for this kind of thunderstorm study has been proved. With quite inexpensive equipment and making little demand on astronaut time or capability, he now has the prospect of making detailed observations of thunderstorms from the perspective of space.
Dr. Vonnegut says a thunderstorm is still rather a mystery. He describes it as being something like a fountain of warm air rising up to penetrate the stratosphere and reaching speeds of 100 to 200 miles an hour. No one yet knows how that vigorous cloud generates electricity, what the electricity does within it, or what role electrification may play in rainfall.
The puzzle has been compounded, Vonnegut adds, by two relatively recent discoveries. Satellite observations show there is 10 times as much lightning over land as over water. Again no one knows why this should be so. Also, meteorologists had thought that clouds and water were necessary to produce lightning. But planetary scientists now know that other planets do it without water.
Vonnegut says there is some indication that the strength of thunderstorm convection and the area of the storm are related to lightning. By photographing thunderstorms and recording their lightning from space, he expects to gain new insights that should help clear up some of the mysteries. The photographs will include stereo pairs so the storms can be seen in three dimensions. By carrying on this study as shuttle opportunities permit, Vonnegut hopes to build up a library of thunderstorm images and lightning data that will become a unique resource for weather scientists.
For Allan H. Brown and David K. Chapman of the University of Pennsylvania also, the opportunity to do their experiment over again is of paramount importance. Their study of plant growth under weightless conditions needed the full five days to show meaningful results. Thus, when the time in orbit was reduced to 54 hours, their experiment with the dwarf sunflower Helianthus annuus became one of the few aspects of the mission that can be called a near total failure, Dr. Brown says.