Research aboard space shuttle - equipment costs less
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Nevertheless, they did gain valuable experience in working with their experimental package, which is carried in a locker on board the spacecraft. Among other things, they found the temperature running unexpectedly high at 81 degrees F. instead of 5 to ten degrees lower. This could significantly affect both their own and future biological experiments on the shuttle. The cause must be understood and taken account of, Brown says. His experiment is a pilot project for a larger study to be made with Spacelab - a laboratory carried in the shuttle payload bay in which several people can work and which is being supplied by the European Space Agency.Skip to next paragraph
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These biological studies are of more than academic interest. Brown and Chapman are trying to find out the relation between seedling growth and soil moisture content. Brown explains that, on Earth, gravity tends to make moisture migrate downward. In space, without this gravitational effect, moisture and soil may interact differently. What are good growing conditions on Earth might drown seedlings under weightless conditions. If future manned space stations are to provide some of their own food from on-board gardens, a new set of gardening skills needs to be developed based on such experiments.
As a platform for doing science, the shuttle not only allows experimenters to work with relatively cheap equipment, it also is a test bed for developing equipment for other uses. For example, resource scientists would like to have a ''smart'' satellite that took only the images they wanted. Resource-surveying satellites, such as Landsat, now inundate their users with data, much of which is irrelevant. Roger T. Schappell of Martin Marietta Aerospace in Denver and his co-workers are developing a system that would enable such satellites to discriminate between different kinds of surface features and only take data for those in which users are interested.
The FILE (Feature Identification and Location Experiment) package Columbia carried is a step toward such a system. Dr. Schappell says it is equipped to distinguish between water, bare land, vegetation, and clouds and snow. What he calls a ''very preliminary'' look at the data suggests that the system can indeed do this. Even though he didn't get all the data hoped for, Schappell says he has enough to work with.
Other experiments to map ocean surface color, measure carbon monoxide concentrations in the atmosphere, and match infrared ''signatures'' of land features as seen from space with their true geological nature also returned enough data for their respective research teams to carry on with their development. The ocean color test, in particular, allowed Hongsuk H. Kim of the NASA Goddard Space Center and his colleagues to use what he calls off-the-shelf aircraft equipment - not something specifically designed for space - to develop a system for locating concentrations of chlorophyll from orbit. Such concentrations should indicate areas where there is much plant and other food to sustain fish populations.
One of the most successful of the equipment tests was that of the imaging radar. This obtained virtually all the data wanted and confirmed that such radar can indeed obtain high-quality images of land formations from orbit. It is similar to radar used to map the sea surface from the Seasat satellite and that has been successfully used from aircraft.
Its images, which have a photograph-like quality, can be taken day or night, through clouds and vegetation. It was such a radar, carried by aircraft, that uncovered a previously unknown network of ancient Mayan irrigation canals in Central America. Indeed, this is the kind of radar planetary scientists hope to send to Venus to make detailed maps of its surface, if this often postponed project is eventually funded. Meanwhile, the shuttle offers a new opportunity to use that radar for geological mapping here on Earth.