Scientists who sent experiments on the space shuttle Columbia now rate their part of the mission an outstanding success. This is in spite of the fact that some of those experiments achieved less than was hoped for because the flight was cut short last month. The demonstration that the shuttle itself is an excellent platform for doing science in Earth orbit overshadows everything, says chief scientist James Taranik of the National Aeronautics and Space Administration.
At a press conference here, Dr. Taranik explained that such performance was not a foregone conclusion. The shuttle has been designed for scientific uses. But only actual experience could show how well adapted it is for the task.
Scientists have to learn how to work with the shuttle through all phases of an experiment, from design of their equipment to postflight recovery of data and analyses. Also, one of the main features of the shuttle concept is to cut costs through reusable equipment. Taranik noted that experimenters have learned to develop instruments and other equipment more cheaply.
In the past, equipment sent into space had to operate for long periods unattended. If it failed prematurely, an entire research program could be lost. Hence the equipment had to be built to exceptionally stringent, and costly, standards. On the shuttle, the equipment is brought back to Earth where it can be recalibrated, refurbished, and flown again if more data are needed. The standards, and the cost, can be significantly lower.
The recent shuttle flight was a first working test that showed excellent scientific work can be done in orbit with such equipment, Taranik said. It also showed that the shuttle is a stable platform from which to make precision observations - more stable even than had been expected.
The pallet itself proved to be an excellent mount for the instruments. This is a technical point that is basic to the shuttle's scientific work. The pallet provides the interface between instruments and the shuttle proper. This means ensuring that the scientific payload is electrically compatable with the shuttle , among other things.
The stability of the shuttle and pallet was especially critical for instruments such as the imaging radar, which made maps of Earth's surface, and the experiments to identify surface features and rock formations by means of infrared radiation. These all required precise orientation so that the scientists involved could determine just what their instruments were looking at on the ground.
As for the individual experiments themselves, the -scientific results have been mixed. Some of them, such as the radar mapping and infrared scanning, received virtually all the data wanted or enough data for substantial studies.
The project to photograph lightning was less successful. But it did return some results. Bernard Vonnegut of State University of New York at Albany, the project scientist, says he is pleased to have gotten what he did. On the other hand, Allan Brown of the University of Pennsylvania says he is disappointed. His experiment in plant growth under weightless -conditions was worthless because it needed more time in orbit.
However, there is a bright spot. Both of these scientists now look forward to future shuttle flights on which their experiments can be flown again. That's the kind of second chance they wouldn't have had before.