Ability to retrieve satellites gives shuttle edge over rivals
Space shuttle commander Robert Crippen said it all - ''we pick up and deliver.'' By successfully deploying and recapturing a platform full of instruments, as well as having launched two communications satellites, the crew of the Challenger has demonstrated the full capability of the shuttle system.
Rival launch systems such as the European Ariane or Soviet Proton rockets can compete for the business of launching commercial satellites. But only the US shuttle can retrieve an orbiting satellite, repair it if necessary, and put it back in service.
This capability - demonstrated June 22 by five releases and recaptures of the West German Shuttle Pallet Satellite (SPAS) - makes this seventh mission a milestone in the development of the US Space Transportation System (STS).
The mission is, of course, also distinguished as the first space assignment in which a US woman astronaut has participated. In handling the SPAS with the Canadian-built manipulator arm, astronauts Sally Ride and John Fabian showed why shuttle operations require a high degree of individual skill and smooth teamwork. While they maneuvered the SPAS with the arm, astronaut Crippen or shuttle pilot Frederick Hauck maneuvered the shuttle itself.
Tight coordination was required to release and recapture the SPAS. This human capability is as important to the shuttle's operations as are its unique mechanical abilities, exemplified by the manipulator arm. Thus flight director John T. Cox had both the crew and the hardware in mind when he said mission officials are ''just as pleased as we can be with the whole thing.''
So far, this seventh shuttle mission (the second orbital flight for the Challenger) has been highly successful. Such technical problems as have cropped up, as in the case of overheating of components on the SPAS, have been minor and easily dealt with.
At this writing, officials of the National Aeronautics and Space Administration (NASA) were uncertain as to whether or not weather would permit a landing today at Cape Canaveral. However, they had ordered the astronauts to prepare to come down as planned.
One of three auxiliary power units (APU) also was malfunctioning. These units are turned on to power the Challenger's hydraulic system during takeoff and landing. At this writing, technicians were studying the problem to try to learn whether or not the unit would function on landing. Indications are that the trouble has not reappeared. There would be no danger to the Challanger if the unit did fail, however, since the other two units would provide adequate power.
Meanwhile, on orbit, Sally Ride has been exercising the McDonnell-Douglas electrophoresis experiment. This is a system in which electric force is used to separate different types of protein that are mixed together in a solution. It could be used to separate different blood factors, for example, or other biological materials important for drug manufacture.
Tests on two previous flights have shown that, working under low gravity conditions in space, such a unit can boost yield and purity of a separated protein by several hundred percent. Dr. Ride reported that she could see a clean separation into three different product streams once again.
McDonnell-Douglas officials have said that, if the present tests continue to support this production advantage, they expect to move ahead with a prototype factory unit. This would be tested on shuttle flights next year.
The officials have also said they hope to have a fully commercial automatic factory in space orbiting as an independent satellite sometime between 1987 to 1989.
Next year also, NASA officials have scheduled a mission to recover and repair the malfunctioning Solar Maximum Satellite. This is to be done during the 12th shuttle mission in April. (Originally this was the 13th mission, but the 10th mission - a military mission - has been canceled.) The maneuvers with the SPAS were important practice for this rescue attempt.
Thus, besides delivering two satellites to orbit for paying customers, the Challenger astronauts have prepared the way for major shuttle missions next year.
Meanwhile, Valentina Tereshkova of the Soviet Union, the world's first woman astronaut, congratulated her US counterpart Tuesday.
In a telegram to Dr. Ride, Miss Tereshkova wrote: ''Please accept my congratulations on your first space flight. . . . It gives me pleasure to know that a third representative of this planet's women, now from the United States of America, is in outer space today.''