They opened a new era

Five hard-working astronauts and their shuttle Challenger have opened a new era in space flight. For the first time, a free-flying satellite has been deployed, manipulated, and retrieved by a ''mother ship.'' This foreshadows the space engineering of the future when the shuttle and its successors - including vehicles based at orbiting space stations - will routinely service a variety of satellites and robot space factories.

For the first time, also, a US woman astronaut has experienced the challenge and the adventure of orbital flight. This in itself is a significant breakthrough.

Yet one should remember that Dr. Ride won her place on the Challenger crew because of special skills and competence. These were exemplified in her handling of that satellite deployment and retrieval. It was an operation requiring a high degree of both individual ability and teamwork. Dr. Ride and her colleague John Fabian, another mission specialist, had to work closely with mission commander Robert Crippen and shuttle pilot Frederick Hauck. They maneuvered Challenger while the Shuttle Pallet Satellite was deployed and recovered using a manipulator arm.

Thus the US Space Transportation System - the shuttle, the astronaut team, and all the ground support - is emerging as a working industrial unit. The pioneering days, when the space experience itself was the object of the mission, are over. Much still is to be learned. But the role of humans in space will be increasingly justified by the work they do.

Herein lies the United States's real challenge in space.

Europe's Ariane launch vehicle and even the Soviet Proton rocket will give the shuttle strong competition for the business of launching commercial satellites. The shuttle also can retrieve and, if necessary, repair a satellite that already is in orbit. This is a distinctive advantage, but one whose commercial value is uncertain.

For commercial success, the shuttle system must provide reliable and frequent launching services at a price customers will pay. Here the shuttle's future is not at all clear, in spite of seven successful missions. A National Research Council (NRC) study has warned that shuttle logistics - provision for servicing, spare parts, booster rockets - have been inadequately planned. This, plus lack of a fifth shuttle orbiter, will make it impossible to meet the National Aeronautics and Space Administration's official goal of 24 shuttle launches a year by 1990, the NRC study said.

While NASA has asked for a fifth orbiter, neither Congress nor the administration has indicated a willingness to fund it. NASA is beginning to pull its logistics planning together. But here also there is no certainty the shortfalls in parts and boosters can be met. Thus, while the continuing success of the shuttle missions deserves praise, the United States still has to prove to itself, and to potential shuttle customers, that it soon will have a truly viable Space Transportation System.