Florida landing keeps NASA's tight shuttle schedule on track

Feeling ''on top of the world'' after those spectacular space walks and a perfect landing at Cape Canaveral, the space shuttle team is ready to rescue an ailing satellite next April.

The launch-site landing has cut six to eight days off the turnaround time of the space ship Challenger - a critical savings. There are about three days in April suitable for launching the rescue mission. Had Challenger landed in California, that mission probably would have been postponed at least till late May.

Now, according to Lt. Gen. James A. Abrahamson, who directs the shuttle program, Challenger should be ready for an April 4 launch, as scheduled. Thus, in spite of disappointment over losing two satellites, General Abrahamson called the successful return to Cape Canaveral ''a superb end to a mission I'm very proud of.''

Engineers are still investigating the failure of solid-fuel booster rockets to place two communications satellites in their proper orbits. Astronauts had deployed the satellites properly. But the booster motors did not complete their burns.

Abrahamson said the trouble seems to have been traced to a batch of bad nozzle material. If that is all there was to the problem, the remaining boosters can be repaired, allowing future satellite deployments to proceed on schedule.

It is important for the National Aeronautics and Space Administration to maintain its schedule, now that the shuttle system has become operational. There is little leeway for slippage. NASA has eight more shuttle flights planned for this year. Then the launch rate rises, with 12 due in 1985 and 16 in '86. When four orbiters are available, NASA expects a rate of 24 launches a year by 1988.

This is why the landing at the Cape - a capability critical to a high launch rate - is considered the high point of the recent mission.

Nevertheless, for the five mission astronauts, the jet-powered, free-flying maneuvers of Robert Stewart and Bruce McCandless stole the show. ''I think we've been on top of the world since they (the jetpack tests) came off, because they were very exciting things to pull off up here,'' mission commander Vance Brand said. Asked what it was like to be a satellite on his own, astronaut Stewart said, ''My impressions were of the immensity of the entire universe . . . what a beautiful Earth, what a beautiful flying machine.''

Astronaut George Nelson will use one of the jetpacks in earnest next April to help retrieve the Solar Maximum Mission satellite. That satellite, which is in a 260-mile-high orbit, is spinning slowly. Astronaut Nelson has to dock with it and use his jetpack to stop the spin. Then the satellite can be brought into the shuttle bay, where Nelson and James van Hoften will replace faulty equipment on the $100 million vehicle.

In all, NASA has scheduled 42 astronauts, including six women, for missions this year. In August, Kathy Sullivan is to become the first woman astronaut to work outside a spacecraft, when she practices satellite refueling. She is teamed with Sally K. Ride, the first US woman astronaut to go into space.

Also, in June, the orbiter fleet will be expanded to three, when the Discovery makes its maiden flight. This will be the next opportunity for NASA to redeem its reputation as a commercial satellite launcher, if the booster trouble-shooting doesn't upset the schedule.