Discovery's astronauts are heading for home with a record of 100 percent accomplishment. At this writing, they were buttoning down the shuttle and preparing to land at the Kennedy Space Center at an estimated touchdown time of 6:59 a.m. Eastern standard time.
They have successfully launched two communications satellites and, for the first time in space history, retrieved two ''lost'' satellites for return to Earth. It was a feat that ''ushers in a new era of insurance practice in space programs,'' according to James Barrett, president of International Technology Underwriters of Washington. He said that ''as insurers we . . . have gained confidence in the NASA space transportation system.''
The US Department of Defense (DOD) is unlikely to share that confidence, however. Weakening of the bonding of many heat-resistant tiles on Discovery's sister ship Challenger has delayed its DOD mission from Dec. 8 until late January.
And, as if to show there is an alternative to the shuttle, Western Europe's Ariane launcher system orbited two commercial satellites on schedule last Friday. This was the 11th launch of Ariane - the third purely commercial mission - since its first test some five years ago. It was designed and built by the 11 -nation European Space Agency. This time, it successfully orbited ESA's Maritime Communications Satellite, Marecs B-2, which will be stationed over the Marshall Islands in the Pacific Ocean. It also carried the Spacenet 2 communications satellite, which will be stationed above the Amazon River in Brazil. Its owner - GTE-Spacenet, a subsidiary of GTE Corporation - is Ariane's first United States customer.
Meanwhile, mission commander Frederick H. Hauck and his four fellow astronauts have, as of this writing, experienced an unmarred success with what flight director Jay Greene called ''the most challenging flight we've flown.''
Discovery's takeoff at 7:15 a.m. EST Nov. 8 was ''a very, very spectacular, successful launch,'' in the judgment of Tom E. Utsman, director of shuttle operations at the National Aeronautics and Space Administration (NASA). The launch had been delayed one day because of strong high-altitude winds. But that was well within the planned launch period.
The launch was timed to put the shuttle into the same orbital plane as that of the derelict Palapa B2 and Westar 6 satellites. These satellites were stranded in useless orbits when their payload assist module (PAM) booster rockets misfired. Hughes Aircraft Company, which built the satellites, lowered their orbits from an altitude of 650 miles to 225 miles to bring them within the shuttle's range.
Before rescuing the wayward satellites, Discovery's crew launched two commercial satellites - Canada's Anik D2 and Hughes Communications Services's Leasat 2. The latter is part of a communications network that Hughes has leased to the DOD. Both satellites were successfully orbited - Anik on Nov. 9 and Leasat on Nov. 10.
Then commander Hauck and shuttle pilot David M. Walker brought Discovery close to Palapa Nov. 12 so that Joe Allen - acting as a free-flying, jet-propelled astronaut - could fix a four-foot-long ''stinger'' in the satellite's PAM rocket nozzle. Then, with the help of astronaut Dale A. Gardner, he moved Palapa to the shuttle and prepared to stow it in the cargo bay.
The two astronauts were to attach a special fitting, which would allow Anna L. Fisher to grab the satellite with the shuttle's maneuverable arm. But an antenna fitting, which Hughes engineers had overlooked in their retrieval planning, prevented this. It took more muscle power than NASA had planned for the two astronauts to wrestle Palapa into place. They were aided by the fact that the 1,200-pound satellite is weightless on orbit. Although it still had the inertia of a massive object, it was relatively easy to move about.
When the astronauts retrieved Westar Nov. 14, the shuttle team had worked out a new procedure. This time, Dale Gardner flew over to secure the satellite while Joe Allen rode the mechanical arm. It was, he said, much easier to handle the object from that vantage point.
Insurance underwriters now have an opportunity to recoup some of their losses. Between them they paid out $75 million to Indonesia for Palapa B2 and $ 105 million to Western Union for Westar 6. In each case, that covered the $35 million cost of the satellite itself plus related expenses and loss of revenue. They have also paid $5.5 million to NASA for the retrieval and $5 million to Hughes for retrieval preparations. They will later pay Hughes to refurbish the satellites.