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.