New delay for next space station launch; shuttle schedule also uncertain

September 30, 1999
Web posted at: 9:32 p.m. EDT (0132 GMT)

From Space Correspondent Miles O'Brien

ATLANTA (CNN) - During meetings in Moscow and Houston Thursday, NASA managers debated ever-changing launch schedules for the space shuttle fleet and the next piece of the international space station.

They decided that the Russian-built Zvezda Service module will be launched no sooner than December 26 -- more than a month later than the most recent projection.

The shuttle fleet's immediate future remains uncertain -- with a launch likely no sooner than November 21 -- as a pair of new problems join wiring as a source of concern among engineers. NASA had scheduled the Discovery launch for no earlier than November 19, but the flight team now is shooting for the date two days later to avoid the tail end of the Leonids meteor shower.

MESSAGE BOARD Space Shuttle

In Moscow, NASA and the Russian Space Agency engaged in high-level talks all through the day. A NASA source told CNN the U.S. team felt there were simply "too many open issues and too much work to do" to launch in mid-November as the Russians had hoped.

The Service module is at the Baikonaur Cosmodrome in Kazakhstan. Engineers are working on its computer system so it will be compatible with the computers on the U.S.-built Unity docking node, which was delivered in orbit last December by the space shuttle Endeavour.

Computers on the Russian module are made by the European Space Agency, and do not operate on the same computer language as the U.S. computers. So far, the computers are not communicating as well as they should.

In addition, Zvezda must be tested in a vacuum chamber for possible leaks -- and general functionality. That process could take as long as 10 days.

Photo showing the worn section of shuttle wiring and burn marks from the short

The launch window opens December 26 and closes on January 16. After that, sun angles will not be desirable for a daylight docking in space as the international space station passes over Russian ground stations.

Russian controllers will not attempt to dock Zvezda in darkness -- and cannot control the vehicle if it is not flying overhead.

A final decision on the launch date for this critical piece of the space station will be made at the end of October -- or in early November when the ISS partners hold a general design review in Moscow.

The Russians are apparently still insisting they could make the previous launch date of November 12, although that launch date likely also would have slipped forward to avoid the end of the Leonids. But NASA feels "that is pushing too hard -- and does not make sense."

Meanwhile, shuttle launch managers meeting in Houston and Florida assessed their launch-delay woes. Inspections and repairs to the wiring inside Discovery and Endeavour are still under way. In the case of Discovery, workers are nearing the "home stretch," but no one is certain when they will be finished.

So far, they have located about 100 dings that are deep enough to require a fix. As a precaution against future damage, they are wrapping the wiring bundles with Teflon and hard plastic. NASA believes the wiring damage was caused by workers either stepping on wires or by dropped tools.

In July, a damaged wire caused a short circuit that shut down a critical main engine controller. A redundant system saved the crew from losing an engine and perhaps having to fly a risky abort maneuver.

Meanwhile, a pair of problems loom as possible show stoppers. While inspecting the wiring, technicians discovered some corrosion on the aluminum foot restraint used by spacewalkers working at the end of the shuttle's 50-foot robotic arm. It is unclear how laborious this fix might be.

And they have discovered a leak of propellant used to fuel the so-called Orbital Maneuvering System, an engine that helps the shuttle fine-tune its orbit. The leak is apparently in a valve.

Depending on the nature of the problem, the inspection, which involves the use of an electronic sniffer to detect spilled propellant, could require extensive work dismantling the the OMS pods, which are located near the shuttle's tail. And if the problem does not appear to be isolated, it may prompt a fleet-wide inspection.

If that occurs, a NASA source said, "you can kiss shuttle flights goodbye for this year."

NASA mangers will meet again next Thursday. As it stands right now, they are aiming to roll Discovery out to the pad no later than October 22 for a November 21 launch.

Discovery is on tap to attempt the third Hubble Space Telescope repair mission. After a series of failures, the Hubble is down to only 3 operative gyros -- one failure away from becoming scientifically useless. Discovery's crew is slated to install new gyros.