Damaged wire found on Endeavour, affect on launch uncertain

Endeavour at Cape Canaveral

February 8, 2000
Web posted at: 11:37 a.m. EST (1637 GMT)

By CNN Space Correspondent
Miles O'Brien

CAPE CANAVERAL, Florida (CNN) -- Technicians preparing the space shuttle Endeavour for a Friday launch discovered a damaged sensor wire at the base of one of the solid rocket boosters. It is unclear if the repair will prompt another launch delay for the radar-mapping mission.

"Engineers at the pad are assessing the situation right now," said NASA Launch Director Scott Lyons at a Tuesday news conference. "The damage is not significant and we should be able to correct it with tape."

If that is the case, the repair would have not affect the launch schedule. But if engineers determine the wire needs to be replaced, "it would jeopardize our (launch) attempt on Friday," said Lyons.

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The wiring harness is attached to a sensor that tells launch controllers if pyrotechnic devices that cause the boosters to separate from the shuttle are "armed" or in "safe" mode. The shuttle cannot launch if the sensors -- or their wiring -- fail to operate during the countdown.

The weather outlook is favorable for the first launch attempt, a roughly two-hour period that begin at 12:30 p.m. EST on Friday. Meteorologists predict only a 1 in 5 chance that weather will keep Endeavour on the ground. However, there is some concern about predictions of gusty winds if the shuttle is forced to make an emergency landing at Cape Canaveral.

Should the shuttle not launch on Friday, NASA will try again about 24 hours later, but the weather is forecast to worsen significantly. Meteorologists predict a 70 percent chance that clouds, rain and wind will make conditions unfavorable for a shuttle launch on Saturday and Sunday.

The six person multinational crew of Endeavour arrived at Cape Canaveral on Monday. They are slated to fly an 11-day radar-mapping mission that will create an unprecedented 3-D map of more than 70 percent of the Earth's surface. The $600 million mission is spearheaded by the Pentagon.

The mission was originally scheduled to fly in September, but was delayed after NASA ordered a wiring inspection and repair campaign for the entire shuttle fleet. The work was prompted by a short-circuit six seconds after the liftoff of Columbia in July. The short left the shuttle one failure away from losing an engine.

The wire that is the focus of concern then was checked during the inspection campaign, and again prior to the last launch attempt. As a result, NASA is surmising the damage happened over the past week.

NASA re-scheduled the launch of Endeavour to January 31. That countdown was plagued by bad weather and a technical problem. A Master Events Controller -- which relays commands from the shuttle's on-board computers to the pyrotechnics on the rocket boosters and the external fuel tank -- flunked a safety check during the countdown.

Although it subsequently worked, NASA decided to replace the 65-pound box, which led to a one-week delay. An unmanned launch of a Titan rocket at the Cape moved Endeavour's next launch attempt to Friday.

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