CAPE CANAVERAL, Fla. Shuttle Atlantis will remain in its cavernous Kennedy Space Center assembly building for cable repair work over the holidays, triggering at least a few days' delay in its planned launch next month.

Atlantis and a crew of five astronauts had been scheduled for launch Jan. 18 on a mission to deliver the U.S.' Destiny science laboratory to the International Space Station.

That target date, however, will be pushed back at least two or three days so technicians can repair a damaged cable that plays a key role in the shuttles booster-separation system.

A more significant launch delay, however, likely will be avoided because NASA engineers now think the damaged cable can be either repaired or replaced without disconnecting Atlantis from its 15-story external tank and attached solid-fuel rocket boosters.

Doing so would have resulted in a launch delay of at least a week or more.

"Thats not an option that is being discussed at this point," KSC spokesman Joel Wells said Tuesday.

The repair work in the assembly building was ordered after NASA engineers discovered a damaged electrical cable designed to route computer commands to small explosive devices used to separate the shuttles rocket boosters from its external tank during flight.

The faulty cable was found during an investigation into problems that cropped up with shuttle Endeavours booster-separation system during its Nov. 30 launch.

One of two explosive cartridges used to separate a lower strut holding Endeavours left-hand solid rocket booster to the shuttles 15-story fuel tank failed to fire during that flight. A back-up detonator did fire, though, and the booster separated cleanly from the external fuel tank.

Had both explosive cartridges failed, however, Endeavour and its crew could have been lost.

Engineers traced the Endeavour problem to a damaged cable, and then ordered tests and inspections on the two boosters that will help propel Atlantis and its crew into orbit.

One of the cables associated with the same lower strut on Atlantis left-hand booster then failed a signal-relaying test last weekend.

Further inspection showed that the woven metal shielding designed to protect electrical connectors within the cable had hardened and consequently, was susceptible to breaking.

An attempt to repair the cable began Tuesday. If that doesnt work, then NASA plans to replace the damaged cable with a spare.

As it stands, Atlantis is tentatively scheduled to be moved from the assembly building to its seaside launch pad on Jan. 2. A more definitive launch date will be announced after the cable repair work or any replacement effort -- is completed.

"Were assessing a new launch date at this point," Wells said. "A few days past Jan. 18 is how it is being characterized right now."

The launch delay is the second in as many weeks for NASAs shuttle program.

A planned Feb. 15 launch of shuttle Discovery and a fresh space station crew already has been delayed until March 1 so technicians could replace faulty shuttle jet thrusters.

Consequently, a planned Feb. 26 return to Earth for the three-man crew now working on the station now is being postponed until March 13.