NATIONAL BRIEFING / FLORIDA

NASA delayed next week’s launch of the space shuttle Discovery while it runs tests to determine whether newly installed valves would cause serious damage if they broke during liftoff.

The launch will take place no sooner than Feb. 19, seven days after the shuttle had been scheduled to leave on a space station construction mission. The delay is needed to make certain that Discovery can fly safely with the valves that control the flow of gaseous hydrogen into the external fuel tank, NASA’s space operations chief, William H. Gerstenmaier, said at Cape Canaveral.

At the space station, meanwhile, a two-minute engine firing Jan. 14 caused the outpost to shake as never before. It was supposed to be a routine procedure to raise the altitude of the station; this time, though, there were errors in the firing commands sent up by Russian flight controllers outside Moscow.

NASA’s space station program manager, Mike Suffredini, said although the vibration exceeded acceptable limits, no structural damage occurred. Engineers also have determined that the 15-year design lifetime of the station is not in jeopardy, he said.