A leaky oxygen valve in ground equipment slowed countdown preparations Monday , but officials said the lost time would be recouped to keep work on schedule for the maiden launching of the space shuttle Columbia Friday. The flight will make John Young and Robert Crippen the first Americans in space since 1975.
The leaking valve was found when technicians were checking pipes between the launch pad and ground storage tanks. The pipes will be used to feed hydrogen and oxygen to the Columbia's fuel cell generators. The valve was replaced, but a space agency spokesman said the problem delayed work by about three hours.