Shuttle Liftoff Date Due Soon

CAPE CANAVERAL, Fla. — The space agency, trying to minimize the impact of Challenger’s last-second launch abort, decided today to press for a second launch attempt at the end of July and to delay two other flights, officials said.

NASA spokesman Charles Redmond said a firm launch date is not expected until July 23 when Challenger’s three main rocket engines, which fired up and shut down Friday during the abort, will be evaluated. But various sources said the shuttle cannot be readied for blastoff until at least July 27.