• Florida blast-off had been targeted for Monday
• Artemis program seeks to return humans to moon, perhaps by 2025
• Program is successor to Apollo moon missions 50 years ago

(Reuters) – An engine-cooling problem forced NASA on Monday to postpone for at least four days the debut test launch of the colossal new rocketship it plans to use for future astronaut flights back to the moon, more than 50 years after Apollo’s last lunar mission.

Senior NASA officials declined to set a precise time frame for retrying a launch of the mission, dubbed Artemis I. But at a news briefing hours after the aborted countdown they said a second launch attempt was still possible as early as Friday, depending on the outcome of further data review.

If engineers can resolve the issue on the launch pad in the next 48 to 72 hours, “Friday is definitely in play,” Michael Sarafin, NASA’s Artemis mission manager told reporters.

The mission calls for a six-week, uncrewed test flight of the Orion capsule around the moon and back to Earth for a splashdown in the Pacific.

The planned journey will mark the kickoff of NASA’s highly vaunted moon-to-Mars Artemis program, the successor to the Apollo lunar missions of the 1960s and ’70s.

A problem surfaced just ahead of Monday’s planned launch of the Space Launch System (SLS) as its fuel tanks were being filled with super-cooled liquid oxygen and hydrogen propellants at the Kennedy Space Center in Cape Canaveral, Florida.

Launch teams began a “conditioning” process to chill the engines sufficiently for liftoff but one of the four main engines failed to cool down as expected, NASA said. The launch was called off two minutes after the targeted launch time, as the 32-story-tall, rocket and its capsule awaited liftoff.

Late-hour launch postponements are routine in the space business, and Monday’s was not in itself an immediate indication of a major setback for NASA or its primary contractors, Boeing Co (BA.N) for SLS and Lockheed Martin Corp (LMT.N) for Orion.

“We don’t launch until it’s right,” NASA chief Bill Nelson said in a webcast interview just after the liftoff was scrubbed. “It’s just illustrative that this is a very complicated machine, a very complicated system, and all those things have to work. And you don’t want to light the candle until it’s ready to go.”

Still, the delay was a disappointment to thousands of spectators who had gathered on the shores around Cape Canaveral, with binoculars in hand.

Vice President Kamala Harris had just arrived at the space center, joining a throng of dignitaries and invited guests attending the event, shortly before the scrub was called.

SOURCE REUTERS, Read more..