NASA moonshot delayed until March by hydrogen fuel leaks

NASA’s astronaut moon mission has been postponed until at least March after hydrogen fuel leaks disrupted the countdown dress rehearsal for its giant new rocket.

CAPE CANAVERAL, Florida (AP) – The leaks are the same issue that pushed back the Space Launch System rocket’s maiden flight three years ago. That uncrewed test mission was delayed by months because hydrogen, an extremely flammable and hazardous fuel, was leaking.

"Actually, this one caught us off guard," NASA’s John Honeycutt said on Tuesday, shortly after the test was suddenly stopped at Kennedy Space Center.

Before the frustrating hydrogen leaks emerged, the agency had been aiming for a launch as early as this weekend, which would have marked humanity’s first journey to the moon in more than 50 years.

"When you're dealing with hydrogen, it's a small molecule. It's highly energetic and we like it for that reason and we do the best we can," Honeycutt explained.

Hydrogen leaks halt Space Launch System dress rehearsal

Officials said the delay of around a month gives the launch team time to carry out another fuelling test before sending the four-person crew – three Americans and one Canadian – on a flight around the moon. It remains unclear when the countdown dress rehearsal can be attempted again.

Managers said repairs to misshapen or damaged seals, or to other parts, should probably be possible on the launch pad. Taking the rocket back to the Vehicle Assembly Building would probably extend the delay further.

The leaks appeared at the start of Monday’s propellant-loading operation, then returned several hours later. They eventually stopped the countdown clocks with five minutes remaining. Controllers had hoped to reach the 30-second point, but the hydrogen escaping from the system went beyond safety limits.

NASA repeatedly paused the liquid-hydrogen flow – at minus 253 °C – to try to warm the connection between the rocket and its fuel lines, in the hope that any loose seals would reseat. The effort failed, as did changes to the hydrogen flow. Those adjustments had enabled the first SLS rocket to lift off without astronauts in 2022.

Artemis crew and the next moon launch attempt

With launch now ruled out until at least 6 March, commander Reid Wiseman and his crewmates received approval to leave quarantine in Houston. They will return to quarantine two weeks before the next launch attempt.

Wiseman wrote on the social platform X that he was proud of the way the dress rehearsal had unfolded, "especially knowing how challenging the scenario was for our launch team doing the dangerous and unforgiving work."

According to officials, the very cold conditions at the launch site neither caused the fuel leaks nor contributed to any other fault. Heaters kept the Orion capsule warm at the top of the 98-metre rocket, while continuous purging safeguarded the rocket and ground equipment.

Amit Kshatriya, NASA’s associate administrator, emphasised that the Space Launch System is "an experimental vehicle," and said more still needs to be learned. He added that the long intervals between fuelling tests and flights make matters more difficult.

"I'm just reminded again almost four days and 40 years from Challenger, nobody sitting in one of these chairs needs to be calling any of these vehicles operational," Kshatriya said at a news conference.

NASA’s lunar flight plans

NASA has only a limited number of days each month in which it can send a crew around the moon. It will be the first time astronauts have travelled there since 1972.

During the mission, which will last almost 10 days, the astronauts will not land on the moon or enter lunar orbit. Instead, they will assess life-support equipment and other essential capsule systems ahead of a lunar landing by another crew in several years.

NASA sent 24 astronauts to the moon during the Apollo missions of the 1960s and 1970s. Its newer Artemis programme is targeting new ground – the moon’s south polar region – and seeks to keep crews on the lunar surface for far longer periods.