Nasa will try to go back to Moon at end of September – but might not make it

Nasa is targeting 23 September or 27 September for the third launch attempt of the space agency’s Artemis I Moon mission, a pair of dates selected to avoid conflict with other Nasa missions and launches.

But those launch dates are tentative pending an important fueling test of the Space Launch System (SLS) rocket scheduled for 17 September, and a safety waiver from the US Space Force, which manages range safety at Cape Canaveral, Florida, according to Nasa Associate Administrator Jim Free.

Nasa first attempted to launch the SLS rocket on 29 August, but scrubbed that launch attempt due to weather concerns, a faulty valve and problems bringing one of the rocket’s engines to the proper preflight temperature. The second launch attempt on 3 September was canceled after a Nasa could not contain a leak in the interface between the liquid hydrogen fuel line and the rocket’s fuel tank.

Those issues that led to the scrubbing of the previous two launches have been addressed, according to Mr Free, including the replacement of a seal in the interface that led to the hydrogen leak on 3 September. But before Nasa can attempt another launch, he said, the space agency must test the seal in the interface by loading the rocket with liquid hydrogen fuel in a “tanking test.”

Nasa must also get a waiver from the US Space Force on a requirement to retest the batteries on the flight termination system aboard the SLS rocket. The proposed launch dates lie beyond the 25 day certification period on the batteries for the system, which is designed to protect the surrounding population from an errant rocket, and Nasa would have to roll the rocket back into the Vehicle Assembly Building to reset the batteries if not granted a waiver.

Should Nasa receive the necessary waiver and the tanking test prove successful, the 23 and 27 September launch dates were selected in order to thread the needle between other Nasa operations and missions, according to Mr Free. Nasa’s Crew 5 mission to the International Space Station is expected to launch from Cape Canaveral on 3 October, while the space agency’s Nasa’s Double Asteroid Redirection Test, or Dart, is expected to smash into an asteroid on 26 September.

“The 27th of September keeps us on the right side of Dart,” Mr Free said, “and then in advance of some other activities on the range that are scheduled for the 30th.”

Artemis I will be the first mission of Nasa’s Artemis Moon program, a program which aims to return humans to the lunar surface with the Artemis III mission scheduled for 2025. Artemis I is an uncrewed test flight of the SLS rocket and Orion spacecraft that will take astronauts to lunar orbit, the pair functioning similar to the Saturn V rocket and Apollo spacecraft of the 1960s and 1970s.