Nasa is studying the results of a recent crucial test of its mega Moon rocket to see whether it is ready for launch this summer.
The 101-metre Space Launch System (SLS) was fuelled and a practice countdown was held on Monday, in a process known as a wet dress rehearsal.
But as the countdown fell 20 seconds short, it remains unclear whether the US space agency has acquired sufficient data to proceed with a launch.
The Artemis 1 mission will feature an uncrewed flight around the Moon and will measure the rocket and the Orion spacecraft’s performance before more flights under the programme can take place.
The ambitious programme aims to build a sustainable human presence on the Moon, including sending the next man, first woman and first person of colour to the lunar surface before the end of the decade.
Nasa edges closer to lift-off
During a virtual media briefing on Tuesday, Nasa officials said they were still analysing the data to establish the next steps.
This was the fourth testing rehearsal, with three others held in April that failed because of a hydrogen leak.
Charlie Blackwell-Thompson, Artemis launch director, said although all objectives were met during the recent test, “very few things” were left to work through.
“We learnt some things as part of our prior wet dress attempts,” she said.
“And those lessons were incorporated into our approach. We did have a couple of things and a couple of challenges that we worked our way through.
“But we did have some amazing milestones that we got through and it was the first time that we had fully loaded the SLS rocket core stage and the upper stage or interim cryogenic propulsion stage with both liquid oxygen and liquid hydrogen.”
Mike Sarafin, Artemis mission manager, said the team will now determine how to progress.
“We're going to take a little bit of time, step back and look to see what all that means moving forward,” he said.
“But we had a very, very successful test and the team itself, whether it was our industry partners, our engineering, technical, operations or the mission management team, demonstrated tremendous discipline, perseverance and fortitude discipline, because they worked quickly through each of the issues.”
Rocket could blast off within weeks
Nasa previously revealed several launch windows for the Artemis 1 mission.
It could blast off as soon as July 26 but there are many other possibilities from then until June 2023.
Whenever it may be, the SLS will eventually take off with 3,991 tonnes of thrust, soaring at speeds of 40,233 kilometres per hour in about eight minutes to reach space. It will deliver Orion into its intended orbit, where it will begin its journey towards the Moon.
The spacecraft will fly 100km above the Moon’s surface and then use its gravitation force to be captured into an opposite orbit about 70,000km from the Moon, where it will stay for six days to collect data and allow mission control to measure the spacecraft’s performance.
The launch of Artemis 2 is planned for 2024 and includes a crewed mission that will orbit the Moon.
Artemis 3, the first human lunar landing mission under the programme, has been delayed until 2025.