NASA has again delayed its planned launch of the uncrewed lunar mission Artemis 1 by at least a month. The space agency had initially targeted the launch of the mission on February 12, 2022, but issues in the integrated testing programme have forced another schedule delay. The space agency has said it is now looking at launch opportunities in March and April. The Artemis programme aims to return astronauts to the Moon’s surface later this decade for a sustainable presence in a bid to reach Mars in the 2030s.

Artemis 1, which was first scheduled to launch by the end of this year, will also be the first flight of NASA’s new Space Launch System (SLS) megarocket. At least two more flights are planned under the programme. Artemis 2 is set for 2023 and Artemis 3 for the following year when humans will walk on the Moon for the first time since 1972. But the repeated delays in launching Artemis 1 is likely to push back the next two missions.

NASA said in a blog post that its engineers have detected a problem with one of the engine flight controllers. They performed a series of inspections and troubleshooting but finally decided to replace the engine controller. “NASA is developing a plan and updated schedule to replace the engine controller while continuing integrated testing and reviewing launch opportunities in March and April,”  the agency said.

The SLS rocket consists of a core booster and four RS-25 engines, each with an independent flight controller which NASA describes as the “brain” of the engine. And even a minor glitch in the “brain” can cause big problems for the space agency. NASA engineers, however, are continuously testing the SLS rocket and the Orion spacecraft at NASA’s Kennedy Space Centre in Florida, US.

Once all the final tests are done, rocket engineers will conduct a “wet dress” rehearsal, during which crews execute each step of launch preparations, including filling the rocket with propellant.