Nasa Artemis I lunar mission’s Space Launch System (SLS) rocket has successfully completed first four Green Run tests for its 212ft-tall core stage.

During Test 4, an initial functional checkout of the main propulsion system components was conducted. It lasted for three weeks and involved the use of gaseous nitrogen and helium.

The test validated the command and control operability, including valve response, timing and more.

Engineers at Nasa’s Stennis Space Centre near Bay St Louis, Mississippi, also carried out leak checks on the core stage-to-facility umbilical fluid and gas connections.

SLS core stage main propulsion system manager Jonathan Looser said: “With test gases flowing through these many parts of a complex rocket stage, we expected the test team to encounter some issues.

“Historically, there’s never been a Nasa human-rated launch vehicle flown without one or more full-up tests before the flight, and they have all encountered first-time issues.

“As expected, we found a few with valves and seals and addressed them, and now we’re ready to complete the next four Green Run tests.”

The Green Run consists of a series of eight tests and around 30 firsts, including first propellant tanks loading, first flow through the propellant feed systems, the firing of all four engines for the first time, and more.

Engineers will move to the Green Run Test 5, where the stage thrust vector control system will be checked.

Nasa’s Artemis 1 is the first in a series of missions to enable human exploration to the Moon and Mars.

Last month, Nasa announced that the Mars 2020 Perseverance rover cleared its flight readiness review, marking a key milestone in preparation to its launch.