US space agency Nasa will carry out an engine test on the world's most powerful rocket on Thursday, part of a larger plan to establish a base on the Moon by 2030.
This is the second core stage test of the Space Launch System (SLS). The first one in January ended prematurely after a problem with the hydraulics system.
The "Green Run hot-fire test" at the Stennis Space Centre in Mississippi will measure the performance of the giant rocket’s four engines.
If successful, it will help Nasa set a launch date for the Artemis I mission – an uncrewed test flight around the Moon that will check performance, life support and communication capabilities.
The initial launch date was scheduled for November 2021, but there could be a delay depending on the outcome on Thursday.
"Nasa's SLS rocket is the most powerful rocket in the world, built to send both astronauts aboard Orion [spacecraft] and supplies on missions to the Moon and beyond," Nasa said.
“The Green Run is a comprehensive test of the SLS core stage, a complex new rocket stage that not only includes four RS-25 engines and enormous propellant tanks that hold more than 700,000 gallons [2.46 million litres] of super-cold propellant, but also flight computers and avionics that control the first eight minutes of flight.”
When the engines fire, the test will simulate the core stage’s operation during launch, generating 725,474 kilograms of thrust.
The window for the test opens at 11pm tonight, Gulf Standard Time.
The Artemis programme
Nasa launched the programme to establish a human base on the Moon, a stepping stone to sending astronauts to Mars.
The space agency revealed plans for three Artemis missions under the programme.
It involves the development of the Lunar Gateway – a research station that will orbit the Moon.
If the Green Run test on Thursday satisfies Nasa, the core stage of the rocket will be shipped to the Kennedy Space Centre in Florida for integration with the Orion spacecraft.
The Artemis I mission will take off this year and pave the way for future crewed lunar missions.
Human beings have not been to the Moon since the last Apollo lunar mission in 1972.
The second flight will send the next man and first woman to the Moon by 2023. The crewed Orion spacecraft will do a flyby.
Nasa will conduct additional tests before launch, because astronauts will have to manually pilot the Orion for part of the flight.
The manual piloting will help the agency to assess the spacecraft’s hardware and software performance.
Astronauts will land on the lunar South Pole in 2024.
They would either directly board a commercial human landing system or dock to the Gateway after arrival.
Three commercial space companies – SpaceX, Blue Origin and Dynetics – are building human landers for the Artemis programme under a contract awarded by Nasa.
Astronauts will spend nearly seven days collecting samples and conducting science experiments on the surface. They will then use the Orion to return to Earth.