Elon Musk‘s giant Starship rocket will need up to 22 refueling missions in space in order to make it to the Moon, according to some estimates.
SpaceX is developing the world’s biggest rocket to be operational for Nasa’s Artemis III mission next year, which will test in-orbit docking with a crewed spacecraft.
The US space agency then hopes to use Starship to send astronauts to the Moon in its Artemis IV mission in 2028.
In order to do this, Starship will need to refuel in orbit – a feat that has never before been attempted – multiple times.
A recent estimate from Nasa’s Aerospace Safety Advisory Panel put the number at 22 in-orbit refuelings before Starship has enough fuel to make the onward journey to the Moon.
A Nasa illustration showing Starship refueling for the Artemis IV mission in 2028 (Nasa)
Mr Musk disputed this figure, though said in a post to X that multiple refueling missions would be needed.
“Actual number will be more like 6 to 8,” the SpaceX boss wrote in a post to X.
The plan involves sending a Starship rocket into orbit to serve as a fuel depot.
Subsequent Starship rockets will then be sent up to dock with it and load it up with fuel.
A final Starship will then launch and fill up with the fuel needed to carry the astronauts to the Moon and back.
SpaceX could test aspects of the in-orbit propellant transfer in its upcoming Starship flight test, which is expected to take place next week.
The company is also preparing for a “profound technology milestone” by catching both parts of the rocket during Starship Flight 15.
“Success is not guaranteed on these first flights, but I’d say it’s more likely than not that this succeeds,” Mr Musk said last month.
“If not, we have a steady stream of Starship flight attempts through the end of this year and then accelerating next year.”
Nasa’s concept of operations for the four-person Artemis III mission in 2027 (NASA)
The Artemis III mission will see Starship attempt to rendezvous and dock with Nasa’s Orion spacecraft, which will be carrying four astronauts.
The mission will also see the astronauts dock with a lunar lander test vehicle developed by SpaceX rival Blue Origin.
If successful, Nasa will then attempt to deliver astronauts to the surface of the Moon using either SpaceX’s or Blue Origin’s rocket as part of its Artemis IV mission in 2028.
“For the agency’s Artemis IV mission in 2028, astronauts will launch aboard Orion on the SLS rocket from Nasa’s Kennedy Space Center in Florida,” Jonathan Deal, Nasa’s public affairs officer, said on Wednesday.
“Nasa is working with SpaceX and Blue Origin to develop lunar landers to carry those astronauts to the Moon’s surface… SpaceX’s Starship will refuel in Earth orbit, rendezvous with Orion, and then carry the spacecraft toward the Moon.”
