SpaceX to Attempt Daring Orbital Refueling Test of Starship

By early next year, SpaceX may be ready to have two of its Starships rendezvous in orbit for an ambitious refueling test that will determine the spacecraft’s potential for deep space missions.

During a recent interview with Spaceflight Now, Kent Chojnacki, the deputy manager for NASA’s Human Landing System program, revealed that Starship’s in-flight propellant test is scheduled to take place in March 2025. The orbital demonstration is a major step for Starship, and a crucial part of SpaceX’s capability of delivering NASA’s Artemis mission to the Moon.

SpaceX is under a $53.2 million contract with NASA, signed in 2020, to use Starship tankers for in-orbit propellant transfer. During its third test flight, SpaceX transferred around 10 metric tons of liquid oxygen from Starship’s header tank to its main tank while it was in space. The upcoming demonstration, however, requires a lot more of the launch vehicle. Two Starships will launch to low Earth orbit around three to four weeks apart, the spacecraft will meet and dock in orbit, and one will transfer propellant to another. After the demonstration, the two Starships will undock from one another and deorbit.

“Once you’ve done that, you’ve really cracked open the opportunity to move massive amounts of payload and cargo outside of the Earth’s sphere,” Chojnacki said during the interview. The in-flight propellant transfer tests are set to conclude in the summer.

With in-flight refueling, NASA is aiming to develop technologies to “enable long-term cryogenic fluid management, which is essential for establishing a sustainable presence on the Moon and enabling crewed missions to Mars,” the space agency stated when the contract was signed.

SpaceX is developing a version of Starship to land humans on the Moon in September 2026 as part of NASA’s Artemis 3 mission. To prepare for the Moon mission, SpaceX is expected to launch between eight and 16 propellant tanker Starships into low Earth orbit in rapid succession. Each of the tankers will carry around 100 to 150 tons of liquid oxygen and liquid methane and will dock with a larger fuel depot. The orbiting depot will then connect with the Human Landing System Starship, filling its massive 1,200-ton fuel tanks. Once refueled, the Starship lander will continue its journey toward the Moon.

The development of SpaceX’s Starship for NASA’s Moon missions has been under scrutiny for moving too slow, but the company has made some recent progress with its launch vehicle. In October, the rocket’s Super Heavy 232-foot-tall (71 meters) booster gently came down towards a special launch tower, which caught the massive launch vehicle in its arms to conclude its fifth test flight. Meanwhile, Starship’s upper stage completed its flight with a controlled splashdown in the Indian Ocean. For Artemis, the Human Landing System of Starship’s upper stage needs to be capable of performing a pinpoint landing on the lunar surface.

SpaceX still has a bit of work ahead of them before the company can launch a Starship to orbit and have it stay there, let alone sending two of them to space for a tricky fueling maneuver. The company is under pressure to deliver its part of the contract with NASA as the space agency pushes ahead to make its Artemis dreams a reality, and it’s hard to tell whether Starship will be ready to deliver by early next year.