SpaceX is making progress on Starship in-space refueling technologies

WASHINGTON — NASA says SpaceX is on track to demonstrate spacecraft refueling next year, a technology critical to returning humans to the lunar surface using that vehicle.

Speaking before the Human Exploration and Operations Committee of NASA’s Advisory Board on April 26, Amit Kshatriya, deputy associate administrator for NASA’s Moon to Mars Program, said SpaceX made one step closer to refueling the Starship with a demonstration on the latest Starship test flight. On March 14th.

During that flight, SpaceX conducted a demonstration of transporting propellant on board under the Tipping Point contract awarded by NASA in 2020. SpaceX planned to transfer at least 10 metric tons of liquid oxygen from a vertical tank to the main tank inside the vehicle’s upper stage spacecraft while in the spacecraft. space.

While SpaceX said on the day of the flight that it had conducted the demonstration, neither the company nor NASA have provided any updates since then. But at the advisory committee meeting, Kshatriya said the testing appeared to be going well.

“On Flight 3, they transferred refrigerated material between tanks, and that was successful by all standards,” he said, adding that test analysis is ongoing.

The next major event is a demonstration scheduled for 2025 in which two spaceships will be docked in orbit, one transferring propellant to the other. Plans for that have gone through a flight system review, according to a slide he presented at the meeting, which examined the overall mission architecture and key subsystems, among other topics.

In that mission, the “target” spacecraft will be launched first and go into orbit, followed three to four weeks later by the “chase” spacecraft. The two vehicles will dock with the chaser, which will deliver the propellant to the target. After the demonstration, the two spacecraft will deorbit and deorbit.

SpaceX has some work to do before this test, Kshatriya said, including understanding the flow of propellant in the tanks during spacecraft maneuvers as well as how much “leveling thrust” is needed once the vehicles are docked to ensure propellant flows between them.

“The goal of their flight test program before we do this is to make sure they fully understand the slow dynamics, they fully understand how to maintain the final shape, what the stability thrust should be,” he said. We have gone through it with them regarding their plan for this. It’s a good plan.”

The propellant transport technology is essential to SpaceX’s plans for Starship missions beyond low Earth orbit, including the Human Landing System (HLS) version of Starship that will be used to land astronauts on the Moon starting with the Artemis 3 mission, currently scheduled no later than September 2026. Multiple spacecraft launches will transfer the propellant to a depot in low Earth orbit that will then be used to fuel the HLS spacecraft, sending it to the Moon.

The exact number of refueling launches has been a matter of debate, with estimates reaching approximately 20. Kshatriya did not mention a number of launches in his presentation, suggesting that more work needs to be done to better understand the refueling process.

He said the company is working to understand factors such as propellant boiling and leakage, as well as how much fuel can be effectively transferred from the spacecraft. “These are all things they know are in front of them, but all these are things that are in the plan that will be described,” he said. “This will derive the answer.”

Propellant transport testing in space will be followed by an unmanned HLS Starship test mission, including fueling the vehicle and sending it to the Moon for landing. This mission will also include an “ascension demonstration” that was not originally included in the plan, to prove that the spacecraft can lift off from the lunar surface, he said.

“Full and rapid reuse of boosters and ships and orbital refilling of the ship are the two core technologies we aim to solve by the end of next year,” SpaceX CEO Elon Musk said. Posted on social media April 26 In response to another post about the Kshatriya show. “Those are the critical pieces necessary to make life multiplanetary.”

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