SpaceX is lining up what could be the most jaw-dropping test in Starship’s history: refueling one giant spacecraft with another while both circle the Earth. The company is targeting the first half of 2027 for the first orbital docking and refueling demonstration, and NASA planning slides shared at the International Astronautical Congress reportedly point to the first quarter, which would leave room for a launch as early as February. According to the plan, a “target” Starship goes up first and waits in orbit, then a second “chaser” ship follows about three to four weeks later, finds it, docks and pumps super-cold liquid oxygen and methane across. Nobody has ever moved that much cryogenic propellant between two spacecraft in orbit, and one big worry is how much of it boils away during the wait. The date is not set in stone, because the test was first planned for 2025, then 2026, and has slipped before.

The stakes are enormous because Starship cannot reach the Moon or Mars on a single tank. NASA’s inspector general has said a lunar landing mission would need more than ten tanker flights to top off the lander in orbit, and the amount of fuel needed for Mars is even bigger. SpaceX is under pressure to prove the technique after Starship reached orbit for the first time on its 14th test flight, and NASA is counting on it for Artemis, with a crewed landing now eyed for early 2028. If the demonstration works, it would prove that a rocket can be refueled in space like a plane in the air, which could change how far and how cheaply humans can travel beyond Earth. If it fails, it could push the Moon landing back again and raise fresh doubts about Mars plans. For now, the world is waiting to see whether two of the biggest spacecraft ever built can meet, dock and share fuel without a hitch.