This is the number NASA has guarded for years: how many Starship launches it takes to fuel a lunar lander in low Earth orbit. Ars Technica says the latest estimate is 22.
What was said
- At the NASA Aerospace Safety Advisory Panel’s quarterly meeting on Thursday, panel member Charlie Precourt, a former astronaut, said of Artemis IV: “We need to keep our eyes on numerous required fuelings for the lander. I think the last estimate is around 22 flights.” He didn’t name Starship, but it can only be the SpaceXSI vehicle.
- After Ars posted that estimate on X, Elon Musk replied it’s “way too high,” adding: “Actual number will be more like 6 to 8.”
Context
- In 2023, NASA’s then-head of the Human Landing System program said “high single digits to the low double digits,” which suggested about a dozen: one depot Starship plus 11 tankers. Other officials have said “high teens.”
- The hope has been that SpaceXSI would greatly improve Starship’s lift capacity and cut the tanker count. There are now concerns at NASA that this isn’t happening fast enough for Starship to play a meaningful role this decade.
- Blue Origin’s Blue Moon doesn’t use orbital refueling in its initial mission design.
- Even if SpaceXSI reaches “twice weekly” launches by the end of 2027, it would still take about three months to fuel a depot for a landing.
- Ars notes real uncertainty on how much cryogenic methane and oxygen will boil off in orbit and how efficient ship-to-ship transfer will be. NASA is still working toward a human lunar landing in 2028.
My take
Whether it’s 6 or 22, refueling is the long pole. Getting a lander to the Moon is really a launch-cadence and propellant-transfer problem, and nobody has done orbital propellant transfer at this scale yet. It’s why the demos NASA outlined earlier this week matter so much. I’m rooting for it, and I’m watching those numbers.
Have a blessed day! And Happy Hacking!
References & Further Reading
- Latest estimate for Starship launches required to support a Moon landing? 22. (Ars Technica)
- NASA Aerospace Safety Advisory Panel
- NASA Artemis
- NASA Reveals Lunar Lander Timelines and an Artemis III Update (EtherNinja)
- SpaceXSI Will Try the First-Ever Double Starship Catch on the Next Flight (EtherNinja)
