Demonstrate ship-to-ship propellant transfer in Earth orbit
On-orbit refilling is the capability the Artemis lunar landing architecture depends on. SpaceX plans to launch one Starship, then launch a second to rendezvous with it and transfer propellant between the two.
In progress
What do the status labels mean?
Announced: it has been said out loud, but we have not seen work toward it yet.
In progress: we can point to tests, hardware or contracts that show work under way.
Partially achieved: part of the job is done and shown, but not all of it.
Achieved: evidence matches the whole “done” description we wrote down.
Uncertain: sources disagree or are missing. We say so instead of guessing.
Paused or cancelled: a reliable source says work has stopped or the plan was dropped.
Full definitions →- Said on
- 30 October 2025
- First target In plain English
What is a target window?
A target window is when the company said something would happen. Sometimes that is an exact day. Often it is only a month, a quarter or a year.
We keep it exactly as vague or as precise as the company did. If they said “2026”, we show 2026. We never turn that into a made-up day in December.
When a company gives a new date later, we keep the old one too. You can always see how the plan moved.
Saying “I’ll visit this summer” is a window. Saying “I’ll visit on 14 July” is an exact date. They are not the same promise.
- 2026Year precision, stated 30 October 2025
- Current target
- 2026Year precision, stated 30 October 2025
- Last checked In plain English
Who checked this, and how?
Each record has a review note. It names who did the check and lists every claim that was compared with its source.
Right now these checks were done with AI help and have not yet been re-read by an independent human editor. We say this plainly on every page rather than hiding it.
A “review due” label means the record is older than two weeks and is scheduled for another look. The content is unchanged until then.
- 13 October 2026Next review due 27 October 2026
What would count as “done”
Two Starships rendezvous in Earth orbit and transfer cryogenic propellant from one vehicle to the other, as recorded by SpaceX or NASA.
Why we say this
SpaceX describes preparatory work rather than a completed demonstration: approximately five metric tons of cryogenic propellant transferred between tanks within a single vehicle in space, activation of a hardware-in-the-loop testbed for the propellant transfer flight test, and V3 vehicles equipped with docking drogues, ship-to-ship propellant feed connections and DragonEye navigation sensors. The transfer between two vehicles has not been recorded as flown.
Stated uncertainty. The stated 2026 window has not been restated or withdrawn in the September 2026 update, which describes the first orbital propellant transfer as one of the new flight tests beginning with orbital missions. Flight 14 on 28 September 2026 reached orbit but did not attempt a transfer; the 2026 target window has eleven weeks left at this review.
How the date moved In plain EnglishWhat is a target window?
A target window is when the company said something would happen. Sometimes that is an exact day. Often it is only a month, a quarter or a year.
We keep it exactly as vague or as precise as the company did. If they said “2026”, we show 2026. We never turn that into a made-up day in December.
When a company gives a new date later, we keep the old one too. You can always see how the plan moved.
Saying “I’ll visit this summer” is a window. Saying “I’ll visit on 14 July” is an exact date. They are not the same promise.
What is a target window?
A target window is when the company said something would happen. Sometimes that is an exact day. Often it is only a month, a quarter or a year.
We keep it exactly as vague or as precise as the company did. If they said “2026”, we show 2026. We never turn that into a made-up day in December.
When a company gives a new date later, we keep the old one too. You can always see how the plan moved.
Saying “I’ll visit this summer” is a window. Saying “I’ll visit on 14 July” is an exact date. They are not the same promise.
- Stated 30 October 2025 · recorded here 30 October 2025 · current target2026 (Year precision)
First stated target window. SpaceX also stated that exact timing would be driven by how the Starship V3 flight tests progress.
What actually happened
SpaceX reports the transfer of approximately five metric tons of cryogenic propellant between tanks while in space, which it describes as providing key data for future full-scale propellant transfer operations. The observation date is the date of the company statement, not of the test itself, which the source does not date.
Sources In plain EnglishWhere does the evidence come from?
Every status links to the page we read. We record who published it, when, and which part of it supports the claim.
A company saying something proves that the company said it. It does not prove the thing is true. When we can, we look for a second voice: a regulator, a partner like NASA, or an exchange.
If a page disappears later, we flag it. A missing page is not proof that a claim was wrong.
Source rules →
Where does the evidence come from?
Every status links to the page we read. We record who published it, when, and which part of it supports the claim.
A company saying something proves that the company said it. It does not prove the thing is true. When we can, we look for a second voice: a regulator, a partner like NASA, or an exchange.
If a page disappears later, we flag it. A missing page is not proof that a claim was wrong.
Source rules →Who checked this In plain EnglishWho checked this, and how?
Each record has a review note. It names who did the check and lists every claim that was compared with its source.
Right now these checks were done with AI help and have not yet been re-read by an independent human editor. We say this plainly on every page rather than hiding it.
A “review due” label means the record is older than two weeks and is scheduled for another look. The content is unchanged until then.
Who checked this, and how?
Each record has a review note. It names who did the check and lists every claim that was compared with its source.
Right now these checks were done with AI help and have not yet been re-read by an independent human editor. We say this plainly on every page rather than hiding it.
A “review due” label means the record is older than two weeks and is scheduled for another look. The content is unchanged until then.
Claims we compared with their sources
What this check could not tell us
- AI-assisted review drafted on 14 October 2026 for owner approval before publication; not independent human review.
- Flight 14 outcomes rest on SpaceX's own mission page; no independent tracking or regulator source was checked for the flight.
- The 2025 Florida launch count comes from Launch Library 2, an aggregator, with the range operator's all-provider total as corroboration. SpaceX has published no year-end figure.
- Source pages were read through a browser on 13 October 2026 UTC (14 October in Sydney); accessedAt is normalised to 23:30 UTC.