This market resolves YES if any organization successfully demonstrates a ship-to-ship transfer of cryogenic propellant in orbit before January 1, 2027 ("on orbit refueling"). Only fuel transfer between two separate free-flying spacecraft qualifies as such, not internal tank-to-tank on a single vehicle.

Candidates that would qualify:

• SpaceX's Starship "Chaser"/"Target" propellant transfer demo (NET Q4 2026 as of Sept 2026)

• NASA/Rocket Lab's Eta Space LOXSAT cryogenic fluid management mission, if it completes an inter-spacecraft transfer within the window

• Any other national space agency or company demonstration meeting the ship-to-ship criterion

This market resolves NO if:

• Only intra-vehicle transfer (tank-to-tank on the same spacecraft) is demonstrated

• Only ground/lab-based cryogenic transfer tests occur

• The demo launches but fails to complete a propellant transfer before Dec 31, 2026, 23:59 UTC

Resolution source: Official statements from SpaceX, NASA, or the relevant operator; credible spaceflight trade press (SpaceNews, NASASpaceflight, Ars Technica) confirming success or failure of the specific milestone.