Orbital cryogenic refueling

Can two spacecraft dock in orbit and move extremely cold liquid propellant from one to the other through an automatic connection?[1] [3]

A spacecraft leaving Earth orbit may need propellant delivered by a second vehicle. Can two orbiting spacecraft dock, connect their cold-fluid lines automatically and transfer usable liquid while controlling losses and pressure? The combined operation includes cooling the pipe and receiving tank, called chill-down, and managing where the liquid sits before and during transfer. A cryocoupler must make and break the sealed connection in space.[1] [2] [3]

Cold fuel has moved between tanks on one spacecraft. Connecting two vehicles and transferring it in orbit is the next distinct demonstration.[1] [2] [3]

Completed internal liquid-oxygen transfer informs fluid management. A ground liquid-nitrogen coupler test does not validate the complete interface with mission propellants in orbital conditions.[1] [2]

One spacecraft could bring fuel that another needs for a journey beyond Earth orbit.[1] [3]

Delivering propellant after launch lets a mission build its fuel supply from more than one vehicle before departing for the Moon or farther destinations. That mission benefit requires usable propellant in the receiving tank: successful docking alone, or a transfer inside one spacecraft, does not establish it. Testing the connection and fluid management together ties hardware progress to the fuel supply on which those mission designs depend.[1] [2] [3]