First spacewalk between spacecraft
Who
Michael Collins
What
first first
Where
Not Applicable ()
When

On 20 July 1966, US astronaut Michael Collins performed a spacewalk from Gemini 10 to the unmanned GATV-8 booster using a 50-ft tether and a Hand-Held Manoeuvring Unit. The two spacecraft were around 3 m apart at the time.

Gemini 10 tested orbital rendezvous and docking techniques necessary for the Apollo Program. Prior to launch, an unmanned Agena rocket booster (GATV-10) was sent into orbit first, as a target for astronauts John Young and Michael Collins. After successfully docking with GATV-10, they used it to raise their orbit and rendezvous with GATV-8, which was still in orbit following the aborted earlier Gemini 8 mission. Collins retrieved a micrometeorite collector from the hull of GATV-8 during one of two spacewalks during the mission.