15. Gemini X targeted two different vehicles for rendezvous
Gemini X followed the launch of an Agena Target Vehicle in July of 1966, docked with the ATV, and then used Agena’s engines to reach the highest altitude of any of the Gemini flights yet attempted, more than 400 nautical miles. Astronauts John Young, of corned beef sandwich fame, and Mike Collins, then undocked and maneuvered their spacecraft to join the dead Agena which had been docked with by Gemini VIII before that mission had to be aborted. After Gemini VIII returned to earth the ATV ground controllers continued to maneuver the vehicle until its fuel was expended. Gemini VIII had intended to retrieve experimental equipment from the vehicle before its emergency led to its hasty departure.
Gemini X rendezvoused with the dead ATV, but made no attempt to dock with the vehicle, which had no lights. Astronaut Collins left the spacecraft on an EVA (his second EVA of the mission) and went to the Agena, where he found difficulty obtaining handholds near the docking port. He was able to reach the upper portion of the ATV, which he later reported to be in good condition, and retrieved the micrometeorite collector which was to have been picked up by Gemini VIII. As with earlier EVAs on other missions, securing the hatch following the EVA was a problem, though this time it was because of the unwieldy fifty-foot umbilical Collins had used. The umbilical and chest pack required for the EVAs were later disposed of by ejecting them from the spacecraft into space.