Launch from Cape Canaveral; landing 850 km east of Florida in the Atlantic Ocean.

The main objectives of this mission were again to dock with the Agena target vehicle and to perform a spacewalk. The mission patch was drawn by Barbara Young (John Young's wife at the time).

The docking with the unmanned Agena target vehicle GATV-10 was successfull, even it was need more fuel than planned. So, planned more docking and redocking maneuvers were not performed. During the docking the GATV-10 primary propulsion system was used to raise the dual spacecraft apogee to 764 km (a new record).

Two EVAs were performed by Michael Collins. The first was a standup-EVA on July 19, 1966 (0h 38m) and Michael Collins began photographing stellar UV radiation. After more 44 hours the Gemini spacecraft separated from the GATV-10. The Gemini used its own thrusters to complete the second rendezvous some three hours later with the GATV-8 target vehicle. After a couple more correction burns they were station keeping 3 meters away from the Agena. Then the second EVA on July 20, 1966 (0h 49m) was performed by Michael Collins. First he retrieved a micro meteorite experiment mounted on the Gemini 10 spacecraft, but he lost it, when it floated out of the cabin during the EVA. He then walked from the Gemini spacecraft to the Agena target vehicle to retrieve the second micrometeorite package left in space all those months. While doing this he lost grip in space walk from Gemini to Agena, tumbled head over heels at end of umbilical around Gemini. Michael Collins needed a second attempt using the hand-held gun to turn back to the Agena, save the package and retrieved it. Returning into the capsule was difficult, because Michael Collins had gotten himself tangled in the umbilical. During this EVA he lost his camera.

The crew performed all in all 14 experiments, including experiments to test the radiation, a navigation experiment and others. The reentry was performed without any problems. The recovery ship was the USS Guadalcanal.