This was possible due to new fuel cells that generated enough electricity to power longer missions, a pivotal innovation for future Apollo flights, instead of the chemical batteries used on previous crewed spacecraft.

Command Pilot and Mercury veteran Gordon Cooper was the first person to fly two Earth orbital missions.

He and Conrad took high-resolution photographs for the United States Department of Defense, but problems with the fuel cells and maneuvering system forced the cancellation of several other experiments.

The cause was traced to improper gas levels in an oxidizer standpipe, and severe oscillations did not affect any subsequent Gemini flights.

Film of the launch revealed a series of unexplained light flashes in the first stage exhaust plume, but telemetry data failed to indicate anything that could have caused them.

Subsequent review of previous Gemini launches as well as film of Titan II ICBM tests also showed the presence of these light flashes.

This phenomenon was thought to be caused by duct tape securing desiccant bags to the turbine exhaust pipe.

The top half of the Titan II's first stage, comprising the nitrogen tetroxide tank and its surrounding fuselage, was found floating on the surface of the Atlantic Ocean and retrieved; it is now on display at the US Space and Rocket Center in Huntsville, Alabama.

The first major event on the mission was the ejection of the Rendezvous Evaluation Pod (REP) at 2 hours and 13 minutes into the flight.

While out of radio contact with the ground, the crew found that the pressure in one fuel cell had dropped from 850 to 65 pounds per square inch (5,860 to 450 kPa) 4 hours and 22 minutes into the flight.

The next day, flight controllers discovered another problem with the fuel cells: they were producing waste water not suitable for drinking, as it was too acidic, in 20% higher quantity than expected.

The cells discharged into a storage tank on board used for both potable and non-potable water, separated by a bladder wall.

In general, the fuel cells were successful at producing cool drinking water, but the astronauts reported that it had a high quantity of gas bubbles in it.

This condition was believed to be due to very low ambient humidity in the cabin causing the astronauts' skin to become dry and flaky.

Although the computer had worked perfectly, a programmer had entered the rate of the Earth's rotation as 360° per 24 hours instead of 360.98° See Sidereal day.

[12] This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration.