Four days in orbit and a manual landing

Gemini 4 spent 4 days, 1 hour, 56 minutes and 12 seconds in orbit — the longest American flight to date, an important step toward multi-day Apollo missions. The spacecraft completed 62 revolutions (66 by an alternate count relative to Cape Kennedy).

On the 48th revolution the onboard guidance computer failed when McDivitt tried to update it — it would not shut down and eventually stopped working altogether. The planned closed-loop lifting reentry was therefore impossible, and the crew had to switch to a simpler, open-loop rolling reentry in the Mercury style.

A malfunctioning thruster caused a faster-than-planned roll rate, making the descent rougher than expected — the crew was unharmed. The capsule splashed down in the Atlantic 80 km (50 miles) short of the planned target on June 7, 1965, at 17:12:11 UTC (27°44′N, 74°11′W), and was recovered by the aircraft carrier USS Wasp.