The Gemini had two major units. The reentry module held the crew cabin and heat shield. Behind it was the adapter, which consisted of two sections. The equipment section carried fuel, oxygen, and power supplies. The retrograde section carried retrorockets that slowed the spacecraft to make it fall out of orbit. Using small rockets on the adapter, the astronauts could not only change their orientation in space, but also their orbital path. Gemini was the first manned spacecraft that could alter its orbit during flight.
The adapter sections were discarded before reentry. The nose (rendezvous and recovery section) came off when the main parachute was deployed. The cabin section splashed down horizontally, with the two hatches on top.