What are the main contents of Gemini project in America?

One of the main contents of "Gemini" plan is to realize spacewalk. Considering that designing another transition module for spacewalking will inevitably increase the weight and volume of the spacecraft, the designers of NASA adopted a simplified design, without installing a special transition module for extravehicular activities, and directly used the cockpit as the transition module.

There is a rectangular hatch on the side of Gemini spacecraft, which has excellent sealing performance and can be opened and closed in space. When performing extravehicular tasks, astronauts first reduce the oxygen pressure in the cabin and use the oxygen supply system of the spacesuit to breathe. When the hatch is opened, the oxygen in the cabin is lost and the activity outside the cabin is carried out. When returning to the cabin after completing the mission, close the hatch and release oxygen again to pressurize the cabin.

In the way of recycling, the spacecraft dropped the equipment cabin on the track before returning, then ignited four thrust braking rockets in the engine compartment, pushed the spacecraft into the loading track, and finally dropped the engine compartment. The cockpit re-entered the atmosphere alone like a mercury spacecraft, and when it descended to a low altitude, the parachute was opened, and the astronauts splashed down on the sea together with the cockpit.