The Reaction Control Section of the Gemini two-man spacecraft held two rings of reaction-control thrusters and tanks for the hydrazine and nitrogen tetroxide propellants. This cylindrical section was attached to the front of the conical, crew-cabin section of the Gemini spacecraft. Once the adapter module sections of Gemini were jettisoned before reentry, exposing the heatshield, the astronauts used the thrusters on this section to control the attitude of the reentry module before and during reentry.

McDonnell Douglas Astronautics Company sent this incomplete shell of a Reaction Control Section to the Smithsonian in 1971 along with a large number of NASA or Air Force Gemini artifacts from the Gemini B/Manned Orbiting Laboratory (MOL) program. MOL was a crewed reconnaissance satellite project that the Nixon Administration cancelled in 1969 before any were ever launched. A modified Gemini spacecraft was attached to the laboratory and would have been used for launch and reentry.