Please make a donation to support Gunter's Space Page.
Thank you very much for visiting Gunter's Space Page. I hope that this site is useful and informative for you.
If you appreciate the information provided on this site, please consider supporting my work by making a simple and secure donation via PayPal. Please help to run the website and keep everything free of charge. Thank you very much.


Gemini-B [USAF]

NASA's Gemini capsule was extensively redesigned for the MOL Manned Orbiting Laboratory program. The resulting Gemini B, although externally similar, was essentially a completely new spacecraft. Gemini B was not designed to fly separately, but rather was launched with the crew aboard attached to the manned orbiting laboratory. After reaching orbit, the crew would shut down the capsules systems and put them into hibernation. They would crawl through an 0.635 m diameter hatch in the heat shield, leading to a tunnel that accessed the MOL itself. After thirty days of operations, the crew would return to the Gemini B, separate from the MOL, and reenter the atmosphere. Gemini B had only 14 hours of free flight time for autonomous operations after separation from the MOL.

Several changes were made from the original NASA Gemini, including:

  • Internal systems were containerized and designed for long term orbital storage
  • The cockpit layout was completely redesigned and new instruments were developed
  • The cant of the ejection seats were changed in order to make room for the hatch in the heat shield between the crew's shoulders
  • cabin atmosphere was changed to Helium-Oxygen in place of pure oxygen. At launch, the crew breathed pure oxygen in their suits while the cabin was filled with pure helium. During ascent, oxygen from the suits slowly brought the cabin atmosphere up to the helium-oxygen content of the station itself.
  • In order to handle higher energy reentries from polar orbit, the heat shield was increased in diameter, so that it actually stuck out a bit from the base of the reentry vehicle.
  • The OAMS maneuvering thrusters of the NASA Gemini were deleted; spacecraft orientation in orbit was handled by the forward RCS thrusters.
  • The number of solid propellant retrofire motors was increased from four to six. These served double-duty: for deorbit of the Gemini B and as abort rockets for separation of the Gemini from the enormous Titan 3M in case of launch vehicle failure.

The prototype Gemini-B, which was launched on a suborbital trajectory, was the refurbished Gemini-2 capsule, making it the first reused spacecraft. It was launched with the MOL-Heatshield Qualification Test on a Titan-3C launch vehicle.

Nation: USA
Type / Application: Experimental crewed spacecraft
Operator: US Air Force (USAF)
Contractors: McDonnell-Douglas
Propulsion: 6 × Star-13E (TE-M-385) retro rockets ?
Power: batteries
Lifetime: 30 days
Mass: 3851 kg
Orbit: suborbital
Satellite COSPAR Date LS Launch Vehicle Remarks
Gemini B N/A 03.11.1966 CC LC-40 * Titan-3C with OV4 3, OV4 1R, OV4 1T, OV1 6

* = suborbital

Cite this page: