Gemini Ferry Credit - McDonnell-Douglas

The Gemini Ferry vehicle would have been launched by Titan 3M for space station replenishment. A MOL-type hatch in the heat shield would allow the crew to enter the space station through an Apollo-type probe and drogue hatch at the base of the spacecraft - a design very like the Soviet TKS. Much shorter than the MOL, the cargo module could be left attached to the station and the reentry vehicle return to earth on its own.

In 1962 NASA funded studies with several contractors on Operations and Logistics for Space Stations. McDonnell's study was dated 20 March 1963 and proposed three alternatives, all of which could be boosted by either a Titan 3M or Saturn IB Launch Vehicle, and all of which would be equipped with aft-mounted docking systems:

• Two-crew Gemini, relatively unmodified, with a cargo module
• Modified Gemini with a stretched re-entry vehicle (later fully developed into the Big-Gemini)
• New winged spaceplane, capable of accommodating two crew plus four passengers

Crew Size: 2. Length: 8.30 m (27.20 ft). Maximum Diameter: 3.05 m (10.00 ft). Habitable Volume: 2.55 m3. Mass: 15,590 kg (34,370 lb). Payload: 9,090 kg (20,040 lb).

• Gemini Ferry RM.  Other Designations: Reentry Module. Part of: Gemini Ferry. Class: Manned. Type: Spacecraft Module.

  Crew Size: 2. Length: 3.35 m (10.99 ft). Basic Diameter: 2.32 m (7.61 ft). Maximum Diameter: 2.32 m (7.61 ft). Habitable Volume: 2.55 m3. Mass: 1,910 kg (4,210 lb). Structure Mass: 638 kg (1,406 lb). Heat Shield Mass: 144 kg (317 lb). Reaction Control System: 133 kg (293 lb). Recovery Equipment: 98 kg (216 lb). Navigation Equipment: 62 kg (136 lb). Telemetry Equipment: 51 kg (112 lb). Electrical Equipment: 125 kg (275 lb). Communications Systems: 26 kg (57 lb). Crew Seats and Provisions: 426 kg (939 lb). Crew mass: 144 kg (317 lb). Miscellaneous Contingency: 99 kg (218 lb). RCS Fine No x Thrust: 16 x 98 N. RCS Propellants: N2O4/MMH. RCS Isp: 283 sec. RCS Impulse: 90 kgf-sec. Main Engine Propellants: N2O4/MMH. Main Engine Propellants: 33 kg (72 lb). Main Engine Isp: 283 sec. L/D Hypersonic: 0.16. Electrical System: Batteries. Electric System: 4.00 kWh. Battery: 180.00 Ah.

• Gemini Ferry AM.  Other Designations: Adapter Module. Part of: Gemini Ferry. Class: Manned. Type: Spacecraft Module.

  Length: 1.40 m (4.50 ft). Basic Diameter: 3.05 m (10.00 ft). Maximum Diameter: 3.05 m (10.00 ft). Mass: 1,180 kg (2,600 lb). Structure Mass: 300 kg (660 lb). Reaction Control System: 200 kg (440 lb). RCS Coarse No x Thrust: 6 x 420 N. RCS Fine No x Thrust: 8 x 98 N. RCS Propellants: N2O4/MMH. RCS Isp: 273 sec. Main Engine Propellants: Solid. Main Engine Isp: 255 sec. Spacecraft delta v: 101 m/s (331 ft/sec).

• Gemini Ferry CM.  Other Designations: Cargo Module. Part of: Gemini Ferry. Class: Manned. Type: Spacecraft Module.

  Length: 4.00 m (13.10 ft). Basic Diameter: 3.05 m (10.00 ft). Maximum Diameter: 3.05 m (10.00 ft). Mass: 12,050 kg (26,560 lb). Payload: 9,090 kg (20,040 lb).