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Big Gemini
Part of Gemini

Big Gemini Mockup

Big Gemini Mockup
Mock-up of the Big Gemini re-entry module on display at the McDonnell plant, St Louis, in 1967. The large windows allowed viewing of the interior of the mock-up and were not going to be part of the flight version! By simply adding a passenger compartment behind the basic Gemini B, McDonnell produced a ballistic re-entry vehicle with the same total mass and base diameter as the Apollo Command Module, but over twice the cargo capacity.
Credit: McDonnell Douglas

American manned spacecraft. Reached mockup stage 1967.

Status: Mock-up 1967. Payload: 2,500 kg (5,500 lb). Gross mass: 15,590 kg (34,370 lb). Height: 11.50 m (37.70 ft).

Big Gemini ('Big G') was proposed by McDonnell Douglas to the US Air Force and NASA in 1967 as a ballistic manned orbital logistics spacecraft to provide economical resupply of planned military and civilian space stations.

By the end of 1966 NASA's Gemini program was nearing its conclusion and the design phase of the USAF Manned Orbiting Laboratory (MOL) project was nearly finished. McDonnell-Douglas had a large manned spacecraft engineering team, built up over eight years on the Mercury, Gemini, and MOL programs that was facing dissolution. At the same time both USAF and NASA had funded space station projects. The USAF's MOL and the NASA's Apollo Applications Program Orbital Workshop (later Skylab) were to fly in 1969-1974. Both USAF and NASA were planning even larger follow-on stations - the USAF LORL and NASA MORL.

The capability of existing spacecraft (Apollo CSM, Gemini) for manned resupply missions to these stations was severely limited. In the 1970-1980 period, it appeared that at least a dozen launches would be required for logistics purposes for the Apollo Applications Program alone. MOL and the AAP workshop would require 3 to 6 flights a year, each flight delivering a crew of two or three, with 1 to 7 metric tons of cargo being sent up and up to 0.6 cubic meters of cargo being returned. Planned late 1970's stations would have crews of 6 to 24, requiring a resupply craft that could deliver up to 12 passengers and 12 metric tons of payload 6 to 14 times a year, returning up to 7 cubic meters of cargo each time. Big G could provide such a capability by 1971, using Gemini technology applied to Gemini and Apollo hardware, with minimum interference to the higher priority Apollo lunar landing program.

McDonnell Douglas conceded that the initial flights to Orbital Workshop 1 (then planned for 1970) would have to be supported by the Apollo CSM. However Big G could be available in 1971 to provide improved crew and cargo versatility for Orbital Workshop 2 and USAF MOL resupply.

Big G would consist of the following modules:

It was possible to transfer crew and cargo from Big-G to the space station without extra-vehicular activity. A pressurized tunnel led from the passenger compartment to the cargo area, and another tunnel to the docking probe.

Big G used the "packaged return capability" of the Gemini-B. This included "sealed-until-needed" oxygen supply, RCS system, and retrograde and separation motors. These features, compared to Apollo, improved crew safety by assuring the spacecraft could endure extended in-orbit quiescent storage while docked to the space station.

As another alternative (obviously not favored by McDonnell Douglas) the Big G re-entry capsule could be used with an Apollo Service Module and the Apollo Applications Program Multi-Mission Module (a palletized cargo carrier mounted, like the Lunar Module, behind the SM, with which Big G would have to dock and extract from the spent booster).

Total mass of the Big G would depend on the launch vehicle. The Titan 3M version would total 15,600 kg, delivering 9 crew and 2,500 kg of supplies to MOL in a 480 km, 50 degree inclination orbit. The NASA INT-20 version weighed 47,300 kg and could deliver 9 crew and 27,300 kg of payload to the same orbit. The Titan 3G configuration would have an orbital insertion mass of 59,000 kg in a 28.5 degree, 150 x 220 km orbit.

McDonnell's sales pitch was summarized as follows:

Big G was not to be. Even at the time the concept was originated both NASA and USAF manned space projects were being cut back. Within 18 months, MOL would be cancelled, and AAP would be limited to using only spacecraft and boosters surplus to the moon landing program. Soon thereafter the shuttle became the only funded space project for the 1970's, and all space station work was abandoned. The Gemini spacecraft - and the American push to rapidly exploit the cosmos - were dead.

Crew Size: 9. Habitable Volume: 18.70 m3.



Family: Manned spacecraft, Space station orbit. People: McDonnell. Country: USA. Spacecraft: Big Gemini AM, Big Gemini CM, Big Gemini RV. Launch Vehicles: Titan, Saturn I. Bibliography: 207, 208, 210, 6387.
Photo Gallery

Big GeminiBig Gemini
Credit: NASA


Big Gemini ConfigsBig Gemini Configs
Compared are the Big Gemini configurations planned for use with the Titan 3G for the Air Force (180 inch diameter base) and for use with Saturn launch vehicles for NASA (260 inch diameter base). A shorter version of the Titan 3G version could be used with the Titan 3M.
Credit: McDonnell Douglas


Big Gemini LandingBig Gemini Landing
Big Gemini would land on dry lake beds or airstrips on skids, as were used on the X-15 and were planned for the X-20 and basic Gemini. A parasail would allow the pilot to manoeuvre to a pinpoint landing.
Credit: McDonnell Douglas


Big Gemini CutawayBig Gemini Cutaway
Dimensioned cutaway view of Big Gemini as proposed for NASA. This view shows: The location of the aft control station for docking. The ejection seats provided for all crew members. The locations of the parasail 'recovery system'. The underfloor location of the passenger environmental control system.
Credit: McDonnell Douglas


Big Gemini ModelBig Gemini Model
Cutaway model of the Big Gemini re-entry module. This version would accommodate two crew and six passengers; versions for NASA with ejections seats would accommodate two crew and four passengers plus return cargo.
Credit: McDonnell Douglas


Big Gemini /Titan 3MBig Gemini /Titan 3M
Minimum Air Force version of Big Gemini, launched by a Titan 3M for advanced Manned Orbiting Laboratory (MOL) resupply. This version had a minimal cargo module capability. Total mass was 15,600 kg, and it could deliver 9 crew and 2,500 kg of supplies to a 480 km, 50 degree inclination orbit.
Credit: McDonnell Douglas


Big Gemini / LORLBig Gemini / LORL
Big Gemini docked to one version of the planned Air Force Large Orbiting Research Laboratory (LORL), planned late 1970's follow-on to the Manned Orbiting Lab (MOL).
Credit: McDonnell Douglas


Big Gemini EvolutionBig Gemini Evolution
Chart showing how the Big Gemini could be derived from existing hardware. Use of the basic re-entry module with a range of propulsion and cargo modules was possible. A further evolutionary development would lead to the 'Advance Logistic Spacecraft' of the late 1970's (eventually the Space Shuttle).
Credit: McDonnell Douglas


Big Gemini / SIVBBig Gemini / SIVB
Big Gemini as launched by a Saturn derived launch vehicle composed of five solid motors with an S-IVB upper stage. This version weighed 47,300 kg and could deliver 9 crew and 27,300 kg of payload to a 480 km, 50 degree inclination orbit. The sketch shows the flight phases of the capsule, including the parasail landing.
Credit: McDonnell Douglas


Big Gemini / OWSBig Gemini / OWS
Use of Big Gemini as a more cost-effective manned logistics vehicle for use with the Apollo Applications Orbital Workshop (eventually Skylab).
Credit: McDonnell Douglas


Big Gemini NASABig Gemini NASA
Comparison of potential NASA configurations for Big Gemini. The preferred, top configuration uses all new hardware. The middle ALSS configuration uses a logistics module developed for the Apollo Orbital Workshop program. The bottom configuration uses the Big Gemini re-entry capsule with an Apollo Service Module and Apollo Applications Multi-Mission Module.
Credit: McDonnell Douglas


Big Gemini NASABig Gemini NASA
Larger version of comparison of potential NASA configurations for Big Gemini. The preferred, top configuration uses all new hardware. The middle ALSS configuration uses a logistics module developed for the Apollo Orbital Workshop program. The bottom configuration uses the Big Gemini re-entry capsule with an Apollo Service Module and Apollo Applications Multi-Mission Module.
Credit: McDonnell Douglas


Big Gemini BriefingBig Gemini Briefing
Cover page of Big Gemini briefing to NASA, Dec 20 1967. Big Gemini is shown returning its crew of ten to a runway landing beneath its Rogallo wing paraglider.
Credit: McDonnell Douglas



1969 August 21 - .

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