The study was performed to generate a preliminary definition of a logistic spacecraft derived from Gemini that would be used to resupply an orbiting space station.

Two baseline spacecraft were defined: a nine-man minimum modification version of the Gemini B called Min-Mod Big G and a 12-man advanced concept, having the same exterior geometry but with new, state-of-the-art subsystems, called Advanced Big G. Three launch vehicles-Saturn IB, Titan IIIM, and Saturn INT-20 (S-IC/S-IVB) were investigated for use with the spacecraft.

The parametric analysis and point design of the parawing were accomplished by Northrop-Ventura Company under a subcontract, and the contents of their final report were incorporated into the document.

The Office of Management and Budget was much more favorable to the idea than NASA, concluding in a staff paper that Big Gemini launched aboard an uprated Titan III would be a more cost-effective option than any shuttle design.

Ultimately OMB Deputy Director Caspar Weinberger helped to broker a compromise where Big G was taken off the table and NASA was given the greenlight for immediate development of a partially-reusable thrust-assisted orbiter shuttle.