AACB Class 3 Credit - NASA

The AACB Class III launch vehicle was an advanced concept use air-breathing stages, but still requiring two stages to achieve orbit. The joint NASA/USAF panel concluded that the technology did not yet exist to develop this concept, so it was only regarded as an option by 1982 at the earliest.

The vehicle would have a gross mass of 450,000 kg and a payload to orbit of 16,000 kg. Stage 1 would be powered by a turbofan-ramjet and have a takeoff mass of 306,000 kg; stage 2 would be powered by a scramjet and rocket and have an mass of 132,000 kg. The evaluation used a design investigated by Lockheed in 1965-66.

Manufacturer: Lockheed. LEO Payload: 15,876 kg (35,000 lb). Total Mass: 306,175 kg (675,000 lb).

• Jenkins, Dennis R,, Space Shuttle: The History of the National Space Transportation System : The First 100 Missions, Third edition, Voyageur Press, 2001. ISBN: 0963397451. Excellent - the most comprehensive account of the design, development, and flights of the space shuttle.Takes the reader from the maze of designs during the first shuttle competition to future plans. More at amazon.com...