The AACB Class II launch vehicle was a fully reusable, two-stage-to-orbit launch vehicle. Both stages would be lifting bodies and be powered by Lox/LH2 engines. The system would be operational by 1978 and place 9,100 kg of payload in orbit.

Two alternates were considered:

• Alternate I was a vertical-takeoff vehicle, with both stages equipped with turbojet engines to assist in landing back at airfields. The orbiter retained the lifting-body shape of the Class I vehicle but was much larger since it had to carry internal tanks for the Lox/LH2 rocket propellants. Total mass vehicle mass at lift-off was 745,500 kg; development cost $ 3 billion; cost to operate per flight, $ 4 million
• Alternate II was a horizontal takeoff vehicle. Cost would be $ 4 billion to develop. The gross mass would be 600,000 kg, with the first stage weighing 465,000 kg and the second stage 125,000 kg.

Manufacturer: USAF. LEO Payload: 9,072 kg (20,000 lb). Total Mass: 745,479 kg (1,643,499 lb). Development Cost $: 3,000.000 million. in: 1966 average dollars. Launch Price $: 4.000 million. in: 1966 price dollars.