Proposed Earth-to-Orbit Segment booster for Andrews CEV architecture. Consisted of an Atlas V core, two Zenit-2 booster strap-ons, and a new-development Lox/LH2 upper stage.

The new expendable Lox/LH2 upper stage would require development of a new RL-X engine. The stage would be 6.5 m in diameter and 17.6 m long, with a gross mass of 283,793 kg and a dry mass of 14,402 kg. All stages would be only partially fuelled for delivery of a low-earth orbit payload of 40 tonnes, with a gross lift-off mass of 865,950 kg in that configuration.

Manufacturer: Andrews. LEO Payload: 40,000 kg (88,000 lb). to: 300 km Orbit. at: 28.00 degrees. Payload: 22,000 kg (48,000 lb). to a: trans-lunar injection trajectory. Other Associated Spacecraft: Andrews CEV. Total Mass: 1,213,618 kg (2,675,569 lb). Core Diameter: 5.40 m (17.70 ft). Total Length: 84.70 m (277.80 ft). Span: 17.00 m (55.00 ft). Launch Price $: 240.000 million. in: 2005 price dollars.