Earl 1 Spaceplane - Credit: Mark Lindroos. 24,372 bytes. 251 x 274 pixels.

Vertical takoff/horizontal landing two stage launch vehicle study from the 1980s. A larger Earl 14 configuration was studied, but the study centered on the Earl 5 / 18 / 7 configurations. The second stage was mounted on top of the booster. Earl 5 and 7 had winged second stages, with payloads to low earth orbit of 5380 kg to 7180 kg. Earl 14 featured an expendable upper stage which increased payload to 18,000 kg.

LEO Payload: 5,380 kg. Liftoff Thrust: 430,000 kgf. Total Mass: 270,000 kg. Core Diameter: 5.5 m. Total Length: 52.4 m.