Status: Study 2005. Thrust: 333.00 kN (74,861 lbf). Gross mass: 158,400 kg (349,200 lb). Unfuelled mass: 27,000 kg (59,000 lb). Specific impulse: 925 s. Height: 47.60 m (156.10 ft). Diameter: 10.00 m (32.00 ft). Span: 10.00 m (32.00 ft).
Late 1980's update of 1960's Nerva design.
Unit Cost $: 200.000 million.