Boeing Mach 2 Reusable HLV

Last crawled date: 3 years ago

This unnamed partially-reusable launch vehicle was proposed by Boeing Phantom Works in 2008. Little serious development was done beyond the basic concept, but it had several interesting features distinguishing itself from other RLVs of the time. Its two parallel stages were of nearly identical structural and propulsion system design, except that the second stage was expendable and high slightly stretched tanks. Both used four RS-68 engines, which, while not normally considered reusable due to their ablative nozzle design, were good enough for a few flights before being disposed of. Performance was heavily driven by the second stage, which allowed atypically slow staging of the first stage, uniquely allowing it to fly with no heat shielding. Aeroheating was low enough to even allow conventional spray-on insulation for the cryogenic propellant tanks, and so little time would be spent outside the atmosphere that the first stage required no RCS for attitude control. The result was a vehicle that cost little to develop, a moderate amount to operate, and could put 70 tons of payload in LEO