System architecture
A reusable aircraft owns atmospheric ascent. A dedicated rocket owns vacuum acceleration. Neither carries the other's compromises to orbit.
The baseline is not a single-stage spaceplane. It is a reusable first stage and a separate orbital vehicle, joined only for the first part of flight.
An uncrewed, runway-recoverable aircraft that accelerates the orbital vehicle through the atmosphere and releases it during a low-dynamic-pressure coast.
A compact rocket-powered vehicle sized around the velocity that remains after carrier release—not around the demands of sea-level launch.
At 300 km, circular orbit requires about 7.73 km/s sideways. The carrier is valuable because it supplies useful downrange velocity and eliminates first-stage onboard oxidizer—not because it simply climbs high.
Mach 5 contributes roughly 20% of orbital speed and 4% of orbital kinetic energy. Rocket mass changes exponentially with required velocity, so that contribution can still materially improve the orbital stage's propellant fraction.
The hypersonic vehicle requires an integrated cradle, not a conventional bomb bay. Separation is commanded, measured and complete before the orbital engine is allowed to start.
The orbital vehicle sits in a ventral cradle that limits wave drag while preserving a direct, downward escape path.
Pneumatic or cold-gas ejectors create relative velocity. Weightlessness alone does not separate two coasting vehicles.
Independent sensing confirms distance, attitude and divergent trajectories before the orbital stage commits to powered flight.
Credibility is a design constraint. These boundaries keep the program tied to physics and test evidence.
The carrier still needs onboard fuel. Atmospheric air supplies oxidizer and reaction mass.
The orbital stage still provides the majority of velocity and all sustained vacuum propulsion.
Hypersonic structures, inlets and separation remain experimental until proven through repeated flight.
Performance numbers remain design objectives until closed by mass models and validated in hardware.