Space Rapid Transit (SRT)

SRT is a revolutionary horizontal-takeoff launch vehicle for both the space launch and flight transportation industries. The full system, comprising a ferry with reusable orbiter upper stage, is expected to cost less than $150/lb for low earth orbit missions. The horizontal-takeoff design ensures successful rapid launch, recovery, and reconstitution of the first stage vehicle.

Furthermore, SRT provides a clear path for the development and implementation of advanced technologies, in a way that traditional vertical launch systems simply cannot match. It serves as a test platform for maturing the technology required for affordable, routine space access and global reach aircraft. For instance, the development of the SRT concept will lead to a market for the turboramjet engine, just as the nascent electric car market has sparked the development of advanced battery technologies.

Ferry The Ferry is a hypersonic air-breathing vehicle employing dual F135 engines at low velocity and ramjet engines at high velocity. The Ferry reaches 15 km and Mach 4.5 under air breathing engine propulsion at which point the Ferry ignites four RL10 engines to reach the optimal separation altitude of 48 km at Mach 10 and a flight path angle of 6 degrees.

Orbiter The payload is carried by the Orbiter, which is capable of controlled reentry and is fully reusable. The Orbiter is powered by three RL10 engines which are used for transfer orbit insertion and orbit circularization. Attitude control of the Orbiter is by means of a reaction control system, the engine gimbals and aerodynamic effectors.


"Space Rapid Transit Navigation and Control", Paul Griesemer, Joseph Mueller, Michael Paluszek and Pooja Raghavan at EUCASS 2011, 4 - 8 July 2011 in St. Petersburg Russia.

"System Design of a Reusable, Horizontal Take-Off/Horizontal Landing Two Stage to Orbit Vehicle", Paul R. Griesemer, Joseph B. Mueller, Michael A. Paluszek and Jingwen Du at the 2010 Joint Propulsion Conference, 5 - 28 July 2010 in Nashville, TN, USA.

"Unified GN&C System for the Space Rapid Transit Launch Vehicle", Joseph B. Mueller, Paul R. Griesemer, Michael A. Paluszek and Jingwen Du at the 2010 AIAA GN&C Conference, 2 - 5 August 2010 in Toronto Ontario, Canada.

"Space Rapid Transit for Rapid Spacecraft Deployment", Paul R. Griesemer, Michael A. Paluszek, Joseph B. Mueller and Eloisa de Castro, at the 2011 Reinventing Space Conference, 3 - 5 May 2011 in Los Angeles, California.

For more information: SRT Inquiry