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First Stage of a Highly Reliable Reusable Launch SystemElectromagnetic launch assist has the potential to provide a highly reliable reusable first stage to a space access system infrastructure at a lower overall cost. This paper explores the benefits of a smaller system that adds the advantages of a high specific impulse air-breathing stage and supersonic launch speeds. The method of virtual specific impulse is introduced as a tool to emphasize the gains afforded by launch assist. Analysis shows launch assist can provide a 278-s virtual specific impulse for a first-stage solid rocket. Additional trajectory analysis demonstrates that a system composed of a launch-assisted first-stage ramjet plus a bipropellant second stage can provide a 48-percent gross lift-off weight reduction versus an all-rocket system. The combination of high-speed linear induction motors and ramjets is identified, as the enabling technologies and benchtop prototypes are investigated. The high-speed response of a standard 60 Hz linear induction motor was tested with a pulse width modulated variable frequency drive to 150 Hz using a 10-lb load, achieving 150 mph. A 300-Hz stator-compensated linear induction motor was constructed and static-tested to 1900 lbf average. A matching ramjet design was developed for use on the 300-Hz linear induction motor.
Document ID
Acquisition Source
Armstrong Flight Research Center
Document Type
Conference Paper
Kloesel, Kurt J.
(NASA Dryden Flight Research Center Edwards, CA, United States)
Pickrel, Jonathan B.
(NASA Dryden Flight Research Center Edwards, CA, United States)
Sayles, Emily L.
(NASA Dryden Flight Research Center Edwards, CA, United States)
Wright, Michael
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Marriott, Darin
(Embry-Riddle Aeronautical Univ. Prescott, AZ, United States)
Holland, Leo
(General Atomics Co. San Diego, CA, United States)
Kuznetsov, Stephen
(Power Superconductor Applications Corp. New Castle, PA, United States)
Date Acquired
August 24, 2013
Publication Date
September 14, 2009
Subject Category
Launch Vehicles And Launch Operations
Report/Patent Number
Meeting Information
Meeting: AIAA SPACE 2009 Conference and Exposition
Location: Pasadena, CA
Country: United States
Start Date: September 14, 2009
End Date: September 17, 2009
Sponsors: American Inst. of Aeronautics and Astronautics
Distribution Limits
Public Use Permitted.
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