NTRS - NASA Technical Reports Server

As of October 27, 2023, NASA STI Services will no longer have an embargo for accepted manuscripts. For more information visit NTRS News.

Back to Results
Performance Tests of a Liquid Hydrogen Propellant Densification Ground System for the X33/RLVA concept for improving the performance of propulsion systems in expendable and single-stage-to-orbit (SSTO) launch vehicles much like the X33/RLV has been identified. The approach is to utilize densified cryogenic liquid hydrogen (LH2) and liquid oxygen (LOX) propellants to fuel the propulsion stage. The primary benefit for using this relatively high specific impulse densified propellant mixture is the subsequent reduction of the launch vehicle gross lift-off weight. Production of densified propellants however requires specialized equipment to actively subcool both the liquid oxygen and liquid hydrogen to temperatures below their normal boiling point. A propellant densification unit based on an external thermodynamic vent principle which operates at subatmospheric pressure and supercold temperatures provides a means for the LH2 and LOX densification process to occur. To demonstrate the production concept for the densification of the liquid hydrogen propellant, a system comprised of a multistage gaseous hydrogen compressor, LH2 recirculation pumps and a cryogenic LH2 heat exchanger was designed, built and tested at the NASA Lewis Research Center (LeRC). This paper presents the design configuration of the LH2 propellant densification production hardware, analytical details and results of performance testing conducted with the hydrogen densifier Ground Support Equipment (GSE).
Document ID
Document Type
Conference Paper
Tomsik, Thomas M.
(NASA Lewis Research Center Cleveland, OH United States)
Date Acquired
September 6, 2013
Publication Date
June 1, 1997
Subject Category
Propellants And Fuels
Report/Patent Number
NAS 1.15:107469
AIAA Paper 97-2976
Meeting Information
Meeting: Joint Propulsion Conference and Exhibit
Location: Seattle, WA
Country: United States
Start Date: July 6, 1997
End Date: July 9, 1997
Sponsors: Society of Automotive Engineers, Inc., American Society of Mechanical Engineers, American Inst. of Aeronautics and Astronautics, American Society for Electrical Engineers
Accession Number
Funding Number(s)
PROJECT: RTOP 242-33-01
Distribution Limits
Work of the US Gov. Public Use Permitted.
No Preview Available