X-42 Pop-Up Upper Stage

The X-42 is an experimental expendable liquid rocket motor upper stage designed to boost 2000-4000lb payloads into orbit.

Pop-Up Upper Stages can expand the utility of advanced military spacecraft, allowing for wider ranges of payload deployment. This project includes concepts on technologies which will improve pop-up upperstage technologies and/or stages themselves. The Orbit Transfer Propulsion AT DTO will demonstrate individual orbit transfer propulsion capabilities that significantly enhance low-cost, high-performance access to space via revolutionary propulsion techniques with improved designs, combustion and mixing technologies, and material advancements; and will develop and demonstrate chemical propulsion systems for military, civil, and commercial orbit transfer applications. Future orbit transfer systems will require advanced materials, low-cost power processing developments, and increased thruster efficiency in order to maintain the US global presence capability through enhanced strategic agility.

Specific demonstrated capabilities for chemical orbit transfer systems include an increased payload capability of 10% in FY00 and 20% in FY05. FY00 chemical/solar thermal orbit transfer propulsion demonstrations will achieve specific improvements of +10% Isp, and +15% mass fraction.

Milestones for orbit transfer propulsion include chemical thrust chamber assembly proof testing and hardware completion in FY97 for integration into the FY00 chemical upper-stage/orbit-transfer demonstration.