Title of Presentation: Performance Optimization of Storable Bipropellant Engines to Fully Exploit Advanced Material Technologies

Primary (Corresponding) Author: Scott Miller

Organization of Primary Author: Aerojet Redmond

Abstract: This paper summarizes the work to date on the NASA Cycle 3A Advanced Chemical Propulsion Program. The goals of the program are to design, fabricate, and test high performance bipropellant engines using Ir/Re chamber technology to obtain 335 seconds Isp with NTO/hydrazine propellants and 330 seconds Isp with NTO/MMH propellants. Aerojet has successfully completed the Base Period of this program, wherein (1) mission and system studies have been performed to verify system performance benefits and to determine engine physical and operating parameters, (2) preliminary chamber and nozzle design has been completed and a chamber supplier has been downselected, (3) high temperature, high pressure off-nominal hot fire testing of an existing state-of-the-art HiPAT engine has been completed, and (4) thermal and performance data from the engine test have been correlated with new thermal models to enable us to design the new engine injector and injector/chamber interface. In the next phase of the program, Aerojet will complete design, fabrication, and test of the NTO/hydrazine engine to demonstrate 335 seconds Isp, and also investigate improved technologies for Ir/Re chamber fabrication. At the conclusion of the program, the objective is to have an engine ready for final design and qualification for a specific science mission or commercial application.