Advanced auxiliary propulsion system (APS) technology has the potential to both, increase the payload capability of earth-to-orbit (ETO) vehicles by reducing APS propellant mass, and simplify ground operations and logistics by reducing the number of fluids on the vehicle and eliminating toxic, corrosive propellants. The impact of integrated cryogenic APS on vehicle payloads is addressed. In this system, launch propulsion system residuals are scavenged from integral launch propulsion tanks for use in the APS. Sufficient propellant is preloaded into the APS to return to earth with margin and noncomplete scavenging assumed. No propellant conditioning is required by the APS, but ambient heat soak is accommodated. High temperature rocket materials enable the use of the unconditioned hydrogen/oxygen in the APS and are estimated to give APS rockets specific impulse of up to about 444 sec. The payload benefits are quantified and compared with an uprated monomethyl hydrazine/nitrogen tetroxide system in a conservative fashion, by assuming a 25.5 percent weight growth for the hydrogen/oxygen system and a 0 percent weight growth for the uprated system. The combination and scavenging and high performance gives payload impacts which are highly mission specific. A payload benefit of 861 kg (1898 lbm) was estimated for a Space Station Freedom rendezvous mission and 2099 kg (4626 lbm) for a sortie mission, with payload impacts varying with the amount of launch propulsion residual propellants. Missions without liquid propellant scavenging were estimated to have payload penalties, however, operational benefits were still possible.
Advanced APS Impacts on Vehicle Payloads
1989
10 pages
Report
Keine Angabe
Englisch
Unmanned Spacecraft , Rocket Engines & Motors , Auxiliary propulsion , Hydrogen oxygen engines , Payload delivery (Sts) , Propulsion system performance , Propulsive efficiency , Spacecraft propulsion , Cryogenic rocket propellants , Liquid hydrogen , Liquid oxygen , Propellant transfer , Scavenging , Specific impulse , Storable propellants , Thrust chambers
Advanced APS Impacts on Vehicle Payloads
NTRS | 1989
|Advanced APS impacts on vehicle payloads
NTRS | 1989
|STS-85: PAYLOADS, PAYLOADS AND MORE PAYLOADS
Online Contents | 1997
|