Improved propellant loading strategy and launch operation of hydrazine propulsion subsystem to enhance safety of solar synchronous orbit satellite

Paper number

IAC-06-C4.P.1.03

Author

Dr. Xin Hong, Shanghai Institute of Space Propulsion, China

Coauthor

Dr. Jie Chen, Shanghai Institute of Space Propulsion, China

Year

2006

Abstract

Hydrazine, a widely used monopropellant in spacecraft propulsion system, has the inherent disadvantage in application for its flammability, toxic and explosive characteristics. So the safety measure for hydrazine application is continually investigated in spacecraft development. However, the conventional mechanical isolation method in propellant delivery pipes was not took the full advantage of in SSO satellite because of propellant loading strategy.

To enhance the ground and launch safety of SSO satellite with monopropellant propulsion subsystem, an improved propellant loading strategy and launch operation procedure of propulsion subsystem was designed and validated by hot firing both in atmosphere and vacuum vessel. The propellant hydrazine are loaded upstream of latch valves of propulsion subsystem and fill the pipelines downstream of latch valve with helium of appropriate pressure. After propellant filling, the operation of latch valves and thruster valves were prohibited by electrical protection until satellite separation with launch vehicle, then the latch valve were opened according to schedule and propulsion subsystem was activated. 

Another advantage of this method is the propellant pressure growth phenomenon with temperature rise downstream of latch valve before separation could be eliminated.

The simulated propellant prime tests and hot firing had indicated that the risk of rapid compression detonation of hydrazine and water hammer pressure peak during propellant prime process were eliminated, the delay time of thruster impulse response for attitude control is too short to be a problem.

The first flight application of this innovative idea was realized in satellite of China in 2005. Propulsion system worked well to now.

Abstract document

IAC-06-C4.P.1.03.pdf

Manuscript document

IAC-06-C4.P.1.03.pdf (🔒 authorized access only).

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