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8 Propulsion Technology of Lunar Lander
Fig. 8.2 Schematic of descent propulsion subsystem of Apollo lunar module
The N 2 O 4 /mixed hydrazine bi-propellant propulsion subsystem pressurized with
gaseous Helium of constant pressure was used for reaction control. The propellant
tanks of fluoro-plastic bladder with total propellant loaded 2352 kg were used. The
schematic of reaction control propulsion subsystem is shown in Fig. 8.4. 2 sets of
reaction attitude control propulsion subsystems (8 engines for each subsystem) were
equipped independently, in which 16 engines distributed on 4 modules with 4 engines
on each module (2-to-2 correspondent respectively to each independent subsystem)
and their pipelines were connected to serve as redundancy for engines and propellant
supply. Meanwhile, propellant tanks in reaction control propulsion subsystem were
connected with that of ascent propulsion subsystem to supply propellant for each
other. The thrust of all engines for reaction control was 445 N.
The specifications of main engines of Apollo lunar module are shown in Table 8.2.