Exhibit B
7.0 REACTION CONTROL SUBSYSTEM
A reaction control subsystem (RCS) using hydrazine shall be provided for longitudinal orbit control, orbit inclination control, orbit injection trim, and spin axis attitude control.
7.1 Reliability Considerations
Reliability and redundancy features shall be required as follows:
1) Two independent control systems.
2)
Total fuel equally divided.
3)
Series redundant thruster control valve.
4)
Pressure instrumentation for each system.
5) The continuously pressurized portion of each system shall contain
no mechanical joints upstream of the valve.
6)
Series redundant switching transistors shall be used in the valve. drivers.
7.2 Leakage
The pressurant leakage shall not exceed 5 percent of the initial weight of helium over mission life.
7.3
Performance
All
curves
ΟΙ
pulse mode operation. thrusters are capable of continuous
and tabular values shall be provided by the Complete calibration Contractor for each thruster in accordance with 7.3.2(4). curves and tabular values are extant for the radial will be generated upon test of the new axial thrusters.
7.3.1
i
Continuous Operation
Continuous operation of А
greater.
These calibration thrusters (no retest) and
of duration a thruster for
one spin or
}
7.3.1.1 Total Impulse Predictability
For any given thruster the total
the total impulse for continuous operations shall be predictable within ±7.5 percent.
7.3.1.2
Thrust Predictability
The thrust of any given thruster shall not deviate from the mean axial engine thrust for this spacecraft by more than 15 percent when operated under identical inlet conditions over the entire engine operating range of inlet pressure and temperature.
L.
B-25
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