CONTOUR Spacecraft Performance Test

NGIMS Operational Constraints:

Power up:
NGIMS power must be at least 15 seconds before receiving any commands.

Heater Operation:
Heater operation is independent of instrument operation. The spacecraft will enable survival heaters operation after power off of NGIMS and disable survival heaters when NGIMS is turned on. Reference: John Winchester Thermal Document TBD? Testing will be accomplished by an independent test procedure.

Breakoff Pyro Testing and Operation:
Pyrotechnics shall not be armed if live pyros are mounted and connected to NGIMS. APL shall be responsible for testing, disarming and arming the pyros. Pyros firing must be safed while testing and must be tested thoroughly. Question: When do we make the pyro connection?

Operational temperature:
The minimum storage temperature is -40C. The Maximum RF operating temperature and RF AGC temperature is 55C.

Operational pressure:
Ambient instrument pressure should be at atmospheric pressure or at 10E-5 mbar (or lower) for 24 hours to prevent corona effects due to high voltages on NGIMS electronics.

Internal Sensor Pressure
NGIMS has internal voltages up to 3.5kV and must not be operated between 10-5 mbard and atmosphere. Operation at atmosphere is OK. BA pressure check must be performed prior to exercising the detectors, filaments, or high voltage elements of NGIMS. This should be exercised as the first operation on any day that NGIMS is operated.

Note: In a vacuum, the thermistor pressure reading should be ignored, instead, the ion gauge reading should be the accepted reading.

Filaments:
The instrument has two sources, Open Source and Closed Source, with two filaments each. However, Only 1 filament per source should be turned on at any time.

High Voltage Multipliers:
The two high voltage multipliers must be set within specified values. On power up, the multipliers are set to 0V as specified in the INITMODE table in EEPROM. These values are TBD.

Software Patch policy:
Patches must be done in either standby or init mode. Patches must followed by a dump and a verification prior to allowing the patch to take effect.

NGIMS physical constraints:
A "hat" for the NGIMS sensor housing shall be in place to prevent accidental damage to the NGIMS sensor.

Data rate limitations:
NGIMS can accept commands at a maximum of 3 per second when TM is on, and 8 per second when in init and standby modes.
C:\Documents and Settings\FTan\My Documents\NGIMS\documents\NGIMS_Operational_Constraints.doc