1. Propulsion Jon Lewis Mike Rhee 8/19/99
MAXIM
Propulsion
Jon Lewis
Mike Rhee
8/19/99

2. Stationkeeping and Pointing Control
Hydrazine thrusters used as much as possible
Initial S/C separation DV ~ 0.09 m/s (grams)
Slew to new target (10º) requires a few kg each time (150 times)
10º change approximated by making detector S/C lag orbit S/C by prescribed distance and in a reasonable amount of time
Finer control will require different propulsion device
Short term acceleration requires constant mN thrust, minimal propulsion mass, may be accomplished with pulsing of hydrazine, possible use ion engine or PPT
Longer term effects and fine control will utilize mN thrusters with good precision, will involve creative schemes with flight dynamics and attitude control, as well as compromise with science

3. Future Considerations
Separation/Slew fairly well defined and understood
Fine control will require several design considerations
Knowledge of position, drift rates
Accuracy and precision of mN thruster
Contamination and EMI
Integration with science duty cycles, power availability and overall mission requirements