Page:Project Longshot - Advanced Design Program Project Report.pdf/55

ATTITUDE CONTROL TECHNIQUE COMPARISON

TYPE	COST	ACCURACY	MISSIONS	COMMENTS
3-AXIS ACTIVE CONTROL (1) REACTION WHEELS	VERY HIGH	.007 ARC-SECONDS–1.0 DEG.	ASTRONOMICAL, WEATHER	VIBRATIONS AT HIGH RPM'S MAY REDUCE ACCURACY
(2) HYDRAZINE THRUSTERS	VERY HIGH	.1–1.0 DEG	DEEP SPACE	FUEL LIMITED
SPIN STABILISATION	LOW TO MODERATE	.1–2.0 DEG.	EARTH ORB, INTERPLANETARY	SPIN RATE AND DIRECTION REQUIRE CONTROL
DUAL-SPIN STABILIASATION (1) HALF SPIN, HALF STABILIZED	HIGH	.01–.1 DEG.	GEOSYNCH. COMMS. SATELLITES	REQUIRES COMPLEX ELEC. AND MECH. CONNECTIONS
(2) INTERNAL MOMENTUM WHEELS	HIGH	.01–.1 DEG.	GEOSYNCH. COMMS. SATELLITES	HIGH TECHNOLOGY REQUIREMENTS
MAGNETIC STABILIZATION	VERY LOW	10–20 DEG.	LOW ALT., SCIENTIFIC	REQUIRES A MAGNETIC FIELD
GRAVITY-GRADIENT STABILIZATION	LOW	1.0–10 DEG.	CIRCULAR, LOW ALT.	REQUIRES A GRAVITY FIELD AND A LARGE MOMENT OF INTERTIA FOR SATELLITE