The Microcosm Orbit Control Kit (OCK) is an on-board software system that autonomously maintains the spacecraft in a pre-defined (or adjustable) stationkeeping box.* The OCK uses sensing, control, and computing hardware already on board most spacecraft and typically requires less propellant than orbit maintenance done from the ground. Because the future positions of the spacecraft are known, the OCK not only reduces operations costs for orbit maintenance, but dramatically simplifies operations and mission planning. Ground station and user passes can be planned one time, as far in advance as desired, with no recalculation or last-minute updates. The specific geometry of each pass, including viewing angles from both the spacecraft and the ground and Sun angles if desired, is known in advance and can be fully controlled if needed. The OCK is the control system for the spacecraft orbit and is applicable for orbits from LEO to GEO.

Accuracy

The achieved accuracy depends on a number of variables, the most important of which are the accuracy of the navigation information, the satellite orbit, and what the orbit is being controlled with respect to. In a normal low Earth orbit in the range of 400 to 800 km altitude, the OCK will maintain the in-track position to within ±0.30 sec (3-sigma) indefinitely, corresponding to an in-track error of ±2 km.

Benefits The key benefits to autonomous orbit control are improved performance, greater reliability, and reduced cost. Improved System Performance Know where the satellite will be at all future times to ±2 km Full in-track and cross-track control, rather than just altitude maintenance Put the satellite where you want it and keep it there Improved Safety and Reliability Inherently fail safe operation (unlike attitude control) Reduces communications and commanding failure modes Full insight (and oversight) by operations personnel Reduced Mission Life Cycle Cost Typical propellant savings of 3% to 4% relative to nominal ground control of a LEO spacecraft For constellations: eliminates stationkeeping and orbit maintenance planning, commanding, execution, and verification (typical savings 0.5-1.0 FTE** per spacecraft per year) For single spacecraft: dramatically simplifies pass planning, activity planning, and planning update process (typical savings 1-2 FTE per year) *The process of autonomous orbit control is covered by patents No. 5,687,084 and 5,528,502(U.S.), 69109266.4(Germany), and 0496879(Great Britain, Italy, and France). **1 FTE (Full Time Equivalent person) typically costs $150K-$170K per year.

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