The Charles Stark Draper Laboratory, Inc.

Massachusetts Institute of Technology

Sungyung Lim

Seamus Tuohy

Timothy Henderson

Laurent Duchesne

Leena Singh

Matthew W Smith

Christopher M Pong

Joseph Shoer

David W Miller

Daniel Dionne

Sara Seager

Shawn Murphy

Louis Breger

A conical scanning method and system is provided for orienting a spacecraft with respect to a source. The system includes a spacecraft and an incidence angle sensor secured to the spacecraft to sense a signal from a source. The incidence angle sensor has a boresight that is canted with respect to the principal axis. A processor communicates with actuators on the spacecraft to adjust an attitude of the spacecraft based on information received from the incidence angle sensor and to thereby align a principal axis of the spacecraft with a direction from the spacecraft to the source. The method and system can also rely on information received from source presence sensors. The source may be the Sun, or a non-solar signal source.

Conical scanning process for spacecraft sun pointing

A new approach for rapid slew and settle of small satellites is based on four single degree-of-freedom control moment gyroscopes with variable speed flywheels (or reaction wheels) in a pyramid configuration, combined with path and endpoint constraint time-optimal control. The path and endpoint constrained time-optimal control can be augmented with momentum management without the use of additional actuators.

Rapid slew and settle systems for small satellites

An optical system for use in an Earth-orbiting satellite includes a plurality of image sensors disposed on a focal plane having a reference axis orthogonal thereto, optics configured to focus incident light onto the image sensors, a piezoelectric actuator coupled to the image sensors and configured to translate the image sensors in at least two axes each orthogonal to the reference axis, and at least one controller operably coupled to the plurality of image sensors and the piezoelectric actuator. The image sensors are configured to generate at least one image frame from light detected by the plurality of image sensors, the image frame including a target star and at least one guide star. The controller is configured to stabilize the position of the target star by adjusting the position of the piezoelectric actuator based on the changes in the position of the guide star.

Multi-functional star tracker with precision focal plane position control for small cubesat-class satellites

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Acton, MA, United States of America

Sungyung Lim