Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, June 2013. / This thesis was scanned as part of an electronic thesis pilot project. / "May 2013." Cataloged from PDF version of thesis. / Includes bibliographical references (p. [81]-85). / The Microsized Microwave Atmospheric Satellite (MicroMAS) combines two traditional control approaches: a dual spinner and a three-axis gyrostat. Unlike typical dual spinners, the purpose of MicroMAS 's 2U bus and spinner assembly is to actuate a iu payload, not to add gyroscopic stiffness. An orthogonal triple reaction wheel assembly from Maryland Aerospace, Inc., will both counter the angular momentum from the payload and rotate the satellite's bus about its orbit-normal vector to maintain bus alignment with the orbital frame. The payload spins about the spacecraft velocity axis to scan successive swaths of the Earth. However, the CubeSat form factor restricts the velocity axis to be along the spacecraft minor axis of inertia. This orientation leaves the spacecraft at a gravity-gradient-unstable equilibrium. Further, imperfect cancellation of the payload's angular momentum induces nutation behavior. An extended Kalman filter is implemented on a 16-bit P1C24 microcontroller to combine gyroscope, limb sensor, and magnetometer data to provide attitude estimation accuracy of approximately 20 arcminutes. Simulations show that the reaction wheels can consistently maintain pointing to within 30 arcminutes for orbits above 400 kilometers with the payload rotating at 0.83 hertz. / by Evan Dale Wise. / S.M.
| Identifer | oai:union.ndltd.org:MIT/oai:dspace.mit.edu:1721.1/82509 |
| Date | January 2013 |
| Creators | Wise, Evan Dale |
| Contributors | ., Massachusetts Institute of Technology. Department of Aeronautics and Astronautics., Massachusetts Institute of Technology. Department of Aeronautics and Astronautics. |
| Publisher | Massachusetts Institute of Technology |
| Source Sets | M.I.T. Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 85 p., application/pdf |
| Rights | M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission., http://dspace.mit.edu/handle/1721.1/7582 |
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