My Husband - The Genius

Josh thinks he may have decided on a thesis topic! Here are the main elements:
(If you can only get through the first word or so, it's alright, we can't all be rocket scientists. Some of us have to teach them when they're three, you know, or they'd never get this far!) Anyways, read through as much as you can, and try to comprehend the brilliance of my husband. :-D

Angular Velocity Estimation

Traditionally, the angular velocity of a spacecraft is measured using a mechanical or MEMS gyroscope. These instruments are typically very expensive or significantly inaccurate, however. Likewise, the inclusion of such instruments adds complexity to the overall satellite bus. It is therefore advantageous to search for numerical methods to estimate this quantity from attitude parameter measurements. There are two methods available for doing this, one is derivative-based and the other is filter-based. I would like investigate the performance of these methods as well as see if anything can be said about total system stability when using such methods.

Adaptive Control

Many modern spacecraft are characterized by changing inertial parameters. Such spacecraft include systems with movable (or deploying) parts, expulsion of fuel or smaller spacecraft from the main spacecraft, and the docking of other spacecraft to the main spacecraft. In these situations, and others like them, the satellite inertia matrix my have significant uncertainty or may simply be unknown. To accommodate such spacecraft, one must create an adaptive control
structure that is capable of identifying the model plant and changing the control structure accordingly. The aforementioned satellite under consideration would be an excellent testbed for such systems. -- I also want to note that such systems would be of great interest to the Air Force, which is currently looking into the feasibility of responsive space missions (ones which go from mission definition to launch integration in six days). If the control structure could adapt for whatever spacecraft it is placed in, one could effectively have a control system that is ready for launch without a known model of the spacecraft (within some range of uncertainty of course).

Tether Dynamics

Tethered spacecraft attitude control strategies have received much attention over the years and are a continued area of research today. The satellite in question will most likely contain a back up tether for gravity gradient stabilization. Thus, there is a possibility for experiments in tether dynamics and control.