Abstract: A test maker accesses a test computer and inputs a question for a test. The test maker then inputs a plurality of acceptable answers for the question and an expression related to the question. The test maker then inputs acceptable values for each element in the expression and corresponding credit percentages. The test server determines an aggregate rubric of answers based on the answers and expression input by test maker and from transposes of these numbers. A test taker accesses the test and inputs his answers. The test server compares the answers of the test taker with the aggregate rubric and scores the test.

Abstract: A method for maintaining the attitude of a three-axis controlled satellite by use of magnetic torquers includes using magnetometers for measuring the direction of the ambient geomagnetic field. The direction of the net reaction wheel momentum is also determined. The angle between the direction of the geomagnetic field and the net reaction wheel momentum is determined. The angle is compared with a threshold value. Magnetic torquer power consumption is reduced by operating the magnetic torquers only when the angle exceeds the threshold value.

Abstract: A method for making a transition between a spin-stabilized spacecraft operating mode and a 3-axis stabilized mode includes the step of determining the orientation of the spin axis. A reference object detector such as a sun sensor produces a pulse as it crosses the reference, thereby completely specifying the attitude of the spinning spacecraft at that instant. Angular rate information is used to update the attitude information while a feedback system controls torques for slowing the spin and for assuming the desired attitude.