Engineering topics
Publications and source records attributed to Orr, D. H..
Six-degree-of-freedom simulator uses economical components. Reduction in complexity makes this or similar system cost-effective for training manipulator operators, such as those in industries handling nuclear wastes and hazardous chemicals.
A survey of the test and checkout requirements of the tracking portion of the communications and tracking subsystem was performed to evaluate adequacy of planned tests and test requirement documents. Emphasis is placed on identifying test completeness, duplications, and omissions. Items that may save time, aid in testing, and present a more complete integrated test program are also noted. The results of this survey are summarized.
Automatic switching of the shuttle orbiter S-band quad antennas by the orbiter on-board computers was evaluated. The development and use of an extensive computer program to determine antenna switch position states as a function of time for various orbital activities is described. The selection of the optimum quad antenna element at any given time is based on the look angle to the appropriate Tracking Data Relay Satellite (TDRS). It is shown that a 2.4 second period is required for updating the S-band quad antenna switch state based on a maximum roll rate of 2 deg per second. The possibility of a variable update period is suggested since the 2 deg per second attitude rate is seldom encountered and would, for example, dictate approximately 248,000 on-board computer calculations during Reference Mission 2. The average number of antenna switch state changes was found to be in the range of 1,300 for Reference Mission 2.