Abstract We have had an opportunity to develop engineering technology in support of two missions which have applications for other physics experiments. This paper discusses the application which could be extended to other missions. In 1972, we flew a drag-free control system for the Navy's transit navigation satellite. Using an unsupported internal proof mass as a reference, the satellite was forced by feedback to thrusters to follow the shielded internal reference. Thus, the path of the satellite was also drag free. A performance level of five times 10−110 was confirmed by tracking data. The principal disturbance is the mass attraction of the satellite on the proof mass which is two thirds of the error budget. We are developing a gyro test of General Relativity in a program called Gravity Probe-B (GP-B). It will be drag free and also require precision pointing. The gyroscopes will have drift rates some six orders of magnitude better than the best earth-bound gyros. The entire satellite can be considered an instrument since the design of all aspects of the satellite interact with the performance of the experiment. Thus, the principal axes of inertia of the vehicle, the drag-free performance, the attitude control, the temperature environment, the use of liquid helium and temperatures near the absolute zero, the consequent opportunity to use superconducting technology all are essential parts of achieving acceptable performance. The design drift rate for the gyros is less than one milliarcsecond per year.


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    Title :

    Engineering technology for physics experiments in space


    Contributors:

    Published in:

    Publication date :

    1989-01-01


    Size :

    7 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English