Technology for Small Spacecraft (1994) / Chapter Skim
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7 Guidance and Control Technology
7 Guidance and Control Technology
Pages 57-65
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From page 57... ...
In this regard, the pane} considers the proposed TIMED program to be critical; it should be augmented with sufficient funds to ensure adequate "validation" and full documentation of hardware and software. However, for NASA to take full advantage of these developments, additional funding for space qualification; radiation hardening; adaptation; and, in some cases, further refinement, is required.
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From page 58... ...
Interferometric fiber-optic gyroscopes employ optical fibers and electro-optical transducers similar to those used in optical communication links and, hence, will continue to benefit from ongoing developments in commercial communications. Developers believe that necessary performance and radiation resistance in interferometric fiber-optic gyroscopes are readily achievable with further effort.
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From page 59... ...
While current performance falls short of that which is desired for many applications, the commercial effort on detector arrays is almost certain to improve the discrimination and accuracy achievable in the near future. Even though flight tests of these devices are currently scheduled on the proposed NASA TIMED and the ongoing BMDO Clementine missions, the pane!
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From page 60... ...
Advantage should be taken of the conventional-bearing design skills in industry and in the Charles Stark Draper Laboratory, and the development of magnetic-bearing reaction wheels should be limited to those programs requiring the special properties of such bearings, namely, very long life and lower level of vibration. Magnetic bearings could become important, but the complexity of associated electronics, the added power requirements, and the increased cost and weight are disadvantages, particularly if properly designed conventional bearings can satisfy the requirements.
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From page 61... ...
. The information obtained using the various differential techniques can then be used to develop velocity, attitude, and even attitude rate signals, as well as extremely precise relative position data.
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From page 62... ...
it is understood that some space flight testing _ ~ ~ ~ ~ - - -I -- - - 0 will always be required, but hopefully not the extended space testing that was necessary in the past. Considerable progress has been made in predicting radiation effects and in ground testing, enabling radiation hard and tolerant design and reducing the need for flight tests.
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From page 63... ...
Development is being funded largely on corporate independent research and development, with a small program underway at GSFC. INTERFACES Considerable emphasis has been placed on spacecraft bus standards by industry and government.
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From page 64... ...
fiber-optic interferometric gyroscope; miniature focal plane array star tracker; space-hardened GPS receiver/processor with attitude capability; advanced, miniaturized small reaction wheel; hardened 32-bit processor; and hardened solid-state recorder.
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From page 65... ...
subsystems (e.g., Military Standards 1553 and 1773) to simplify integration activities should be evaluated, and standardization should be implemented as indicated by the evaluation.
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