NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Experimental study of solar simulator mirror cryocontaminationThe background and tasks formulation of the study of Solar Simulator collimation mirror cryocontamination in Large Thermal Vacuum Facility are outlined, research methods and experiment procedures are described, experimental relationships obtained are analyzed and practical recommendations are given. The accepted procedure of thermal vacuum tests as a rule defines the sequence of operations for verifying the spacecraft under test without taking into account measures for preventing Solar Simulator collimation mirror contamination and degradation. On the other hand, evacuation procedures is defined for conditions of achieving the required vacuum in the shortest possible time with using the available evacuation equipment at a regime close to the optimum one. Similarly, cryopanel cooling down cyclogram and test object preparation process are not analyzed from the viewpoint of ways of reducing environmental detrimental effects on thermal vacuum facility contamination-sensitive systems. Solar Simulator mirror contamination and its reflective characteristics change results in degradation of solar flux parameters and reduction of simulator continuous operation time. Methods of consideration of optical effects due to mirror surface contamination are actually missing. The effects themselves are not quite understood and data cited in literature as a rule, were obtained under conditions different from real thermal vacuum facility and therefore should be subjected to additional experimental verification. Only in the last few years contamination effect on optical surfaces degradation has been considered with using empirical relations. Mirror reflective properties degradation leads to the increase of Solar Simulator errors. This ultimately has an adverse effect on S/C ground development, schedule and cost of thermal vacuum tests. Besides, the mirror maintenance in operable state becomes more expensive. The present paper is dedicated to the study of Solar Simulator collimation mirror contamination and to the search of ways for improving the mirror design and thermal vacuum test procedure. On the basis of tests performed, recommendations are devised on reducing chamber inner-optical surfaces cryocontamination and degradation.
Document ID
19950007652
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Galjaev, V. L.
(Nauchno-Issledovatelskii Inst. Grafit Moscow, Russia)
Makarov, A. A.
(Nauchno-Issledovatelskii Inst. Grafit Moscow, Russia)
Afanassiev, N. A.
(Nauchno-Issledovatelskii Inst. Grafit Moscow, Russia)
Date Acquired
September 6, 2013
Publication Date
November 1, 1994
Publication Information
Publication: NASA. Goddard Space Flight Center, Eighteenth Space Simulation Conference: Space Mission Success Through Testing
Subject Category
Optics
Accession Number
95N14065
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available