Results from a 'small box' real-time molecular contamination monitoron STS-3

Triolo, Jack J.; Kruger, R.; Mcintosh, R.; Maag, Carl R.; Porzio, P. A.

doi:10.2514/3.25670

Cited by 5 publications

(2 citation statements)

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“…62 QCMs have been used in the space industry since the early 1960s, initially for measuring the deposition of contaminants on spacecraft surfaces resulting from material outgassing. [77][78][79] Hence, advantages of QCMs include their proven pedigree as space instruments, and their ''off-theshelf'' availability. By directly measuring mass change, data analysis is kept simple, and experimental application is also simplified, as equipment does not have to be retrieved from orbit.…”

Section: Quartz Crystal Microbalancesmentioning

confidence: 99%

Satellite and rocket-borne atomic oxygen sensor techniques

Osborne¹,

Harris

Roberts

et al. 2001

Review of Scientific Instruments

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Neutral atomic oxygen (AO)—the dominant atmospheric species at typical low Earth orbit altitudes—is responsible for the erosion, or other degradation, of many satellite materials. Therefore, AO has become an important consideration for spacecraft designers and manufacturers. The study of AO is also of interest to atmospheric physicists because it is involved in many of the chemical reactions occurring naturally in the mesosphere and lower thermosphere. Both these groups rely on atmospheric models for computer-based simulation and prediction of atomic oxygen concentrations. Such models require, or are enhanced by, empirical input data—that is, actual measurements of AO number densities. A review is presented of the different measurement techniques that, to date, have been used on satellites and sounding rockets to perform AO studies. Rather than reporting results from every sensor application, this article takes a more general view of the experimental methods, using example devices to highlight their advantages and disadvantages. New or promising equipment, or techniques that could be exploited for performing such measurements, are also described. We attempt some semiquantitative comparison of the techniques, although the most appropriate experimental method for any given flight opportunity depends heavily on the mission conditions and science goals. Our emphasis is on missions where the available mass and power are limited. In these situations the most suitable established device is probably that of the thin film actinometer. If more risk can be assumed then a more promising, but as yet unqualified, method is that of the fiber-optic reflectance sensor. However, since both these devices are nonreusable, it is shown that semiconducting sensors may be better for long duration, mass- and power-limited applications.

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Section: Quartz Crystal Microbalancesmentioning

confidence: 99%

Satellite and rocket-borne atomic oxygen sensor techniques

Osborne¹,

Harris

Roberts

et al. 2001

Review of Scientific Instruments

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“…8 However, their high cost, complexity and power, mass, and size budgets make their use infrequent. Quartz crystal microbalances, small mass change sensors, have also been used in orbit, 9,10 but their size and mass is still such that only one or two can be used on a microsatellite, 11 with similar implications for secondary experiments on larger spacecraft. The instrument described here was therefore based on a third technique, that of electrical resistance monitoring.…”

Section: Introductionmentioning

confidence: 99%

A low cost microsatellite instrument for the in situ measurement of orbital atomic oxygen effects

Harris

Chambers

Roberts

1997

Review of Scientific Instruments

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A simple, inexpensive, hyperthermal atomic oxygen sensor Rev.A small, low-cost sensor for measuring orbital atomic oxygen fluxes and their corrosive effect on spacecraft materials has been developed. Its operation is based on the reaction between hyperthermal atomic oxygen and a thin silver film. The electrical conductivity of the silver oxides formed is negligible allowing the reaction rate to be monitored through resistance measurements of the film. Atomic oxygen effects on spacecraft coatings can be investigated by placing a sample above the silver film. The construction of the sensor emphasizes simple techniques and components to improve reliability and reduce costs, while its small size and mass will allow it to be used on a wide range of spacecraft, increasing flight opportunities. An instrument comprising 12 of the sensors has been tested in orbit on the Space Technology Research Vehicle ͑STRV-1a͒ microsatellite mission. Results from this experiment agree well with those from ground-based simulation facilities. The successful outcome of this demonstration flight shows that the sensor can operate successfully and usefully in space. Several improvements to the technique are suggested for follow-on flights.

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