Search NASA⌕ Search

Engineering topics

Stephens, J. B.

Publications and source records attributed to Stephens, J. B..

68 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1969

Space simulator Patent

Space environment simulator for testing spacecraft components under aerospace conditions

Stephens, J. B.↗
NASA NTRS1967

Molecular sink.

Molecular sink for simulated testing of spacecraft components noting vessel construction, vacuum pump system, molecular trap array, etc

MOLECULAR PUMP↗
NASA NTRS1967

Quartz crystals detect gas contaminants during vacuum chamber evacuation

Piezoelectric quartz crystals detect condensable gas contaminants backstreaming into a vacuum chamber when a pump is evacuating the chamber. One crystal acts as a thermometer, the other detects mass change. They are energized by electronic equipment which records frequency changes.

Stephens, J. B.↗
NASA NTRS1967

Crystal microbalance measures condensable molecular fluxes

Quartz crystal quantitatively measures molecular fluxes emanating from and condensing on spacecraft surfaces. Vibrating in a thickness shear mode, the crystal is frequency sensitive to changes in mass on its surface and can measure a fractional monolayer of a condensate.

Stephens, J. B.↗
NASA NTRS1964

Helium tube separates nitrogen gas from liquid nitrogen

To prevent a boiloff problem, liquid nitrogen flowing from a storage tank to a container, is separated into liquid and gaseous components. This is accomplished by centrifugal and venting action, using a section of perforated helical aluminum tubing.

Stephens, J. B.↗