THEMIS INSTRUMENT NITROGEN PURGE THEMIS TIM PURGE1 UCB

THEMIS INSTRUMENT NITROGEN PURGE THEMIS TIM PURGE-1 UCB, JUNE 16, 2005

Purge Design Requirements The purge system was designed to comply with the following standards: NASA-STD-5005 Ground Support Equipment Design Criteria EWR 127 Eastern and Western Range Safety Policies and Practices PAIP THEMIS Performance Assurance Implementation Plan (UCB Document) THM-SYS-011 THEMIS Configuration Management Plan (UCB Document) THM-SYS-004 THEMIS Contamination Control Document (UCB Document) SAI-PLAN- 0647 THEMIS Mission System Program Safety Plan (Swales Document) THEMIS TIM PURGE-2 UCB, JUNE 16, 2005

THEMIS Purge Overview ESA & SST Instruments Require Nitrogen Purge • Nitrogen Purge Required Two of the instruments on the THEMIS probes require high purity (99. 999%) nitrogen purging – the SST (Solid State Telescope) and ESA (Electrostatic Analyzer) instruments. The ESA microchannel plates are sensitive to condensable hydrocarbons, particulates, and water vapor. The SST detectors are sensitive mainly to particulates. • Low Pressure / Very Low Flow (5 psi / 68 sccm (. 0024 cfm) per Probe) • UCB SSL will supply all hardware Oxygen Sensor, 2 -stage Regulator, Gages (Blow-Out-Back Type), Relief Valve (10 psi), Shutoff Valve, Filter/Moisture Separator, Flow meter, Hose Assemblies with Quick Disconnects, Manifolds etc. • UCB SSL Responsible for Purge With some assistance in monitoring gas supply and providing gas at non-UCB facilities. • Purge up until PCA Integration When impractical to purge, 24 hr off-purge limit. Lumaloy bonnets on instruments when covers are off (up until PCA integration)/ • Bag PCA and Backfill With Nitrogen Reference THM-SYS-032 PURGE PLAN REV B for more detail THEMIS TIM PURGE-3 UCB, JUNE 16, 2005

Probe Purge THEMIS TIM PURGE-4 UCB, JUNE 16, 2005

Purge Hardware THEMIS TIM PURGE-5 UCB, JUNE 16, 2005

Purge Outline THEMIS TIM PURGE-6 UCB, JUNE 16, 2005

Purge Outline cont. THEMIS TIM PURGE-7 UCB, JUNE 16, 2005

PCA Bagging THEMIS TIM PURGE-8 1. Final Instrument Purge Just Prior to PCA integration 2. Bag PCA After Integration 3. Purge Bag For 24 Hours 4. Remove Purge Line. 5. Transport to Pad 6. Remove Bag Just Prior to Installing Shroud UCB, JUNE 16, 2005