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Polymers are one of the major constituents in electrical components. A study investigating pre-combustion off-gassing and particle release by polymeric materials over a range of temperatures can provide an understanding of thermal degradation prior to failure which may result in a fire hazard. In this work, we report simultaneous measurements of pre-combustion vapor and particle release by heated polymeric materials. The polymer materials considered for the current study are silicone and Kapton. The polymer samples were heated over the range 20 to 400°C. Response to vapor releases were recorded using the JPL Electronic Nose (ENose) and Industrial Scientific's ITX gas monitor configured to detect hydrogen chloride (HCl), carbon monoxide (CO) and hydrogen cyanide (HCN). Particle release was monitored using a TSI P-TRAK particle counter.

An array-based sensing system based on 32 polymer/carbon composite conductometric sensors is under development at JPL. Until the present phase of development, the analyte set has focused on organic compounds (common solvents) and a few selected inorganic compounds, notably ammonia and hydrazine. The present phase of JPL ENose development has added two inorganics to the analyte set: mercury and sulfur dioxide. Through models of sensor-analyte response developed under this program coupled with a literature survey, approaches to including these analytes in the ENose target set have been determined.

As part of the Mars Exploration Rover (MER) project, the National Aeronautics and Space Administration (NASA) launched two rovers in June and July of 2003 and successfully landed both of them on Mars in January of 2004. The cruise stage of each spacecraft (S/C) housed most of the hardware needed to complete the cruise from Earth to Mars, including the propulsion system. Propulsion lines brought hydrazine propellant from tanks under the cruise stage to attitude-control thrusters located on the periphery of the cruise stage. Hydrazine will freeze in the propellant lines if it reaches temperatures below 1.7°C. Thermal control of the propulsion lines was a mission critical function of the thermal subsystem; a frozen propellant line could have resulted in loss of attitude control and complete loss of the S/C.

The Trace Gas Analyzer (TGA, Figure 1) is a self-contained, battery-powered mass spectrometer that is designed for use by astronauts during extravehicular activities (EVA) on the International Space Station (ISS). The TGA contains a miniature quadrupole mass spectrometer array (QMSA) that determines the partial pressures of ammonia, hydrazines, nitrogen, and oxygen. The QMSA ionizes the ambient gas mixture and analyzes the component species according to their charge-to-mass ratio. The QMSA and its electronics were designed, developed, and tested by the Jet Propulsion Laboratory (1,2). Oceaneering Space Systems supported JPL in QMSA detector development by performing 3D computer for optimal volumetric integration, and by performing stress and thermal analyses to parameterize environmental performance.

In order to meet microbial reduction requirements for all Mars in-situ life detection and sample return missions, entire planetary spacecraft (including planetary entry probes and planetary landing capsules) may have to be exposed to a qualified sterilization process. At JPL, we are developing a low temperature (~45°C) vapor phase hydrogen peroxide sterilization process. This process is currently being used by the medical industry and its effectiveness is well established. In order to effectively and safely apply this technology to sterilize a spacecraft, which is made out of various man-made materials and electronic circuit boards, the following technical issues need to be resolved: 1. Efficacy of sterilization process. 2. Diffusion of H2O2 under sterilization process conditions into hard to reach places. 3. Materials and components compatibility with the sterilization process. 4. Development of methodology to protect (isolate) sensitive components (i.e. electronic ) from H2O2 vapor.

A miniature quadrupole mass spectrometer array and gas chromatograph have been designed and built for NASA flight missions. Without the gas chromatograph the mass spectrometer is to be used for detection, by astronauts in EVA, of N2, O2, the hydrazines, and NH3 leaks in the hull of the International Space Station, and of adsorbed hydrazines on the astronauts’ suits. The fully-adapted astronaut system, with all software and visual readout, is called the Trace Gas Analyzer. When interfaced with the miniature gas chromatographic system, the mass spectrometer will be useful for a variety of NASA missions involving more complex gas mixtures. The missions include planetary exploration (to Venus, Europa, Titan, etc.), as well as cabin-air monitoring for long-duration human flight to the Moon, Mars, and beyond.

Human exploration of Mars as well as unmanned sample return missions from Mars can benefit greatly from the use of propellants produced from the resources available from the atmosphere of Mars. The first major step of any in-situ propellant production (ISPP) system is to acquire carbon dioxide (CO2) from the Mars atmosphere and compress it for further chemical processing. One system that performs this step is called a Mars Atmosphere Acquisition and Compression (MAAC) unit. A simple prototype MAAC was developed by JPL as part of the Mars ISPP Precursor (MIP) experiment package for inclusion on the Mars 2001 Surveyor Lander. The MAAC consists of a valved enclosure packed with a sorbent material which selectively adsorbs CO2 from the Mars atmosphere (valves open), desorbs and compresses the acquired CO2 by heating (valves closed) and then delivers the pressurized CO2 to an oxygen generating system where the CO2 is electrolyzed to produce oxygen.

Various candidates for nonpetroleum electric and hybrid vehicle (EHV) subsystems have been evaluated as part of the Advanced Vehicle (AV) Assessment at the Jet Propulsion Laboratory. The subsystems include battery and power-peaking energy storage, heat engine and fuel cell energy conversion devices, motor/controller subsystems, transmissions, and vehicle subsystem (structure and body) technologies. The primary objective of this effort, was to project the mature capabilities of the various components in the 1990’s for application in the systems evaluations in the next phase of this activity. This paper presents the basic characteristics of the subsystems and compares their capabilities with projected AV subsystem requirements.

Hydrogen, gasoline, and mixtures thereof were compared as fuels for lean-burn engines. Hydrogen for the mixed fuels tests was generated by partial oxidation of gasoline. Hydrogen combustion yielded the highest thermal efficiency at any NOx level. Gasoline yielded the second highest thermal efficiency for NOx levels greater than or approximately equal to two gm/mi. For lower NOx levels and high vehicle inertia weights, progressively more hydrogen supplementation was the second most efficient system. For vehicle inertia weights below 5000 lbm (2300 kg), the statutory NOx standard (0.4 gm/mi) could be met with one lb/hr (0.13 g/s) hydrogen supplementation.

Bladders, diaphragms, and pistons used for the positive expulsion of earth-storable liquid rocket propellants are discussed in general terms. The history of PL's work on these devices is reviewed as a background to the current programs. A detailed account of the development and use of bladders in Ranger and Mariner spacecraft is presented. The final section describes an advanced development program aimed at providing technology for future spacecraft.