Tech Briefs

NanoRacks-Scale MEMS Gas Chromatograph System

This is a compact, simple, cost-effective system.

In order to study atmospheric or evolved gases, it is highly advantageous for an instrument (e.g. mass spectrometer (MS), thermal conductivity detector (TCD)) to simplify the gas stream with a front-end gas chromatograph (GC). When used for planetary missions, highperformance GCs have to satisfy the additional challenging requirements of surviving high inertial loads with low mass, power, and volume in order to be included in Ventures-, Discovery- and New Frontiers-class missions in today’s budget-constrained reality.

The development and adoption of advanced MEMS-GCs at JPL would provide a key enabling technology for near-term missions to Mars or Venus. A MEMS (Micro-Electro-Mechanical Systems)-based GC system would be significantly smaller, about 1 kg (including electronics), with a power consumption of less than 1 W (for isothermal operation). It would also not have the many complicated fittings and joints of a conventional GC, significantly enhancing inertness and robustness.

JPL partnered with Cbana Labs to couple their MEMS-GC to a miniaturized adaptation of a JPL ion trap mass spectrometer, a version of which is currently operating in the Vehicle Cabin Atmosphere Monitor (VCAM) on the International Space Station (ISS). However, since a MEMS-GC has never flown in space before, JPL is looking at ways to reduce risk and to test the MEMS-GC cheaply and rapidly using the NanoRacks service to the ISS.

The MEMS-GC system includes the MEMS-GC chip (with MEMS-preconcentrator, MEMS-valves, MEMS-column in the middle of a Vespel block), a MEMSTCD (in a separate Vespel block), a miniature diaphragm sample pump, and electronics. Cabin air would be used as the carrier gas.

This work was done by Richard D. Kidd, Murray R. Darrach, Vachik Garkanian, and Stojan Madzunkov of Caltech; and Byunghoon Bae of Cbana Labs for NASA’s Jet Propulsion Laboratory. NPO-48859