Engineering topics

Reese, Eric

Publications and source records attributed to Reese, Eric.

3 records

NASA NTRS2010

Evaluation of the Air Quality Monitor's Performance on the International Space Station

The Air Quality Monitor (AQM) was flown to the International Space Station (ISS) as an experiment to evaluate its potential to replace the aging Volatile Organic Analyzer (VOA), which ceased operations in August 2009. The AQM (Figure 1) is a small gas chromatography/differential mobility spectrometer (GC/DMS) manufactured by Sionex. Data was presented at last year s ISIMS conference that detailed the preparation of the AQM for flight, including instrument calibration. Furthermore, initial AQM data was compared to VOA results from simultaneous runs of the two instruments. Although comparison with VOA data provided a measure of confidence in the AQM performance, it is the comparison with results from simultaneously acquired air samples (grab sample containers-GSCs) that will define the success (or failure) of the AQM performance. This paper will update the progress in the AQM investigation by comparing AQM data to results from the analyses of GSC samples, returned from ISS. Additionally, a couple of example will illustrate the AQM s ability to detect disruptions in the spacecraft s air quality. Discussion will also focus upon a few unexpected issues that have arisen and how these will be a addressed in the final operational unit now being built.

Limero, Thomas↗

NASA NTRS1999

A Second-Generation Volatile Organic Analyzer for the International Space Station

Early in the development of the Crew Health Care System (CHECS) for the International Space Station (ISS), it was recognized that detection of target volatile organic compounds would be a key component of the air monitoring strategy. Experiences during the NASA/Mir program supported the decision to include a real-time volatile organic analyzer (VOA) aboard ISS to help assess the impact of air quality events on crew health and determine the effectiveness of decontamination efforts. Toward this end, a joint development by the Toxicology Laboratory at Johnson Space Center and Graseby Dynamics produced a VOA that has been delivered and is ready for the first 5 years of ISS operation. The first-generation VOA selection criteria included minimizing size, weight, and power consumption while maintaining analytical performance. Measuring available technologies against these criteria, a VOA system based upon gas chromatography/ion mobility spectrometry (GC/IMS) was selected in the mid-90's. However, as NASA looks forward to later-stage ISS operations and to new frontiers such as human exploration of Mars, the ISS VOA (weighing 43 kg and consuming 160 watts) must be replaced by a smaller, less resource-intensive device. This paper will present a possible second-gene ration VOA based upon the same technology as the first-generation unit. Utilizing GC/IMS technology again will permit the instrumental data and experience gained during the initial phase of ISS to be applied to later ISS phases and advanced spacecraft missions. During the past 3 years, efforts to reduce the size of ion mobility spectrometers have been pursued by Graseby Dynamics, the manufacturer of the first-generation VOA. The concept of operation, expected analytical performance, and estimated size of a fully functional second-generation VOA based upon GC/mini-IMS technology will be presented. Furthermore, results of initial laboratory evaluations will be shown.

Limero, Thomas↗

NASA NTRS1999

Evaluation of Gas Chromatography/Mini-IMS to Detect VOCs

The Toxicology Laboratory at Johnson Space Center (JSC) has pioneered the use of gas chromatography-ion mobility spectrometry (GC/IMS) for measuring target volatile organic compounds (VOCs) aboard spacecraft. Graseby Dynamics, under contract to NASA/Wyle, has built several volatile organic analyzers (VOA) based on GC/IMS. Foremost among these have been the volatile organic analyzer-risk mitigation unit and the two flight VOA units for International Space Station (ISS). The development and evaluation of these instruments has been chronicled through presentations at the International Conference on Ion Mobility Spectrometry over the past three years. As the flight VOA from Graseby is prepared for operation on ISS at JSC, it is time to begin evaluations of technologies for the next generation VOA, Although the desired instrument characteristics for the next generation unit are the same as the current unit, the requirements are much more stringent. As NASA looks toward future missions beyond Earth environs, a premium will be placed upon small, light, reliable, autonomous hardware. It is with these visions in mind that the JSC Toxicology Laboratory began a search for the next generation VOA. One technology that is a candidate for the next generation VOA is GC/IMS. The recent miniaturization of IMS technology permits it to compete with other, inherently small, technologies such as chip-sized sensor arrays. This paper will discuss the lessons learned from the VOA experience and how that has shaped the design of a potential second generation VOA based upon GC/IMS technology. Data will be presented from preliminary evaluations of GC technology and the mini-IMS when exposed to VOCs likely to be detected aboard spacecraft. Results from the evaluation of an integrated GC/mini-IMS system will be shown if available.

Limero, Thomas↗