Variation in gas concentration near active volcanoes could provide valuable information about the state of the internal activity beneath the Earth’s crust. Compounds such as acetone (C3H6O), sulfur dioxide (SO2), and carbon dioxide (CO2) in the atmosphere could be used as key indicators to predict when the volcanic eruption would occur. In an effort to promote scientific cooperation among NASA, the United States Air Force, and the University of Costa Rica, KSC is in the process of developing a small mass spectrometer system to be flown onboard a research aircraft known as WB-57 (figure 1) for in situ gas sample collection. The goal of this joint project is to determine the correlation between in-flight gas concentration data and the states of various volcanoes during their evolution process in order to provide early warning of the volcanic activity to the local residents. This will be the first time that a mass spectrometer is used in a high-altitude (approximately 50,000 feet), low-pressure (150 torr), and low-temperature (-50 degrees Celsius [°C] or -58 degrees Fahrenheit) environment. The instrument has to be small enough to fit into a dedicated compartment of the aircraft, light enough so that it will not exceed the aircraft’s overall load limit, and rugged enough to withstand the g-force during takeoff and landing. Above all, it should be operational continuously and autonomously during the entire estimated 7-hour flight. Success of this test flight would be crucial for future hardware development of the advanced hazardous gas detection system onboard the Space Shuttle.

Figure 2 depicts the major components of the mass spectrometer system to be tested before flight: an SRS RGA 100 quadrupole analyzer; an Alcatel ATH 30+ Turbo molecular pump; an Alcatel ACT 200 Turbo Pump controller; a 24-volt direct-current, dual-stage Spyradyn Scroll pump; a Granville-Phillips Ion Gauge Module; a Granville-Phillips Convectron Gauge Module; an MKS Mass Flow Controller; an MKS Baratron Pressure Gauge; and an MKS Cluster Controller. The entire unit weighs about 90 pounds and is currently being assembled in the Engineering Development Laboratory at KSC. Preliminary environmental testing on the system indicates that most of its components appear to be functional nominally at 150 torr, but some of its components, especially the turbo molecular pump, may require heaters to keep them warm and operational at -50 °C. Vibration tests will also be performed to ensure the system’s functionality in the presence of shock and vibration during takeoff, landing, and in-flight turbulence.

Key milestones:

• Complete system design and buildup.
• Complete system test at low pressure. All components performed nominally.
• System test at low temperature is still in work. Some components require heaters.
• Vibration test will follow after environmental test.
• Transport to Johnson Space Center for WB-57 flight.