Steven Feng

Volatile Analysis by Pyrolysis of Regolith for planetary resource exploration

The extraction and identification of volatile resources that could be utilized by humans including water, oxygen, noble gases, and hydrocarbons on the Moon, Mars, and small planetary bodies will be critical for future long-term human exploration of these objects. Vacuum pyrolysis at elevated temperatures has been shown to be an efficient way to release volatiles trapped inside solid samples. In order to maximize the extraction of volatiles, including oxygen and noble gases from the breakdown of minerals, a pyrolysis temperature of 1400°C or higher is required, which greatly exceeds the maximum temperatures of current state-of-the-art flight pyrolysis instruments. Here we report on the recent optimization and field testing results of a high temperature pyrolysis oven and sample manipulation system coupled to a mass spectrometer instrument called Volatile Analysis by Pyrolysis of Regolith (VAPoR). VAPoR is capable of heating solid samples under vacuum to temperatures above 1300°C and determining the composition of volatiles released as a function of temperature.

The Planet-B neutral gas mass spectrometer

The Planet-B neutral gas mass spectrometer is designed for in-situ measurements of the gas composition in the upper atmosphere of Mars. The sensor uses a dual frequency quadrupole mass analyzer with a mass range of 1–60 amu (atomic mass units) and two electron multipliers to cover the dynamic range required. The ion source, which is collinear with the analyzer, operates in two different modes: 1) a closed source mode measuring non-surface reactive neutral species that have thermally accommodated to the gas inlet walls; and 2) an open source mode measuring chemically surface active species by direct beaming with no surface collisions. The in-line Retarding Potential Analysis (RPA) system selects the mode of operation. An onboard Field Programmable Gate Array (FPGA) is used to control the instrument operating parameters in accordance with pre-programmed sequences and to package the telemetry data. The sensor is sealed and maintained in a vacuum prior to launch and will be opened to the environment of Mars after orbit insertion. Measurements of He, N, O, CO, N2, NO, O2, Ar, and CO2 will be done at periapsis and the data will be used to determine the variation of the neutral atmosphere density and temperature with altitude, local solar time and season. Measurements are possible from 130–140 km to 500 km depending on the gas species, chemical background, and instrument measurement mode. The data will contribute to the studies of thermosphere energetics, lower atmosphere meteorology (e.g. dust storms) and serve as a resource for studies of the interaction of the upper atmosphere with the solar wind.

Organics Analyzer for Sampling Icy Surfaces: A liquid chromatograph-mass spectrometer for future in situ small body missions

Liquid chromatography mass spectrometry (LC-MS) is an important laboratory technique for the detection and analysis of organic molecules with high sensitivity and selectivity. This approach has been especially fruitful in the analysis of nucleobases, amino acids, and measuring amino acid enantiomeric ratios in extraterrestrial materials. We are developing OASIS, Organics Analyzer for Sampling Icy Surfaces, for in situ analysis on future landed missions to astrochemically important icy bodies, such as asteroids, comets, and icy moons. The OASIS design employs a microfabricated, on-chip analytical column to chromatographically separate liquid analytes using known LC stationary phase chemistries. The elution products are then interfaced through spray ionization and analyzed by a time-of-flight mass spectrometer (TOF-MS). A particular advantage of our design is its suitability for microgravity environments, such as for a primitive small body.

Science of opportunity: Heliophysics on the FASTSAT mission and STP-S26

The FASTSAT spacecraft, which was launched on November 19, 2010 on the DoD STP-S26 mission, carries three instruments developed in joint collaboration by NASA GSFC and the US Naval Academy: PISA, TTI, and MINI-ME.1,2 As part of a rapid-development, low-cost instrument design and fabrication program, these instruments were a perfect match for FASTSAT, which was designed and built in less than one year. These instruments, while independently developed, provide a collaborative view of important processes in the upper atmosphere relating to solar and energetic particle input, atmospheric response, and ion outflow. PISA measures in-situ irregularities in electron number density, TTI provides limb measurements of the atomic oxygen temperature profile with altitude, and MINI-ME provides a unique look at ion populations by a remote sensing technique involving neutral atom imaging. Together with other instruments and payloads on STP-S26 such as the NSF RAX mission, FalconSat-5, and NanoSail-D (launched as a tertiary payload from FASTSAT), these instruments provide a valuable “constellation of opportunity” for following the flow of energy and charged and neutral particles through the upper atmosphere. Together, and for a small fraction of the price of a major mission, these spacecraft will measure the energetic electrons impacting the upper atmosphere, the ions leaving it, and the large-scale plasma and neutral response to these energy inputs. The result will be a new model for maximizing scientific return from multiple small, distributed payloads as secondary payloads on a larger launch vehicle.