Gordon Chin

SELFI: Submillimeter Enceladus Life Fundamentals Instrument, a 3-Year MatISSE Program to mature submillimeter heterodyne spectrometer technology for the remote sensing of Enceladus water plumes that sample its subsurface ocean

SELFI Science Objectives: SELFI observes simultaneously 14 molecular species that are important in the context of life and habitability (five of CHNOPS elements necessary for life) of the Enceladus’ subsurface ocean.

• Assess plume spatial/temporal compositional variability;
• H2O, HDO, and H218O, and H217O evidence of ocean evolution;
• H2O2, and O3 oxidation state of the sub surface ocean;
• CO, NH3, CH3OH, HCN and HNC are biologically relevant species;
• SO2 and H2S links to pre-biotic molecules and volcanoes;
• NaCl provides salinity level of the subsurface ocean and the source of salt in the Saturn ring system.
• Continuum observations measure surface temperature from 30 - 250 K with 0.1 K resolution.
• Correlation of plume activity with surface temperature.

Technical Objectives:

• Advance the TRL of RF Low Noise Amplifier (RF LNA)
• Advance TRL of Mixer & LO Assembly (MLA)
• Design, build and test Microwave Assembly (MWA)
• Design, build and test Digital Spectrometer Assembly (DSA)
• Raise TRL to 6 of SELFI RF-to-Digital Spectrometer through functional and environmental testing
• Reduce risk of flight instrument development

WISHeS: Wideband Imaging Submillimeter Heterodyne Spectrometer for Solar System Exploration and Earth Science Atmospheric Studies - a cross-cutting GSFC 3-year IRAD program for Radical Innovation Initiative

Project Motivation: Submillimeter spectroscopy is a powerful remote sensing tool to study numerous Solar System targets including Earth. The spectral regions in the submillimeter are rich in molecular transitions that probe chemistry and dynamics of planetary atmospheres
⟶ e.g., for Venus: H2O, H218O, H217O, H2O2, NH3, H2S, HDO, SO, SO2 , OCS, 12CO, 13CO, ClO, HCl

Three Year Objectives:

1. Design, integrate, and test a ≥2-pixel 530 – 600 GHz system with broadband IF output as a demonstration of a full receiver array (~8 pixels);
2. Design, integrate, and test noise source diodes across 530 – 600 GHz;
3. Demonstrate a 32 GHz integrated digital spectrometer with 500 kHz spectral resolution using COTS parts with path to space, e.g. Pacific Microchip ASIC, Omnisys, Xilinx RFSOC;
4. Conduct studies and laboratory demonstrations using photonic integrated circuits for up/down conversion to split the IF into sub bands compatible with a bandlimited digital spectrometer;
5. Develop AI smart-sensor system simulator;
6. Antenna design and modeling for array detectors;
7. Support NASA’s investment in imaging spectroscopy through presentations, publications, and partnering with industry and academia.
    

SSOLVE: Submillimeter Observation of Lunar Volatile Experiment -A DALI program to develop and advance lunar instruments.

ScienceObjective:

• Settle the matter of water vapor abundance in the lunar atmosphere
• Compare water vapor with its photolysis product, OH radical
• Diurnal variability of H2O/OH
• Stretch goal: evaluate D/H ratio
• Technology applicable to other species, other landed missions, e.g., Mars, Europa, Enceladus.

Platform: Lander; adaptable to Orbiter

Measurement Scxheme:

• Heliostat to track Sun.
• Measure spectral absorption of water species against Sun.
• Calibrate internal water by measuring against calibration source.
• Calibrate local water against nearby surface.
   

CoI on Submillimeter Solar Observation Lunar Volatiles Experiment (SSOLVE)

GSFC - Greenbelt, MD

2019 - Present

PI Wideband Imaging Submillimeter Heterodyne Spectrometer (WISHeS)

GSFC - Greenbelt, MD

2018 - Present

PI Submillimeter Enceladus Life Fundamentals Instrument (SELFI)

GSFC - Greenbelt, MD

2017 - Present

Science member of GSFC System Review Team for the OSIRIS-Rex Mission.

GSFC - Greenbelt, MD

2013 - 2016

Executive Council Member of NASA Venus Exploration Analysis Group (VEXAG)

GSFC - Greenbelt, MD

2012 - 2015

Co-I, Lunar Exploration Neutron Detector (LEND) instrument on LRO

GSFC - Greenbelt, MD

2008 - Present

LRO Associate Project Scientist

GSFC - Greenbelt, MD

2008 - 2012

LRO Project Scientist

GSFC - Greenbelt, MD

2005 - 2008

Member, NSF ALMA Management Advisory Committee; Chair, 2003–2004

GSFC - Greenbelt, MD

1998 - 2009

Program Scientist, Small Explorer Program, detailed to NASA HQ

GSFC - Greenbelt, MD

1994 - 1995

Project Scientist, Submillimeter Wave Astronomy Satellite (SWAS)

GSFC - Greenbelt, MD

1989 - 2005