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Atmospheric Water Experiment for a Small Orbiter at Mars (AWESOM)
Paul Hayne1, Matt Siegler1,2, Imran Mehdi1, Erich Schlecht1, Goutam Chattopadhyay1, and David Paige3
1Jet Propulsion Laboratory – Caltech, 2Planetary Science Institute, 3UCLA
Overview
• Possible liquid-water features recently observed on Mars indicate potentially habitable environments
• Submillimeter (microwave) spectroscopy is a powerful technique for observing water vapor and constraining its concentration and isotopic composition
• Recent developments at JPL have led to miniaturized instruments compatible with cubesats
3
McEwen et al., 2013Ojha et al., 2014
“Recurring slope lineae” (RSL)
Hypotheses: 1. Spring and summer temperatures get warm enough to melt subsurface (salty) ice2. Deliquescence draws H2O vapor out of the atmosphere gradually, until droplets form
Could Evaporation at RSL Generate H2O Plumes?
Mumma et al., 2003
(Not water)
Seasonal (background) Water Vapor
Smith, 2002
Continuous coverage at all local times needed in order to detect (or rule out) water plumes
Time
Why Microwaves?
MIRO (Rosetta)
Why Microwaves?
Can measure water vapor at ~10-6 pr-μm!
Heterodyne Instruments(JPL has a long and distinguished history)
Earth Science: Atmospheric science, temperature and pressure profiling, cloud physics and dynamics, ozone depletion, wind velocity etc
Astrophysics: Study galaxies far away, star formation, star decay, D/H ratio measurement, water detection, C+ detection, HD detection, etc HIFI on Herschel
MLS on Aura
MIRO on Rosetta(sending data right now!!)
STO
Planetary Science: Planetary atmospheres and the search for water and life signatures, sounding, etc
Heterodyne Technology Development (1 of 2)JPL continues to lead with MDL fabricated diode MMICS and silicon
micro-machining that are robust and enabling
Integrated Receiver Front-ends provide compact foot-print and lower mass
W-band input waveguide
RF input waveguide
LO waveguide
SH
M
Trip
ler
Complete Receiver in
silicon package
2-11 GHz IF output
85-100 GHz30-80 mW
520-600 GHzIntegral feedhorn
20 mm
Low-parasitic membrane MMICs
Heterodyne Technology Development (2 of 2) Infusion of advanced CMOS technologyEnhance functionality with lower mass and power
28 GHz – 35 GHz Frequency Synthesizer for Local Oscillator (LO)
Total Power Consumption: Less than 100 mW
• A Full 2.0 GS/s spectrum analyzer chip in advanced 65nm CMOS is developed in collaboration with UCLA.
• Integrated 7b digitizers, offset and interleaving calibration functions, clock management system and vector accumulation.
• 512 channel quadrature output with integrated USB 2.0 controller.
• Reduce volume, mass, and power consumption! • Investigate simplified testing and calibration schemes
Approx. 20 cm
SHM Tripler PA
X3
Sextupler
X6
VCOAntenna
> 50xReducedVolume size
Challenges for Cubesat Accommodation
Possible Discoveries
• Water vapor available for deliquescence?
• Water vapor plume after RSL activity?
• Diurnal water vapor variations• Water vapor isotopic
abundances (origins?)• Vertical winds, surface
temperatures, pressures
Summary
• Possibility of liquid H2O activity on present-day Mars is real, but controversial
• Water vapor measurements could resolve debate
• Microwave spectroscopy is an ideal technique for measuring H2O vapor abundance and composition
• Highly-compact JPL microwave spectrometers are being developed for cubesats