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