Europa Lander Stereo Spectral Imaging Experiment (ELSSIE)
Abstract
In support of landed investigation to search for biosignatures on Europa, determine habitability of Europa's ocean, and understand physical processes that modify Europa's crust, we are prototyping ELSSIE under a ICEE-2 grant. ELSSIE would: 1) provide panoramic and workspace views to support sampling and geological analyses; 2) collect visible and infrared data to identify and map enrichments in organics and non-ice phases and determine which ice is least radiation-damaged, thus supporting selection of the best samples for detailed in situ analysis; and 3) survey the landscape for morphologic or spectral evidence of active surface processes. ELSSIE provides stereo and imaging/spectroscopic measurements of reflected light from visible to shortwave-infrared wavelengths. ELSSIE's Sensor combines a multispectral stereo imager with 20 filters over the 0.4-3.6 micrometer wavelength range with a 0.8-3.6 micrometer point spectrometer, which share a single radiation-shielded 2048 x 2048 HgCdTe focal plane. The Sensor is supported by a Data Processing Unit (DPU) based on that of the Mapping Imaging Spectrometer for Europa (MISE) on Europa Clipper. Current work focuses on minimizing Sensor mass and volume, qualifying mechanical designs over the wide temperature range from cryogenic surface operation to dry heat microbial reduction (60°-398°K), and demonstrating resiliency of the DPU data processing pipeline Each of the 2 refractive cameras has two 6-position filter wheels (providing 10 spectral filters plus a clear position), each subtending a 15 x 15 degree field-of-view with 700 x 700 pixels. The point spectrometer samples a 2-mrad spot at 8.5 nm/channel, augmenting multispectral imaging detections of compositional variations with higher spectral resolution assessment of the spectral signatures of phases that are present. All three optics include calibration lamps behind a partially silvered mirror to provide non-uniformity calibrations when pointing to space before and after each imaging campaign. The DPU architecture adapts elements and image processing approaches from flight and ground systems of both MISE and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on the Mars Reconnaissance Orbiter to mitigate radiation noise and return data within a low downlink budget.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMP044.0009M
- Keywords:
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- 5215 Origin of life;
- PLANETARY SCIENCES: ASTROBIOLOGY;
- 6221 Europa;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 6282 Enceladus;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 5494 Instruments and techniques;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS