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Mars Descent Imager (MARDI)

NSSDC ID: 1999-001A-02
Mission Name: Mars Polar Lander
Principal Investigator: Dr. Michael C. Malin

Description

The Mars Descent Imager (MARDI) is a camera mounted on the bottom of the Mars Polar Lander and designed to obtain images of the Martian terrain as the Lander descends. These images will be used to provide geologic and geographic context for the results of other lander investigations, to provide near-realtime planning information for lander operations, and to study specific attributes of the geology and geomorphology of Mars. Observational goals include studies of surface morphology, local and regional geography, and relationships to features seen in orbiter data. MARDI will acquire 10 images of the surface, with the first image taken about 10 seconds after parachute deployment, just before heat shield jettison less than 8 km above the surface, and the last image taken just before touchdown from an altitude of roughly 6 meters.

MARDI is approximately 5 x 5 x 10 cm in overall dimension. The imager consists of a single camera head holding optics and focal plane assembly. The camera uses 9 element refractive optics with a focal length of 0.7135 cm. The field of view is 73.4 degrees, or 1.25 mrad/pixel, giving image resolution of 7.5 m/pixel at 6 km altitude and 1.25 cm/pixel at 10 m altitude. The filter bandpass is panchromatic, allowing wavelengths from 500 nm to 800 nm. The image is focused onto a Kodak KAI-1001 electronically shuttered CCD with an array of 1024 x 1024 pixels, 1018 x 1008 of which are photoactive. The pixels are 9 micrometers across. The exposure time is 0.250 milliseconds. After acquisition, images are compressed and stored in the spacecraft DRAM for later transmission to Earth. A digital signal processor (DSP) is used for system control and high-level operation of the detectors. The analog processing chain uses analog ASICs for clock generation, and square-root encoding to eliminate the need for gain settings.

Alternate Names

  • MARDI

Facts in Brief

Mass: 0.42 kg
Power (avg): 2.0 W

Funding Agency

  • NASA-Office of Space Science Applications (United States)

Discipline

  • Planetary Science: Geology and Geophysics

Additional Information

Questions or comments about this experiment can be directed to: Dr. David R. Williams.

 

Personnel

NameRoleOriginal AffiliationE-mail
Dr. Michael C. MalinPrincipal InvestigatorMalin Space Science Systems, Incmalin@msss.com
Dr. Steven W. SquyresCo-InvestigatorCornell Universitysws6@cornell.edu
Dr. Michael H. CarrCo-InvestigatorUS Geological Surveycarr@usgs.gov
Dr. Joseph F. VeverkaCo-InvestigatorCornell Universityjfv4@cornell.edu
Dr. Peter C. ThomasCo-InvestigatorCornell University 

Selected References

Malin, M. C., et al., Mars Descent Imager (MARDI) on the Mars Polar Lander, J. Geophys. Res., 106, No. E8, 17635-17650, Aug. 2001.

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