Malin Space Science Systems, Inc. (MSSS), has delivered the first of four science cameras it is developing for the NASA/Jet Propulsion Laboratory 2009 Mars Science Laboratory (MSL) rover mission. This camera, the Mars Descent Imager is designed to provide a sequence of hundreds of 2 Megapixel color images of the martian surface during the rover's descent about two years from now. MARDI was transported to JPL last week to participate in a contamination measurement test. That test was completed satisfactorily on 10 July, and instrument functionality was verified in imaging testing the following day (Figure 2). The instrument will shortly be integrated with the MSL rover avionics (computer) for testing, and will be integrated with the rover mechanical systems within the month. Prior to delivery to JPL, MARDI was calibrated in the cleanroom at MSSS (Figure 3).
Figure 1. The Mars Descent Imager (MARDI) flight camera head. MARDI's 90 degree field of view lens is visible at the front of the camera. Figure credit: Malin Space Science Systems.
Figure 2. An image taken with the flight MSL MARDI camera head in the Building 306 Low Bay Cleanroom at JPL. This image was acquired during post-outgassing test checkout. Figure credit: Malin Space Science Systems.
Descent imaging gives mission scientists and engineers early, high resolution, overhead perspectives of the landing site that can be used to plan initial operations after landing. They also permit determining the precise location of the vehicle within observations made from orbit. "Context is always an important element of surface science studies," said Michael Malin, who leads the descent camera effort. "Local topography, surface features, nearby regions of loose debris--all affect both operational planning and scientific interpretation of our results."
Figure 3. An image taken with the flight MSL MARDI camera head in the MSSS cleanroom during MARDI calibration testing, showing MARDI Deputy Principal Investigator Ken Edgett holding a six-foot metal ruler being used as a depth of field test target. The MARDI is focused at 7 m, so that everything between about 2 m (6.6 feet) and infinity are in focus. This image shows a slightly out-of-focus rock (a rounded cobble of Icelandic basalt with mm-scale crystals and vesicles) at a distance of about 70 cm, 2.3 feet), equivalent to the distance MARDI will be from the ground after the rover has landed. Figure credit: Malin Space Science Systems.
MARDI will begin photographing the surface as soon as the MSL spacecraft's protective heatshield is jettisoned, several kilometers above the martian surface, and continue acquiring images at roughly four frames per second until the spacecraft lands. The video-like sequence of pictures will be stored in digital memory in the camera during the descent and later transferred from the camera's memory to the spacecraft's memory for transmission to Earth.
MSSS is also providing three other cameras for the MSL mission: the two Mast Cameras (Mastcams) and the Mars Hand Lens Imager (MAHLI). The two Mastcams will provide moderate resolution and high-resolution telephoto still and motion imaging capability in color, and will be the science imaging "workhorse" for the MSL rover. The Mars Hand Lens Imager (MAHLI) will be mounted on the MSL instrument arm and will provide color images of the fine detail martian rocks and soils.
The Mastcam, MAHLI, and MARDI investigations were selected in 2004 by NASA's Science Mission Directorate in an open competition. The instruments share a common electronics design and are being developed by Malin Space Science Systems, Inc., of San Diego, CA, under a single $18.9 million contract with Caltech's NASA-funded Jet Propulsion Laboratory in Pasadena, CA.
MSSS is also currently operating two cameras onboard NASA's Mars Reconnaissance Orbiter 2005 Mission (MRO), the Mars Color Imager (MARCI) and the Context Camera (CTX). MARCI provides a daily global weather map of Mars in five colors and two ultraviolet bands. CTX images Mars at 6 m per pixel resolution, and has already mapped more than one third of the planet at that resolution. Other activities of the company are described at www.msss.com.