MSSS delivers MSL Mast Camera to JPL, restarts work on zoom version of 'Mastcam'

These cameras, known collectively as the Mast Camera (or Mastcam) are designed to be the science imaging "workhorse" for the MSL rover. The cameras, capable of taking full color images analogous to those taken by consumer digital cameras, will be mounted on the rover's remote sensing mast, where they can be panned and tilted to provide image coverage around the rover, both near the rover and out to the horizon.

One of the two Mastcams has a telephoto lens, providing the rover with a long-distance reconnoitering capability. Also delivered to JPL for MSL with the two Mastcams was the Digital Electronics Assembly (DEA), which compresses and buffers the images from the Mast Cameras, and the Mars Hand Lens Imager (MAHLI) and Mars Descent Imager (MARDI), cameras also developed by MSSS for the MSL mission.

The Mastcams were transported from the MSSS facility in San Diego to JPL on 17 March 2010 for an extremely sensitive contamination measurement. Prior the contamination test, the each camera was shown to be operating normally and capable of taking in-focus images. The contamination test was completed satisfactorily on 18 March, and instrument functionality was verified in testing the following day. The cameras and the DEA now await integration with the MSL rover.

The Mastcam focus and filter wheels are driven by precision mechanisms developed by Alliance Spacesystems (www.alliancespacesystems.com). The focus mechanism uses a stepper motor to position an internal focus group by means of a cam. The filter wheel mechanisms use stepper motors to drive 8-filter wheels to position the desired color filters in front of each camera's CCD detector.

The Mast Camera (Mastcam) instrument for NASA's Mars Science Laboratory will use a side-by side pair of cameras for examining terrain around the mission's rover. The instrument pairs two cameras with fixed focal lengths: a 34-millimeter focal length for one, shown here, and a 100-millimeter focal length for the other. This one, called Mastcam 34, offers wider-angle viewing while the other, Mastcam 100, offers telephoto capability. Each can provide color images and high-definition video, and they can be combined for stereo views. This image includes a Swiss Army Knife for scale. Mastcam 34 is a duplicate of Mastcam 100 except for the lens. Each includes refractive optics, a focus mechanism, a filter wheel, a charge-coupled device (CCD) sensor and associated electronics. Credit: NASA/JPL/Malin Space Science Systems




This one, called Mastcam 100, offers telephoto capability while the other, Mastcam 34, offers a wider-angle view. Each can provide color images and high-definition video, and they can be combined for stereo views. The only external indication of which camera is which is that the front baffle opening for the Mastcam 100 is smaller than the front baffle opening of the Mastcam 34. Credit: NASA/JPL/Malin Space Science Systems




During post-transportation instrument checkout in a cleanroom at JPL, the 34-millimeter focal length camera, called Mastcam 34, was used to take this picture of Mastcam Principal Investigator Michael Malin and a test target derived from the "1951 U. S. Air Force Resolution Chart." The test target can be used to determine the spatial resolution of the camera as a function of contrast, a standardized test to demonstrate that the camera is functioning properly and that the optics have not experienced any change during transport to JPL. In this image, the camera is demonstrating a resolution of about 4.5 line pairs per millimeter (9 pixels per millimeter, or about 111 micrometers per pixel) at a distance of 2 meters (6.6 feet). Credit: NASA/JPL/Malin Space Science Systems

The versions of the Mastcams delivered to JPL have fixed focal lengths (34 mm and 100 mm), and relatively small fields of view (15 degrees and 5 degrees). They would be used to build up coverage of the martian landscape around the rover from a series of small individual images.

The two Mastcams were originally proposed to have the identical 15:1 zoom (variable focal length) lenses on each camera [each camera could image from 100 mm focal length (telephoto) down to 6.5 mm focal length (wide angle)]. NASA directed that the development of the zoom lens be abandoned in 2007 as a cost saving measure, and the Fixed Focal Length Mastcams just delivered were developed to replace the zoom versions. With the two completed and delivered fixed focal length cameras in hand, NASA recently decided to fund completion of the zoom cameras by the Mastcam team, with the possibility of swapping out the old cameras for the new ones provided they can be assembled and tested in the time remaining before the MSL rover begins final testing early next year. The effort to build the zoom lens cameras has just started at MSSS.

"Restoring the zoom is not a science issue," said Michael Malin, Mastcam Principal Investigator, "although there will be some science benefits." "The fixed focal length Mastcams we just delivered will do almost all of the science we originally proposed. But they cannot provide a wide field of view with comparable eye stereo. With the zoom Mastcams, we'll be able to take cinematic video sequences in 3D on the surface of Mars. This will give our public engagement Co-Investigator, James Cameron, tools similar to those he used on his recent 3D motion picture projects."

Source: Malin Space Science Systems
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