NASA has selected three proposals from Malin Space Science Systems, Inc., for imaging experiments for the Mars Science Laboratory (MSL) 2009 rover mission to be conducted by the Jet Propulsion Laboratory. The MastCam will provide still and motion imaging capability in color and in 3-D, and it 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 Mars Descent Imager (MARDI) will acquire high-resolution, high-definition color motion imaging during the descent to the surface of Mars, providing a "bird's eye" perspective for the early phases of the mission. Each of these cameras represents a substantial improvement in capability over instruments previously flown on landers and rovers to Mars.
"I had just completed four months of Mars Exploration Rover operations when we finalized the MastCam definition for our proposal," said Dr. Michael Malin, MastCam principal investigator and President of MSSS. "The lessons-learned from that experience were crucial in guiding that definition."
The MastCam consists of two duplicate camera systems, mounted side by side to provide a stereo imaging capability. Each of the MastCam "eyes" is made of up a camera head, which includes the optics and detector, and a separate electronics box, which includes the image compressor and data buffer (Figure 1). The MastCam incorporates a number of innovative features that make it much more capable than previous rover cameras. Specifically:
Zoom: each stereo eye of the MastCam has a 10:1 zoom lens,
Single-frame color: in addition to being able to take images through narrowband filters, the MastCam can also take color images with a single exposure, like a consumer digital camera, High definition video: images can be acquired at 10 frames per second in HD (1280 x 720 pixel) format,
Compression: the MastCam electronics compresses its own still and moving image data, relieving the rover computer of that computing burden, and
Buffering: the MastCam has its own internal data buffer, which can hold thousands of still images or several hours of compressed HD video
"In a number of ways, the MastCam exceeds the state of the art for consumer cameras, which is unique for a spaceflight instrument," said Michael Ravine, the MSSS project manager for the MastCam and MAHLI development. "We wanted to extract as much imaging science value as we could from this MSL rover opportunity, and that required exploiting some technologies not previously qualified to spaceflight."
Figure 1 . The MastCam (housings rendered translucent to better illustrate the instrument components). Figure credit: Malin Space Science Systems.
The MastCam's high definition motion imaging mode is an unprecedented capability for a Mars mission. All previous cameras sent to Mars took many seconds to take a single picture. With those cameras, true motion imaging was not possible--only short, jerky, stop-motion animation sequences. "Our goal was to have the same capability on Mars as I have with the 3D high definition motion imaging system I developed for deep ocean exploration and motion pictures," said James Cameron, filmmaker and MastCam co-investigator. " Since the MastCam is twenty times smaller, some compromises were necessary. But we will have the basic 3D high definition motion imaging capability on Mars, and that will allow all of us to accompany the rover on its journey."
The Mars Hand Lens Imager (MAHLI) uses many of the same technologies in the MastCam design, but with a different set of goals. Rather than a zoom, the MAHLI has a focus mechanism, allowing it to focus on objects from one to ten inches. At the short focal distance, MAHLI images have a resolution of better than a thousandth of an inch. "The Microscopic Imagers on the Mars Exploration Rovers have revolutionized Mars science, providing critical clues about the past action of water and wind on Mars," said Kenneth Edgett, the MAHLI principal investigator. " The MAHLI will continue that revolution by imaging finer details than MER could do, and it will do it in color." Like MastCam, MAHLI will be able to take true color images--like those obtained by any typical consumer digital camera. Also like MastCam, MAHLI is packaged as a camera head and separate electronics box (Figure 2).
Figure 2 . The Mars Hand Lens Imager (MAHLI). Figure credit: Malin Space Science Systems.
The Mars Descent Imager (MARDI) also uses the electronic technologies of the MastCam and MAHLI to provide an "astronaut's view" of the descent and landing. 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 Malin, who will also lead the descent camera effort. "Local topography, surface features, nearby regions of loose debris--all affect the lander's local environment. Knowing they're nearby, and in which direction, provides important clues to deciphering these effects."
MARDI will acquire mega-pixel color motion imaging compressed using the MPEG-2 standard for video cameras. It will begin photographing the surface as soon as the spacecraft's protective heatshield is jettisoned, several kilometers above the martian surface, and continue acquiring images until the spacecraft lands. The video 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.
Figure 3 . The MSL Mars Descent Imager (MARDI). Figure credit: Malin Space Science Systems.
The MastCam, MAHLI, and MARDI investigations were selected by NASA's Science Mission Directorate in an open competition. The MastCam instrument will be developed and operated by Malin Space Science Systems, Inc., of San Diego, CA, under a $17.0 million (current year) contract, with the Jet Propulsion Laboratory, Pasadena, CA. The MAHLI instrument will be developed and operated by MSSS under a similar $12.9 million contract. MARDI will cost $7.9 million and will also be developed by MSSS under JPL contract.
MSSS recently delivered two cameras for JPL's Mars Reconnaissance Orbiter 2005 Mission (MRO), the Mars Color Imager (MARCI) and the Context Camera (CTX). Those instruments will be launched with MRO in August 2005. MSSS is also providing an earlier version of the Mars Descent Imager for the NASA's 2007 Mars Scout mission, Phoenix , and continues to operate the Mars Orbiter Camera (MOC) on Mars Global Surveyor. The MOC has returned over 175,000 images of Mars since MGS went into orbit around Mars in September 1997. On-going activities of the company are described at www.msss.com .