Cameras and Image Sensors for the Mars Rover 2020 Mission
The 2020 Mars Rover mission has 23 cameras on board. Descent cameras will help pilot the rover’s descent to the Martian surface. Engineering cameras will allow the rover to navigate the rocks and dust that cover the planet. And finally, scientific cameras will make observations and help collect samples.
The 2020 Mars Rover launched July 30th, with a planned landing on February 2021. Every time we go to Mars, decisions of what to bring become a balance of what scientists would like, and what engineers feel will reliably work. This makes each mission part of a continuing chain of innovation, with the learning from past missions informing proven technologies and innovations to future missions.
Over the last twenty years, one perfect example has been CCD sensors. It has been the go-to standard for cameras in space. „A CMOS sensor would probably die very rapidly as soon as it went into space,“ points out Robert Groulx, Product Manager for CCD technology at Teledyne Dalsa Semiconductor. Extremes of heat and cold can wear out electronics, and radiation and cosmic rays can wreak havoc on electronic integrated circuits by altering the states of the elements inside them. On five of NASA’s missions to Mars the CCD image sensors on its cameras were made by Teledyne, in collaboration with NASA’s Jet Propulsion Laboratory (JPL). The camera on the InSight lander helped scientists and engineers choose where to place instruments on the surface of Mars. This included the Instrument Deployment Camera, which is placed under the lander and pointed at 120° with a fisheye-type lens, and the Instrument Context Camera, which is on the lander’s robotic arm, looking at a 45° angle. Besides their lenses, both cameras are identical, collecting 1MP images to help with the placement of other instruments. The Insight cameras were monochrome frame-transfer CCD models left over from an earlier program. „But this time JPL wanted to take color photos. Color cameras are much larger, and new models couldn’t be qualified in time for launch,“ says Groulx. The solution was to put color filters over the monochrome sensors. „We knew from the users of those color filters that the potential for qualification was good. We had used them on Teledyne Dalsa CCD sensors for many years but we had never sent them to space! JPL had to make sure that those color filters would endure the trip to Mars.“ „For the color filters, we use a technology that is unique to Teledyne Dalsa that we’ve been doing since 2002/03,“ says Groulx. „It uses color pigments that are evaporated onto the CCD. It’s more expensive but produces very good results in terms of color separation and reproduction, better than the typical dyed resist method.For this mission, our colleagues at Teledyne e2v have contributed their CCD42-10 image sensor for SuperCam and Sherloc. These instruments will help to determine evidence of wateras an influence on the Martian environment.“