Here’s a quick series of posts on Curiosity (or as it’s still known by many, Mars Science Laboratory). For each day prior to the launch Cosmoboy will write a short piece on Curiosity’s scientific instruments and/or design. For many people the most fun is going to come from the movies and images Curiosity sends back, so let’s start with a quick overview of the cameras onboard – and there are plenty!
The cameras break into two separate groups, those designed specifically for taking pictures and those designed to do a job, such as help navigate. The three imaging cameras are:
MastCam is actually two cameras, one with a 15 degree field or view and another with a 5 degree field of view. Both cameras take images that are about 1200×1200 pixels in size (so a bit less than your standard digital camera) using a CCD sensor (note many consumer digital cameras now use “CMOS” sensors). the images can be “tiled” together to create even bigger images (it takes about an hour to aquire the entire panorama around Curiosity). Both cameras can also take 720p high definition video (1280×720 pixels) at 10 frames per second. More importantly (at least for the science!) these cameras are sensitive across a wide range of wavelengths of light and can take images through filters in the visible through to near infra-red.
MAHLI, short for Mars Hand Lens Imager, will allow Curiosity to get a close up look at things around it the way we might use a magnifying glass or microscope. MAHLI will be mounted in a turret on the end of Curiosity’s robotic arm so that it can be moved in close to interesting features on the ground. At its closest focus MAHLI will be able to resolve features 0.0006 inches or 0.015 mm in size, i.e. microscopic. The sensor in this camera will be the same as the two Mastcams, and it will also have a small LED light so that it can take images at night. 3-d views will be taken by slightly moving the camera between two separate positions. Seeing as this camera will operate close to the ground, it also has a carefully designed dust cover!
MARDI, the MSL Mars Descent Imager, will be the first camera to provide images. For about 100 seconds, from the time the heat shield is jettisoned until touch down, MARDI will aquire 4 images per second of what is happening to Curiosity. As well as the obvious interest of seeing the landing, the images captured by MARDI will be use in assess geological features on the ground and to plan the initial rover path. These images will be balanced to provide “natural colours” as the human eye will see them.
So that’s the list of imaging cameras, what about the navigation and hazard avoidance cams?
Two pairs of hazcams are located in fixed positions on the front and rear of the rover. Since the cameras come in pair separated to the left and right of the rover, Curiosity can take forward and aft 3-d images. From this information a detailed map of the upcoming terrain (out to about 10 feet in front, in a patch up to 13 feet wife) is made. Then from these images, software running on Curiosity’s onboard navigation system will determine the best path to take. Unlike the imaging cameras, the hazcams work in black and white only.
To complement the hazcams, there are two additional navcams mounted on Curiosity’s mast. This pair of images will provide additional 3-d imagery for the navigation software from a higher vantage point (complementing the data from the hazcams). The navcams will also be able to take 3-d panoramas.
That’s the cameras! Tomorrow: ChemCam.