If a group of tourists piled out of a transport vehicle onto the surface of Mars, they'd no doubt start snapping pictures wildly. NASA's Curiosity rover, set to touch down on the Red Planet the evening of Aug. 5 PDT (early morning EDT), will take a more careful approach to capturing its first scenic views.
The car-size rover's very first images will come from the one-megapixel Hazard-Avoidance cameras (Hazcams) attached to the body of the rover. Once engineers have determined that it is safe to deploy the rover's Remote Sensing Mast and its high-tech cameras, a process that may take several days, Curiosity will begin to survey its exotic surroundings.
"A set of low-resolution gray scale Hazcam images will be acquired within minutes of landing on the surface," said Justin Maki of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Once all of the critical systems have been checked out by the engineering team and the mast is deployed, the rover will image the landing site with higher-resolution cameras."
Maki led the development of Curiosity's 12 engineering cameras -- eight Hazcams at the front and back of the rover, and four Navigation cameras (Navcams) at the top of the rover's "look-out" mast. All the engineering cameras acquire black-and-white pictures from left and right stereo "eyes," which are merged to provide three-dimensional information. Half of the cameras are backups, meaning there's one set for each of the rover’s A- and B-side redundant computers.
The very first images are likely to arrive more than two hours after landing, due to the timing of NASA's signal-relaying Odyssey orbiter. They will be captured with the left and right Hazcams at the back and front of the rover, and they will not yet be full-resolution (the two images arriving on Earth first are "thumbnail" copies, which are 64 by 64 pixels in size). The Hazcams are equipped with very wide-angle, fisheye lenses, initially capped with clear dust covers. The covers are designed to protect the cameras from dust that may be kicked up during landing; they are clear just in case they don't pop off as expected.
These first views will give engineers a good idea of what surrounds Curiosity, as well as its location and tilt. "Ensuring that the rover is on stable ground is important before raising the rover's mast," said Mission Manager Jennifer Trosper at JPL. "We are using an entirely new landing system on this mission, so we are proceeding with caution."
Color pictures from the rover's Mars Descent Imager, or MARDI, acquired as the rover descends to the Martian surface, will help pinpoint the rover's location. Initial images from MARDI are expected to be released Aug. 6, the day after landing. These will also be in the form of thumbnails (in the case of the science cameras, thumbnails can vary in size, with the largest being 192 pixels wide by 144 pixels high). One full-resolution image may also be returned at this time.
Additional color views of the planet's surface are expected the morning of Aug. 7 from the Mars Hand Lens Imager, or MAHLI, one of five devices on the rover's Inspector Gadget-like arm. The camera is designed to take close-up pictures of rocks and soil, but can also take images out to the horizon. When Curiosity lands and its arm is still stowed, the instrument will be pointed to the side, allowing it to capture an initial color view of the Gale Crater area.
Once Curiosity's mast is standing tall, the Navcams will begin taking one-megapixel stereo pictures 360 degrees around the rover as well as images of the rover deck. These cameras have medium-angle, 45-degree fields of views and could resolve the equivalent of a golf ball lying 82 feet (25 meters) away. They are designed to survey the landscape fairly quickly, and, not only can they look all around but also up and down. Navigation camera pictures are expected to begin arriving on Earth about three days after landing if the mast is deployed on schedule.
Like the Hazcams, Navcam images are used to obtain three-dimensional information about the Martian terrain. Together, they help the scientists and engineers make decisions about where and how to drive the rover and which rocks to examine with instruments that identify chemical ingredients. "A large part of the surface mission is conducted using the images returned from the cameras," said Maki.
Also, about three days after landing, the narrower field-of-view Mast Cameras (Mastcams) are expected to start snapping their first shots. These two-megapixel color cameras will reveal the rover's new home in exquisite detail. Small thumbnail versions of the pictures will be sent down first with an initial high-resolution panorama expected more than a week later.
The camera of the Chemistry and Camera (ChemCam) instrument will provide a telescopic view of targets at a distance.
As the mission progresses, the entire suite of cameras and science instruments will work together to hunt for clues to the mystery of Mars and help answer the long-standing puzzle of whether our next-door-neighbor planet has ever offered environmental conditions favorable for microbial life.
NASA's Mars Science Laboratory and its Curiosity rover are a project of NASA's Science Mission Directorate. The mission is managed by JPL, a division of the California Institute of Technology in Pasadena. Curiosity was designed, developed and assembled at JPL.
