On Mars, a self-portrait of NASA's rover Curiosity, combining dozens of exposures taken by the rover's Mars Hand Lens Imager (MAHLI) during the 177th Martian day, or sol, in this February 3, 2013 image. The rover was positioned at a patch of flat outcrop called "John Klein," which was selected as the site for the first rock-drilling activities by Curiosity. #

Preparation for one phase of testing of the Mars Science Laboratory rover, Curiosity. The testing during March 2011 in a 25-foot-diameter space-simulation chamber was designed to put the rover through operational sequences in environmental conditions similar to what it will experience on the surface of Mars. The technician in the picture is using a wand to map the solar simulation intensities at different locations in the chamber just prior to the start of the testing. The space-simulation chamber is at NASA's Jet Propulsion Laboratory, Pasadena, California. #

A United Launch Alliance Atlas V rocket carrying NASA's Mars Science Laboratory (MSL) Curiosity rover lifts off from Launch Complex 41at Cape Canaveral Air Force Station in Cape Canaveral, Florida, on November 26, 2011. #

An orbiting probe sent to Mars previously by NASA, the Mars Reconnaissance Orbiter (MRO), looked down on August 5, 2012 and managed to catch a glimpse of the newest member of NASA's robotic Mars team as it parachuted to the surface. At upper left, you can see two white dots, the upper one is the the parachute, the lower, the spacecraft and backshell. #

Flight director for the Mars rover Curiosity, Bobak Ferdowsi, who cuts his hair differently for each mission, works inside the Spaceflight Operations Facility for NASA's Mars Science Laboratory Curiosity rover at JPL in Pasadena, California, on August 5, 2012. #

This color full-resolution image showing the heat shield of NASA's Curiosity rover was obtained during descent to the surface of Mars on August 5, 2012. The image was obtained by the Mars Descent Imager instrument known as MARDI and shows the 15-foot (4.5-meter) diameter heat shield when had fallen about 50 feet (16 meters) from the spacecraft. This image shows the inside surface of the heat shield, with its protective multi-layered insulation. The bright patches are calibration targets for MARDI. #

An image taken by NASA's Mars science rover Curiosity shows what lies ahead for the rover -- its main science target, Mount Sharp, in this photo released by NASA on August 6, 2012. The rover's shadow can be seen in the foreground, and the dark bands beyond are dunes. Rising up in the distance is Mount Sharp at a height of about 3.4 miles, taller than Mt. Whitney in California. The image has been linearized to remove the distorted appearance that results from its fisheye lens. #

The landing site of NASA's newest Mars rover, seen on August 17, 2012. The descent stage crash site (left), backshell and parachute (bottom), and Curiosity Rover (right). This image was acquired by the HiRISE instrument aboard the Mars Reconnaissance Orbiter. #

On Mars, NASA's Curiosity rover images itself -- this image shows the rover's Alpha Particle X-Ray Spectrometer (APXS), with the Martian landscape in the background. The image was taken by Curiosity's Mast Camera on the 32nd Martian day, or sol, of operations on the surface (September 7, 2012). APXS can be seen in the middle of the picture. This image let researchers know that the APXS instrument had not become caked with dust during Curiosity's dusty landing. Scientists enhanced the color in this version to show the Martian scene as it would appear under the lighting conditions we have on Earth, which helps in analyzing the terrain. #

This mosaic of images from the Mast Camera (Mastcam) on NASA's Mars rover Curiosity shows Mount Sharp in a white-balanced color adjustment that makes the sky look overly blue but shows the terrain as if under Earth-like lighting. White-balancing helps scientists recognize rock materials based on their experience looking at rocks on Earth. The Martian sky would look more of a butterscotch color to the human eye. Mount Sharp, also called Aeolis Mons, is a layered mound in the center of Mars' Gale Crater, rising more than 3 miles (5 kilometers) above the crater floor, where Curiosity has been working since the rover's landing in August 2012. #

A blink pair of images taken before and after Curiosity performed a "mini drill" test on a Martian rock shows changes resulting from that activity. The resulting hole and surrounding pile of drill cuttings are not the only changes. The images were taken by the Mast Camera instrument on Curiosity. The diameter of the hole created by the drill is 0.63 inch (1.6 centimeters). The before image was taken on the 178th Martian day, or sol, of Curiosity's mission, February 4, 2013. #

People look at the 'Mars Window' a projection of images taken one of NASA's Mars rovers at the Visions of the Universe exhibition at The National Maritime Museum in Greenwich, London, on June 5, 2013. #

This pair of images shows a "bite mark" where NASA's Curiosity rover scooped up some Martian soil (left), and the scoop carrying soil. The first scoop sample was taken from the "Rocknest" patch of dust and sand on October 7, 2012, the 61st sol, or Martian day, of operations. #

The Chemistry and Camera (ChemCam) instrument on NASA's Mars rover Curiosity used its laser to examine side-by-side points in a target patch of soil, leaving the marks apparent in this before-and-after comparison. The two images were taken by ChemCam's Remote Micro-Imager from a distance of about 11.5 feet (3.5 meters). The diameter of the circular field of view is about 3.1 inches (7.9 centimeters). Researchers used ChemCam to study this soil target, named "Beechey," during the 19th Martian day, or sol, of Curiosity's mission, August 25, 2012. #

Curiosity making nighttime images of the drill hole at Cumberland, lighting the scene with its white LEDs. This image was taken by the Mastcam on Sol 292, June 6, 2013. #

This image from the Mars Hand Lens Imager camera on NASA's Mars rover Curiosity shows a small bright object on the ground beside the rover at the "Rocknest" site. The object is just below the center of this image. It is about half an inch (1.3 centimeters) long. The rover team has assessed this object as debris from the spacecraft, possibly from the events of landing on Mars. The image was taken during the mission's 65th Martian day, or sol October 11, 2012. #

A view of the United States flag medallion on NASA's Mars rover Curiosity that was taken by the rover's Mars Hand Lens Imager (MAHLI), on September 19, 2012. The flag is one of four "mobility logos" placed on the rover's mobility rocker arms. The circular medallion of the flag is made of anodized aluminum and measures 2.68 inches (68 millimeters) in diameter. The medallion was affixed with bolts to locations on the rocker arms where flight hardware was once considered, but ultimately deemed unnecessary. #

NASA's Mars Science Laboratory rover Curiosity appears as a bluish dot near the lower right corner of this enhanced-color view from the HiRISE camera on NASA's Mars Reconnaissance Orbiter. The rover's tracks are visible extending from the landing site, "Bradbury Landing," in the left half of the scene. Two bright, relatively blue spots surrounded by darker patches are where the Mars Science Laboratory spacecraft's landing jets cleared away reddish surface dust at the landing site. North is toward the top. For scale, the two parallel lines of the wheel tracks are about 10 feet (3 meters) apart. HiRISE shot this image on June 27, 2013, when Curiosity was at an outcrop called "Shaler" in the "Glenelg" area of Gale Crater. Subsequently the rover drove away from Glenelg toward the southwest. #

The lower slopes of Mount Sharp appear at the top of this picture taken by the right Navigation Camera (Navcam) on Curiosity, at the end of a drive of about 135 feet (41 meters) during the 329th Martian day, or sol, of the rover's work on Mars in this July 9, 2013 NASA image. The turret of tools at the end of Curiosity's robotic arm is in the foreground, with the rover's rock-sampling drill in the lower left corner of the image. #

Using an onboard focusing process, the Mars Hand Lens Imager (MAHLI) aboard NASA's Mars rover Curiosity created this closeup image of a Martian rock by merging two to eight images previously taken by the MAHLI, located on the turret at the end of the rover's robotic arm, on July 4, 2013, Sol 324. #