Curiosity leads on new paths

17:00, Aug 27 2012
Mount Sharp on Mars
Mount Sharp on Mars photographed by Nasa rover Curiosity.
Mount Sharp on Mars
A view obtained by Curiosity is given colour derived from images acquired from orbiting spacecraft. The view looks north, showing a distant ridge that is the north wall and rim of Gale Crater.
Mount Sharp on Mars
This image comparison shows a view through a Hazard-Avoidance camera on Curiosity before and after the clear dust cover was removed.
Mars Curiosity Mission
A portion of the first colour 360-degree panorama from NASA's Curiosity rover on Mars.
Mars Curiosity Mission
This artist's concept of Curiosity using its Chemistry and Camera instrument to investigate the composition of a rock surface.
Mars Curiosity Mission
This Picasso-like self portrait of Curiosity was taken by its Navigation cameras, located on the now-upright mast.
Mars Curiosity Mission
An artist's concept of Nasa's Mars Science Laboratory spacecraft approaching Mars.
Mars Curiosity Mission
An artist's concept shows the sky crane manoeuvre during the descent of Nasa's Curiosity rover to the Martian surface.
Mars Curiosity Mission
An atist's concept depicts the moment that Nasa's Curiosity rover touches down onto the Martian surface.
Mars Curiosity Mission
An artist's concept features of Nasa's Mars Science Laboratory Curiosity rover on the surface of Mars.
Mount Sharp on Mars
The martian landing site of NASA's Curiosity rover, which landed on Mars, is seen in 3-D colours in this picture released by NASA. The anaglyph was made from a stereo pair of Hazard-Avoidance Cameras on the front of the rover. The image is cropped but part of Mount Sharp, a peak that is about 3.4 miles (5.5 kilometers) high, is still visible rising above the terrain. This image was captured by the rover's front left Hazard-Avoidance camera at full resolution shortly after it landed. It has been linearized to remove the distorted appearance that results from its fisheye lens.
Mount Sharp on Mars
This 360-degree, full-resolution panorama from NASA's Curiosity rover, shows the area all around the rover within Gale Crater on Mars. The rover's deck is to the left and far right. The rover's "head" or mast, where the Navigation cameras that took this picture are located, casts a shadow seen near the center.
Mars Curiosity Mission
This colour image from NASA's Curiosity rover shows part of the wall of Gale Crater, the location on Mars where the rover landed.
Mars Curiosity Mission
The Mars Hand Lens Imager on the Mars rover Curiosity shows a patch of rock cleaned by the first use of the rover's Dust Removal Tool.
Mars Curiosity Mission
The surface of the planet Mars inside Gale's Crater is shown as NASA's Mars rover Curiosity drives toward a flat rock with pale veins that may hold clues to a wet history on the planet.
Mars Curiosity Mission
An outcrop at the "Sheepbed" locality taken by NASA's Curiosity Mars rover with its right Mast Camera, shows well-defined veins filled with whitish minerals, interpreted as calcium sulfate.
Mars Curiosity Mission
An image from the Mast Camera on NASA's Mars rover Curiosity shows the surface of the planet with inclined layering known as cross-bedding in an outcrop called "Shaler" on a scale of a few tenths of a meter, or decimeters.
Mars Curiosity Mission
This image from the right Mast Camera of NASA's Curiosity Mars rover shows rough spherical features on the surface of the planet in an area called 'Yellowknife Bay'.

Nasa's latest Martian explorer Curiosity has been quite the headline catcher recently.

First there was its novel and daring descent through the Martian atmosphere. A few days later there was its first panoramic picture of from Gale Crater (and there was Mohawk Guy, of course, who almost stole the whole show). But Curiosity is not there to just take pictures. It has to start moving. Sounds simple enough, but for Curiosity, stranded millions of kilometres from its human operators, moving about safely is far from simple.

Curiosity is the size of a car, with a long-lasting radioactive power source, a rock-vaporising laser, a fully articulated arm and numerous scientific instruments to test for water and the organic chemicals that make up life as we know it. But before it can analyse any samples it has to reach them, and to do that it relies on some very futuristic technology.

Mars Rover Curiosity
MARS ROVER CURIOSITY: An engineering marvel and a practical planetary explorer.

On the mechanical side Curiosity's mobility comes from its six wheels, each driven by an independent electric motor. The wheels are mounted on a so-called rocker bogie suspension that evens out the ride for the rover as it travels over rough terrain. It can tilt 45 degrees in any direction without tipping. Each of the front and rear wheels also has its own steering motor which, among other things, allows it to turn 360 degrees on the spot.

Curiosity's handling may be out of this world but its top speed of less than one kilometre per hour would leave a terrestrial traveller cold. But Curiosity is only expected to drive up to 20 kilometres during its primary mission, and has at least 23 months to do it. Which is good, since driving on Mars comes with an additional complication.

Because radio waves take several minutes to travel between here and Mars it's not possible to drive the rover like an oversized remote-control car. By the time commands from earth reach Mars and feedback from the rover returns to earth half an hour or more may have elapsed: plenty of time for Curiosity to have fallen off a cliff operators on earth haven't yet seen.

To prevent such a catastrophe Curiosity has some intelligence built into it. It is equipped with several pairs of stereo cameras which give it a comprehensive view of its surroundings, with depth perception. Earthbound operators use these to plan Curiosity's next move, and Curiosity uses them to measure its progress against the plan and to avoid known obstacles. When it encounters something unexpected the rover can often take evasive action on its own, or it can stop and wait for fresh instructions.

Curiosity is an engineering marvel but it is this software that gives the rover the autonomy it needs to become a practical planetary explorer. Perhaps humans will eventually be doing the driving on Mars, but by the time we make that giant leap machines might be doing all the driving anyway - even back here on earth.

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