In Depth: All About NASA's Curiosity Mars Rover

NASA may not be sending up manned shuttles anymore, but that doesn't mean we're done exploring the solar system -- not by a long shot. On August 5, the space agency's new flagship rover is expected to land on Mars as part of an unprecedented search for traces of life on the Red Planet.

You can ascertain the rover's importance simply by its size. This thing is huge compared to NASA's previous explorers, Spirit and Opportunity. Curiosity measures 3m long, 2.7m wide, and 2.1m tall -- taller than the average NBA centre -- weighing a hefty 907kg. NASA's previous pair weighed just 185kg apiece. Tack on the added reach of Curiosity's 2.1m long manipulation arm and the rover has roughly a two-storey vertical reach. Not that there are many two-storey-tall objects around the rover's planned landing site but a good ability to have, nonetheless.

To move beyond wherever it comes to rest after being lowered via sky crane from the Mars Lander Engine, Curiosity will rely on a set of six oversized wheels attached to a rocker-bogie suspension, much like its predecessors. Fun fact: the wheel treads will leave an impression in the Martian soil spelling "JPL" in Morse code. Why? Who cares, it's cool. The rover will propel itself along at up to a relatively-swift 91 metres per hour in automatic drive with an average speed of just 30 metres per hour when hunting for signs of life. In all, this $US2.5 billion program is going to traverse just 19.3km during its two-year stay on Mars.

Powering the scientific behemoth is some surprisingly old tech. Curiosity relies on a radioisotope thermoelectric generator (RTG) -- the same nuclear engine that powered the Viking Spacecrafts from the 1970s -- but hey, you stick with what works. These engines generate an electrical charge from the heat created by the 4.5kg power cell's decay of plutonium-238 -- 125W of electrical power at the start of the mission decreasing to about 100W at the end of the plutonium's 14-year life span. That heat is also employed to keep the rover's fluids and mechanisms from freezing during the cold Martian nights. You could even say that NASA's built itself a warm-blooded robot.

Beyond keeping the rover itself alive, the RTG system will power the machine's extensive suite of sensors, X-Band transmitter, UHF radio, a pair of onboard computers -- each with 256KB of EEPROM, 256MB of DRAM, and 2GB of flash -- and an Inertial Measurement Unit (IMU) that helps the rover keep track of its bearings and balance with 3-axis sensor input. And gadgets. Hooo boy, does it have gadgets.

The Rover boasts a trio of primary cameras: the 720p multi-spectrum Matcam, the Mars Hand Lens Imager which is attached to the arm and capable of taking 1600 x 1200 microscopic shots, and the Mars Descent Imager, which will snap five frames/second for about two minutes as the rover makes its final approach to the surface. It also sports four hazard-avoidance cameras and a pair of stereoscopic navigation cameras.

Some would call Curiosity a rolling geology lab -- and they'd be right. It's packed to the gills with scientific instruments: X-ray spectrometer, a laser-induced breakdown spectroscopy (LIBS) system, rock-vapourising lasers, organic sample analysis systems; and even radiation and neutrino detection systems. In fact, during the year-long trip to Mars, Curiosity is actually standing in for a human astronaut, recording the amount of solar radiation that penetrates the spacecraft. August 5 can't get here fast enough. [Wikipedia -- JPL]