NASA is pushing the boundaries of technology as it readies its next mission to Mars, loading up its fourth Mars Rover with nearly a dozen instruments and employing an innovative but risky landing procedure.

Scientists and engineers were piecing together some of the final components to the new rover, dubbed Curiosity, on Saturday as it ramps up for a high-stakes launch in November.

The $2.5-billion-dollar rover is more advanced than the Pathfinder, Spirit and Opportunity that roamed the Red Planet in past years.

Curiosity will house a fully fledged science laboratory that can perform real-time tests on the planet, making it the most sophisticated unmanned spacecraft ever built. It is about twice as long and more than five times as heavy as any previous Mars rover.

Key to the trip will be a suite of instruments named Sample Analysis at Mars that will analyze samples of material collected and delivered by the rover's arm, plus atmospheric samples.

It includes a gas chromatograph, a mass spectrometer and a tunable laser spectrometer with combined capabilities to identify a wide range of organic compounds and determine the ratios of different isotopes of key elements. Isotope ratios are clues to understanding the history of Mars' atmosphere and water.

An X-ray diffraction and fluorescence instrument called CheMin will also examine samples gathered by the robotic arm. It is designed to identify and quantify the minerals in rocks and soils, and to measure bulk composition. A retractable arm will house instruments for sampling data from afar. Mounted on the arm, the Mars Hand Lens Imager will take extreme close-up pictures of rocks, soil and, if present, ice, revealing details smaller than the width of a human hair.

Also on the arm, the Alpha Particle X-ray Spectrometer for Mars Science Laboratory will determine the relative abundances of different elements in rocks and soils.

An instrument named ChemCam will use laser pulses to vaporize thin layers of material from Martian rocks or soil targets up to 7 meters (23 feet) away. It will include both a spectrometer to identify the types of atoms excited by the beam, and a telescope to capture detailed images of the area illuminated by the beam.

Power for all of these instruments will come from a radioisotope power source which will also provide heat to the rover.

Because of its weight and sheer size, NASA cannot use the airbag padded rolling landing used for previous flights. Curiosity's landing will use a different method, lowering the rover on tethers from a rocket-backpack "sky crane."

The craft will hit the Mars atmosphere traveling some 13,000 miles-per-hour. During the three minutes before touchdown, the spacecraft slows its descent with a parachute to roughly 1,000 MPH then uses retro rockets mounted around the rim of an upper stage. In the final seconds, the upper stage acts as a sky crane, lowering the upright rover on a tether to the surface.

"Mars is firmly in our sights," said NASA Administrator Charles Bolden. "Curiosity not only will return a wealth of important science data, but it will serve as a precursor mission for human exploration to the Red Planet."

While previous rovers have identified that water has indeed flowed on Mars, Curiosity will look for clues of organic compounds necessary for life.

But long-term preservation of organic compounds requires special conditions. Certain minerals are good at latching onto organic compounds and protecting them from oxidation.

Because of it, NASA chose the crater Gale to land the craft.

"Gale gives us attractive possbilities for finding organics, but that is still a long shot," said Michael Meyer, lead scientist for NASA's Mars Exploration Program at agency headquarters. "What adds to Gale's appeal is that, organics or not, the site holds a diversity of features and layers for investigating changing environmental conditions, some of which could inform a broader understanding of habitability on ancient Mars."

The five-ton mobile laboratory is slated to blast off onboard a United Launch Alliance Atlas V rocket between Nov 25 and Dec.18, embarking on a nearly 9 month journey.

It's expected to arrive on Mars next summer.

NASA's Jet Propulsion Laboratory in Pasadena manages the mission for the agency's Science Mission Directorate in Washington. JPL is a division of Caltech.