We've had our sights on NASA's Curiosity Rover (also known as the Mars Science Laboratory or MSL) for quite some time now. Well, it's finally ready and in a few short weeks, this amazingly advanced one-ton (900 kg) explorer will find itself atop a massive Atlas V rocket for the eight-month, 354 million-mile (570 million-km) trip to our red neighbor - the culmination of over seven years of development and US$2.5 billion in funding.

Space exploration doesn't come cheaply, as its detractors are quick to point out, but its cost is easier to understand when one considers the amazing conditions such craft must endure, and the array of complex, sensitive instruments they carry.

Once the MSL lands (using parachutes and a unique "Sky Crane," as depicted in the excellent NASA animation video at the bottom of the page), it will encounter gravity only 38 percent as strong as Earth's, harsh temperatures ranging from -130°F to 32°F (-90C to 0C), an atmosphere of almost pure carbon dioxide and no planet-wide magnetic field. That can make navigation challenging, to say the least, especially with the added complication that command transmissions will take close to 14 minutes to travel from Earth.

Curiosity's initial mission, currently scheduled to last one Martian year (99 earth-weeks), is to determine whether its carefully-chosen landing site, the Gale Crater area, contains evidence of previous and current habitability. Of the three conditions considered essential to sustain life - liquid water, an energy source and a handful of organic (carbon-containing) compounds - the Gale area is known to have contained water at some point. Sensors in the craft's heat shield will also gather data about the Martian atmosphere as it descends.

Once deployed on the Martian surface in early August of 2012, the 118 inch-long (3 m) Curiosity will be able to tool about at 295 feet (90 m) per hour on 20-inch (.5 m) diameter wheels. When fully deployed, its mast will reach to 7 feet (2.1 m).

The MSL's science payload of ten analytical instruments weighs in at 165 lbs (75 kg), roughly fifteen times the weight of those carried by the twin rovers Spirit and Opportunity. Powered by a combination of lithium-ion batteries and a radioisotope thermoelectric generator, the MSL is literally bristling with sensitive devices designed to explore the area above, below and around its Gale Crater landing area. These include:

Alpha Particle X-ray Spectrometer (APXS) - Contributed by the Canadian Space Agency, this instrument will determine rock and soil composition by analyzing x-rays given off by samples exposed to a small amount of radioactive material.

Chemistry and Camera (ChemCam) - Built by the French national space agency (laser and telescope) and Los Alamos National Laboratory (spectrometers and data processors), this device will hit a target rock sample with a one million watt infrared laser for five billionths of a second, then determine its composition by analyzing the spectrum of the resulting flash.

Chemistry and Mineralogy (CheMin) - This experiment will use x-ray diffraction to analyze the chemical composition of soil and powdered rock samples gathered by Curiosity's robotic arm.

Dynamic Albedo of Neutrons (DAN) - Provided by the Russian Federal Space Agency, this device will shoot neutrons into the soil to detect water bound to minerals up to 20 inches (50 cm) deep. The word "albedo" here refers to "reflectance," as in the neutrons rebounding from contact with atomic nuclei in the ground.

Mars Descent Imager (MARDI) - One of three cameras provided for MSL by Malin Space Science Systems, MARDI will capture full-color aerial video of the surrounding area as Curiosity descends.

Mars Hand Lens Imager (MAHLI) - Developed and operated by Malin Space Science Systems, this powerful macro-lensed camera will capture high-resolution images of rocks, soil and the surrounding area.

Mast Camera - Twin cameras, also provided by Malin Space Science Systems, mounted 10 inches (25cm) apart, 6.5 feet (2m) above the ground, capable of imaging Curiosity's surroundings in exquisite detail.

Radiation Assessment Detector (RAD) - NASA teamed up with Germany's national aerospace research center to construct the RAD, which will track high-energy atomic and subatomic particles bombarding Mars from the sun and other sources, such as remote supernovas.

Rover Environmental Monitoring Station (REMS) - Provided by Spain, the REMS is essentially a fully-functioning meteorological laboratory that will measure wind speed and direction, air temperature and pressure, humidity and UV radiation for five minutes every hour throughout the entire mission (98 weeks).

Sample Analysis at Mars (SAM) - Built by NASA's Goddard Space Flight Center, one of its tasks will be to heat powdered samples in tiny quartz crucibles then use a mass spectrometer to search the resultant gases for life's essential building blocks: carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorous.

The Curiosity/MSL mission, while incredibly ambitious, is also amazingly international in scope. Indeed, it comes close to realizing the "United Earth" concept first discussed on Star Trek so many years ago - over 1.24 million names, submitted online and etched onto silicon chips, will accompany the rover to Mars. Simultaneously bringing humanity together as we expand our horizons seems like pretty darn good value for the money spent, all things considered. Keep an eye peeled for the launch on November 25th!

Source: NASA