On November 26, 2011, an Atlas V rocket shot out of our atmosphere with a payload destined for Mars, in a mission known as the Mars Science Laboratory (MSL). Riding inside the craft like a giant robot astronaut is Curiosity, the fourth Mars rover to visit the red planet since 1997.
Curiosity is currently around 73,000,000 km out from Earth and slated for landing on August 6th, 2012. The rover is already living up to its name: conducting experiments en route.
Image: Charles Atkeison
When radiation from an X-class solar storm hit the MSL in January, Curiosity’s Radiation Assessment Detector (RAD) measured radiation levels inside the craft. These data will help in planning future manned missions.
Experimentation will continue in the Martian atmosphere, where sensors in the heat shield will test atmospheric pressure and heat levels upon entry. Recovered data will allow scientists to calculate what kind of craft living astronauts will need for safe entry.
Image: NASA Goddard Photo and Video
Unlike previous rovers that were simply dropped into the atmosphere and allowed to bounce to the surface surrounded by cushions, Curiosity, weighing in around a ton, will have to rely on new technology to land.
When the MSL approaches Mars, the cruise stage will jettison, leaving the flying saucer-like “aeroshell”. The aeroshell will hit the top of the atmosphere at a mind-melting 13,000 mph and deploy a chute.
The heat shield will unsnap from the bottom of the aeroshell, allowing the rover within to deploy. But with 10 minutes to go until touchdown, the craft will need more than a measly chute.
This is a job for the “sky crane”, a revolutionary NASA development using retro-thrusters to push against gravity. At about 60 feet from the surface, the sky crane will lower the rover with cables and fly away when Curiosity is safely aground.
From the landing site inside Gale Crater, Curiosity’s plutonium-powered systems switch on. The rover’s goal is the mountain of debris at the crater’s center. Scientists believe that the mountain is all that’s left of material that once filled the entire crater, after two billion years of erosion. If the mountain is indeed composed of layers of sediment, clues at its base could give us a two-billion-year geologic history of the red planet’s ecology.
Investigations will be carried out by Curiosity’s roving laboratory. It has a mast camera mounted at human height, which can take high-definition photos and videos. Alongside the mastcam is the ChemCam, capable of pulverizing minerals on the surface of rocks to determine the chemical makeup of any possible organic mineral traces.
The sophisticated robotic arm contains a Hand Lens Imager that can snap almost microscopic close-ups. The arm also contains an x-ray spectrometer that can determine rock and soil mineral levels. The robot can even see underground with the “DAN”, an instrument that shoots neutrons below the surface to detect minerals associated with water. And Curiosity will rely on the versatile RAD to measure radiation levels on the surface and determine if the planet is able to support life.
Image: Brett Jordan
The MSL represents our most ambitious attempt to collect data on the Martian surface. Not only does it seek evidence of previous life, its findings will set the stage for manned missions and the possibility of supporting future life on Mars.