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The Curiosity Rover Explores Mars
Curiosity is still enthusiastically chugging away on the Martian surface, performing its roving duties, drilling holes, taking pictures, measuring things. It was launched November 26, 2011 aboard the Mars Science Laboratory mission. Eight months and ten days later, after covering 350 million miles (563 million kilometers), it landed on Aeolis Palus in Gale Crater, August 6th, 2012.
Compared to Spirit and Opportunity the earlier rovers launched in 2003, Curiosity is a monster truck. It is 10 feet long, nine feet wide and taller than most humans, but weighs five times as much as either Spirit or Opportunity, resembling something more akin to a ridiculously heavy Earth ATV (All-Terrain Vehicle) in design, it weighs in at two thousand pounds (900 kilograms). It can surmount obstacles up to 26 inches (65 cm) high, travel over two hundred and twenty yards (200 meters) per day and all while running on a nuclear pile of Plutonium-238 that generates more than 100 watts of power via radioactive decay. Not only does the radioactive fuel supply power it also circulates its coolant to the electronics as a free heat source to keep everything at a suitable operating temperature. This also means no bulky, flopping “wings” of solar panels to get covered in dust or to bang around and break as torsional stresses are applied when the vehicle traverses nasty terrain.
Landing the Heavy Rover on the Surface was a Tricky Process
Because the distance between Earth and Mars is so great, radio telemetry takes tens of minutes (currently about 24 minutes) to make the round-trip. There is no real-time control of such a remote craft. Everything has to be pre-planned and implemented autonomously by computers. If anything goes wrong, there is nothing that can be done from controllers on the Earth. Yet this was probably only the second most daring landing ever to take place in human history, comparable to “Buzz” Aldrin and Neil Armstrong’s landing on the Moon in Apollo 11 (July 20th, 1969).
Curiosity, on the other hand was far too heavy to use the air-bag bounce-and-roll technique that had successfully gotten Spirit and Opportunity safely on the surface. Instead it used a hypersonic parachute (withstanding 65,000 pounds/29,500kgs of force) to slow it down to 200 mph (320 kph) before beginning its alternate landing method that had far more in common with the lunar landers. Of course, that speed was still too fast, so shearing the parachute free, the Martian Sky Crane was deployed. Essentially a rocket powered hovering platform, it slowed the speed to about 2 mph (3.5kph), winching Curiosity to the ground, sheared its support cables and then went happily off on a planned suicide landing well-away from Curiosity’s landing spot. It was a complete success, greeted by cheers and arm-pumping back in Mission Control.
Curiosity’s main mission is to find evidence that microbial life might have been able to thrive in the environment at some time in the past. It toured around Gale Crater, its landing site, photographing, drilling, and scraping. It only took one third of the allowed mission time of twenty-three months to succeed. Clearly, where it had landed, there was strong evidence of plentiful liquid water flowing on the surface in the form of rounded pebbles, channels, and clumped, solidified sand. It trekked eastward to the palindromically named Glenelg, where three types of terrain met. Here it found suitable soil chemistry, and that the vanished water had been neither too acidic nor salt-laden for life. Microbes could have called it home.
The relativity large size of the Curiosity Rover has allowed for a wide array of scientific instruments to be on-board.
- The Mast Cam is a color stereoscopic camera used to image the surroundings in Hi-Res and store High Definition video. It can also view materials collected or manipulated by the robot arm.
- The Chem-Cam sitting high atop the machine is equipped with a powerful laser which can vaporize samples (or attacking Martians if they are less than 1/25th of an inch (1 mm) in size) and analyse the elemental composition with its spectrometer’s readings of the vapor. Its telescope allows analysis of the surrounding area to make decisions about likely objects to visit before travelling.
- The Robotic Arm can apply tools to the soil and rocks up to 7 feet (2.1 meters) beyond the vehicle.
- The Alpha Particle X-Ray Spectrometer The CSA’s (Canadian Space Agency) tool measures the relative abundance of different elements in the soil.
- The Mars Hand Lens Imager takes extreme close-ups of approximately .005 inches (0.15mm) or less, smaller than a human hair
- Collection and Handling for In-situ Rock Analysis(CHIMRA)
- The MMRGT Nuclear Power Source with 10.6 pounds (4.8 kg) of plutonium dioxide will outlast the two (Earth) year life span of the main mission, starting at 110 watts and diminishing over the life of the mission, for as long as 14 years.
- Radiation Assessment Detector characterizes the radiation environment and preparatory work for the needs of protecting humans that will visit one day.
- The Rover Environmental Monitoring Station (Center for Astrobiology, Madrid, Spain) monitors atmospheric pressure, temperature, humidity, winds, plus ultraviolet radiation levels
- Sample Analysis at Mars (SAM) has an array of tools to identify carbon-containing compounds and determine the ratios of different isotopes of key elements delivered by the robotic arm including:
- Gas Chromatograph
- Mass Spectrometer
- Turntable Laser Spectrometer
- CheMin designed to identify and quantify minerals fetched by the robotic arm, is an X-Ray Diffraction and Fluorescence instrument
- he Mars Descent Imager originally used to record color HD video on the touchdown site and surrounding area to help determine likely investigation sites, it can now be used for surface imaging
- Dynamic Albedo of Neutrons RFSA’s (Russian Federal Space Agency) instrument to measure hydrogen up to 3 feet (1 meter) beneath the surface to detect water bound up in minerals.
- Sample Acquisition/Sample Preparation and Handling system does most of the dirty work, drilling, scooping/collecting, cleaning, sorting particle by size, and delivering samples to the various onboard devices.
- Navigation Hazard Cams stereo cameras designed to avoid trouble both front and rear during movement.
The Extended Science Mission
Curiosity found its mission objective at Yellowknife Bay, within eight months of landing. This wasn’t expected to happen before it had reached Mount Sharp so being ahead of the game the rover sped (at 1.5 inches/4cm per second, or about one basketball player length per minute) along to the Pahrump Hills to begin its extended science mission with few stops along the way for interesting rocks and outcroppings. The terrain has been rougher than expected and the aluminium wheels are showing enough wear to give scientists and mission managers some cause for concern. Curiosity also took some detours for safety around sand that might have bogged it down and trapped it, but its extended science mission for 2014 is still on schedule.
Curiosity’s location as of this writing (October 2014). These are the foothills of Mt. Sharp, and the rover is encountering them 1 ¼ miles (2 km) earlier than expected due to a route change. The rover will climb the mountain slowly, starting at the Murray Formation, experiencing each layer as thoroughly as possible, to develop a deep insight into the geology of Mars. This understanding may help us when explorers first arrive. The expectation is that early visitors will use local resources to survive to reduce the necessity of bringing everything they need with them.
Latest New from NASA on Curiosity
- Mars Science Laboratory - Curiosity | NASA
The latest news, images and videos from NASA's car-sized rover exploring the red planet for evidence the planet could have once supported life.