The Mars Science Laboratory (MSL), now rechristened Curiosity (NASA spacecraft usually receive new, less technical names prior to launch) is the next major rover mission bound for Mars. After it launches in 2011, it will conduct a ground mission similar to those currently being undertaken by Spirit and Opportunity, though it will be much more capable and, hopefully, operate for an even longer time period on the surface of the red planet.
– Development and Design –
The Mars Science Laboratory was designed to further several high-priority objectives with respect to Mars, including studying its climate and searching for evidence of the building blocks of organic life, such as carbon organic compounds, oxygen, and water. As with most major space probe missions, the Mars Science Laboratory is both late and over-budget. When first approved in 2006, it was supposed to be launched in 2009; two years later, it was delayed until 2011.
Previous probes to Mars have been very small: the Sojourner rover was the size of a large remote-controlled toy car, and Spirit and Opportunity were three times as large. The Mars Science Laboratory will be the size of a small car, and weigh almost 2000 pounds. An autopilot unit will drive it over the surface of Mars at the relaxed pace of 300 feet per hour, and mission parameters call for it to travel at least 12 miles over the course of its mission. (If the mission is as successful as the Spirit and Opportunity ones, it will travel much farther.)
Aside from much more sophisticated scientific research and computer components, one of the most important differences between the Mars Science Laboratory and its predecessors is that it will be scrapping their solar panel configuration in favour of radioisotope generators, the nuclear-powered generators which were used by the Viking probes in the 1970s. These generators are far more expensive than solar panels, but also produce several times as much power. Their second chief drawback is that they will run out of fuel in about 15 years, whereas solar panels could theoretically keep the Spirit and Opportunity probes under power indefinitely. However, if the Mars Science Laboratory lasts long enough for its generator to be exhausted, it will still be considered an outstanding success.
– The Mission –
In October 2011, according to current planets, Mars Science Laboratory will blast off atop an Atlas V rocket, the same as that used to launch the recent probe to Pluto, New Horizons.
Once at Mars, instead of using the large airbag apparatus designed for the previous generation of Mars landers, the Mars Science Laboratory will use a combination of heat shields (similar to those used by spacecraft re-entering Earth’s atmosphere), parachutes, and rockets, in order to make an unprecedented soft landing on the surface. Once landed, a crane built into the re-entry vehicle will lift the Science Laboratory vehicle itself and lower it out onto the surface of the planet. At that point the ground mission will be ready to begin.
This system should, at least in theory, allow much greater precision in landing than the previous Spirit and Opportunity missions, which used large airbag systems to bounce repeatedly along the surface before coming to a standstill. NASA has not yet chosen which site will be selected for the landing (a decision which will be made early in 2011, as part of the final preparations for launch), but likely targets include the Mawrth Valley, believed to be the site of an ancient water river; and several large craters.
Minimum requirements stipulate that the Mars Science Laboratory will operate for two years on the surface of Mars. However, successful space missions routinely far exceed their requirements. For example, the Opportunity probe was required to survive for three months; instead, it is still operational today, over six years later.
