As NASA's Curiosity rover roams across the Martian surface, the space agency is already looking towards its next mission to the red planet.
Announced on 20 August, NASA's next Discovery-class mission will be a new Mars lander called InSight.
This will place an immobile lander on the surface to investigate the interior of the planet. Despite a good deal of research into the surface characteristics of Mars, relatively little is known about the planet's interior or how it was formed.
The probe, due to launch in 2016, will drill about 9m (30ft) beneath the Martian surface to measure heat and seismic activity. It will also use radio equipment to measure how the planet is affected by the sun, which will reveal more about the planet's internal composition.
The InSight mission was included as a possibility in the National Academy of Sciences' influential Decadal Survey for planetary sciences, the once-a-decade list of the US government's scientific priorities, which is used to guide science funding. Two riskier missions to comets and Titan, one of Saturn's moons, were rejected. The mission is planned to last for 720 days.
Due to planetary alignment, flights to Mars are much less energy-intensive during certain timeframes, and missions outside of those periods become much more expensive - and thus less feasible. Because of the mission's complexity and the frequent delays associated with space programmes, researchers were concerned that the 2016 launch window would slip away unused, concerns which now appear largely mollified.
As with the ongoing Curiosity mission, InSight will be flown by NASA's Jet Propulsion Laboratory in California.
NASA is currently undertaking an intensive study of Mars, the nearest planet in the solar system. The Mars Atmosphere and Volatile Evolution (MAVEN) orbiter is scheduled for launch in late 2013, and landing people on Mars remains a stated, albeit distant, goal.
NASA is developing the Space Launch System (SLS), an ultra-heavy launch vehicle, and the Lockheed Martin Orion capsule for long-range spaceflight and interplanetary exploration; while no destinations have been set for the SLS, Mars is considered to be a prime candidate.