The Mars Science Laboratory (MSL), part of the Science Mission Directorate's Mars Exploration Program (Mars Program), is the most technologically challenging interplanetary rover ever designed.

This NASA flagship mission, whose life-cycle costs are currently estimated at approximately $2.5 billion, will employ an array of new technologies to adjust its flight while descending through the Martian atmosphere, including a sky crane touchdown system that will lower the rover on a tether to the Martian surface.

Contributing to the complexity of the mission are the Project's innovative entry, descent, and landing system; the size and mass of the rover (four times as heavy as the previous Martian rovers Spirit and Opportunity); the number and interdependence of its 10 science instruments; and a new type of power generating system.

The primary objective of the Mars Program is to determine whether Mars has, or ever had, an environment capable of supporting life.

In pursuit of this objective, the MSL rover – known as Curiosity – will assess the biological potential for life at the landing site, characterize the geology of the landing region, investigate planetary processes that influence habitability, and analyze surface radiation.

Due to planetary alignment, the optimal launch window for a mission to Mars occurs every 26 months. MSL was scheduled to launch in a window between September and October 2009.

However, in February 2009, because of the late delivery of several critical components and instruments, NASA delayed the launch to a date between October and December 2011.

This delay and the additional resources required to resolve the underlying technical issues increased the Project's development costs by 86 percent, from $969 million to the current $1.8 billion, and its life-cycle costs by 56 percent, from $1.6 billion to the current $2.5 billion.

If the Project is delayed to a late 2013 launch window, NASA's costs would further increase, at least by the $570 million that would be required to redesign the mission to account for differences in planetary alignment and the Martian dust storm season.

In light of the importance of the MSL Project to NASA's Mars Program, the Office of Inspector General conducted an audit to examine whether the Agency has effectively managed the Project to accomplish mission objectives while meeting revised cost and schedule projections.