Opportunity is to complete its three-month mission on April 26.

Having only been designed for three-month missions, they both lasted much longer than planned, and Spirit lost contact with Earth in March 2010.

They're nearly 8 years into a (planned) three-month mission.

Both completed their three-month prime missions in April 2004 and continued years of extended operations.

Both rovers landed the following January and completed their three-month prime missions in April 2004.

After a three-month mission, the team's report was optimistically favourable to the scheme.

This marked the course Defiant would take on its three-month mission.

It could have returned from a three-month mission and been sent immediately on this one.

That force has 4,000 troops and a three-month mission.

The solar-powered lander operated two months longer than its three-month prime mission.