On 10 March 2006 the MRO (Mars Reconnaissance Orbiter) reached the orbit of Mars.
And what is the mission or because of this probe was launched?, because deep appreciation for the surface of this planet to (also) see potential landing sites for future missions (manned or not).
Therefore, it stands out from this probe, the camera system imaging has high resolution that has served to not only know precisely the surface but helped decipher some of the doubts of the Martian surface.
Also, some of the missions of the probe, is “proxy” communications. It has been used as a communication relay when the object or probe that is on the surface (Opportunity, Spirit, …) have been out of direct view of the Earth.
As you can see, space missions require years of foresight and remember that not all the gold of the same or recognition, you have to give to the mission itself but also to the accessory that have helped achieve the goal, for example small MRO.
More info: NASA