Here is the "Mars Reconnaisance Orbiter"

This artist's concept of the Mars Reconnaissance Orbiter features the spacecraft's main bus facing down, toward the red planet. The large silver circular feature above the spacecraft bus is the high-gain antenna, the spacecraft's main means of communicating with both Earth and other spacecraft. The long, thin pole behind the bus is the SHARAD antenna. Seeking liquid or frozen water, SHARAD will probe the subsurface using radar waves at a 15-25 MHz frequency band, "seeing" in the first few hundreds of feet (up to 1 kilometer) of Mars' crust. The large instrument (covered in black thermal blanketing) in the center is the HiRISE camera. This powerful camera will provide the highest-resolution images from orbit to date.

The other easily visible instruments are: the Electra telecommunications package which is the gold-colored instrument directly left of the HiRISE camera. It will act as a communications relay and navigation aid for Mars spacecraft. To the right of the HiRISE camera is the Context Imager (CTX).