NASA's Phoenix Mars Lander communicates with Earth using the Odyssey orbiter as a two-way communications link in the Martian sky. For example, Phoenix sent this image of one of the lander's footpads on pebbly, north polar terrain to Odyssey, which sent it to NASA's Deep Space Network of antennas on Earth. Meanwhile, the Deep Space Network transmits instructions to Odyssey, which relays them to Phoenix on the surface of Mars.
This image was taken by the Surface Stereo Imager shortly after Phoenix landed May 25, 2008.
Credit: NASA/JPL-Caltech/University of Arizona/Texas A&M