Space.com: Spaceweather.com is sponsoring a space photo contest with cash prizes for the best views of NASA’s NanoSail-D satellite. This NanoSail-D skywatching guide has some tips on how to track the satellite from the ground. NanoSail-D‘s primary mission is a demonstration of a compact solar sail system. This technology could lead to further development of solar sails for future missions, and could help satellites de-orbit cheaply and efficiently, according to officials.