NASA's Desert RATS, or Research and Technology Studies, team made its 13th trip to the desert for another round of analog testing. The Desert RATS tests offer a chance for a NASA-led team of engineers, astronauts and scientists to conduct technology development research in the Arizona desert. The location offers a good stand-in for destinations for future planetary exploration missions. This year's tests take place Aug. 31-Sept. 15. This image is a night-time shot of the rover and habitat unit. Image Credit: NASA