From the description: "The Google Lunar X PRIZE seeks to create a global private race to the Moon that excites and involves people around the world and, accelerates space exploration for the benefit of all humanity. The use of space has dramatically enhanced the quality of life and may ultimately lead to solutions to some of the most pressing environmental problems that we face on earth -- energy independence and climate change. For more information, please visit www.googlelunarxprize.org."
This railway goes up and down a mountain in England, but it does not have a motor. Instead, each car has a 700 gallon tank of water, and the two cars are connected by a cable. At the top, the car that will be going down fills up its tank. As it falls, it pulls the other car up. At the bottom, it empties its tank so the other car can pull it up.