Moon dust probably destroyed the bearings. That stuff is brutal on seals. http://www.newyorker.com/online/blogs/elements/2013/11/the-mystery-of-moon-dust.html

Moon dust probably destroyed the bearings. That stuff is brutal on seals. http://www.newyorker.com/online/blogs/elements/2013/11/the-mystery-of-moon-dust.html http://www.newyorker.com/online/blogs/elements/2013/11/the-m...