The Hubble Space Telescope still shines in the eyes of astronomers after 36 years in orbit, but it is not as nimble as it once was. Left alone, the observatory will plunge back into the atmosphere in the early-to-mid-2030s, closing the book on one of the most famous scientific instruments of the century. NASA last raised the orbit of Hubble in 2002, when the Space Shuttle Columbia visited the observatory for a servicing mission…