How do NASA astronauts make the most of their limited time during spacewalks? They practice on intricate models, like this one of the Hubble Telescope at the Neutral Buoyancy Lab (NBL) near Johnson Space Center. This water environment closely replicates the weightlessness of space, allowing the crew to perfect their techniques so by the time they actually reached Hubble there were few or no surprises. Credit: NASA #nasa #hubblefriday #exploration #space