Two NASA astronauts helped launch a new exhibit at the American Museum of Natural History in New York, museum officials said. NASA astronauts Mike Massimino and John Grunsfeld, who both participated in the last space shuttle mission to service the Hubble Space Telescope, were at the museum as the \"Beyond Planet Earth: The Future of Space Exploration\" exhibit opened Saturday. \"I used to come here as a little guy growing up here in New York,\" Massimino told SPACE.com. \"I used to come here to dream about being an astronaut. I look at this as a great way for people to come and get inspired about what they might want to do as they get older, even for grownups, \'cause we still need inspiration too.\" Among the items on display in the exhibit are space artifacts such as a soviet space helmet, a lunar rover tire and patches from the Chinese space program. Dioramas, videos, and models are also a part of the exhibit, which will run through August. The exhibition coincides with a critical time for NASA, museum officials said. \"We\'re at a kind of crossroads,\" lead curator Michael Shara, an astrophysicist, said. \"We all know that the shuttle program has ended, and I think that that is a little bit like us graduating from kindergarten. \"We want to take those next steps out of our backyard into the neighborhood and then into the big city to visit all the other places in the solar system.\"