“I actually was not particularly sad,” Grunsfeld recalls. Once they finished everything on their checklist, he adds, “there wasn’t anything more we could do for Hubble.” Still, his tone is wistful as he recalls thinking, “That may be the last time human eyeballs look at Hubble … the last time people will ever crawl around with the telescope.”

The team’s repairs and additions should keep the telescope going until at least 2014, with more capability and sensitivity than ever. Hubble can now directly image planets in other solar systems, and thanks to its increased range in the infrared, it can see through cosmic dust to peek at stars being born. It has already produced spectacular images of the most distant sections of the universe ever seen–galaxies as they appeared just 600 million to 800 million years after the Big Bang. In a universe estimated to be 13.7 billion years old, that’s almost the first generation of galaxies, Grunsfeld says.

“These are the things we never expected Hubble to be able to do,” he told MIT students. “[It’s] a fun time to be in science and to have these great tools.”

In January, Grunsfeld left NASA to become deputy director of the Space Telescope Science Institute, a job he got after e-mailing his résumé from space with the message “I am holding Hubble hostage until you read my application.” There he will help keep Hubble’s science operations on track and gear up for the launch of the next-generation James Webb Space Telescope, planned for 2014. He will also continue his astronomical work with Hubble, this time using the telescope’s new capability in the ultraviolet spectrum to study cratering effects on the moon. Just as excited about science and the stars as when he began, Grunsfeld shows no signs of slowing down.

Nor, with its brand-new equipment, does the Hubble Space Telescope. “We’ve reinvented the Hubble with what we did on orbit,” Grunsfeld says. “The Hubble story is really just beginning.”