Astronaut John Grunsfeld (S.M. ’84, Ph.D. ’88) shared the ups and upside-downs of repairing one of the world’s largest and widely used telescopes in a lecture Wednesday at the Art Institute.

“I like to eat upside down like a bat,” said Grunsfeld, who has spent almost 60 days in space, this time taking with him a piece of U of C history.

Including this summer’s mission, Grunsfeld has repaired the Hubble Space Telescope three times. So many pieces were replaced this time, Grunsfeld said, “it’s really a brand-new telescope.”

Grunsfeld and the rest of his crew launched in May on the Atlantis, hurtling through space at 17,500 miles per hour. “We were chasing Hubble,” Grunsfeld said. Once they were close enough to the telescope, which is about the size of a school bus, a robotic arm was used to tether Hubble to Atlantis.

Grunsfeld said the operations were “like surgery” and involved unscrewing cover plates and removing and replacing circuit boards. While the operations may seem mundane, even simple tasks in space require great precision—some steps took eight hours to complete.

Grunsfeld, a former Hyde Parker, once did a biography of Enrico Fermi for a school report. “[He] was my hero when I was growing up,” Grunsfeld said. Grunfeld said visiting the site of the first nuclear reactor, just blocks from his own home, was “one of the most pivotal moments of my life.”

Since childhood, “I’ve dreamt of being an astronaut,” he said. In his career, Grunsfeld has been on five space missions and gone on eight spacewalks. Grunsfeld said he’s spent over 58 hours of time outside of the shuttle floating in space.

Famed astronomer Edwin Hubble (S.B. ’10, Ph.D. ’17) wasn’t just a student at the U of C, but an all-star basketball player as well. In honor of his astronomical and athletic achievements, Grunsfeld brought one of Hubble’s basketballs into space. The ball was used in the 1909 championship game, when the U of C won its second Big Ten championship with Hubble as point-guard.

Before the Hubble telescope was launched in 1990, there were no images of other planets; Since its launch, over 350 planets have been discovered. Because of its new spectrograph, the atmospheres of some planets can be observed in light of other neighboring stars.

The repairs should hold up for another five to 10 years, and then the Hubble program will be abandoned.

Even though the mission was a serious one, Grunsfeld found time to enjoy the journey. “Everything in space is fun and magical.”