In May 2009, on the last mission ever flown to repair the Hubble Space Telescope, the whole job came down to one stripped bolt. Astronaut Mike Massimino could not turn it with any tool he carried and could not work around it, so engineers on the ground sent up an unusual answer: grab the handrail and break it off.

A Dead Instrument and a Long To-Do List

The target of that day's spacewalk was the Space Telescope Imaging Spectrograph, known as STIS. It splits starlight into its colors so astronomers can read what distant stars and planets are made of.

A power supply board inside it had failed in 2004, and the instrument had been dark ever since.

Fixing it meant opening a cover held on by 111 screws, every one of which had to be removed and caught so none floated away. Massimino worked the job with his partner, astronaut Michael Good.

Three Screws Out, One Stuck

A handrail sat in the way of that cover. It was held down by four screws. Three came out cleanly.

The fourth would not budge, and when Massimino put his power tool on it, the head stripped. "I'd stripped the bolt head," he later wrote. "No longer a pristine hex shape, it was now gnarled up and unusable."

He knew exactly what that meant. "If that screw doesn't come off, the handrail doesn't come off, and then 111 screws don't come off the panel," he said.

Crewmate John Grunsfeld put it plainly: "For four hours, we were completely stopped in our tracks."

The Test on the Ground

At NASA's Goddard Space Flight Center, engineers worked out a new plan. They found a matching handrail and pulled on its free end with a fish scale. At 60 pounds of force, the handrail snapped off.

They tried the pull on a mock-up twice before sending the plan up to orbit.

The plan called for wrapping the base of the handrail in Kapton tape to catch any pieces that broke loose, and for keeping the sharp edges well away from his suit.

"I gave the handrail a couple yanks until I felt the bolt start to yield," he wrote. "Then I gave it one last good pull and... it broke off!"

After a moment of quiet, he calmly asked for a disposal bag.

NASA photo S125-E-008656: astronauts Michael Good and Mike Massimino in white spacesuits working inside the open instrument bay at the back of the Hubble Space Telescope during the fourth spacewalk of STS-125, May 17 2009, with the shuttle's robotic arm reaching in — Michael Good and Mike Massimino inside Hubble's open instrument bay during the STIS repair spacewalk.

Eight Hours and Two Minutes

With the handrail gone, Massimino and Good pulled the 111 screws, swapped in a new power supply board and closed the instrument back up.

The spacewalk ran about 90 minutes over plan and lasted 8 hours and 2 minutes, at the time the sixth longest spacewalk in history. The first check from the ground showed STIS was alive.

On the same mission, Massimino also sent the first tweets from space, relayed to Twitter through Mission Control. A few years later he appeared as himself in six episodes of The Big Bang Theory.

Still Reading the Stars

The repair held. The Space Telescope Science Institute lists STIS as operational in 2026, and in summer 2026 it was still observing planets around other stars.

Massimino now teaches engineering at Columbia University and advises on space programs at the Intrepid Museum in New York. The instrument he helped bring back is still at work 17 years later.

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