“I was quite worried,” NASA Associate Administrator Thomas Zurbuchen said after NASA announced its success on Friday.
“We all knew this was riskier than we normally do,” he added, in a video shared on Twitter.
Even though NASA has probably fixed the issue, it’s a sign that Hubble’s age may be catching up to it. The telescope hasn’t been upgraded since the last astronauts serviced it in 2009. Some of its hardware is more than 30 years old.
“Someday, a component will randomly fail that we won’t have a backup for. That’s the most likely way the Hubble mission will end,” Paul Hertz, director of NASA’s astrophysics division, told Insider the week before Hubble switched to the backup hardware .