But, over a 60-year career as an optical engineer working with and for NASA, there is plenty more to know about the Warren County resident.

Servant of Light, the biography of John Mangus, is available on Amazon and at the Warren County Historical Society.

“I want people to know what I really did and what I did not do, to really clarify it,” Mangus said. “People only associated me with Hubble. I wanted to clear that up. I wanted people to know how my career really evolved.”

For that, he needed a biography.

In March of 2021, Mangus sent Times Observer Reporter Josh Cotton an email asking if he’d be interested in writing his biography.

“I wanted someone to really get it right,” Mangus said. “I knew it would be technically a challenge. I’d seen Josh’s articles every week. I was impressed by his due diligence.”

“It wasn’t something I hadn’t considered before,” Cotton said. “People in our profession write books.”

He agreed. Over two months he collected about 24 hours of recorded interview.

There was some time pressure associated with the writing.

“I’m getting old,” Mangus said.

For a year, Cotton crafted Servant of Light. “This has been the last 15 months of my existence,” he said.

“It’s not just a scientific retelling of his career,” he said. “He’s an exceedingly interesting guy. I consistently tried to avoid technical minutiae. If that’s what he wanted, he wouldn’t have asked me to write it.”

Mangus was born and raised in Warren.

“His family lived in a home on Melrose Place that still stands,” Cotton said. “He attended East Street Elementary, Beaty, and Warren High School.”

Mangus and his wife, Louise, retired to a Warren County property that has been in his family since the 1870s. He spent the past 30 years or so working out of that home.

Mangus has also helped local leaders and local students reach for the stars — mostly figuratively.

He has been a regular at the Beaty-Warren Middle School Rocket Day events.

“It was much more than a fun day,” Mangus said. “It’s team building, confidence building. It’s like you turn a switch. They go from nervous to totally confident.”

He has spoken before Leadership Warren County.

He told them to be willing to take a risk if the reward is right.

Decades ago, “I was working for a bunch of a solar physicists,” Mangus said. He told them he wanted to start an optics branch at Goddard Space Flight Center with a group of “blue-collar workers who had been trained in the Cold War. I saw great opportunity to turn that group around.”

He told the Leadership group, “if you see these opportunities, take the risk. Things will pan out. They did for me.”

He said he was pleased when Cotton took the risk and agreed to tackle the biography.

“I’m glad he did,” Mangus said. “For him it was a whole new experience.

Like turning a group of blue-collar workers into the Goddard Space Flight Center Optics Branch, “it’s a similar jump for Josh’s career. You are now a published author.”

“It wasn’t all about me, it was about him, too,” Mangus said.

When he first held a copy of Servant of Light in his hands, “I was very much relieved. I checked that off my bucket-list.”

Mangus’ career stretches a little beyond the publication of his biography. The book does not include the release of the first images from his final major project — working on the James Webb Space Telescope.

“My last review was the delivery of the telescope and the instruments, assembled together, cryogenically-qualified, to Northrop Grumman,” Mangus said.

The telescope was launched on Christmas Day, 2021, and arrived at its new home about a million miles from earth last week. It almost immediately began sending images.

Those are not in the book.

But, short of that, “as far as I’m concerned, if you have a question about my career, it’s there,” Mangus said.