Space Telescope Science Institute
Interview Date: March 2004
EDUCATIONStudied physics and astronomy at the University of South Florida. Obtained a masters in computer science from the University of Florida and a PhD in Astronomy from the University of Maryland.
BACKGROUNDStudied physics and astronomy at the University of South Florida. Obtained a masters in computer science from the University of Florida and a PhD in Astronomy from the University of Maryland.
Michael Regan held a transparent disk, embedded with a set of fingernail-sized dark squares, up to the sunlight filtering through his office window.
The light revealed barely discernable divisions within the squares. Each square consists of a collection of around 16,000 tiny shutters, he explained.
The shutters are part of an instrument called a spectrograph. Typically, it's a simple astronomy device — an aluminum plate drilled with holes that only lets in the light the observer needs to see, and blocks out the rest. A laser drills a single hole for each object to be observed.
On the James Webb Space Telescope, the Near Infrared Spectrograph will have to be able to observe several hundred objects at a time. “It's required the development of a whole new technology,” Regan said.
He holds part of that new technology in his hand. Thousands of tiny shutters will be installed on JWST, to be swept closed by a magnet and winked open on command. “It takes the light and spreads it out so you can learn different things — the chemical composition of a galaxy, what type of stars it has in the galaxy. It has to generate a lot of information very fast, at wavelengths you can't access from the ground.”
Regan is an instrument scientist on the Near Infrared Spectrograph, or NIRSpec. He's been working on JWST since 1990, after an 8-year stint as an IBM programmer working on Air Force satellite ground systems.
“I liked being able to get in on the ground floor,” he said. “You get to influence how it's going to be built. In my previous experience at IBM, I found important decisions were made early that affect you later on.”
So he's worked on “target acquisition” — figuring out how to point the telescope where it needs to look. And he helped put together the laboratory that was instrumental in deciding which infrared detectors JWST would use.
The detectors, used in two of JWST's instruments, are the equivalent of film in a camera. They're cousins to the charge-coupled devices, or CCDs, in digital and video cameras — just sensitive to a different kind of light. “Their quality relates directly to how much science data you can get,” Regan said. “At some level, it's better to make the detectors good than to build a bigger telescope.”
The detectors have provided the highlight and low point of Regan's work so far. Giving an independent analysis of which of two possible detectors to use, after building the lab from scratch, was a triumph. But getting there had its pitfalls.
He doesn't hesitate over his worst moment in the project: “When we broke a detector in the lab,” he said.
The detectors are made of two different materials, so they expand at different rates when the temperature changes. A bug in the equipment caused the temperature to change too fast, and the detector — valued at hundreds of thousands of dollars — shattered.
“We actually did it twice, which was even worse,” Regan said.
But generally the excitement at work is of a more appealing type. “You're just always finding out new things,” he said. “It's not the same job as you go along — the job changes.”
He's currently on the brink of another such change. The detector question is settled, and the European Space Agency will build NIRSpec. Next year, the building begins. At that point, Regan's involvement ends for a time, until the new instrument is ready for testing.
It's exciting, Regan said. “But scary too, because most of our influence is at the design stage. You wonder: Are the requirements correct? Is it going to work the way we think it will work?”
It's normal for minor problems to crop up as the construction goes along, he said. The question is one of catching them early enough, before it becomes overwhelmingly costly. The instruments are tested first individually, then together, then with the rest of the telescope. It becomes increasingly expensive to fix flaws through each stage.
Regan's interest in astronomy started as a child, prompting him to earn a bachelors degree in that subject. There weren't a lot of astronomy jobs when he graduated, so he went for a masters in computer science. The JWST job, he said, is the kind of work he had been hoping for.
His personal goals for JWST are still amorphous. “There are so many projects I can do between now and when it launches. I have my half-formed ideas, but I don't think it's close enough yet to think about.”
Patience, after all, is part of the job. Information is just starting to come in from a project on the Spitzer Space Telescope that Regan was involved in 5 years earlier. “We're just now getting the data, so I'm just starting to realize that's real,” he said. “JWST is much farther out.”
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