This week Chelen Johnson will be flying 42,000 feet above the earth, peering into a 17-ton telescope to study the stars, planets, gases, comets and black holes that populate the universe.

The Breck science teacher was selected to go on two research flights aboard the Stratospheric Observatory for Infrared Astronomy (SOFIA). SOFIA is a heavily modified Boeing 747 jet equipped with a 2.7-meter diameter infrared telescope that pokes out of a special door in the fuselage.

On Tuesday and Thursday of this week, Johnson was taking a 10-hour flight aboard SOFIA out of the Dryden Aircraft Operations Facility in Palmdale, Calif.

She and 25 other science teachers from across the United States were selected as part of the Airborne Astronomy Ambassadors program. The teachers were selected in 13 pairs. Johnson's partner is Constance Gartner from the Wisconsin School for the Deaf in Delavan, Wis.

"I've had the opportunity to do infrared research on the ground, or with satellites orbiting the Earth, but this is the only place we can do it in an airplane," said Johnson, who is in her 28th year teaching at Breck.

The advantages of performing infrared research in a plane high in the atmosphere are threefold. First, they will be flying above 99 percent of the water vapor in the atmosphere. Water vapor blocks some infrared rays from reaching Earth's surface, so a much fuller range of the infrared spectrum will be visible at 42,000 feet.

Second, SOFIA has a range of 6,625 miles, allowing it to travel to nearly any point on Earth. Different astronomical objects are visible from different points on Earth at different times, so that range gives the crew greater flexibility in studying the cosmos.

And third, having the telescope on-site instead of orbiting Earth on a satellite will allow the crew to make adjustments to the telescope on the fly.

Johnson grew up in Orono and graduated from Mound High School. She received her undergraduate degree from St. Olaf and completed her graduate work in aeronautics at the University of North Dakota.

The daughter of an architect and a kindergarten teacher, Johnson grew up in a scientifically inclined family.

"When I was growing up, we were empowered to do whatever we wanted to do," she said. "I would lie out on the dock and look at the stars at night, grab lake water and look at it under my microscope, or just sit under a tree and read for hours."

Now as an educator, Johnson has made empowering girls in the subjects of physics and astronomy a top priority.

Five years ago, she started an astronomy club for junior and senior girls at Breck. Every Saturday morning for about three hours they work with data from satellites with infrared telescopes.

The Saturday astronomy research group works in collaboration with three other schools, two from Hawaii and one from Texas. They have been published in two professional journals, and this year they discovered new stars and classified a black hole no one had previously classified.

"I never really was a science person until I joined the group, so it's definitely changed my opinion on the subject," said Alayna O'Bryan, a senior at Breck.

O'Bryan was one of three students who accompanied Johnson to an American Astronomical Society conference in Long Beach, Calif., in early January. At the conference, the students presented a poster they had been working on in their astronomy group. They also visited the SOFIA booth, attended an hourlong talk on the project and met a lot of people Johnson will be working with.

"Everyone knew her," said Melissa Clark, a senior at Breck and a member of the Saturday astronomy club. "She was kind of like a celebrity."

Ben Johnson is a Twin Cities freelance writer.