Students Build Telescopes to Track Satellites

May 22, 2017

Why should you buy what you can make for yourself?

That's the principle that drove five undergraduate students from the University of Arizona's College of Engineering, led by assistant professor Vishnu Reddy of the Lunar and Planetary Laboratory, to build two telescopes from the ground up to track satellites and space junk.

Reddy joined the UA faculty eight months ago, offering expertise in space situational awareness. A large part of SSA involves tracking satellites and space junk around Earth. Federal entities such as the U.S. Department of Defense do so on a regular basis. It's work that requires a large amount of observing time on small telescopes.

While the UA runs more than 20 large telescopes across the globe, few of them are suited for tracking satellites. Having a telescope on campus provides an easy opportunity for student access without a trip to Kitt Peak or Mount Lemmon.

Reddy identified the perfect — and conveniently vacant — space for a small telescope. In the 1990s, a room on the sixth floor of the Kuiper Space Sciences Building was transformed into a small observatory, complete with a retractable roof, so that Bob McMillan, Reddy's colleague in the Lunar and Planetary Lab, could observe stars. The room was last used for observation in 1995, later becoming a storage facility.

Instead of buying the telescopes off the shelf for upward of $50,000 apiece, Reddy recruited five undergraduate engineers to build them through the Engineering Design Program. The program, aimed at preparing the students for careers in engineering, requires all engineering students at the UA to spend their senior year designing, building and testing technologies in teams of four to six, culminating in an annual Engineering Design Day, which this year was held on May 1.

Reddy's team included Lindsie Jeffries, senior in biomedical engineering and mathematics; Sameep Arora, senior in mechanical engineering; Ryan Bronson, senior in optical sciences and mathematics; Damon Marco Colpo, senior in optical sciences and mathematics; and Evelyn Hunten, senior in electrical and computer engineering.

Asked if anything about the project surprised him, Reddy responded unequivocally.

"(It's) the students," he said. "Undergrads are some of the most optimistic people on campus. They're full of life, they feel positive about the future, and they inspire me to be enthusiastic."

Hunten, who landed a post-graduation position at IBM, said she loves space science and exploration.

"This project was the one I wanted to work on," she said. "It was my first choice. I love the instrumentation behind scientific discoveries."

Together, the students built two 24-inch telescopes in seven months for $30,000 total. The mirrors they installed in the new telescopes were recycled from the telescope in the old Kuiper observatory. Written off as junk, the mirrors were headed for the UA's Surplus Store.

A local astronomy business, Starizona, was instrumental in training the students and testing the telescopes' optics, Reddy said.

Starting June 20, after a first light ceremony at 6 p.m., one of the telescopes will run autonomously each night in the place where the old one once stood. It's the first time that a telescope has been installed on campus since the 1990s. The location for the second telescope has yet to be determined, but Biosphere 2 has been discussed as a possibility.

Arora, who designed the telescope model in SolidWorks, a design program, said that making "an actual product that will be used for science" — rather than a prototype — was a rewarding experience.

Jeffries, who will pursue a graduate degree in biomechanical engineering at Stanford University, said, "It was exciting putting the telescope together and confirming that everything fit and worked. I also enjoyed getting to know my teammates. They were all hard workers who cared about the project and pushed me to do my best."

While the team was building the telescopes, Reddy was writing a proposal to the Air Force Research Laboratory, requesting funding for a spectroscopic survey of satellites in the geostationary orbit. Satellites in geostationary orbit revolve around Earth at the same rate that Earth rotates on its axis. This makes them hover above the same location on Earth.

Because their rotation matches ours — moving from west to east — they appear as fixed in space when we look at them from telescopes on Earth. More than 500 such satellites are in orbit today.

Rather than tracking satellites as mere nondescript dots in space — which is not uncommon — Reddy will be able to use the telescopes to identify some unique color signatures of satellites, to find out exactly which one is which.

"The UA is going to be a leader in space situational awareness, and we really want to capitalize on our exceptional undergraduate students," Reddy said. "This is also workforce development. We need an American workforce that can rise to the challenges of our national security needs, and the needs of our nation."