Beyond the Big Bang

Associate Professor of Physics and Astronomy Mark Devlin is having a BLAST. That stands for Balloon-borne Large Aperture Sub-millimeter Telescope, a NASA project designed to view some of the oldest galaxies in the universe.

Penn heads up a four-school collaboration on the project, and Devlin is in charge of Penn’s portion. But before he could look for new star clusters, he had to find a place on campus to assemble the largest balloon-borne telescope ever built.

Today, in the space where General Electric once manufactured re-entry vehicles, amongst the mid-century modern chairs that dot the new Facilities Services office atrium in the Left Bank building, sits a hulking 25-foot-tall metal frame fitted out with electronic gear.

Across the room sits a mirror measuring 2 meters (6.5 feet) in diameter that will survey a patch of sky about four times the size of the moon looking for dimmer, fainter, smaller objects.

Five Penn faculty and graduate students, along with colleagues at Brown University, the University of Toronto and the University of British Columbia, have joined Devlin in this “build your own telescope” project with cosmic implications.

After integrating all of the components to make sure they perform flawlessly, the telescope will be disassembled and shipped to the National Aeronautics and Space Administration’s National Scientific Balloon Facility in Ft. Sumner, N.M., in October 2003 for the first test flight.

A helium balloon large enough to fill Franklin Field will lift the telescope 130,000 feet up, beyond the Earth’s atmosphere. There it will be able to observe wavelengths that are invisible when viewed from the surface of the Earth, where the atmosphere is opaque.

On board, 260 detectors, the largest number ever used on a balloon flight (10-15 is the norm), will convert photons into heat, measure the temperature rise and thereby measure the number of photons from galaxies formed 5 to 12 billion years ago, when the universe was one-tenth its current age.

The real technical challenge will be in pointing the telescope while it is hanging by a cable from a balloon.

The techniques being used in this project, Devlin said, are similar to those physicists have long used to learn about the Big Bang. But, he added, “[This] is much more challenging [than looking for evidence of the Big Bang] by a factor of 10.

“There are lots of stars and galaxies, and it takes time to make stars. If BLAST can show galaxies that were well formed with many stars millions of years ago, we will have new clues to the evolution of star formation.”

Originally published on November 14, 2002