“NuSTAR will open up a whole new window into the universe,” said Hailey, the Pupin Professor of Physics and co-director of Columbia’s astrophysics lab.
X-rays, a high-energy form of light, help astrophysicists observe phenomena that are typically invisible to the naked eye. Black holes, for example, hide behind clouds of dust and gas, and their centers of gravity are so strong that optical light cannot escape. Black holes do, however, emit X-rays, which can penetrate dust and gas, making them visible to NuSTAR.
Compared with Chandra, the NASA X-ray mission that launched in 1999, NuSTAR will record a much higher energy band. The stronger the X-rays, the denser the matter they can penetrate, enabling NuSTAR to find black holes and other cosmic events that have previously escaped detection.
Building such a sensitive instrument required patience and precision. More than 10 years ago Hailey pioneered a technique called thermal glass slumping, which involves placing flat sheets of glass into a hot oven until they melt. The glass is then shaped to curved molds beneath it. Then, starting in December 2009, a team that included NASA Goddard Space Flight Center, the Danish Technical University as well as engineering and project management support from NASA Jet Propulsion Laboratory and the Lawrence Livermore National Laboratory, manufactured and assembled NuSTAR’s “eyes” out of 4,000 sheets of glass. Using thermal glass slumping helped bring NuSTAR’s cost to about one-tenth the price of Chandra, which cost $2 billion.
Once the pieces were slumped, they were shipped to Copenhagen, where scientists coated them with a reflective material before sending them back to Nevis. Hailey then layered the curved glass sheets into concentric rings—12 to 24 sheets per ring, 130 rings in all. The result: two cones mounted onto the finished body of the telescope in California.
NuSTAR, which stands for nuclear spectroscopic telescope array, is scheduled for launch on Wednesday, June 13 from Kwajalein Atoll in the Pacific Ocean. (Coverage and commentary will be broadcast here beginning 90 minutes before launch.) The project’s principal investigator, Fiona Harrison of the California Institute of Technology, was responsible for building the telescope’s detectors, which will record the images collected by Hailey’s optics. Components assembled by collaborators at the University of California, Berkeley and other institutions include shields to protect NuSTAR from meteors; a deployable mast; and the launch vehicle, a lightweight Pegasus XL rocket.
Hailey, who dislikes travel, will watch the launch on NASA TV from his office, but distance won’t lessen the thrill of watching NuSTAR lift off into the sky.
“It’s enormously exciting,” he says. “I can tell you that we’ll discover black holes of all masses, supernova remnants and young stars. But what really sends chills up my spine are the things we’ll discover that I can’t conceive of yet, that no one can envision.”