You don’t have to be big to hunt black holes. NASA’s telescope NuSTAR, which was due to take off from an island in the South Pacific on 13 June, is small enough, even including its launch rocket, to fit beneath the belly of an aircraft. Once in orbit, it will unfold to the length of a school bus.
The Nuclear Spectroscopic Telescope Array will be the first telescope to bring high-energy X-ray light into focus, letting astronomers map and study the extreme physics around black holes and the explosions of massive stars. Its images of these objects will be 10 times crisper and 100 times more sensitive than those of previous telescopes.
To make such sharp images, the telescope needs to focus X-rays with energies of up to 100 kiloelectronvolts â€“ 10 times more energetic than those sought by previous X-ray telescopes â€“ onto a small area. Visible light telescopes can manage this with a focusing lens relatively close to the eyepiece. But because the X-rays are so energetic, NuSTAR’s camera needs to be 10 metres away from the focusing lens.