Telescope mirrors made with carbon nanotubes could soon turn small satellites known as CubeSats into space-based observatories. Researchers at Goddard Space Flight Center led by Theodor Kostiuk and Peter C. Chen are now characterizing the mirrors’ optical performance over a range of wavelengths, NASA announced last month. And should the mirrors survive upcoming terrestrial tests mimicking the thermal and mechanical stresses of spaceflight, the optics would be available to use aboard CubeSats to snoop on nearby comets, asteroids, moons, and planets, Kostiuk says. To make the mirrors, the researchers first pour a mixture of epoxy and multiwall carbon nanotubes, both commercially available, onto a smooth mold. The nanotubes act like rebar, frustrating the epoxy’s natural tendency to shrink as it hardens. Thus, the epoxy-nanotube composite faithfully reproduces the mold. The researchers then coat the hardened composite with a reflective layer of aluminum. This scalable process not only allows NASA to create identical mirrors for CubeSats on the cheap, Chen says, but it’s also the first step toward establishing nanotubes as an advanced material for larger space telescopes.