A lightweight telescope that a team of NASA scientists and engineers is developing specifically for scientific investigations in its CubeSat Launch initiative (CSLI) could become the first to carry a mirror made of a composite of carbon nanotubes in an epoxy resin.
As NASA explains, “CubeSats” are a class of research spacecraft called nanosatellites. The CSLI provides opportunities for small satellite payloads to fly on rockets planned for upcoming launches. These CubeSats are flown as auxiliary payloads on previously planned missions.
This particular telescope project, led by Theodor Kostiuk, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., seeks to develop a CubeSat telescope that would be sensitive to the ultraviolet, visible, and infrared wavelength bands. NASA says the telescope “would be equipped with commercial-off-the-shelf spectrometers.” A spectrometer is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum. In this CubeSat, the spectrometers are connected by fiber optic cables to the focused beam of a three-inch diameter carbon-nanotube mirror.
To make a mirror, the technicians pour the mixture of epoxy and carbon nanotubes into a custom mold. They then heat the mold to cure and harden the epoxy. Once set, the mirror then is coated with a reflective material of aluminum and silicon dioxide.
NASA says most telescope mirrors are made of pure glass or aluminum. The agency says carbon nanotubes “exhibit extraordinary strength and unique electrical properties, and are efficient conductors of heat.” However, according to Peter Chen, the president of a contractor working on the telescope, there’s a reason no one has been able to make a mirror using a carbon-nanotube resin before.
“This is a unique technology currently available only at Goddard,” Chen said. “The technology is too new to fly in space, and first must go through the various levels of technological advancement. But this is what my Goddard colleagues (Kostiuk, Tilak Hewagama, and John Kolasinski) are trying to accomplish through the CubeSat program.”
In addition to its strength and electrical properties, Hewagama says the use of a carbon-nanotube optic in a CubeSat telescope offers light weight, high stability, a low of amount of polishing, and is easily reproducible.
Chen says there are many potential applications for the technology, including larger telescopes such as NASA’s James Webb Telescope.
“This technology can potentially enable very large-area technically active optics in space,” Chen said. “Applications address everything from astronomy and Earth observing to deep-space communications.”