NASA Creates First Ever Carbon Nanotube Telescope Mirrors
The technology development effort is aimed at giving the scientific community a compact inexpensive telescope that would fit easily inside a CubeSat, a class of research spacecraft built to standard dimensions that can be deployed from a Poly-Picosatellite Orbital Deployer, or P-POD.
NASA’s CubeSat Launch initiative (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.
Small satellites are playing an increasingly larger role in exploration, technology demonstration, scientific research and educational investigations at NASA. These miniature satellites provide a low-cost platform for NASA missions, including planetary space exploration. They also allow an inexpensive means to engage students in all phases of satellite development, operation and exploitation through real-world, hands-on research and development experience on NASA-funded ride share launch opportunities.
The first ever carbon-nanotube resin mirror could prove central to creating a low-cost space telescope for a range of CubeSat scientific investigations.
Unlike most telescope mirrors made of glass or aluminium, this particular optic is made of carbon nanotubes embedded in an epoxy resin. Sub-micron-size, cylindrically shaped, carbon nanotubes exhibit extraordinary strength and unique electrical properties, and are efficient conductors of heat. Owing to these unusual properties, the material is valuable to nanotechnology, electronics, optics, and other fields of materials science, and, as a consequence, are being used as additives in various structural materials.
The use of a carbon-nanotube optic in a CubeSat telescope offers a number of advantages. In addition to being lightweight, highly stable, and easily reproducible, carbon-nanotube mirrors do not require polishing — a time-consuming and often times expensive process typically required to assure a smooth, perfectly shaped mirror.
To make a mirror, technicians simply pour the mixture of epoxy and carbon nanotubes into a mandrel or mould fashioned to meet a particular optical prescription. They then heat the mould to cure and harden the epoxy. Once set, the mirror then is coated with a reflective material of aluminium and silicon dioxide.
Many of the mirror segments in these telescopes are identical and can therefore be produced using a single mandrel. Carbon-nanotube mirrors can also be made into ‘smart optics’. To maintain a single perfect focus in the Keck telescopes, for example, each mirror segment has several externally mounted actuators that deform the mirrors into the specific shapes required at different telescope orientations.
This technology can potentially enable very large-area technically active optics in space, and can address everything from astronomy and Earth observing to deep-space communications.