NASA engineers design carbon-nanotube resin mirror for small space telescopes
New low-cost optics, plus off-the-shelf components, may enable CubeSats to incorporate mini space telescopes.
NASA scientist and engineers are hoping that their latest mirror development will be a low-cost solution central for the proper function of small space telescopes, like those found in the range of CubeSat scientific investigations.
The project, led by Theodor Kostiuk, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, aims to give the scientific community a compact, reproducible, and relatively inexpensive telescope that would fit easily inside a CubeSat. This new mirror could prove central to creating this low-cost space telescope.
The mirror was developed using carbon nanotubes in an epoxy resin. This unique structure differs from traditional telescope mirrors, which usually are made of glass or aluminum. The team believes that this unique mirror construction will have enhanced properties perfect for this particular application. Sub-micron-size, cylindrically shaped, carbon nanotubes exhibit extraordinary strength and unique electrical properties, and are efficient conductors of heat.
“No one has been able to make a mirror using a carbon-nanotube resin,” said Peter Chen, a Goddard contractor and president of Lightweight Telescopes, Inc., a Columbia, Maryland-based company working with the team to create the CubeSat-compatible telescope.
This technology will go through various levels of technological advancement before it is space ready.
However, the team is optimistic that this mirror will be suitable for space telescopes.
The use of a carbon-nanotube optic in a CubeSat telescope offers a number of advantages. It is lightweight, highly stable, and easily reproducible. Furthermore, carbon-nanotube mirrors do not require polishing – a process that is time-consuming and often times expensive. Mirrors typically require a smooth, perfectly shaped surface to function correctly.
To make a mirror, technicians simply pour the mixture of epoxy and carbon nanotubes into a mandrel or mold fashioned to meet a particular optical prescription. 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.
“After making a specific mandrel or mold, many tens of identical low-mass, highly uniform replicas can be produced at low cost,” Chen said. “Complete telescope assemblies can be made this way, which is the team’s main interest. For the CubeSat program, this capability will enable many spacecraft to be equipped with identical optics and different detectors for a variety of experiments. They also can be flown in swarms and constellations.”
These miniature satellites provide a low-cost platform for NASA missions, including planetary space exploration; Earth observations; fundamental Earth and space science; and developing precursor science instruments like cutting-edge laser communications, satellite-to-satellite communications and autonomous movement capabilities.
Kostiuk’s team hopes to develop a CubeSat telescope that would be sensitive to the ultraviolet, visible, and infrared wavelength bands. It would be equipped with commercial-off-the-shelf spectrometers and imagers and would be ideal as an “exploratory tool for quick looks that could lead to larger missions,” Kostiuk explained. “We’re trying to exploit commercially available components.”
“This technology can potentially enable very large-area technically active optics in space,” added Chen. “Applications address everything from astronomy and Earth observing to deep-space communications.”