NASA Scientists Pioneer Method for Making Giant Lunar Telescopes (Forwarded)

Robert Naeye
Goddard Space Flight Center, Greenbelt, Md. June 4, 2008
301-286-4453

NASA Scientists Pioneer Method for Making Giant Lunar Telescopes

Scientists working at NASA's Goddard Space Flight Center in Greenbelt, Md.,
have concocted an innovative recipe for giant telescope mirrors on the Moon.
To make a mirror that dwarfs anything on Earth, just take a little bit of
carbon, throw in some epoxy, and add lots of lunar dust.

"We could make huge telescopes on the moon relatively easily, and avoid the
large expense of transporting a large mirror from Earth," says Peter Chen of
NASA Goddard and the Catholic University of America, which is located in
Washington, D.C. "Since most of the materials are already there in the form
of dust, you don't have to bring very much stuff with you, and that saves a
ton of money."

Chen and his Goddard colleagues Douglas Rabin, Michael Van Steenberg, and
Ron Oliversen are presenting their mirror-making technique in a poster at
the 212th meeting of the American Astronomical Society in St. Louis, Mo.
They will also describe their results in a press conference on Wednesday,
June 4 at 9:30 a.m. CDT.

For years, Chen had been working with carbon-fiber composite materials to
produce high-quality telescope mirrors. But Chen and his colleagues decided
to try an experiment. They substituted carbon nanotubes (tiny tubular
structures made of pure carbon) for the carbon-fiber composites. When they
mixed small amounts of carbon nanotubes and epoxies (glue-like materials)
with crushed rock that has the same composition and grain size as lunar
dust, they discovered to their surprise that they had created a very strong
material with the consistency of concrete. This material can be used instead
of glass to make mirrors.

They next applied additional layers of epoxy and spun the material at room
temperature. The result was a 12-inch-wide mirror blank with the parabolic
shape of a telescope mirror. All of this was achieved with minimal effort
and cost.

"After that, all we needed to do was coat the mirror blank with a small
amount of aluminum, and voil we had a highly reflective telescope mirror,"
says Rabin. "Our method could be scaled-up on the moon, using the ubiquitous
lunar dust, to create giant telescope mirrors up to 50 meters in diameter."
Such an observatory would dwarf the largest optical telescope in the world
right now: the 10.4-meter Gran Telescopio Canarias in the Canary Islands.

The capabilities of a 50-meter telescope on the Moon boggle the imagination,
according to NASA. With a stable platform, and no atmosphere to absorb or
blur starlight, the monster scope could record the spectra of extra solar
terrestrial planets and detect atmospheric biomarkers such as ozone and
methane. Two or more such telescopes spanning the surface of the Moon can
work together to take direct images of Earth-like planets around nearby
stars and look for brightness variations that come from oceans and
continents. Among many other projects, it could make detailed observations
of galaxies at various distances, to see how the universe evolved.

"Constructing giant telescopes provides a strong rationale for doing
astronomy from the moon," says Chen. "We could also use this on-site
composite material to build habitats for the astronauts, and mirrors to
collect sunlight for solar-power farms."

Chen notes that his group achieved this breakthrough with only the support
of small NASA internal seed funds. The carbon nanotubes were contributed by
Dan Powell, Lead Nanotechnologist for NASA Goddard. Several amateur
astronomers made key contributions by advising and making special epoxy
formulations, helping with polishing experiments, and vacuum coating the
12-inch mirror.