UCLA professors develop stratospheric space observatory for infrared light

Three UCLA professors are leading the way to the development of
a new space observatory that will fly around the country in the
belly of a modified Boeing 747 airplane.

As an observatory dedicated to investigating infrared light
““ light that is redder, or has longer wavelengths, than light
which can be seen with the human eye ““ the Stratospheric
Observatory for Infrared Astronomy will observe objects such as
newborn stars and distant galaxies that are not hot enough to emit
visible light.

The project will provide information about how stars and planets
form and will increase scientist’s knowledge about the moons
and planets in the solar system, as well as the stars and galaxies
at the edges of the known universe.

Scheduled to begin observations late in 2006, SOFIA will be
operated out of the NASA-Ames Research Center, based near San
Francisco Bay.

“A lot of people forget that (NASA) is the National
Aeronautics and Space Administration; it’s not all to do with
flying in space,” said Ian McLean, professor of physics and
astronomy and director of the Infrared Astrophysics Lab at
UCLA.

McLean, a co-investigator for SOFIA, is also a principal
investigator for one of the infrared cameras that will operate on
board the plane.

Another physics and astronomy professor, Eric Becklin, is chief
scientist and director designate for the SOFIA Science Center,
making UCLA the hub of the consortium of American and German
institutions collaborating on SOFIA, McLean said.

SOFIA will fly its telescope up to 45,000 feet, above
atmospheric carbon dioxide and water vapor, which block infrared
radiation from reaching ground-based telescopes.

“That part of the spectrum is badly absorbed by
Earth’s atmosphere,” McLean said. “That’s
why we have to fly above it,” McLean said. McLean explains
that there is a lot that scientists can do on a flying observatory
that would be too difficult, if not impossible to do, from the
ground or in space.

“(SOFIA) really opens up a new opportunity for infrared
astronomy, for two reasons: it’s a large facility, and
it’s mobile,” McLean said.

Its mobility will allow SOFIA to travel across the western
United States to capture images which can only be seen from certain
locations, according to McLean.

The relative ease of transporting the instruments and the
telescope by airplane instead of packaging them into a rocket to
launch them into space allows scientists to install a bigger
telescope into the airborne observatory, McLean said.

“This telescope is even bigger than the Hubble, and more
cost-effective than you could ever send into space,” McLean
said, adding that SOFIA’s proposed 25-year mission is much
longer than most missions, which are only a few years long.

The 2.5-meter-wide telescope on board the airplane is more than
twice as wide as SOFIA’s space-borne counterpart, the Spitzer
telescope, allowing it to produce images 10 times more detailed
than Spitzer’s images.

Mark Morris, professor of physics and astronomy at UCLA,
explains that the greater detail in the images will not only allow
scientists to see more objects but will also allow them to observe
how a single object moves and changes.

The fact that live people will be present during the mission
will also allow scientists to have more direct control over what
the telescope is observing than they would if the telescope were
launched into space, Morris said.

“The strength of SOFIA is that there are people on
board,” said Morris, who also leads the UCLA Data Cycle
System Team in designing the data archiving system for system
future users of the telescope.

“If the camera goes wrong, there’s someone there to
fix it; if there’s something exciting to see, there’s
someone to point the camera … There’s no reaction time
possible on a space(-borne) camera,” he added.

McLean said that unlike space-borne observatories, whose
technology is out of date by the time the instruments are launched
into space, SOFIA’s technology can be state-of-the-art, since
it will return to Earth after each mission, which can be up to 9
hours long.

“(With SOFIA,) you can take a chance, put in absolutely
state-of-the-art technology, even right on the edge, (and) try
things out. That’s a huge attraction,” McLean said.

McLean and his team at UCLA are putting the finishing touches on
FLITECAM, one of several cameras that will detect infrared
radiation of wavelengths ranging from a few millionths of a meter
““ slightly longer than the wavelengths of light we can see
““ to those a thousand times longer, nearly as long as radio
waves.

“It’s one of the simpler instruments on board, one
of few that will simply take pictures and produce a result
that’s immediately apparent,” McLean said.

Scientists hope to use SOFIA to study star births by locating
and observing the patches of interstellar dust and gas that are
beginning to collapse under their own gravity in the process of
forming new stars.

“We’d like to find that moment, where these big
clouds of hydrogen gas just begin to collapse,” McLean said.
“To do that, we’ve got to look far into the infrared
““ when it’s a little hotter than the cold interstellar
medium around it, but it hasn’t begun to glow.”

Other cameras will observe the infrared light coming from
distant stars and galaxies, whose visible light has been stretched
by the expansion of the universe so that it can only be detected as
infrared light.

Besides its scientific goals, SOFIA is also intended to be used
as an educational tool, Morris said. Seats in the top deck of the
747 will allow educators and non-professional astronomers to
experience a flight mission themselves, while the data collected
from the observations will be made available to the entire
astronomy community.

“We hope that our camera will help promote some of that
(community) outreach by taking pictures of galaxies, star
formations,” McLean said.

Morris is currently designing a program of demonstration
science, he said, “to demonstrate to the world how fabulous
this observatory can be.”