SUN-POWERED SPACE PROPULSION SYSTEM
SUN-POWERED SPACE PROPULSION SYSTEM
2005-05-08 at 10:43:00 am #9178
Ohio Lab Tests Sun-Powered Space Propulsion System
SANDUSKY, Ohio (May 05) – Scientists working with a
synthetic material 100-times thinner than a piece of paper are testing their
theory that the sun can power interplanetary spacecraft. They believe that
streams of solar energy particles called photons can push a giant, reflecting
sail through space the way wind pushes sailboats across water.
The National Aeronautics and Space Administration has
invested about $30 million in space-sail technology, something that existed
solely in science-fiction novels a decade ago. Yet the reflective solar sail
could power missions to the sun and beyond within a decade.
”It’s OK to breathe on it and touch it,” said David
Murphy, of ATK Space Systems, showing off the sail.
ATK Space Systems, based in California, is one division of
a $2.4 billion company that makes rocket motors, advanced weapons systems and
ammunition for the military and the Department of Homeland Security. It has
about 14,000 employees at operations in 23 states.
Last year it delivered 1.2 billion rounds of small-caliber
ammunition to the Army.
The Space Systems division developed the solar sail, which
is being tested in the world’s largest vacuum chamber at the Cleveland-based
NASA Glenn Research Center’s Plum Brook Station in Sandusky. It has a space
environment simulation chamber 100 feet in diameter and 122 feet high.
In that chamber, Murphy displayed four silvery, triangular
pieces of sail stretched over four long booms, which form a square about 70 feet
on each side. Murphy and others want to study how the sails will deploy and
operate in a vacuum under various temperatures.
”We’re going to cool it down and shake it out,” Murphy
Just in case, the fabric, which resembles Mylar, has
rip-stop threads to keep it from pulling apart when the chamber is closed and
the air is pumped out.
”To get a lower pressure you’d have to go to space,” said
Edward Montgomery, an engineer from NASA’s Marshall Space Flight Center in
The chamber has been used to test rocket components,
radiators for the International Space Station and the crash bags that protected
twin rovers when they landed on Mars last year.
The plasticlike fabric used to make the sails is a spinoff
from technology used to develop spacecraft paint.
First missions – scientific payloads of a few hundred
pounds – are likely to be to the inner planets, Venus and Mercury, and to the
sun. But NASA scientists think the technology is a good bet for eventually
powering spacecraft into deep space.
Since its fuel is free and doesn’t have to be stored, a
craft with solar sails would not have to slingshot around the moon or other
planets for a gravity boost to reach distant destinations, as other craft
Craft propelled by solar sails could be launched on
conventional rockets or released from space stations. In space, the force of
sunlight would push the reflective sails, causing the craft to move, said NASA
Marshall physicist Les Johnson.
The first sail tested in space will be about 130 feet on
each side. Those on an actual mission could be twice as large.
While its thrust is low, it would be continuous so that the
craft accelerates steadily, eventually reaching speeds of tens of thousands of
miles an hour. Changing the sail’s angle to the sun would allow the craft to
slow down or speed up.
”Just by morphing its shape we can get it to turn,”
With the science worked out, Murphy said, it is now a
matter of building larger sails.
”We have everything we need to do this,” he