The Bush administration’s plan to develop space-based
missile defense systems has generated heated debate, but most commentators
have overlooked an important and potentially destructive consequence of
placing weapons in orbit around the Earth. The militarization of space could
create a permanent halo of orbiting debris that will interfere with
important scientific and communication satellites, according to Joel
Primack, professor of physics at the University of California, Santa Cruz.

“In science fiction movies like Star Wars there are constant explosions, but
a few seconds later the screen is clean. It’s not going to work that way
near a planet,” Primack said.

About 3 million kilograms of space debris (roughly 6 million pounds), from dead satellites to paint chips, already orbit the Earth. The U.S. Space Command tracks over 9,000 objects larger than four inches in diameter, and
operational satellites can take evasive action to avoid
being hit by one of these larger objects. In the range from four inches down
to about the size of a marble, there are relatively few objects now in

The most serious hazard currently is the non-trackable debris smaller than a marble that orbits the planet at speeds around 17,000 miles per hour, 10
times faster than a bullet from a high-powered rifle, Primack said. A
BB-sized fragment traveling that speed has the destructive
power of a bowling ball moving over 60 miles per hour, and a marble-sized
fragment can do even more damage. Satellites are armored, but they can only
withstand BB-sized particles. Even the International Space Station is
vulnerable to any debris much larger than a BB.

Space-based missiles will generate huge amounts of small debris particles,
said Primack. Some will arise from weapon explosions, but even more will
come from the resulting small projectiles hitting larger objects already in
orbit and fragmenting them. According to Primack, so many bits of junk could
eventually be orbiting the Earth that no satellite or space station could be
operated in Low Earth Orbit, 200 to 1,250 miles above the planet. Space
shuttles and other space vehicles would need heavy armor to pass through the

Most communications satellites are located in higher orbits that would not
be as affected by the debris, but some, such as those for mobile phones, are
in lower orbits and already in danger. No methods to remove space debris now

“If we do this, we’re going to create a terrible problem there’s no easy
solution for, but the space debris aspect of a ‘Star Wars’ missile system is
just not talked about in the public arena,” Primack said.

Primack will give a talk on this issue on April 19 at the United Nations
Educational, Scientific and Cultural Organization (UNESCO) headquarters in
Paris during the Science and the Quest for Meaning Conference. The
conference explores the connections between science and spirituality.

Primack said it would be unethical and immoral to jeopardize peaceful uses
of space for short-term military gains. Like many researchers, Primack
relies on data from astronomical satellites in Low Earth Orbit, where
missile defense systems would also be located. His theoretical work on the
nature of the “dark matter” in the universe, for example, was supported by
evidence from the Cosmic Background Explorer (COBE) satellite, which
detected fluctuations in the first light of the universe. Space-based
telescopes are ushering in a new era in space research, and Primack said he
believes researchers will soon be able to answer fundamental questions in

“The data from COBE, the Hubble Space Telescope, and other new observatories
should at last give astrophysicists a solid foundation on which to construct
an overarching theory of the origin and evolution of the universe, an achievement that
is also bound to have deep implications for the development of human culture,” Primack said.

In 1993, NASA issued the Policy to Limit Orbital Debris Generation, but it
has had little impact, Primack said. He hopes that an international treaty
prohibiting explosions in space and requiring all satellites to carry mechanisms
to de-orbit them safely will be created in the future.

“Every person who cares about the human future in space should also realize
that militarizing space jeopardizes the possibility of space exploration,”
Primack said.

Primack is not new to questions of scientific ethics and policy. He helped
to create the American Physical Society Forum on Physics and Society and
teaches a course on “Cosmology and Culture” with his wife, attorney Nancy
Ellen Abrams, at UC Santa Cruz.

The Science and the Quest for Meaning Conference is sponsored by Science and
the Spiritual Quest II and the UniversitŽ Interdisciplinaire de Paris.

# # #

Editor’s note: Reporters may contact Joel Primack at (831) 459-2580 or until April 17, or after the conference. To reach him
during the conference, contact Tim Stephens in the UCSC Public Information
Office at (831) 459-2495 or .

Additional information about the conference,