nuclear-news

Effects of a nuclear explosion just above the atmosphere

High-Altitude Nuclear Explosions Dangerous, but not for Reasons Gingrich Cites Scientific American By Michael Moyer | December 14, 2011 | “………In the June 2004 issue of Scientific American, the national security journalist Daniel G. Dupont wrote “Nuclear Explosions in Orbit” [subscription required], a story that details the sequence of events that would follow a nuclear detonation just above the atmosphere.

The initial blast of high-energy gamma rays would strike air molecules
and create a shower of high-energy electrons, he writes. These
electrons, once they reached ground, would indeed disrupt sensitive
electronic equipment. But only that equipment within direct
line-of-sight of the blast—taking out a city, perhaps, not a
continent.

More fearsome would be the effects of radiation on orbiting
satellites. After the initial nanoseconds-long blast of gamma rays, a
nuclear bomb releases about 70 percent of its total energy in the form
of x-rays. Dupont writes:

“Soft,” or low-energy, x-rays produced by a HANE would not penetrate
deeply into any spacecraft they encountered. Instead they would
generate extreme heat at the outer surfaces, which itself could harm
the sophisticated electronics inside. Soft x-rays would also degrade
solar cells, impairing a satellite’s ability to generate power, as
well as damaging sensor or telescope apertures. When high-energy
x-rays strike a satellite or other system components, however, they
create strong internal electron fluxes that produce strong currents
and high voltages that can fry sensitive electronic circuitry.

He quotes K. Dennis Papadopoulos, a plasma physicist at the University
of Maryland who studies the effects of high-altitude nuclear
explosions for the U.S. government, who concludes that “a 10-kiloton
nuclear device set off at the right height would lead to the loss of
90 percent of all low-earth-orbit satellites within a month.” The
exception would be U.S. military satellites, many of which have been
hardened against exactly this kind of threat.
http://blogs.scientificamerican.com/observations/2011/12/14/high-altitude-nuclear-explosions-dangerous-but-not-for-reasons-gingrich-cites/

December 15, 2011 - Posted by Christina Macpherson | 2 WORLD, technology