DOD braces for space storms
- By Gregory Slabodkin
- Oct 19, 1998
Computer crashes are not the only threat to military and civilian systems come 2000.
Air Force experts and other government scientists have concluded that violent
electromagnetic space storms will wreak havoc on systems at about the same time unfixed
date code fails.
Were going to have a huge storm [about] Jan. 1, 2000, so people wont
know what to blame it on, said Ernie Hildner, director of the National Oceanic and
Atmospheric Administrations Space Environment Center in Boulder, Colo. The
centers Space Weather Operations, operated by NOAA and the Air Force, issues
extraterrestrial event alerts to government and industry scientists hourly, much as the
National Hurricane Center issues tropical storm or hurricane alerts.
Solar and geomagnetic events such as ion bombardments and explosions on the surface of
the sun can damage or knock out satellite transmissions, hamper navigation systems, cut
electric power and bring down telephone systems.
Unlike the year 2000 problem, space weather is a natural phenomenon that occurs in
11-year cycles. During the cycles, powerful geomagnetic storms generated by the sun spew
bursts of high-energy particles and clouds of ionized gas that can damage satellites and
affect the Earths magnetic field.
Sunspots, flares, filaments, coronal holes and mass ejections emanating from the sun
throw off bursts of electromagnetic particles, radiation and solar wind. Geomagnetic
storms occur when blasts of solar wind bend and stretch the Earths magnetic field.
The latest solar cycleCycle 23is expected to reach its maximum strength
around 2000, far surpassing the strength of its predecessor, Hildner said.
Geomagnetically induced current from space weather can be picked up by power lines and
disable transformers, Hildner said. Solar Cycle 22 in 1989, for instance, left more than 6
million people in Quebec, Canada, without electric power for 12 hours, he said.
Weve had three pulses now of activity in this cycle, and in all three we
have anecdotal information that the Northeast United States power grid has felt the
effects, Hildner said. So far it hasnt risen to the level of where
anybody has shut down or there has been enormous equipment damage.
Recent pulses have also damaged navigation systems, especially those that depend on
satellites. We know that Global Positioning System users such as NOAA have been
unable to carry out high-precision surveying during these pulses of activity, he
The accuracy of GPS, a constellation of 24 Navstar satellites managed by the Defense
Department for military and civilian use, depends on the transmission properties of the
atmosphere, Hildner said. When those properties change unexpectedly during a geomagnetic
storm, navigational fixes from GPS can be grossly inaccurate, he said.
Such vulnerability could have devastating consequences, Hildner said. DOD relies on GPS
to provide precise and accurate navigation signals to military aircraft and targeting
information for its guided missiles and bombs, he said.
Even though GPS satellites are hardened against electromagnetic pulses from
nuclear-weapons detonation, nothing can protect the ionosphere, through which satellites
transmit radio waves, from heightened solar activity.
The only way to guard satellites from the suns magnetic fields, which are
thousands of times stronger than Earths, is to wrap them with 6-inch-thick lead
plating, Hildner said.
Instead, DOD is turning to cheaper commercial satellites rather than military-unique
systems such as Milstar, designed for strategic communications during nuclear war, he
Iridium, which will be the largest commercial satellite constellation with 72
low-earth-orbit satellites, will also fall prey to the effects of the sun, Hildner said.
The $5 billion commercial satellite communications system is designed to provide
long-distance cellular telephone service to subscribers anywhere on Earth. Its customers,
including DOD, will experience signal strength dropouts as a result of increased solar
activity, he said.
We know that during the last solar cycle there were times when we had
scintillationthe flickering of a satellite signal, Hildner.
During a solar storm, energized electrons race around the Earth, creating uneven
buildups of negative and positive charges on satellites. The fluctuations can affect the
performance of circuits within the satellites.
A solar eruption in 1995, for instance, disrupted the operations of NOAAs
Geostationary Operational Environmental Satellites. GOES satellites continuously monitor
space weather by measuring solar X-rays, the Earths magnetic field and
electromagnetic particles in space.
Space weather data and information are available from the Space Environment Center at http://www.sec.noaa.gov.