I've read about the recent very large “solar storm” and would like to know what kinds of damage can be experienced by the many satellites in orbit around the earth. Are some types of satellite more likely to be damaged than others- ie communication vs optical like Hubble.

Solar storms can be energetic particles from the sun, disturbed regions of magnetic fields, large amounts of x-rays and radio waves from the sun, or combinations of these. Normally, Earth's magnetic field is strong enough that most satellites, even the weather satellites (which are in geosynchronous orbit 22,000 miles away) are within the magnetic field and therefore protected from most of the cosmic rays.

However, when a magnetic storm passes the Earth, Earth's magnetic controll shrinks. Often satellites in higher orbits (especially geosynchronous orbits) and orbits that cross Earth's poles can end up outside of Earth's magnetosphere, and these satellites are then exposed to damaging cosmic rays. Satellites in low orbits (like the space station, space shuttle, Hubble, etc.) are generally still protected.

The solar storm you heard about also featured a “proton event,” where high-energy protons from the sun stream toward the Earth. These protons have enough energy to penetrate Earth's magnetic field, and so all satellites are in danger from these storms. The worst danger is for spacewalking astronauts, who would receive very high (perhaps dangerously high) levels of radiation. Astronauts onboard the space shuttle and the space station are usually protected from these storms by special shielding.

You can read more about solar storms, and especially about currently active storms, from the Space Environment Center: http://www.sel.noaa.gov/

Thanks for writing!

Sincerely, Kurtis Williams