A NewScientist.com summary of Wednesday’s House Armed Services Committee strategic forces subcommittee hearing on “space and U.S. national power” plays up the worst-case scenario of an attack on US civil and military satellites:
If the US does not protect its Earth-orbiting satellites, the equivalent of a car bomb in space could take the economy back to the 1950s, according to witnesses testifying in Washington DC earlier this week.
The article goes on to discuss the effects of detonating a nuclear weapon in low Earth orbit, a move that could devastate the satellites there. However, as the witnesses at the hearing pointed out, most major communications satellites are not in LEO but in GEO, which is much harder to reach (the exceptions are the ORBCOMM, Iridium, and Globalstar satellite constellations), while navigation satellites are in MEO, which is also difficult to reach. It still makes for a very bad day for satellites (and astronauts) in LEO, but it doesn’t necessarily “take the economy back to the 1950s”. That makes the doomsday scenario hyped by NewScientist.com less of a worry that more conventional attacks on specific satellites, through anti-satellite weapons, terrestrial jamming, or attacks on ground stations.