If so-called "Rods from God"--an informal nickname of untraceable origin--ever do materialize, it won't be for at least 15 years. Launching heavy tungsten rods into space will require substantially cheaper rocket technology than we have today. But there are numerous other obstacles to making such a system work. Pike, of GlobalSecurity.org, argues that the rods' speed would be so high that they would vaporize on impact, before the rods could penetrate the surface. Furthermore, the "absentee ratio"--the fact that orbiting satellites circle the Earth every 100 minutes and so at any given time might be far from the desired target--would be prohibitive. A better solution, Pike argues, is to pursue the original concept: Place the rods atop intercontinental ballistic missiles, which would slow down enough during the downward part of their trajectory to avoid vaporizing on impact. ICBMs would also be less expensive and, since they're stationed on Earth, would take less time to reach their targets. "The space-basing people seem to understand the downside of space weapons," Pike says--among them, high costs and the difficulty of maintaining weapon platforms in orbit. "But I'll still bet you there's a lot of classified work on this going on right now."