[RHINO369]

It might never, the physics department at my university (university of illinois at urbana)claimed that in order for this to be effective we'd have to launch the counter missiles within 2 minutes of launch. That means you'd have to give the command of the system to a local officer at the sites.

Not a problem except if some air force officer mistakes a Russian space mission for a ICBM we could get into trouble. Or even worse we could launch when nothing was there, and Russia could interpret the counter missile as a ICBM headed towards them.

[Centurion2000]

the physics department at my university (university of illinois at urbana)claimed that in order for this to be effective we'd have to launch the counter missiles within 2 minutes of launch. That means you'd have to give the command of the system to a local officer at the sites.

An SM-3 can go after a re-entry vehicle.

[Blueflag]

The are called ballistic missiles for a reason. Their tracks can be plotted very quickly from radar data.

One would not mistake the flight path and speed of an ICBM for a manned space launch.

SM-3s fly REALLY fast also. They would know it's not an ICBM.

[Blueflag]

Read this also

http://www.globalsecurity.org/space/systems/sm3.htm