"They want the period of a day or two to assess the effect of the first missile ... to probably get an orbit or two, to get an understanding of what effect the first intercept had on the satellite before launching another interceptor, " Ham said.

CNN: Attempt to shoot down spy satellite to cost up to $60 million

Inversely, if the sea based interceptor misses, you could still have a satellite, airborne, and ground based capability.

CENTERFORSECURITYPOLICY: 33 Minutes