ICBMs (and SLBMs) are allowed to fail more often than spysat launchers or human rated rockets. For important targets, you can afford to launch 2 missiles, but N

ICBMs (and SLBMs) are allowed to fail more often than spysat launchers or human rated rockets. For important targets, you can afford to launch 2 missiles, but NSA can't afford 2 $4B birds, and can't afford the lead time for a replacement if one is lost during launch. 1 year on ISS is launching on Soyuz in 40 minutes!