Having a U.S. Navy destroyer able to take out intercontinental ballistic missile (ICBM) is a radical development that multiplies defenses in unprecedented ways.
The mid-course phase of flight during which an ICBM travels through space toward its descent back into the earth’s atmosphere, is typically a twenty-minute process depending upon launch origin and trajectory. That period of the ICBM’s flight is longer than any boost phase ascent or terminal phase descent onto a target, offering the best opportunity to shoot it down.
But ICBMs are designed to survive through a salvo the use of countermeasures such decoys or other methods of ensuring an ICBM passes through space. This means that an ability for a defender to take multiple intercept “shots” would be of enormous tactical value. Ground-based interceptors (GBIs) can travel great distances, yet they are land-launched and restricted in terms of point of origin.
A Navy-ship fired SM-3 IIA, recently demonstrated to be capable of destroying ICBMs, brings new geographical launch possibilities. For example, a group of Aegis-capable Navy destroyers could fire SM-3s from the middle of the Pacific Ocean at ICBMs speeding through space for the United States from China. While an ICBM is likely to be at a higher altitude in space during the major portions of the mid-course phase, the period of time just after it leaves the earth’s atmosphere, or the minutes right before it reenters the earth’s atmosphere upon descent, present optimal windows for defense with the SM-3 IIA. A ship operating not far off the coast of the United States, or near enemy shores in the vicinity of a potential enemy launch location, could provide a unique opportunity for SM-3 IIA-armed destroyers to fire intercepts at ICBMs operating just above the boundary of the earth’s atmosphere.
There is yet another interesting tactical possibility here which might include the idea that a highly-precise, larger and long-range SM-3 IIA interceptor could be used to intercept hypersonic weapons. Is it fast enough? Can ship-based radar track something at that speed? That may remain to be seen, however one interesting nuance can be found in the Pentagon’s current effort to accelerate defenses against hypersonic weapons.
Hypersonic boost-glide vehicles, which skim along the boundaries of the earth’s atmosphere, occupy what Principal Pentagon Director for Hypersonics Michael White recently described as “in between space,” meaning it was difficult for most interceptors or ship-based defenses to reach. The areas just above and below the earth’s atmospheric boundary may be too high for certain ballistic missile defenses, such as ship-fired SM-3s to reach, yet simultaneously be too low for space-traveling GBIs to hit. Could the newer SM-3 IIA reach this area? Why not? Especially if it is empowered by extended and networked radar tracking systems and had the engineering to travel at the necessary speeds to create a collision.
Kris Osborn is the Defense Editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University.