Today’s ABM strategies are competitive and complicated. Do they work?
The latest ABM (anti ballistic missile) interceptor failed another test in June of 2013. This missile has had an erratic record, 8 fails out of 16 tests.
Information like this is a little confusing because this week you read “Test of ABM interceptor failed, has failed half its tests so far” and next week you read : “New test of ABM interceptor successfully hit its target and has done well in the last 11 tests.”
Although these sound contradictory, both reports could be right – it is U.S. strategy that is confusing.
This second part of our study of the American ABM effort focuses on current techniques being used to defend against attacking missiles. Here is where confusion arises:
- An attack missile has 3 phases in its trajectory, each with its own defense strategy.
- The 3 military branches have developed their own ABM solutions.
- The Department of Defense has an additional Missile Defense Agency ‘doing its thing.’
There are many ABM solutions in our messy situation and opportunities for confusion abound. We discuss the major systems and how they fit into the general scheme – this will prove to be a fairly long post!
The key way to destroy the threat is for the ABM to have a fast moving Hit-To-Kill (HTK) tip, also called a Kinetic Kill Vehicle. We discuss the how & why in our Appendix.
In this post, the focus is on the ABM launch vehicles (the missiles themselves), but the keys to success – operations and modifications – are in the network of detection, control, and communication hardware that make them work. We make only occasional reference to these.
Fig 1 shows the flight path of a ballistic attack missile. Also shown are the main ABM defense strategies.
- Boost Phase: It has powered flight only during launch, until it leaves the the atmosphere, at an altitude of 100-120 km (60-75 miles) with sufficient speed to reach target.
- Mid-course Phase: Little activity during this unpowered exo-atmospheric part other than deploying countermeasures (metalized balloons, highway cones – or whatever).
- Terminal Phase: The calm ends when it re-enters the atmosphere on its final approach to target. Somewhere below 100 km (60 mi) altitude, all the counter measures burn away and the true warheads become apparent.
Today’s ABM defense
The old adage was Kill the archer, not arrow updated to Kill the sniper, not the bullet. In other words, do the possible, not the other.
Fig 2 shows that there are some bullets we must stop, the sniper can come later.
This picture shows the arrival at Kwajalein island of the 8 warheads from a single U.S. Peacekeeper ICBM from Vandenberg base, California. Had it been armed, there would have been the blossom of a nuclear explosion at the base of each of the 8 streaks.
Strategies have been devised against all the attack missile types (ref: Part 1, Safeguard.)
A. Boost-mode ABM
The nicest time to defeat the attack is during the boost phase. The launch vehicle (LV) is under extreme stress and is not maneuverable. During the 1991 Desert Storm pilots reported watching helplessly as SCUD missiles were launched toward Israel from Iraq. In close quarters between combatants, this may be more reasonable. We have nothing deployed but at least two technologies have been proposed.
(1) ABL, YAL-1 Air born lasers.
We have built 2 planes equipped with ABM lasers. In the mid 1980s, an NKC-135 was fitted with a laser with depressing results. This plane was sent to the technical taxidermist in 1988 for museum display.
George Bush was always eager to show Daddy up and in the middle of his reign, a Boeing 747 was modified with a ‘megawatt’ Chemical Oxygen Iodine laser (Fig 3). It had an infrared beam (1.315 micron) and flew at altitudes of 12 km (40,000 ft), above most moisture. The needed specs are not easily available (beam spot diameter as a function of distance, laser cycle time, power delivered in a shot), so cannot make a technical analysis.
Boeing wanted funding as a Boost Mode defense but here is what they proposed. The beam could not punch through the fuel tank wall, but for liquid fueled rockets (not a solid fueled one) they would keep the beam focused at one spot, heat until the fuel caused ruptures due to overpressure. Or they could draw a circle about the wall of the rocket, soften it so that it crumbles under its own g force. All this and 90 miles away! Sheesh! It was terminated for cause in 2010. Hope to not see this again until they fly a 5 Hz, Petawatt laser.
(2) NCADE Network Centric Airborn Defense Element
Air launched ABM proposed by Raytheon in the early 2000s and successfully tested in 2007. This is an air launched missile that actually looks interesting.
NCADE uses components that make up the AIM-120 AMRAAM missile (Advanced Medium Range Air-to-Air Missile) used by most of our fighters. In fact, it really is a same-sized upgrade to the 120. NCADE would be carried by supersonic F-15, F-22 (etc.) which provide much of the missile’s attack speed.
AIM-120 Upgrade: Same size, weight, and center of mass so few aircraft modifications need be made. The fuel would be changed to hydroxyl ammonium nitrate (HAN) which is a mono-propellant. The upgrade would replace the high explosive (HE) warhead with an operational HTK (hit to kill) unit: a touch to the booster would destroy it. Side vernier jets on the second stage and upgraded controls complete the upgrade.
This could be a perfect counter to nearby ballistic missiles during boost phase. So much so that Lockheed has countered with a proposal to do the same with its PAC-3 unit. It appears to have not yet been funded, although fielding this ought to be pretty simple. With the 180 km range, this looks right for combatants who are close together.
B. Terminal Mode ABM
The Safeguard system of the 1970s used nuclear detonations to render the attacker’s electronics inoperable. It would have worked well.
The only issues: The enhanced neutron bombs of the Sprint (Fig 5) endangered everyone near the target area and the 5 Mt × 30 Spartan launchers endangered the electronic capability for anyone in the world to wage modern warfare.
Re-entry starts about 120 km altitude; an ICBM warhead can arrive on target at up to 7 km/s and there are about 15 seconds to impact if it were to drop straight down. At a 45º angle (as in Fig 2), the time might increase to 20 sec. If the real warheads are not identifiable until 70 km, we might have 10 seconds to respond – 15 s a reasonable deadline for ICBM warhead interception.
15 seconds-to-doom is the basis for ABM terminal-phase strategy.
We focus on the missiles themselves, but the keys to success, modifications and replacements are in the network of detection, control, and communication hardware that provide battlefield management.
The system was designated MIM-104 Patriot Air Defense Missile System after it destroyed a drone target in 1975, and replaced the high medium altitude defenses Nike Hercules and Hawk.
The Patriot (Fig 6) was sealed into a single canister for long term storage, 4 canisters to a launcher. When fired it broke through its end seal as the SPRINT had done.
It was hurriedly modified for the 1991 Gulf War operation and had ‘some application’ against short range missiles like the SCUD. This means it was most useful as a political tool. When a SCUDs was hit, the shock wave shook loose the warhead which happily continued to target. Some application is military jargon: Really shouldn’t use the technique this way.
PAC-2 series upgraded the Patriot with control modifications and can be used against aircraft, cruise missiles, with some application against tactical missiles.
(4) PAC-3, MIM-104F Patriot Advanced Capability – 3
Although it is labeled in the Patriot genealogy, PAC-3 (Fig 7) is based on the SDI’s ERINT missile. Its range places it as a point defense weapon, not for theater-wide coverage.
It is smaller, lighter and much faster, though with a restricted range and ceiling; it is meant as point defense against BM threats. The payload is a kinetic HTK Vehicle with high explosive backup.
PAC-3 is the principle TBMD (terminal ballistic missile defense system. It uses an active Ka band radar seeker and combines its data with ground information during the final approach to its target. 180 forward small vernier rocket motors give it very high agility as it approaches its target, sufficient to destroy the incoming warhead.
Four PAC-3 missiles are sealed into the same size of canister as a single Patriot, thereby increasing the number of ’rounds’ per platform from 4 to 16. The launcher is wheeled and can be moved, but requires extensive installation for use.
PAC-3 is meant for terminal phase low altitude ballistic missile defense and the HTKV means that it will not useful against aircraft. It does not have the 100 g acceleration of the old Sprint and is not as fast – it is not suitable for counter-ICBM work.
PAC-3 It has been selected for a mobility upgrade and integrated into the joint Medium Extended Air Defense System (MEADS) for U.S., Germany and Italy.
Multiple Targets: Lockheed announced (2013 Jun 06) its MSE (missile segment enhancement) pre-deployment upgrade successfully destroyed multiple targets with a single vehicle. This was a significant step in making the system a meaningful low altitude defense tool. Do not confuse this success with a different failure, also announced in June.
The Sparrow was a cruise missile defense, the SM-3 is the principal naval defense tool against ballistic missile attacks; it operates under the Aegis battle management system.
The specifications are for the Block IIA form, expected to be operational in 2015. The main upgrades from Block -I are the rocket diameter, attack speed, and control system.
A test of the Block 1A form is shown in Fig 9 from a Japanese cruiser.
This test missile successfully destroyed its BM target.
Raytheon has a well considered path to upgrades that would turn the SM-3 into an effective ABM (Fig 10).
It is interesting that our current SM-3 is described as having Initial Capability, which means that it occasionally misses its target.
This design roadmap has had political push-back. Early in 2013, Obama officials had to assure Russians that the 2B model was an exercise for 2022 planning, and exists only as a PowerPoint presentation. (Raytheon’s original said 2020, AviationWeek reported 2021).
Whatever. The US would not dream of actually building such a vehicle.
NCADE – Raytheon has also suggested that it could be modified for aircraft and used as its NCADE counter-boost threat.
It is designed to work in the exo-atmospheric region between 100 and 150 km up and strike the incoming warhead with a kinetic kill “bullet.” THAAD performance is classified and many values in the specification table are estimates.
The issues are not with the 2 stage Launch Vehicle, but are common with all ABM systems that employ kinetic kill strategies —
1• Find the tiny warhead in the immensity of space.
2• Select it with perfect accuracy from the active and passive decoys that will be present.
3• Do this during the extremely short endgame when attacker and defender payloads are on final approach at hypersonic velocities.
Figs 11 and 12 show THAAD launches. There have been about a dozen successful intercepts, meaning the HTKV came within range of the red-team warhead. It has been deployed, but no MIM designation has been announced (that I have found). Based on this success, the system was deployed and “active” … while still being prototyped into a trustworthy defense.
The unit price, estimated at 8.9 M$ might be 2× too high or low.
3. Mid-Course Ballistic Missile Defense
The 3 stage GBI has been under development at least as long as THAAD. GBI is the ABM interceptor failure reported in June 2013.
It has a really bad test record, but has hit some payloads when the trajectory was carefully scheduled. At least one success used a radio beacon to aid homing. It clearly has some application for ballistic missile defense.
Although a work in progress, the Bush administration brought it “on line” by constructing a fully operational base in Alaska.
The GBI base now provides a dome of protection for the US from imminent threat by the North Korean missile force, whose weapons also have some application as an international offensive threat.
GBI is meant to stop nuclear warheads from reaching continental U.S. targets. We understand the need when we review Fig 2. Clearly, it is also meant to reach orbital stations that might pose a threat, someday. Although THAAD and SM-3 can reach midcourse altitudes, they are not fast enough for ICBMs, nor high enough for medium-high orbits.
The launch vehicle almost certainly performs to the specifications shown (near escape velocity with apogee ceiling 36× farther than the ISS.) But the kill strategy may not use the nuclear option of the old Spartan system. Successfully guiding a hit-to-kill vehicle through the 3 steps outlined under THAAD is difficult.
What Do All These Mean?
We have no boost phase ABM solutions being funded at this time, and the other solutions all have technically successful demonstrations on their records.
- Patriot Defense of a small “point” target; OK to deflect warhead, not destroy it.
Good for aircraft, cruise missiles.
- PAC-3 Point defense; OK to deflect warhead, not destroy it.
Defense for SRBM (short range). Extended to defend civilian targets.
- SM-3 Point defense of naval craft; OK to deflect warhead, not destroy it.
Close defense could be smaller missiles and ranks of auto-cannon firing thousands of rounds/sec forming a kinetic wall during that final fraction of a second. (Try to not kill the nearby boats!) Scheduled upgrades– destruction of long range missiles.
Proposed upgrades– ICBM destruction, ground deployment, aircraft deployment
- THAAD Area defense, also called theater defense. Must deactivate 100% of all warheads (not a single nuclear payload allowed to slip past).
- GBI Continental area defense against very high speed, long range threats. Must deactivate 100% of the warheads.
The SM-3 and PAC-3 capabilities are probably adequate for their stated usage, but it is not adequate to deflect warheads in a war zone populated with civilians, as shown in the 1991 Gulf War. These systems should be “robust” against all incoming warheads, not “adequate.”
THAAD and GBI are simply inadequate at this current time because they have not demonstrated destruction of the warheads, just the sometimes collision with them.
It is difficult (impossible?) to acquire believable data for independent analysis and so much at stake. The announcement that an interceptor succeeded in making contact with the warhead needs to be expanded upon (see Appendix). In that plain sound-bite form it must be treated as Public Relations, or as deliberate misinformation.
We started the ABM discussion with kill the sniper, not the bullet, do the possible not the other. But we must kill the bullet and so far kinetic kill vehicles have never been tested against a warhead “bullet” that is trying to elude capture. The Russians have a MIRV bus that will dance so that the HTK vehicle cannot acquire a stable target. Russia may have overcompensated since so many cheaper and effective decoy strategies exist.
Right now Congress is arguing over covering the coast with useless GBI installations. Are they discussing many tens of billions of dollars to calm the population, spook the enemy, or pump money into corporations profiteering with sales of faulty weapons? Last Tech Age has released many posts on the American Income Pump; we have to believe the war-profiteering motive dominates the deception.
Charles J. Armentrout, Ann Arbor
2013 July 31
Listed under Technology … Technology > Aerospace
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APPENDIX: Kinetic Kill Vehicles
We cannot use nuclear weapons to defend ourselves, so what are our options? Moving objects carry kinetic energy (KE expressed in joules), the ½ m v2 value studied in physics classes. A car will be destroyed in a truck collision if it absorbs most of the KE from both objects. The space shuttle booster tanks were sprayed with a foam to keep the LOX cold. Blocks of light foam fell during launch and destroyed the rapidly moving, ceramic tiled shuttle wing below because it absorbed the foam’s KE. If light foam can do that, why not use the idea against warheads?
The point is: a 1 kg mass moving at 10 m/s has 50 J of KE, 10 times more than the 5 J of a 10 kg mass moving at 1 m/s. So use high power rockets to get an HTK vehicle moving really fast if you want to take out the incoming warhead.
Here is the table of how much KE (in joules, J) is in a moving object, measured in kg (1 kg = 2.2 lb). Bombers cause damage due to the TNT equivalent energy that is released when the bomb explodes. A 1 ton bomb releases the energy equivalent as from a 1 metric ton TNT explosion. The same KE can be delivered by a small hypersonic chunk of material.
We can estimate how much energy we have to work with. The GBI’s hit-to-kill vehicle (called the EKV) has 64 km of mass and will be moving at Mach 34 when it reaches its target. (Has GBI ever met these specifications?) Its total KE is 3.2 billion joules (Multiply 64 kg by 50,000,000 J/kg).
Issue #2. Once the GBI actually is operational, it will apply that kind of energy against a warhead, but it must stop inside the bomb hiding behind its re-entry shield. It must not exit out the other side. Like a riffle bullet that passes through its target, an EKV that passes through would transfer only part of its KE and may not achieve the desired result. A lot of development has been done on assault weapons, we can only hope such research has been done with HTK vehicles, too.
I saw the movie Red2 last weekend. Very funny on many levels. One mistake they did not make was for Heroes to hide behind plywood while high velocity bullets were fired. Red2 did cut a car in half as the rounds went through its chassis. (Did many of those puncture holes through walls actually point back toward the shooter?)