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After Word War II, with the capture of German V-2 rocket stocks, and with the assistance of German scientists brought to the US under Operation Paperclip, the US Army began an aggressive program to study and build its own ballistic missile systems. And as soon as nuclear weapons were designed that were more compact than the Fat Man and Little Boy types used in World War II, of course the Army looked to integrate them as well.

For much of the 1950s and 1960s, it was simply assumed any war with the Soviet Union would involve nuclear weapons, and thousands of weapons were deployed at the strategic, operational, and tactical levels.

The Army and the newly established US Air Force both vied for the ballistic missile mission, with the Air Force eventually winning the role. But the Army was allowed to pursue short and intermediate range weapons, eventually fielding the Corporal and Sargent short ranged ballistic missile systems, and the Redstone intermediate range ballistic missile.

The Redstone, far better known for lofting early Mercury space capsules on sub orbital flights than for any battlefield efficiency, was quickly seen as far too cumbersome to be a practical weapon, and the Army looked to replace it with something more advanced than what was essentially a warmed over V-2.

Working with Martin Marietta and Thiokol, the new missile was named Pershing, in honor of General John J. Pershing.

The MGM-31 Pershing missile was a two stage solid propellant missile with inertial guidance. It threw a W50 nuclear warhead to a maximum range of 400 miles. The W50 had a selective yield of 60, 200, or 400 kilotons. It was, for its time, a rather accurate missile, with a Circular Error Probable (CEP) of 400 meters.*

The missile was maneuvered during flight by a complex system of both aerodynamic fins and thrust vectoring. Range was controlled by jettisoning the second stage at the desired time. As solid rocket motors can’t be shut off once started, a complex system of exhaust vents at the forward portion of the second stage would be fired to back the stage away from the warhead section. From there, the warhead would continue on a purely ballistic path to either impact or airburst at the target.

The warhead section also carried the inertial navigation system and the guidance computer. In the original Pershing missile, this was an analog computer.

Pershing was a highly mobile missile system. The missile itself was carried on a tracked Transporter/Erector/Launcher, or TEL. Along with the TEL, another tracked vehicle, the warhead transport, carried the warhead itself, as well as carrying the azimuth laying equipment. Two theodolites were used to lay the missile upon the correct azimuth before launch.  A third tracked vehicle carried a Programmer Test Station, which input the required guidance information and performed missile checkout functions. This third vehicle also carried the Power Station, a gas turbine generator which provided prime power for both the missile, and the other equipment of the firing platoon. The final vehicle of the firing platoon carried the TRC-80 Radio Terminal Set to provide secure long range voice and teletype communications to the battery headquarters. The TRC-80 was interesting in that it used an inflatable dish antenna. Remember, this was developed in the late 1950s, early 1960s, when there simply were no satellite communications. Instead, the TRC-80 used the dish either in a direct path, or through tropospheric scatter.

One Pershing battalion was stationed in the United States, primarily for training and support, and three battalions were deployed to West Germany. In addition, the Luftwaffe fielded two wings of Pershing.  As with other nuclear weapon systems, the nuclear warheads remained under US control.

By the mid 1960s, improvements in electronics meant the Pershing was in need of an update. The analog guidance system, as well as the analog PTS were replaced by digital systems, giving much better reliability.  The updated missile was the Pershing Ia, with the original Pershing being retroactively renamed Pershing I.

Importantly, Pershing Ia was much faster to put into operation, and after a series of operational tests, the battalions in West Germany began standing Quick Reaction Alert. That gave the theater commander the ability to conduct deep strikes against Soviet forces in the event of a sudden attack, even if weather or other circumstances would have grounded tactical airpower. Indeed, because of its very high mobility, and ability to move rapidly between a series of launch points, the Pershing system was seen as more survivable than tactical airpower, and often faster to respond.

Eventually, the firing platoon expanded from one to three missiles, with one PTS/PS supporting all three. The artillery brigade that commanded the three firing battalions added a separate Infantry battalion to provide security to the firing platoon when deployed to launch sites.

In 1976, the Automatic Reference System was added, which meant that firing sites no longer need be pre-surveyed.

The equipment for all the launch systems was later removed from the tracked vehicles, and mounted on Ford trucks (or German trucks for the two Luftwaffe wings) which, though slightly reducing their off road mobility, greatly increased their overall mobility over the extensive German road network, particularly since they were no longer tied to pre surveyed launch points.

At about this time, facing Soviet deployment of large numbers of intermediate ranged weapons, the US decided to greatly increase its nuclear deterrent in Western Europe. This would involve the deployment of about 400 Ground Launched Cruise Missiles (a truck launched, nuclear armed version of the Navy’s Tomahawk missile) to be operated by the US Air Force, and a new missile to replace the aging Pershing.

Because of the SALT II treaty, no new launchers could be introduced into West Germany. Accordingly, any new missile would have to be capable of using the existing launchers, though they could be modified.

The new Pershing II, again built by Martin Marietta and Thiokol, was visually almost indistinguishable from the earlier missile. But its range had been extended from 400 miles to 900 miles.

More importantly, it was the first Maneuvering Reentry Vehicle equipped weapon. At the front of the missile was a terrain mapping radar. The radar would map the target area during reentry, and compare it to digitally stored radar maps in the guidance section, and maneuver until both pictures were correlated. This technique gave Pershing II a vastly improved CEP of about 100 feet.  Inertial guidance would still be used for the boost phase of the flight, or if the radar failed during reentry.

Because it was so much more accurate, the Pershing II needed a much smaller warhead, and so was fitted with the W85, with a selectable yield of between 5 and 50 kilotons.

Fielding of the Pershing II began in 1983, amidst massive protest in West Germany (protests that the Soviet Union quietly but thoroughly penetrated and supported).

Still, the Soviet Union saw itself in an arms race over intermediate ranged weapons that it simply couldn’t afford to participate in.

In 1987, the Soviet Union and the United States agreed to the Intermediate Nuclear Forces Treaty, which led to the withdrawal of all INF weapons and their destruction. The last Pershing IIs were removed and destroyed in 1991. Though West Germany was not a signatory of the treaty, they unilaterally agreed to withdraw and destroy their Pershing Ia inventory.

 

*CEP- If you drew a circle of 400 meters around the desired impact point, 50% of missiles fired would land within the circle.