U.S. Pershing MRBM

The MGM-31 Pershing was the first and only solid-fueled MRBM (Medium Range Ballistic Missile) deployed by the U.S. Army. It has been in service for almost 30 years until all nuclear MRBMs were phased out and destroyed according to arms reduction treaties. The Pershing was designed as a two-stage solid-fueled rocket with an all-inertial guidance system, to be fired from a mobile launcher.

 

 Pershing-I (MGM-31A/B)

In February 1960, the first Pershing, designated XM14, was launched. This first test flights used only the first stage, but by the end of 1960, full range two-stage flights (XM19) had been successful. The operational Pershing-I (MGM-31A) was powered by two soild-fueled rocket stages by Thiokol (TX-174 and TX-175), and could carry its thermonuclear warhead to a maximum range of 740 km. A similar version of the Pershing-I used strictly for troop training was designated MGM-31B.



 


TX motor
 


        
Pershing test vehicle XM14
(one-stage vehicle with upper part dummy)


Pershing test vehicle XM19
(two-stage vehicle with upper part dummy)


             

       Pershing-I test vehicle (MGM-31A)

                               Operational Pershing-I (MGM-31A)

Specification

 Length-10.5 m; Diameter-1.02 m; Mass-4,66 t
  Motor Thrust (kN) Spez. Imp. (N*s/kg) Propellant (t) Burn time (sec)

First stage

TX-174

116.9 ~2630 ~1.7 38.3

Second stage

TX-175

85.5 ~2590  ~1.3 39
 Pershing-II (MGM-31C/D)

Because the Pershing-I was no longer competitive as a tactical missile, the Pershing-II was developed. It was also developed a new warhead section for the Pershing, with a high-accuracy maneuvering reentry vehicle (MARV) with active radar terminal guidance.
The new Pershing-II was now intended as a counter to the Soviet SS-20, and its range requirement was more than doubled to a range of about 1770 km. To achive this, completely new rocket motors were developed by Hercules, using high-energy fuels and light-weight casings made of Kevlar. This effectively made the Pershing-II a completely new missile, and it was designated as
MGM-31C. The Pershing-II missile was fully compatible with existing Pershing-I ground equipment. The first flight test of an MGM-31C in July 1982 was a failure, but the next attempt in November that year succeeded.

Note: The one-stage variant Pershing-II RR (Reduced Range), designed as MGM-31D, was not produced in series.




Pershing-II RR (MGM-31D)



Pershing-II (MGM-31C)


   

First stage

                               Second stage

 

 Length-10.6 m; Diameter-1.02 m; Mass-7.46 t
  Motor Thrust (kN) Spez. Imp. (N*s/kg) Propellant (t) Burn time (sec)

First stage

Hercules

172 ~2775 ~3.60 58

Second stage

Hercules

134  ~2680 ~2.30 46

 




Kevlar-cases for the Pershing-II motor



Second stage


      

 


    
Pershing-II



Pershing-II RR