Sprint (rocket)
| Sprint (rocket) | |
|---|---|
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| General Information | |
| Type | Missile defense system |
| Local name | sprint |
| Country of origin |
 United States
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| Manufacturer | Martin Marietta |
| development | 1963-1975 |
| Commissioning | 1975 |
| Working time | 1976 |
| Technical specifications | |
| length | 8.23 m |
| diameter | 1.37 m |
| Combat weight | 3.5 t |
| Drive First stage Second stage |
Hercules X-265 solid rocket engine , 2900 kN Hercules X-271 |
| speed | > Do 10 |
| Range | ~ 47 km |
| Service ceiling | 30,000 m |
| Furnishing | |
| steering | Remote control |
| Warhead | W66 nuclear warhead, approx. 1 kT |
| Lists on the subject | |
Sprint was the name of a nuclear armed US ABM missile . It was developed and produced by Martin Marietta . As part of the Sentinel and Safeguard programs , this missile was primarily intended to complement the short-range LIM-49 Spartan, which is intended for defense over long distances .
The missile was ready for use in 1972 and officially entered service in 1975, but was decommissioned in 1976 with the end of the Safeguard program.
Type of use and concept
The task of the sprint was to defend against attacks with ballistic missiles , primarily against those with nuclear warheads . For this purpose, the re-entry bodies with the explosive charge should be intercepted by missiles and destroyed.
During the Cold War , the USA initially planned a program called Sentinel to defend military facilities and metropolitan areas. The plan was to initially locate approaching missiles and warheads with the long-range Perimeter Acquisition Radar (PAR, type AN / FPQ-16 PARCS ) and to combat them with the Spartan missile even outside the Earth's atmosphere. The missile should then be guided by the separate Missile Site Radar (MSR). The task of the sprint missiles was then to combat those warheads that had not been destroyed by the Spartan and had already entered the earth's atmosphere. This division of tasks was also retained for the Safeguard program, which has now been reduced to point defense.
Since there is only a very small time window left for this task, a very rapidly accelerating rocket was required that could embark on an intercepting course towards the re-entry vehicle at high speed. The target's warhead itself should then be destroyed by the nuclear charge of the sprint missile. In contrast to the Spartan rocket, a comparatively low explosive force was sufficient here, as there is a medium within the earth's atmosphere in which the detonation wave of the explosion can propagate.
technology
The Sprint missile is a two-stage solid -propelled missile . It is around 8.20 m high, has a conical shape and weighs around 3400 kg. The first stage has a Hercules X-265 engine that generates a maximum of 2900 kN of thrust with a burn time of 1.2 s. The second stage uses a Hercules X-271 engine. The exact composition of the fuels is unknown; the technically related HIBEX rocket ( High Boost Experiment ) used FDN-80, a mixture of ammonium perchlorate , aluminum , ballistite and zirconium in a star-shaped fuel geometry.
The Sprint was started from a silo and was driven upwards by a gas generator before the engine was ignited ; the engine itself was only ignited outside the silo. The enormous thrust allowed an acceleration to the maximum speed of Mach 10 within a few seconds. The rocket experienced an acceleration of up to 100 g . The intended interception height was approx. 1.5 to 30 km and the horizontal range was set at approx. 47 km; the maximum flight time for both was less than 15 seconds.
The top speed of Mach 10 made it necessary to heat-coat the tip of the rocket. Correspondingly, no detectors of its own could be accommodated in the rocket, so that the target was steered instead by remote control with the help of the MSR.
A nuclear warhead of the type W66 was used in the Sprint missile, which achieved an explosive force of approx. 1 kT and either destroyed the targeted reentry bodies with the pressure wave or the fissile material in the warheads rapidly heated up and melted by the generated neutron flux should.
history
The development of the Sprint resulted from the implications of the Spartan program. With the advent of dummies and radar jammers that could be carried in newer ICBMs , there was a certain chance for the actual warhead to escape the defense attempt with the Spartan. Typically, dummies and re-entry by PAR could be distinguished only on re-entry into the atmosphere from one another, wherein the dummy lighter due to its lower mass inertia by the friction are braked more than the actual warheads. This drastically shortened the period of time available for a successful defense, so that with the Spartan a defense in the upper atmosphere now appeared realistic.
Should the Spartan fail here too, a defense on shorter distances was necessary. The Sprint missile was supposed to close this gap, so in 1963 Martin Marietta was commissioned to develop the missile. The development was preceded by a test vehicle called Squirt developed by Douglas in 1964. The testing of Sprint itself then began in November 1965 with starts from the White Sands Missile Range , where, however, no MSR was available for steering. From 1970 tests were also carried out on the Kwajalein Missile Range using the MSR, which were directly assigned to the Safeguard program.
The testing was completed in 1975 after a total of 52 starts with the commissioning of the first safeguard position, the Stanley R. Mickelsen Safeguard Complex near Grand Forks ( North Dakota ). 16 sprint missiles were stationed at this base. The decommissioning took place in the same year, and in 1976 the position was already completely dismantled. A total of 70 operational sprint missiles were produced.
The experience with the Sprint later flowed into the development of the High Endoatmospheric Defense Interceptor (HEDI) by McDonnell Douglas as part of the SDI program , which, unlike the Sprint, was not to be equipped with nuclear equipment, but as a hit-to-kill projectile should collide with the intended target. Like the SDI program, HEDI was ultimately not completed, but three test missiles were launched between 1990 and 1992.
Web links and sources
- Richard Garwin , Hans Bethe : Anti-Ballistic-Missile Systems , Scientific American 218 (3), 21-31 (1968)
- Sprint ABM in the Encyclopedia Astronautica (English)