Boost-phase is the EASIEST , MOST VULNERABLE target. (at least from orbit or very close border) Far easier than mid-course or re-entry. And we have successfully shown repeated capability to intercept in mid-course, and with the old (1960-70s era)--yet utterly AWESOME!-- Sprint missile technology...a consistent ability to hit re-entry vehicles coming in at Mach 16. Should have just deployed a few of these around every major U.S. city, and strategic site. Net cost would have been far less today than SDI ( a pure research program) has been to date....

Ping.

Hi Mom!

I've been a longtime proponent of boost-phase missile defense. It should be interesting to see whether these conclusions match my expectations.

Sprint missile technology...a consistent ability to hit re-entry vehicles coming in at Mach 16.

Put some in submarines. The sub, is by far, the best platform for offensive and defensive missiles.
( And no, I was Army!)

Check it out:

(Click diagram for larger image)

Sprint (Continued)
By operating within the atmosphere, terminal defense using the Sprint was able to target only true threats, since other spurious targets such as ICBM booster fragments, decoys, and chaff would have been destroyed by atmospheric friction during re-entry. The trade off for this advantage was the extremely limited amount of time available for Sprint to do its job. Its need for ultra fast acceleration made Sprint a remarkable missile. It was launched from its climate controlled silo by being tossed into the air by a gas discharge mechanism at the bottom of the silo after the silo cover had been blown off by an explosive charge. The first stage ignited as it cleared the silo, propelling the missile to hypersonic speed in seconds. Internal components were designed to withstand accelerations of 100g (100 times gravity). The second stage reached velocities that caused atmospheric friction to heat the skin of the missile to the point that it glowed incandescantly; a flame from an acetylene torch would have cooled it. Terminal defense using the Sprint required "close in" interception. In an attempt to minimize the time between launch and interception, Sprint launchers were dispersed over a wide geographical area. Sprint missile fields were located at the MSR complex as well as at four geographically dispersed remote Sprint launch sites (RSL's) that were arrayed around the MSR complex at 10 to 20 mile distances. Launch, guidance, and warhead detonation were all controlled by the MSR; its high power beam was capable of penetrating the plasma sheath that surrounded the missile after it reached full velocity. Targets were destroyed by detonation of Sprint's neutron warhead which was specifically designed to minimize collateral damage from its "close in" detonation. Click here for a description of Sprint from the Historical American Engineering Record (HAER) document about the SRMSC. Specifications: Launchers: 70 total, 16 at the MSR site and 54 dispersed among the four RSL's (1 (12), 2 (12), 3 (16), 4 (14)). (With the 30 Spartans, there was a total of 100 launchers as specified by the SALT I treaty.) Length: 27 feet Diameter: 4 feet 6 inches (at base) Weight: 7,500 pounds Fuel: Solid propellant Stages: 2 Maximum engagement altitude: 24 miles Range: Approximately 25 miles Guidance: Ground-based radio directed Warhead: Nuclear, low-kiloton range yield Primary Contractor: Martin Marietta
Site Index Site Search	Back to Missiles	Glossary
Home > System Components > Missiles > Sprint (Continued)

And further info:

Sprint

To say Sprint was a phenomenal missile, is putting it mildly. A cone shaped missile that accelerated at 100g, achieved a speed of Mach 10 in 5 seconds, had an ablative coating to dissipate the heat that was generated from the fiction from the atmosphere and was so accurate that the radar had to be de-tuned during testing so that it would not hit incoming RVs. It was a phenomenal missile.

Sprint came about from a study that started in 1959 as a result of identifying the need for a quick acting last ditch missile to intercept incoming RVs, specifically those from sea-launched ballistic missiles (SLBM) and to also intercept RVs that may have got through the higher layer defence. It took three years of research before the study concluded that with the use of phased array radars and appropriate heat shielding, such a terminal defence missile was possible. As a result, in January 1963, the DoD directed that the Nike-X system be developed which included not only the Nike-EX missile (subsequently Spartan), but also another missile called Sprint. In March 1964, Martin Marietta was awarded the development contract for the Sprint missile.

Squirt prior to launch No missile like Sprint is created from a vacuum. Spartan came from years of development of the Nike Zeus missile, and so various programs and other missiles were used to assist the Sprint program. One program which ran concurrently with Sprint for a short time was HiBEX (HIgh Boost EXperiment).

Another program involved which was designed to test Sprint components was called Squirt. It had a different booster to the Sprint missile, but the second stage of the missile was comparable to the Sprint missile. It was used during 196? at White Sands. Its first flight was on 14 July 1964, with another six flights following with at least one more in 1964. Some sources report that flight testing of Sprint components started at White Sands early in 1964 with the first Sprint launch taking place in November 1965. These early flights probably would have been of Squirt missiles

Loading Sprint into launch cell Sprint was 'popped' from its launch silo by a powder gas generator which propelled a piston on which the missile rested. The missile was pushed through a membrane at the top of the cell, while the piston is stopped at the mouth of the silo. Once clear of the cell, the first stage was ignited and the missile tilted over in the direction of the incoming target. Aiming the missile so early in the trajectory reduced the forces involved in moving the missile's trajectory and allowed a very fast interception to take place. Some reports indicate that the missile was supersonic by the time it left the cell.

The first stage had a short burning time, with the second stage igniting 1.2 seconds after launch. Flight control during the 1st stage burning is via fluid injection. Second stage control is obtained via the small aerodynamic fins. Detonation of the warhead was on ground command and was expected to be at an altitude of between 1500m and 30,000m (5,000ft and 100,000ft). The incoming RV was expected to be destroyed by both the nuclear blast, and the high velocity neutrons. (The Sprint warhead was infact one of the so called'neutron bombs' that caused so much controversy during the 1970s). The complete interception was expected to take less than 15 seconds.

Air friction alone during flight of the missile generated temperatures of up to 3400°C (6200°F), and the ablative heat shield could dissipate heat at rates up to 850 BTU/ft/sec. Sprint was also constructed to withstand shocks up to 25,000Gs which meant it could handle nearby nuclear explosions and their resulting blast (how hardened it was to EMP and radiation is unknown). When in flight, the missile was surrounded by a plasma sheath which the command signals from the MSR were able to penetrate. This was achieved due to the sheer high power of the MSR (a beam that was less than 1 degree wide, and had a power of at least 1MW).

Launches

There were two series of test launches of Sprint missiles. The first series covered the initial development launches at White Sands and then testing switched over to system and operational launches at Kwajalein. This first series of launchers had 12 successes, with 2 partial successes and 2 failures. The second series of operational launches took place at Kwajalein of which 29 were successful.

At Kwajalein, missile launches took place from Meck Island which also had a MSR with a single phase array. However, in an operational system Sprint could also be fired from a site which was not co-located with the MSR. To test this capability, a second Sprint launch facility was constructed on Illeginni Island which was north of Meck Island. The first launch from this second site took place in March 1972 and was successful.

#	Date	Site	Comments
Development Launches
1	November 1965	White Sands	Successful.
2
3
4
5
6
7	August 1970	White Sands	??? Last development testing launch at White Sands.
Operational Launches
8	23 December 1970	Kwajalein	Intercepted an ICBM target nose cone. First actual target. Successful.
9
10
11	17 March 1971	Kwajalein	First salvo launch. Two Sprints launched less than 1 sec apart intercepted a Minuteman I RV launched from Vandenberg.
12
13
14
15
16
??	7 May 1971	Kwajalein	First intercept of a SLBM. Polaris launched from USS Observation Island.

2nd Series

#	Date	Site
1	mid-1971	Kwajalein?
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32	December 1973	Kwajalein

Specifications

Sprint was a a cone shaped missile, with four small fins approximately 40% of the way up the missile near the base of the 2nd stage. Sprint was armed with an enhance radiation nuclear warhead in the low kiloton range. This replaced a megaton warhead which was canceled in 1968.

Length:	8.2m (27ft 0in)
Diameter:	1.4m (4ft 6in) at base
Weight:	3400kg (7,500lb)
Range:	40km (25 miles)
Ceiling:	30,000m (100,000ft)
1st Stage Motor:	Hercules solid (Approx 300,000kg thrust)
2nd Stage Motor:	Hercules solid
Guidance:	Radio command
Warhead:	Nuclear, low kiloton range

Sprint II

Development and interest in Sprint did not end with the flight testing of the missile. Martin was awarded a definition study contract for Sprint II in May 1971. This was followed by a design contract in October 1971. In May 1972 a contract worth $168 million was signed for the development and flight testing of Sprint II. The main improvements of the Sprint II missile included greater accuracy, a manoeuvring capability three times greater than the original Sprint, improved reliability, hardening and strengthening against the increased manoeuvring forces and the final improvement included a faster launch process. No known launches of Sprint II were done, and investigations into such a missile were completed during 1983 as non-nuclear forms of ABM defence started taking precedence.

HiBEX

If Sprint was a phenomenal missile, HiBEX was even more interesting in some ways. It was part of a project called Defender run by DARPA in conjunction with the Army for a last ditch ABM missile in a similar vein to Sprint. However, it was literally a last ditch missile and was designed to intercept an incoming RV at less than 6,100m (20,000ft) altitude. At that altitude, the incoming RV would be traveling at around 3,000m/sec (10,000ft/sec) so a very fast reaction time was essential to insure interception. In fact, HiBEX was designed to have exited from its silo within 1/4 second and it accelerated at over 400g.

HiBEX was only 5.2m (17ft) long and due to the high acceleration, the fuel did not last very long at all, so it was characterised with very short rocket burn times and hence a very short range. One of the problems with such a high accelerating missile was that of guidance, and the onboard gyros presented a problem. Mechanical gyros were not really practical due to the spin up times and flight characteristics (ie they took to long to spin up, and didn't take kindly to rapid shifts in trajectory), so ARPA developed the laser gyro. This meant that the gyros and associated guidance system was available essentially instantaneously permitting a very rapid launch which was a major design goal.

HiBEX was not designed to use the MSR, but instead used another radar called the HArd Point Demonstration Array Radar (HAPDAR).

All up, 7 missiles were tested at White Sands Missile Range during 1965.

The Programs: Early Years, Nike Zeus, Nike-X, Sentinel,Safeguard

The Hardware: Nike Zeus, Nike-EX/Spartan, Sprint, Radars, Computers

My Ramblings

Last Modified: 27-Jan-2003

Darn, the pix didn't show, well here is the conceptual schematic of terminal intercept:

</center

Endoatmospheric defense has an edge over exoatmospheric defense during the terminal phase. The atmosphere screens out the decoys.

As for BPI...best ROI, if can actually be done reliably and within reasonable cost restrictions.

Space-based intercept would require getting cost-to-orbit down by an order of magnitude or two--endoatmospheric-based BPI would require massive air dominance.

And some shots of the missile itself, being launched, and another going into its silo:

And also the actual commissioned deployed site, before it was dismantled:

For the contingency of the near-shore SLBM attack, a terminal defense system such as the Sprint is the only near-term and practical defense we could deploy, unless we just happened to have an Air Borne Laser 747 up in the air and in the vicinity and in position... hence, deploying a couple hundred or, what the heck, a thousand SPRINT 2's would not be a waste of money. What would be the economic cost of losing Chicago to a nuke? I wonder how close we were to actually testing Sprint II?

What would be the economic cost of losing Chicago to a nuke?

The Cook County Registrar's Office turns into radioactive vapor, and the Dems never get all those graveyard ballots. :o)

Okay, so the political upside would super, but the economic? I don't think so...

Okay, so the political upside would super, but the economic? I don't think so...

What we'd lose in productivity would be, IN PART, balanced by the termination of all those subsidies, individual and corporate, that go to persons and entities in Chicago.

http://www.freerepublic.com/perl/bump-list

Thanks for the heads up!