new russian weapon...US shield is useless

[Boroda]

Originally posted by Saurdaukar
YES!  Propaganda straight out of the 80's!

Ve haf a missial systam that rendars yor missial shield inoperabal.  Surrendur now and ve wont haf to use it.

Well, in the 80s US didn't have any missile shield, and USSR had it's own system according to 1972 treaty - that possibly only made Moscow with it's 10 million population a not-so-good target for a nuclear attack.

With MAD doctrine in action noone had to surrender.

[Nilsen]

Are you sure its propaganda Saurdaukar?

this was a serious question so please try to give a serious answer

[Saurdaukar]

Originally posted by Nilsen10

this was a serious question so please try to give a serious answer

Man are you barking up the wrong tree.  

[Eagler]

Originally posted by Frogm4n
its a multi billion dollar boon doggle that is creating another arms-race.

how do arms race? are feet involved?

[AKIron]

Originally posted by Boroda
I love this "conclusion" I hope no country will try to reveal this highly classified information. Please notice that it includes: "If you'll fire missiles at us you can suddenly learn that we have spent billions of dollars on useless toys that never were supposed to leave the silos". I hope noone will try to reveal this highly classified information.

"Ó íàñ åñòü ÒÀÊÈÅ ïðèáîðû! Íî ìû âàì î íèõ íå ðàññêàæåì!"

News for ya Boroda, the defensive part is for us. Whether it works or not won't matter much to the ones that fire on us. Well, that may not be completely true, if our defense doesn't work they may be vaporized with a smile on their face.

[Boroda]

Originally posted by AKIron
News for ya Boroda, the defensive part is for us. Whether it works or not won't matter much to the ones that fire on us. Well, that may not be completely true, if our defense doesn't work they may be vaporized with a smile on their face.

Sure. The only thing that stopped you from nuking USSR was not our missile shield over Moscow, but the fact that you'll not survive longer then two hours after first massive launch.

Fear of retaliation, MAD, whatever you call it is the only protection from nuclear attack.

Anyone who believes in his "protection" from nuclear missile attack is dangerous, because he will start what he believes to be "limited nuclear war" sooner or later. Considering nuclear weapons as military but not only political factor is insane.

[Toad]

Jeez, Wolf!

If you did the peer review, how about you give us the short answer without making us read 400 pages?

[Boroda]

Originally posted by GScholz
Tactical nuclear weapons would be used in a large scale war, however taking that step (and it would almost certainly be the losing party of a conventional war) dramatically increase the risk of a fully committed nuclear war ... which is insane. However it may also lead to a cessation of hostilities as each party are not willing to commit to MAD.

Exactly. But it applies to countries with limited nuclear potential, like India or Pakistan.

OTOH - even Hitler didn't dare to use chemical or biological weapons when it was obvious that he is doomed. Maybe he thought his separate peace talks with Americans could be successfull?... He had an enormous stock of chemical weapons, most of them were "buried" in Baltic sea after the Victory.

Originally posted by GScholz

Any large scale war between nuclear powers that threaten the political and territorial existence of one or both nations WILL end with a nuclear exchange. A tactical exchange that ends the war, or a massive exchange that ends both nations and possibly the world.

Russian military doctrine of the last decade is based on a pre-emptive full-scale nuclear strike. We don't have armed forces that can withstand a big conventional war with NATO, that is still our biggest enemy. So, we declare that any attempt of an agression will be anwered with a full-scale nuclear release.

If you think I am happy about it - you are wrong

Another thought: if Americans will persuade everybody that they have a working ABM system - the strike will be redirected to their European allies... I don't mean a Russian strike, if NATO will be involved into a conflict with any country that posesses nuclear weapons - you are hostages again.

[Nilsen]

this war business sounds awful...we better not

[Wolfala]

If you want the answer to the BOOST PHASE BMD question - it is as follows....


Boost-phase intercept systems for defending the United States against ballistic missile attack are being actively considered as a major part of a national missile defense strategy. Spending
on such systems by the U.S. Department of Defense is growing, and there is a prospect of much larger expenditures in the future. Boost-phase intercept weapons would seek to disable attacking missiles during the first few minutes of flight, while the missiles’ boosters are still burning and before they have released nuclear, chemical, or biological munitions.

The technical aspects and feasibility of such weapons are the subject of this report. In spite of the growing interest in boost-phase intercept systems and the increasing resourcesbeing committed to developing them, little quantitative information about their technical
feasibility, required performance, and potential advantages and disadvantages is available to the public. Consequently, the American Physical Society (APS) convened a study group
of physicists and engineers, including individuals with expertise in sensors, missiles, rocket interceptors, guidance and control, high-powered lasers, and missile-defense-related systems,
to assess the technical feasibility of boost-phase intercept systems. The Study Group has based its assessments solely on information found in the open literature about ballistic missiles and missile defense. We have supplemented this information
by our expertise in science and engineering and have confined the assessments reported here to those that can be made with confidence by applying the fundamental principles of rocket propulsion, signal detection and processing, guidance and control, and laser beam propagation. In many instances, as documented throughout this report, we have performed our own analyses to address important issues and to assure ourselves of the validity of our conclusions.

Our main conclusions are the following:
1. Boost-phase defense against intercontinental ballistic missiles (ICBMs) hinges on the burn time of the attacking missile and the speed of the defending interceptor rocket. Defense of the entire United States against liquid-propellant ICBMs, such as
those deployed early by the Soviet Union and the People’s Republic of China (China), launched from countries such as the Democratic People’s Republic of Korea (North Korea) and Iran, may be technically feasible using terrestrial (land-, sea-, or air-
based) interceptors. However, the interceptor rockets would have to be substantially faster (and therefore necessarily larger) than those usually proposed in order to reach the ICBMs in time from international waters or neighboring countries willing to host
the interceptors. The system would also require the capability to cope with at least the simplest of countermeasures.

2. Boost-phase defense of the entire United States against solid-propellant ICBMs, which have shorter burn times than liquid-propellant ICBMs, is unlikely to be practical when all factors are considered, no matter where or how interceptors are based.
Even with optimistic assumptions, a terrestrial-based system would require very large interceptors with extremely high speeds and accelerations to defeat a solid-propellant ICBM launched from even a small country such as North Korea. Even such high-
performance interceptors could not defend against solid propellant ICBMs launched from Iran, because they could not be based close enough to disable the missiles before they deployed their munitions.

3. If interceptor rockets were based in space, their coverage would not be constrained by geography, but they would confront the same time constraints and engagement uncertainties as terrestrial-based interceptors. Consequently, their kill vehicles (the final homing stage of the interceptors) would have to be similar in size to those of terrestrial-based interceptors. With the technology we judge could become available within the next 15 years, defending against a single ICBM would require a thousand
or more interceptors for a system having the lowest possible mass and providing realistic decision time. Deploying such a system would require at least a five- to tenfold increase over current U.S. space-launch rates.

4. The Airborne Laser now under development could have some capability against liquid- propellant missiles, but it would be ineffective against solid-propellant ICBMs, which are more heat-resistant.

5. The existing U.S. Navy Aegis system, using an interceptor rocket similar to the Standard Missile 2, should be capable of defending against short- or medium-range missiles launched from ships, barges, or other platforms o U.S. coasts. However,
interceptor rockets would have to be positioned within a few tens of kilometers of the launch location of the attacking missile.

6. A key problem inherent in boost-phase defense is munitions shortfall: although a successful intercept would prevent munitions from reaching their target, it could cause live nuclear, chemical, or biological munitions to fall on populated areas short of the target, in the United States or other countries. Timing intercepts accurately enough to avoid this problem would be dicult.

[Wolfala]

Boost-phase missile defense systems would disable attacking missiles while their rocket motors are burning by hitting them with an interceptor rocket or a laser beam. For ICBMs, this phase of flight typically lasts 3 or 4 minutes. Boost-phase defense has been proposed as a way to avoid the problems faced by midcourse defense systems, which are intended to disable the attacking missile’s warheads after they have been deployed. The midcourse approach is complicated by the need to counter multiple warheads, submunitions (“bomblets”), lightweight decoys, and other countermeasures. The Study Group was asked to evaluate boost-phase intercept systems that would defend
the United States using land-, sea-, air-, or space-based interceptor rockets or an airborne laser now being developed. Space-based laser systems were not included because
the technology needed for such systems would not be ready within the 10- to 15-year period considered. The Study did not consider the feasibility of the communications, command, control, and battle management that would be required. Nor did it consider policy issues, such as the arms control, strategic stability, or foreign policy implications of testing or deploying a boost-phase defense.

Developing and deploying a reliable boost-phase missile defense would be a major undertaking likely to require a decade or more to complete. We therefore considered missiles that might be developed or acquired by North Korea and Iran during the next 10 to 15 years. These countries were the focus of the Study because the U.S. government has expressed concern specifically about them. According to U.S. intelligence estimates, neither of
them currently has a credible ICBM capability but they are projected to develop or acquire ICBMs within the next 10 to 15 years. The Study Group also considered defense against
ICBMs launched from Iraq. With the changed political situation arising from the events of the Spring of 2003, an ICBM threat from Iraq appears unlikely for the foreseeable future.
We have nevertheless retained the analysis of the Iraq threat in the body of our report, to illustrate the requirements for defending against ICBMs from a country that is intermediate
in size between North Korea and Iran. We began by identifying boost-phase intercept systems that could work in principle and
then determined the system performance that would be required to defend the entire United States, the contiguous 48 states, or only the largest U.S. cities. The attacking missiles were assumed to be similar to the first ICBMs developed 30 to 40 years ago by the United States, the Soviet Union, and China. Both liquid- and solid-propellant missiles were considered, because either type could be developed or acquired within 10 to 15 years.

Key Issues
Hitting the Missile. An important question in boost-phase defense is whether the kill vehicle carried by the interceptor could actually hit a long-range missile, given the inherently unpredictable acceleration that is normal for an ICBM in powered flight and the possibility of programmed trajectory-shaping or evasive maneuvers. Assuming interceptors can reach the missile during its boost phase, we find no fundamental obstacle to homing on the missile accurately enough to hit it. To do so, however, the kill vehicle would have to be very agile and would need to carry enough fuel to continue adjusting to the missile’s acceleration
until the moment of impact. We determined that kill vehicles capable of meeting these requirements would be substantially heavier than those that some have suggested for boostphase
intercept. Our analysis of this agility requirement and its implications for the weight of the interceptor are key new aspects of this study. Time. Time is short for boost-phase defense because ICBMs burn out quickly: in roughly 3 minutes for solid-propellant missiles and 4 minutes for liquid-propellant missiles.
But the time actually available is substantially shorter than the duration of the burn. Even systems with state-of-the-art tracking sensors would require 45 to 65 seconds or longer to
detect the launch of a potentially threatening rocket and determine its direction of flight well enough to fire an interceptor (that is, obtain a firing solution).

Additional time must also be allowed for the decision to fire. We have analyzed the decision times that would be provided by various boost-phase defenses. “Decision time” as used here also includes any additional time required for communication between system elements, estimating the performance characteristics of the attacking missile and its trajectory, resolving uncertainties in the performance of the defense system, and other operational factors.To be successful, the intercept would have to occur before the missile gives its munitions the velocity needed to reach the United States. This velocity could be attained as early as
40 seconds before the missile would normally burn out.
Due to the potentially similar flight profiles of ICBMs and space launchers, in many cases the defense system would not be able to distinguish a peaceful space launch from an
ICBM attack. In these cases, the defense would have to shoot at every rocket, unless it had been established as nonthreatening before it was launched.


Extending the time for intercept beyond the boost phase into the ascent phase (defined here as the period after the missile’s final stage has burned out or its thrust has been terminated but before it has deployed all its munitions and decoys) would not increase the available time significantly. The reason is that once the missile’s thrust has been terminated, it could deploy its munitions and any decoys or countermeasures quickly, possibly in less than a second. With so little time available, interceptors would need to reach high speeds very quickly. Taken together, the short time available for intercept and the size of the kill vehicle needed to hit an unpredictably accelerating ICBM would require large interceptors. In some cases, they would have to be larger and faster than the ICBMs themselves and would have to
accelerate four times more quickly. Such interceptors have never been built and would push the state of the art. Range. The useful range of interceptor rockets is restricted by practical limits on rocket speeds and by the short time available for intercepting the attacking missile. The range of he Airborne Laser is also limited, both by constraints on its power and by the distance ts beam can propagate through the atmosphere and remain focused. Consequently, boostphase defense would be possible using interceptor rockets only if they could be positioned close enough to the required intercept locations, generally within 400 to 1000 kilometers. Defense would be possible using the Airborne Laser only if it could be stationed within 300 to 600 kilometers of the intercept points. The required intercept locations are typically
hundreds of kilometers downrange from the missile launch site, which would further restrict nterceptor basing options.
In general, boost-phase defense using terrestrial (land-, sea-, or air-based) rocket interceptors or the Airborne Laser requires that the missile’s flight path during its boost phase be accessible from international waters or from neighboring countries willing to host U.S. interceptors. The feasibility of boost-phase defense therefore depends not only on the performance of the attacking missile and the speed of the interceptor, but also on the size
of the country that launches the missile, the direction of the missile’s flight, and the local physical and political geography.

Shortfall.

If a missile were hit during its boost phase by an interceptor, it wouldprobably lose thrust quickly, but the missile (perhaps in fragments) and its munitions would not fall straight down. Instead they would continue on ballistic trajectories, falling to Earth short of their target but possibly on populated areas. Thus, unless the missile’s munitions were disabled by the collision—which cannot be assumed because they are loosely coupled to
the missile and hardened to withstand re-entry at hypersonic speeds—a successful intercept could cause live munitions to fall on populated areas. These areas would not be in the
attacking country but might well be in countries friendly to the United States or in the United States itself.
This problem is inherent in boost-phase intercept. Our analysis indicates that it would be extremely dicult to time intercepts to avoid causing live munitions or debris to hit populated areas. This problem would be eliminated if the interceptor could reliably destroy the missile’s munitions, but doing so would be much more dicult than simply disabling the missile’s booster rocket.

.

[Wolfala]

Space-Based Interceptor Requirements.

Boost-phase interceptors fired from orbiting
satellites could in principle defend the United States against ICBMs launched from anywhere on Earth. While their coverage would not be constrained by geography, spacebased interceptors would have the same time constraints and engagement uncertainties as terrestrial-based interceptors. As a result, their kill vehicles would have to be at least as massive as the kill vehicles of terrestrial-based interceptors. Because a satellite orbiting at ow altitude spends so little time over a single spot on Earth, many interceptor-carrying satellites would be needed to defend against even a single missile. The precise number of
satellites and the total mass that would have to be placed into orbit would depend on the type of ICBM as well as the speeds, accelerations, and masses of the interceptors and their
kill vehicles, which would in turn depend on the technology available. Based on the technology that could, in our judgment, be developed within the next 10 to 15 years, we find that a thousand or more interceptors would be needed for a system having the lowest possible mass and providing a realistic decision time. Even so, the total mass that would have to be orbited would require at least a five- to tenfold increase over current U.S. space-launch rates, making such a system impractical


The Airborne Laser’s Performance.

A laser weapon now in development has also
been proposed for boost-phase defense. The Airborne Laser is being developed to disable short- or medium-range ballistic missiles by illuminating them with a powerful laser beam from distances of several hundred kilometers, heating them suciently to cause the structure of the missiles to fail. In principle, this weapon could also disable long-range missiles during their boost phase. Because the laser beam could reach an ICBM within a fraction of a second, its speed is not an issue. However, the range of the Airborne Laser is limited by the distance its beam can propagate through the atmosphere and remain focused. Assuming that it works as planned, its useful range would be about 600 kilometers against a typical liquid-propellant ICBM. This range would be sucient to defend the United States against such ICBMs launched from North Korea but insucient to defend against such missiles launched from Iran, unless the laser could be stationed over the Caspian Sea or Turkmenistan. Because solid-propellant ICBMs are more heat-resistant, the Airborne
Laser’s ground range against them would be only about 300 kilometers, too short to defend against solid-propellant ICBMs from either Iran or North Korea.

Countermeasures.

While boost-phase intercept would not be susceptible to some of the countermeasures to midcourse intercept that have been proposed, there is no reason to think it would not face any countermeasures. Eective countermeasures to boost-phase
intercept by interceptor rockets could include launching several ICBMs at nearly the same time or deploying rocket-propelled decoys and jammers. Furthermore, ICBMs could be programmed to fly evasive maneuvers that might overwhelm the agility and guidance and control capabilities of the interceptor or exhaust its propellant. Shortening the boost phase would also be an eective countermeasure: it would be practically impossible for any interceptor rocket to reach an ICBM with a boost phase of 2 minutes or less, even if it were launched from a very small country. Countermeasures against the Airborne Laser could
include applying ablative coatings or rotating the ICBM to reduce the amount of heat the missile absorbs, launching multiple missiles to overwhelm the Airborne Laser’s capabilities, or attacking the aircraft carrying the laser.

Defending the United States

We considered the eectiveness of boost-phase intercept for defending the United States against ICBMs from the two specific countries of concern, North Korea and Iran. The results summarized here for these countries are based on a series of optimistic assumptions. In particular, we have made optimistic assumptions about the missile detection and tracking
capabilities available to the defense. Also, we have not fully taken into account the many uncertainties likely to be present in any real engagement, such as uncertainties about the performance of the attacking missile and its trajectory, ignorance of the missile’s target, and the unpredictable natural variations in any missile’s flight. Nor have we accounted for possible operational delays in processing and transmitting information. All of these factors would make boost-phase intercept more dicult.
We found that terrestrial-based interceptors that burn out in 40 to 50 seconds and reach speeds of at least 6.5 to 10 km/s would generally be required to defend against ICBMs launched from North Korea or Iran. As noted above, such interceptors would have to be substantially larger and capable of higher performance than any that have yet been built or deployed. In a few situations, a 5-km/s interceptor would work against slow-burning liquid-propellant ICBMs. The time available would be significantly greater for very slowly burning liquid-propellant ICBMs having burn times of 5 minutes or longer, but a defense
that would work only against missiles as slow as the slowest-burning missiles ever built would risk being ineective. North Korea. Defense of all 50 states against typical liquid-propellant ICBMs launched from North Korea would require interceptors with speeds of 6.5 km/s (almost as fast as ICBMs) based in Russia or the Sea of Japan and fired within about 40 seconds of obtaining
a firing solution. The intercept locations for most ICBM trajectories from North Korea would be over China, hundreds of kilometers inside its border. Such interceptors would have ranges as long as ICBMs. Consequently, firing them toward China to intercept a
North Korean missile could be mistaken for an attack on China, Russia, or other countries.

The Airborne Laser might provide an alternative defense against liquid-propellant ICBMs. To defend against typical solid-propellant ICBMs and provide more than a few seconds of decision time would require interceptors that could reach speeds of about 10 km/s, 50 percent faster than a typical ICBM, in one-quarter of the time it would take an ICBM to reach its maximum speed. The interceptors would have to be based in Russia or the Sea of Japan and fired within 30 to 40 seconds after a firing solution was obtained. Such interceptors could be mistaken for oensive weapons. Iran. To defend the entire United States against liquid-propellant ICBMs launched
from Iran using interceptors based in conventional locations would require basing 10-km/s interceptors in the Persian Gulf, and even this deployment would provide only about 15 seconds
of decision time. More decision time would be possible only if interceptors could be based in unconventional locations, such as Turkmenistan or the land-locked Caspian Sea. A system with 6.5-km/s interceptors based in either of these locations could provide a decision time of about 30 seconds.
Defense of the entire United States against solid-propellant ICBMs launched from Iran appears impractical; even a system with 10-km/s interceptors based both in the Caspian
Sea and in Turkmenistan or Afghanistan would provide less than 10 seconds of decision time, which is unlikely to be adequate for an operational system.

Defending Only a Portion of the United States.

 We also considered the feasibility of defending only the contiguous 48 states or only the largest U.S. cities against ICBMs
launched from North Korea or Iran. In most cases, this would be no easier than defending all 50 states. If, however, a boost-phase defense were not solely responsible for intercepting
all missiles from these countries, the required system performance would be less demanding. Interceptors could hit liquid- or solid-propellant missiles launched from these countries
toward some U.S. targets. Such a system could provide a partial defense; for instance, for one U.S. coast but not the other. Coupled with an eective midcourse system, a partially
eective boost-phase defense could improve protection of some targets by hitting missiles before they deploy decoys that could overwhelm the midcourse layer. This possibility, however, depends on the midcourse system’s being able to handle the unpredictable debris generated by a boost-phase intercept while engaging the warheads, which most likely would
survive the intercept. Such a capability would be dicult to achieve.

Defending Against Short- or Medium-Range Missiles Launched from Oshore.

 Missiles that could be used for a sea-based attack probably are already available to nations of
concern to the United States. The Aegis radar system is adequate for tracking such missiles provided it is within a few tens of kilometers of the missile launch location, and a missile similar to the Navy’s Standard Missile 2 is adequate for such an engagement withoutsignificant modification.

[Wolfala]

NOW FOR THE FINDINGS.....


The Study Group analyzed boost-phase defense against liquid-propellant ICBMs, which the United States may face initially, and against solid-propellant ICBMs, which the nation
may face later. The basic parameters of systems that could counter these threats in a variety of geographical situations were identified. In the course of analyzing these systems,
the Study Group identified many significant limitations to boost-phase intercept, especially when confronting solid-propellant ICBMs. However, it made no judgment as to whether any or all of these limitations would rule out deployment of such systems on operational, political, or economic grounds. The analysis in the main body of this report supports the following findings. A number (or letter) in parentheses indicates the relevant chapter (or appendix), section, or subsection of the supporting material.

1. Intercepting missiles during their boost phase presents major challenges not faced
by midcourse-intercept systems.
• Midcourse systems have 20 to 25 minutes to observe and intercept threatening
warheads (A.2); boost-phase intercept systems could have 4 minutes or less to
detect, track, and intercept potentially threatening missiles (4.4, 5.4–5.6, 10.4, 15).
• In midcourse flight, the trajectory of a warhead is ballistic and highly predictable
(B); in powered flight, the trajectory of a missile is inherently unpredictable. This
unpredictability results from uncertainty about the intended target, the eects of the
missile’s maneuvers to manage its energy, shape its trajectory, or evade intercept,
and its unpredictable thrust variations (4, 12.4, 15.2).

2. The eective ranges of boost-phase hit-to-kill interceptors, whether land-, sea-, air-, or space-based, are limited by the short duration of ICBM boost phases and practical limits on interceptor fly-out velocities. The range of the Airborne Laser is limited
primarily by the distance its beam can propagate through the atmosphere while remaining focused, and to a lesser extent on its power. These limitations have the following consequences:

• In a hit-to-kill boost-phase defense, the time remaining after an interceptor is fired is so short—less than 170 seconds for a liquid-propellant threat missile and less than 120 seconds for a solid-propellant threat missile—that the defense could fire only once, either a single interceptor or a salvo of interceptors fired virtually simultaneously. There would be no opportunity to recover from a misfire or failure of an
intercept attempt (5.4–5.6).
• Boost-phase defense with interceptor rockets would be possible only if the rockets could be positioned close to the intended intercept point. The intercept point is
xxxiii
xxxiv Findings typically 400 to 500 kilometers from the missile launch point. The interceptors typically must travel at least 500 kilometers from the interceptor base to reach the intercept point (5.4–5.6).

• Terrestrial-based boost-phase defense—both by interceptors and airborne lasers— also depends on the size of the country that launches the missile, the direction of the missile’s flight, and access to areas adjacent to that country, determined by local
physical and political geography (5).
• Boost-phase defense using terrestrial-based interceptors could not defend the United
States against accidental or unauthorized launches of ICBMs from the interiors of
large countries such as Russia or China (5).

3. The large and unpredictable variations of ICBM boost-phase trajectories and the short time available for engaging them drive the requirements for any boost-phase kinetic kill interceptor.
Factors contributing to uncertainties in the intercept point include:
• Random and systematic errors in the defense detection and tracking system’s measurement
of position and velocity and estimate of acceleration of the attacking
missile (10.1.4, 12.3.1).
• Lack of knowledge of the missile’s target (15.2).
• Normal or induced thrust-time variations of the threat booster (15.2).
• Intentional trajectory shaping, including lofting or depressing the trajectory and
maneuvering to manage energy (15.2).
• Intentional evasive maneuvers, such as dog-legs or other maneuvers (12.4).
• Lack of knowledge of the potential type or characteristics of the threat (3.3).
• Uncertainties in the method and times at which the missiles’ warheads or submunitions
would be deployed (15.2, A.2.2).
These uncertainties reduce the time available for the engagement and require kill-vehicle maneuver velocity and acceleration substantially greater than is generally recognized. These eects are discussed in Chapters 5 and 12.

4. The only way a boost-phase defense can assure that lethal warheads will not strike a defended area is to disable the attacking missile before the earliest time it can
achieve the velocity needed to carry its munitions to that area, because the defense does not know the particular target. This time is uncertain because the missile may fly various trajectories and execute a variety of maneuvers to manage its energy or
evade the defense (4.1, 5.1.3, 5.2.1, A.2).

5. A robust boost-phase defense against ICBMs would require modern space-basedsensors to detect launches and provide initial tracking information needed to launch
interceptors. Even so, it would take at least 45 to 65 seconds to detect the launch of an ICBM and establish a track of its trajectory accurate enough to launch an inter-ceptor. Such sensors would also be needed to provide continually updated tracking information to the interceptors as they fly to the target. A system such as the high-altitude Space-Based Infrared System (SBIRS-High) now under development
Findings xxxv could perform these functions if the boost-phase defense requirement is included in
its design (10.4).
• While radars with sucient sensitivity exist, geographic constraints and horizon limitations would require a modern space-based missile warning and tracking system, such as the planned SBIRS-High system, for the earliest detection and initial
tracking (10.4). The existing Defense Support Program (DSP) system could provide aunch detection and initial tracking, but it would take 30 seconds longer to obtain a firing solution than a system such as SBIRS-High (10.4). Consequently DSP would be useful only against slow missiles, and only if the fastest interceptors were used (5.9.2).
• Additional time margin would be required to allow for the decision to fire and any other intentional or system delays. We use the term “decision time” to encompass any time required beyond the zero decision time case (5.1.3).

6. While boost-phase defense against slow-burning liquid-propellant ICBMs not em-ploying countermeasures appears technically feasible for some geographic scenarios,
the much shorter burn times typical of solid-propellant ICBMs using even 40-year-old technology call into question the fundamental feasibility of any boost-phase inter-
cept of such threats at useful ranges—no matter where or how the interceptors are based—even with the most optimistic assumptions about detection and track times
(5.3, 6.11, 8.6).
• While liquid-propellant ICBMs typically have powered flight times of 4 minutes or more, solid-propellant missiles typically have three boost stages that burn a total
of 3 minutes or less (3.4). This dierence is crucial.
• No matter where or how they are based, interceptors would typically have to travel
500 kilometers or more, requiring prohibitively high flyout velocities (in excess of orbital velocity) and very high accelerations to reach solid-propellant missiles before they have achieved the velocity required to deliver their payloads to the United States (5.3–5.6).
• By comparison, against liquid-propellant ICBMs, small two-stage terrestrial-based interceptors having modest burnout velocities of only about 5 km/s, such as the largest-sized interceptor that could meet the constraints of the Aegis cruiser vertical
launchers or deployment by bombers, could marginally engage threats at about 500 kilometers (5.3). Interceptors having velocities similar to those of ICBMs would provide greater decision time and range for this case but still could not engage
solid-propellant ICBMs.

[Wolfala]

7. According to U.S. intelligence estimates, North Korea and Iran could develop or acquire solid-propellant ICBMs within the next 10 to 15 years (3.3). Boost-phase defenses not able to defend against solid-propellant ICBMs risk being obsolete when
deployed.

8. The time constraints imposed on any boost-phase defense system by the short du- ration of ICBM boost phases would pose significant real-time decision issues.
• In most situations, interceptors would have to be fired within a few seconds after confirmation of the launch of a large rocket to intercept it in time to defend the
xxxvi Findings United States (5.3). The decision to fire interceptors would have to be almost automatic (5.3–5.6).
• Because of the potentially similar flight profiles of ICBMs and space launchers, in many cases the defense system would have diculty distinguishing a space launch from an ICBM attack. In these cases, the defense would have to shoot at every
rocket, unless it had been identified as non-threatening before it was launched (10.4).

9. Despite the variations and uncertainties inherent in the boost-phase trajectories of ICBMs, our analysis indicates that a kill vehicle incorporating current sensor and
guidance technology could home on ICBMs in powered flight with a precision com-patible with direct hit-to-kill requirements, assuming the kill vehicle’s booster could place it on a trajectory that would take it within homing range of the ICBM. The
kill vehicle would also have to meet certain critical performance requirements. Critical kill-vehicle performance requirements include:
• Capacity to shift from guiding on the rocket’s exhaust plume to guiding on the rocket body. The Study Group believes this requirement in particular requires
more investigation (10.4).
• Ability to acquire and track the rocket body within the plume at ranges of at least 200 kilometers and with sucient precision, using sensors on board the kill vehicle
(12.3).

• Sucient kill-vehicle acceleration (7–8 g initially and 15 g in the end game), velocity for maneuvering (2 km/s for terrestrial-based and 2.5 km/s for space-based kill vehicles), and guidance system response (0.1 second or less) (12.5).
These requirements would result in kill vehicles with masses substantially greater than is generally appreciated. In our judgment, kill vehicles using technology that would
be available in the next few years would have masses on the order of 90 kilograms to 140 kilograms: 90 kilograms for the total divert velocities of 2 km/s that would be required for most ground- and air-based interceptors and roughly 140 kilograms for 2.5-
km/s divert velocities that would be appropriate for space-based interceptors and the fastest ground-based interceptors (14.4).
10. Although a successful intercept would prevent munitions from reaching their target, live nuclear, chemical, or biological munitions could fall on populated areas short of the target, in the United States or other countries. This problem of shortfall is
inherent in boost-phase missile defense.
• Warheads and submunitions are loosely coupled to the final stage of the ICBM and cannot be assumed to be destroyed by an intercept that destroys or disables the ICBM booster, as borne out by numerous destruct events during flight tests (13.1).
• After an intercept, the munitions and debris will continue on a ballistic trajectory,
albeit one that is shorter than intended by the attacker (5.8).
• The warheads or munitions and debris of an intercepted missile will not fall on the country that launched it (5.8).

• Preventing warheads or submunitions and debris of intercepted missiles from hitting the territory of U.S. friends and allies would sometimes require the defense to intercept
missiles within a time window as small as 5 to 10 seconds, greatly complicating
the already daunting intercept management problem (5.8.1).
• Given the unpredictable variations in trajectories and thrust that characterize ICBMs in powered flight, it is not clear that the intercept can be timed to occur
within the narrow window required (5.8.2). The problem of controlling shortfall could be avoided if the boost-phase defense system could destroy the missile’s warheads or submunitions during boost, rather than simply disabling the booster. This is a much more dicult task, and it has not been established
that it can be accomplished (13).
11. Airborne interceptors oer some unique advantages for boost-phase defense, but they also have significant limitations in defending against ICBMs. They could be de-
ployed more quickly than land- or sea-based interceptors in response to new threats, but several backup aircraft equipped with interceptors, as well as refueling aircraft and defensive air cover, would be required for every airborne-interceptor aircraft on
station (16.5.3).
• An interceptor of any given size has a slightly greater range if launched from a highaltitude platform, because it uses less energy to overcome gravity and aerodynamic drag as it flies out toward its target. However, the constraints on the size and weight of missiles that an aircraft can carry limit the flyout velocity of high-acceleration airborne interceptors to about 5 km/s (16.5.3).
• Because of their limited flyout velocity, airborne interceptors could engage ICBMs only in situations comparable to the situations in which a 5 km/s surface-based interceptor could engage them. Consequently, using airborne interceptors to defend the United States against long-burning liquid-propellant ICBMs would be possible only if the required intercept locations are within about 500 kilometers of the nterceptor-carrying aircraft (5.3.2, 5.5.1).

Concluding remarks

In assessing the feasibility of boost-phase missile defense using hit-to-kill interceptors or the ABL, we attempted to make optimistic assumptions to bound the performance of such
systems. In some cases we made assumptions that appear technically possible but may not be realistic on other grounds. An important example is the assumption in some of our analyses that interceptors could be fired as soon as a target track has been constructed, without allowing additional time for decision or assessment. In other cases we simply examined the performance that would be required to make the system workable, without
making any judgment about whether such components could realistically be deployed. An example of this kind is our consideration of an interceptor having a flyout velocity 40 percent
higher than an ICBM’s velocity. We emphasize that the choices made in this study were used to obtain upper bounds on performance; their use does not imply that the Study Group endorses these choices as realistic in all cases. Given the results that follow from our assumptions, we conclude that while the boost phase technologies we studied are potentially capable of defending the United States against iquid-propellant ICBMs at certain ranges of interest, at least in the absence of countermeasures, when all factors are considered none of the boost-phase defense concepts studied would be viable for the foreseeable future to defend the nation against even first-generation solid-propellant ICBMs (5, 6.11, 8.6).


FOR THE FULL REPORT GOTO

http://www.aps.org/public_affairs/popa/reports/nmd03.cfm

Boost Phase Defense Timeline - PROBLEMS with it.
http://www.aps.org/media/pressreleases/nmdfig2-2.pdf

Potential Impact Sites
http://www.aps.org/media/pressreleases/nmdfig5-3.pdf

Interceptor Basing areas:
http://www.aps.org/media/pressreleases/nmdfig5-10.pdf

Hypothetical Interceptor Models - LOOK AT IT
http://www.aps.org/media/pressreleases/nmdfig16-9.pdf

[AKIron]

I think they had the right answer 25 years ago.