Sky Captain wrote:Would it be possible that advances in laser technology make missiles mostly useless to reliably attack aircraft and ships? For example a naval cruiser armed with laser point defenses would be very difficult to successfully attack with conventional anti ship missiles. You would probably need to spam dozens of missiles against a single ship to swamp the point defense and achieve a hit.
That's
already true for ships (and task forces) equipped with AEGIS or equivalent; lasers will just raise the threshold from 'dozens' to 'hundreds'. The obvious solution to that is hypervelocity weapons; the faster approach speed gives the beam less dwell time and kinetic penetrators in an unpowered mach 5 dive are much harder to destroy than thin-shelled subsonic missiles packed with explosives and jet/rocket fuel. I would not be surprised if the recent revival of USAF enthusiasm for hypersonic stand-off weapons is at least partly motivated by the need to penetrate future laser point defences.
What would be the most effective ways to counter the laser defense systems?
Some proposed mechanisms to defeat THEL;
A review of the types of technologically feasible countermeasures would include (though not be limited to) the following :
1. Reflective coatings which attempt to reflect a large proportion of the incident radiation which is incident upon the aimed projectiles. This would not necessarily reduce the absorbed incident radiation to such an extent that the projectile is not destroyed - but in combination with other types of countermeasure, reflective coatings would feasibly ensure that target kill is achieved despite the use of THEL.
2. Modification of projectile geometries to take into account the possibility that laser light radiation might be used to neutralize the projectiles. Such geometries might also be concomitant with the purpose of improving the aerodynamic properties of the projectile - thus ensuring that it can travel faster (and, conceivably, would thus be able to rely upon the increased convective dissipation which is associated with heat transfer between the air and the projectile). Note: This includes the possibility of using projectile shapes which are NOT cylindrical. A different missile form would help to ensure that a minimum cross-section surface area is exposed to laser light.
3. As is the case in "hyper-planing torpedoes", which envelope the torpedo in a gaseous envelope so that they may travel at supersonic speeds underwater, it is also found that the use of similar (supersonic) gaseous envelopes around a missile would ensure that a sufficiently cool gas will carry away proportion of the incident radiation energy which is incident upon the missile by both convective and diffusive effects (ie: partial reflection, partial expansion upon being heated by the laser radiation and partial convection due to the temperature increase, though the latter two could arguably be considered as being of similar affect). This would thus also have the effect of a countermeasure to the THEL system. The enveloping gas/substance can be modified so as to consist of fine droplets which carry away a significant proportion of incident radiation and heat on the projectile as they are vaporised (provided, of course, they are chosen so as to absorb the heat radiation corresponding to the frequency of the incident radiation). Note, the larger the gaseous diameter around a cylindrical projectile (measured in terms of its cross section), the disproportionately larger the amount of incident radiation required by the THEL laser to destroy the projectile (consider the volume of the envelope and the highest level of heat dissipation which this corresponds to).
4. An oscillating or chaotic trajectory (one which is difficult to predict, but which will still ensure that the target is killed) will increase the difficulties in the use of the THEL system due to guidance. If guided into windy or turbulent environments, such a chaotic trajectory would also ensure that there more of a turbulent gaseous flow around the missile (though this would be due to the nature movement of air due to the fast moving missile rather than any specifically designed affect as in the case of 3).
5. In a similar vein to the above, a rotating missile will halve the effective area over which the radiation is incident, yet another countermeasure technique or method. This occurs as it is assumed that there would only be one direction from which the THEL radiation would be incident – but this technique has a countermeasure affect even when there are multiple THEL laser radiation sources pointed at the same projectile (assuming that there is some outer boundary area of the missile upon which no laser radiation is incident).
6. Heat Resistant Coating Layers (HRCLs). These are similar to the use of a reflective coating in the sense that coating layers attempt to avoid too much heat causing guidance system malfunction or propellant autoignition within the THEL countermeasure projectile. However, in the case of HRCLs, internal capillaries/coolant mechanisms can be built quite simply into a projective design (consider wrapping the exterior of the projectile in a series of hollow air-pipes which allow air to flow parallel to the fast-moving projectile, but in a manner which does not impede air flow around the projectile - perhaps even aided via the use of a simple internal refrigeration system). Of course the notion of using an internal refrigeration mechanism within a small projectile system is, a priori, not something which seems sensible (though it might very well be economically feasible in the realms of missile design). However, the use of a 'disposable' interior to a THEL type system would ensure that excessively large amounts of heat which are generated due to incident radiation on the missile could be dissipated via the use of 'fall away' layers – such as occurs with the NASA space shuttle as it re-enters the earth's atmosphere (within this type of a design, what occurs is that ceramic heat blocks at the base of the shuttle become red to white hot and are designed to fall off the shuttle, carrying away excess heat with them as they fall – this is clearly a heat dissipation strategy which could be applied as a countermeasure to the THEL type system, and, due to the way in which the heat blocks dissipate large quantities of heat, this method could be applied to artillery as only a thin heat dissipation based ceramic layer would be required for the purposes of carrying away incident heat energy).
By combining all of those you might increase the laser power requirement to destroy the projectile by somewhere between one and two orders of magnitude, but only at significantly increased manufacturing cost and as you say likely reduced range/payload.
