Aster : The millennium antimissile


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English version

(d'après la Revue Aérospatiale - 146 - Mars 1998)

The beginning

The threat from aircraft and missiles remains very real despite the end of the Cold War and is potentially among the most serious hanging over the armed forces. The fleets of combat aircraft around the world are still considerable, and the missile threat is proliférating in a growing number of countries too. And the threat itself is becoming greater with the advent of precision weapons offering hugely differing trajectories that complicate the task of air defense, such as antiship surface skimmers, low-altitude terrain-following cruise missiles, guided bombs, ait-to-ground missiles, terminal-dive antiradar missiles, and tactical ballistic missiles of the improved Scud type which plunge onto their target in a near-vertical terminal dive. Such targets are difficult to hit because they are smaller, faster, more agile and capable of being fired in salvoes to saturate the defense. Such defense system rely heavily on antimissile.

The 1980s were good years for short-range SAMs like the Roland and the Crotale for protecting ground forces out to distances up to ten kilometers or so. The nineties have been marked by sales of close-range SAMs that close the gap by providing low-end protection up to five kilometers. The turn of the century will see the replacement of the medium-range (30 to 100km) SAMs now in servicewinch is where the Aster system currently being developed by France and Italy (with the British expected to join) comes in.

For it must be remembered that naval weapon systems like the US-developed Sea Sparrow and Standard Tartar and Britain's Sea Dart, and the American land-based Hawk and Patriot were all designed in the sixties with the Cold War air threat in mind, i.e. jets flying at Mach 2 at high altitude, or waves of Soviet strike aircraft attacking Central Europe. Though already upgraded several times, however, these aging systems betray their limitations against ever-faster stealthy targets able to follow very diverse flight paths, operating in intense ECM environnients.

A new missiles family

Which is why Aerospatiale is developing a new family of antimissile /antiaircraft missiles - the Aster - as part of the Eurosam consortium, together with Thomson-CSF and Alenia. A novel feature, still unique in the world, of the Aster family is that it is:

  • Interservices, to meet the needs of the armies, navies and air forces
  • Multinational, withjoint development by France and Italy (to bejoined this year by Britain)
  • Modular and extendable, two technical requirements to cover ail interservice air defense needs with maximum commonality and cost cutting.

Accordingly, the Aster family has satisfied at least three requirements from the outset :

  1. Self-protection for navies, with the Aster 15 Naval stem-ming from the SAAM surface-to-air antimissile missile due to be commissioned aboard the Charles de Gaulle nuclear carrier in 2000. The role of the Aster 15 SAAM is to widen the scope of the traditional naval point defense missile system (winch could be described as an ultimate short/ultrashort-range defense against antiship missiles) to include self-protection at extended ranges up to 30km, plus area defense to cover a neighboring vessel.
  2. Ground area defense, using the SAMP/T medium-range SAM Aster 30 missile. The aim is to expand the area defense capability to include countering all known rnodern missiles.
  3. Local and area naval defense, using the Aster 30 Naval missile from the Principal Anti-Air Missile System (PAAMS) due to equip the Horizon air defense frigates. Its combines the capabilides of these last two missiles and provides a naval weapon system unique in the world, able to perform three différent rmssion profiles: self-defense, local defense to cover a neighboring ship, and naval area defense. The Aster, moreover, was designed from the outset to allow a dedicated version to provide expanded air defense against tactical ballistic missiles.

Two high-tech features

High terminal agility

Obtained thanks to the revolutionary PIF-PAF thrust-vectoring system, invented by Aerospatiale, which makes the missile highly accurate and maneuverable at all altitudes. This combines classic control surfaces with a form of thurst vectoring provided by a solid propellant motor having four lateral nozzles located at the missile's center of gravity avoid breaking up the missile at the high G's resulting from sudden changes of direction (The latter are perform without increased angles of incidence to ensure accuracy against the target).

 


High-capacity radars

Technologies developed by Thomson-CSF and Alenia give the radars their multirole capability (combined surveillance, weather, target identification, acquisition and tracking). Processing capacity is as much as one billion data items per second and enables the radars to detect 300 flying objects and to identify 60 targets from among them, and to guide up to 16 missiles simultaneously.

A Run of Successes

The first trials between 1993 and 1994 served to validate all the missile's operating sequences in the guided mode, through its entire interception altitude and range envelope. Likewise validated during this period was the Aster 30's boost phase, with testing in the 1preguidance' mode. With the exploratory tasks ended, the next thing was to validate the realities of opera-tion. May 1996 saw the start of Aster 15 launches against real targets, using terminal homing by an active electro-magnetic seeker. The trials, which are still continuing, have been 100% successful (six out of six firings):

Validation of lock-on by the seeker onto the target, with automatic missile guid-ance up to interception of a C-22 drone simulating a combat aircraft flying at 270m/sec at an altitude of 1000 meters and a distance of 7km;

Successfal interception thanks to the PIF-PAF vec-tored-thrust system at a range of l0km and an altitude of 1000 against a C-22 emu-lating a missile effecting a sideways maneuver at several G's;

Successful interception, on April 8,1997, of a C-22 target drone simulating a sub-sonic antiship missile flying at an altitude of 1 Om, at a range of 7km;

Direct hit on a 1st-generation Exocet on May 23,1997 at a range of 9km. That same day, the Aster, as-sumed to be defending a building located 7km away, completed its first hit-to-kill assignment against an antiship missile.

This last was further confirmed on November 13,1997 by the interception of a surface-skimmer in an extrernely dense ECM environment. The warhead had not been installed for this test to allow better visualization of the miss-distance and permit recovery of the target. So there was great surprise when the recovered C-22 was found to have two deep gashes caused by the Aster's fins! Thus 'hit-to-kill' turned out to be 'hit-to-kiss', to use the expression the Aerospatiale team lost no time in adopting. Had the warhead been installed, the target would have been totallv vanorized without the shadow of a doubt.

On 30 December 1997. It involved the first qualification firing an Aster 30 against a real target. The Aster intercepted C-22 traveling at 900km an altitude of about 36,500 ft at a range of 30 km. In the terminal stage of its flight Aster climbed to an altitude of 50,000 ft before diving onto its prey at a spet 28800 kph, registering a miss-distance of less than 4m!

Some pictures

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