Barrel-launched Weapons.

There are basically two types of canon launched guided projectiles: one fired like a normal round and guided by various means, while the other comes in the form of a submunition fired in a cargo round.

In the first case, the round is usually fired by tank guns, while in the second, larger calibres dictate use from howitzers. As we shall see, guidance of the submunition, usually autonomous, only intervenes once it is released from the cargo shell. In any event, a canon-launched guided projectile (CLGP) needs a guidance system that can survive accelerations of 10 000 to 12 000 G. Ideally, it should maintain the weight and dimensions of the corresponding unguided round.

The 155 mm laser spot-homing XM712 Copperhead was developed by Martin Marietta (since, Lockheed Martin) in the early 1970s and production was terminated in 1990. The US Army used only 90 Copperheads in the Gulf War, presumably because most firings were conducted against area targets, and it was rarely possible to laser-designate point targets at short notice. It may be noted that the Russian philosophy for the longer term appears to favour a combination of laser spot-homing and fully autonomous imaging infrared or millimetre-wave rounds.

Krasnopol, Kitolov

The Soviet response to the Copperhead was the 152 mm KBP Krasnopol, which also uses laser spot-homing, and is fired from Russian D-20, 2S3, 2S3M and 2S19 artillery systems. However, this development involved an increase in the length of the round, hence it is stored in two parts. The Krasnopol is nonetheless claimed to be superior to the Copperhead, in having more range (22 rather than 16 kilometres), a ten per cent lighter weight, and a steeper top-attack dive angle. In a series of demonstration firings at Idex-93 and -95, a total of 19 T-72 tanks were destroyed with only 20 Krasnopol rounds.

KBP next developed the 120/122 mm Kitolov-2/-2M round, using smaller guidance components. Transferring these new components back to the 152 mm round produced the Krasnopol-M, which restored the dimensions of the unguided original, and could thus be handled as a single item.

Fitted with larger driving bands, the Krasnopol-M can also be fired from Western 155 mm guns such as the M109, G5 and G6. It is normally used with the Russian Polyus 1D20 and 1D22 laser designators, but new laser-seekers developed by Lomo can be programmed onsite to suit Nato codes. Compatibility with Western laser designators was demonstrated in 1998, using the DHY307 produced by Cilas of France. France and Russia are now collaborating in marketing Giat artillery systems with Krasnopol ammunition.

Following a highly successful demonstration in the Rajasthan Desert in June 1999, in which three Krasnopols fired from Swedish FH-77B guns produced three direct hits,, the Indian Defence Ministry placed a large order with KBP for these projectiles. It may be noted that the firing tables for Krasnopol, produced to satisfy the standard Russian Army requirement for operation up to 10 000 feet, were subsequently amended for use up to 14 750 feet.

KBP has developed laser-guided rounds in 100 mm for the MT-12 antitank gun, the BMP-3 infantry fighting vehicle and the T-55 tank, in 115 mm for the T-62, and in 125 mm for the T-72S and T-80U. The company is also responsible for the sighting and guidance units for these vehicles.

The KBP Design Bureau is now developing in conjunction with Diehl Stiftung and Krauss Maffei Wegmann the 105 mm Spear for the Leopard 1 and M60 tank series. The Spear is a derivative of KBP's 100 mm 9M117 or AT-10 Stabber (referred to above). It offers the choice of a tandem or fragmentation warhead, and increases the effective firing range of those Western tanks from 2000 to 5500 metres. The Spear is a rocket-assisted round with laser beam-riding guidance.

Term

The US Army has a requirement for a 120 mm Tank Extended-Range Munition (Term). This is currently in Phase 2 development and is expected to enter EMD (engineering and manufacturing development) in FY05, and equip the first Abrams tank unit in FY10. Target unit price is $ 25 000. The Term is to engage targets out to 6000 metres directly, and targets out to 8000 metres in an indirect-fire mode.

One contender is the Alliant Techsystems XM1007 Term-KE (kinetic energy) round. After firing, the munition flies ballistically to a predetermined distance, where the rocket motor ignites. Terminal guidance is provided by an active millimetre-wave radar and lateral thrusters in the nose provide control of the flight-path. The only moving parts are eight fold-out fins at the rear. Its active radar guidance makes the XM1007 an all-weather fire-and-forget missile.

Competing with Alliant's Term-KE is a project from Raytheon (teamed with Primex Technologies) with a shaped charge warhead. It is understood that the Raytheon proposal uses three types of guidance: semi-active laser, an electro-optical system and millimetre-wave radar.

Excalibur, Lahat

Israel has two competitive developments to meet a requirement for the Tank Extended Range Munition programme that can be fired either from 105 or 120 mm guns -- in the latter case using a discarding sabot.

The Rafael-IMI Excalibur employs a pop-up trajectory and dive attack, and either millimetre-wave or imaging infrared guidance. Little information could be obtained, but the Excalibur is described as a fire-and-forget weapon and that it "is compatible with the tank's existing systems".

IAI's MBT Division, on the other hand, is teamed with General Dynamics Armament Systems, Thiokol Propulsion and Primex Technologies in promoting the laser spot-homing Lahat. This was unveiled in late 1998 and has been demonstrated successfully, but requires further development. The Lahat is a 104.5 mm missile that is housed in an otherwise empty shell case, and can be soft-launched from either a 105 mm or -- with sabots -- a 120 mm gun. Target price is $ 20 000. It is claimed that, in combat with a tank armed with a conventional 105 mm gun, the use of the Lahat gives a kill ratio of 4.1:1.

Raytheon has also teamed with Primex Technologies to compete with Alliant Techsystems for the GPS/IMU-guided XM982 Excalibur 155 mm round. Raytheon refers to an accuracy of 20 metres at 50 kilometres range, and a choice of three payload options: either two Sadarm (Sense and Destroy Armor) submunitions, multiple DPICMs (Dual-Purpose Improved Conventional Munitions), or a unitary penetrator. The British Army is reported to have a `Pole-Axe' requirement for a guided 155 mm round, able to produce a 15-metre CEP at a range of 60 kilometres.