To improve land fire capacity Aselsan developed its Tolun air-launched small diameter bomb into a ground launched weapon, the Tolun S, the whole system being unveiled at IDEF 2025 under the name Göktan
The increased interest in indirect fire generated by the Russian-Ukrainian conflict is leading many armies to Improve their capabilities in this area, industry answering with new proposals. Leveraging the work done on its Tolun GPS/INS guided gliding munition, Aselsan developed the Tolun S, the ground-launched version of the Tolun. Both munitions have dimensions and mass in the same range of those of the US GBU-39/B Small Diameter Bomb.
Although not identical, the Tolun S is very similar to the air launched Tolun. The architecture sees a set of wings on top of the weapon, two swept wings folded backwards and a straight wing, semi-wings folding forward, with a set of cruciform wings folding forward at the back, the latter ensuring manoeuvrability. With wings folded the Tolun S is 1,850 mm long, 191 mm wide and 269 mm high, and has a mass of 137 kg. The lower part of the missile is occupied by the 105 kg warhead, which has a 164 mm diameter. This is designed to destroy armoured and non-armoured targets and features a hardened nose that allows it to penetrate up to 1 metre of reinforced concrete. The Göktan fire control system sets the fuse accordingly to the target, ranging from airburst when this is a soft target in the open to different levels of delay when dealing with armoured targets or bunkers.
While the range of the air-launched Tolun depends very much on the platform altitude when it releases the weapon, in the ground-based version this depends mostly on the booster which is added to the missile. At launch the whole system, booster and munition, has a mass of around 700 kg, the booster, developed and manufactured by DeltaV, a Turkish company specialised in rocket propulsion, counting therefore for over 550 kg. This is based on a hybrid-propellant rocket motor, in which the propellant is solid, and the oxidiser is liquid. Such solution solves some of the problems of solid and liquid rocket motors, providing intermediate performances. No details were provided on thrust, the declared maximum range being in excess of 150 km.
The Tolun S is launched from canister, a six-canister launcher being visible at IDEF 2025. This was installed on a Seyit 6×6 tactical truck fitted with an armoured cabin, produced by Anadolu Defence. Powered by a Cummins 510 hp diesel engine coupled to an Allison 4000 SP automatic transmission, it has an 18,500 kg payload and ensures good off-road performances giving the Göktan good deployment flexibility.
Usually, the elevation of the launcher is of 70-75°. The missile leaves the canister under the impulse of the booster, and when this has finished its work the Tolun S separate, opens the wings and continues its flight. At this point the missile starts following navigation instructions provided by the Göktan fire control system, usually based on waypoints. This allows launching the missile in any direction as it will then be able to follow the scheduled course towards the target. Navigation is provided by a GNSS/INS system; a 4-channel CRPA (Controlled Reception Pattern Antenna) should ensure jamming resistance, an embedded spoofing resistant software being also installed. The planning tool allows to decide from which direction the attack will be conducted, as well as the impact angle, in order to maximise damages. As for accuracy, Aselsan declares a CEP under 10 metres.
The Tolun S was first tested in mid-February 2025, launched from a ramp, at the Sinop test firing range, in northern Turkey. Aselsan is talking to the Turkish Land Forces, which should become the launch customer for the Turkish-made Göktan ground-based precision gliding munition.
Photos courtesy Aselsan and P. Valpolini