Guided ammunition for Homar and Langusta

The Polish Army uses 75 multi-track WR-40 Langusta rocket launchers and a number of Soviet BM-21 Grad and Czechoslovak RM-70/85 rocket launchers. The latter two will be completely replaced in a few years« time by the much more modern Homary-K and Homary-A. According to the Ministry of Defence’s plans, the two aforementioned systems are to be integrated with the Polish 122mm calibre Feniks-Z ammunition. This family of munitions will thus be used in the Polish Army for many decades, which creates a reason for its modernisation. This was the proposal presented by the Warsaw University of Technology during the International Artillery Conference. 

The aim of the Warsaw University of Technology’s project, or more precisely the Defence and Security Research Centre, is to increase the precision of the classic 122mm calibre combatant. Work in this direction has been ongoing for several years, so the Warsaw University of Technology team has significant experience in this field. The Warsaw University cooperates with the only manufacturer of these combat means in Poland, i.e. Mesko factories. As the speaker, Robert Głębocki, Ph.D., mentioned, the requirements for reducing the circular hit error are not high. The assumption of the project is to create ammunition with increased area accuracy rather than point accuracy, i.e. with CEP reduced from 800 to 50 metres when firing at maximum range (approximately 40 km).

Despite the modest assumptions , the progression from the starting point is significant. The criteria adopted suggest that the production of such guidance systems could have a favourable cost-effectiveness relationship. The development of an inertial navigation module that would meet the listed requirements is possible domestically. Among the components the PW team is working on are:

• a gasodynamic control executive;
• aerodynamic control actuation system;
• precision guidance system (inertial systems);
• inertial navigation (inertial systems);
• control algorithms;- HWiL modelling and testing;
• smokeless fuels (in collaboration with Nitro-Chem).

As part of the research into different types of guidance systems, it was decided to integrate the rocket with, among other things, a Galileo satellite receiver. Due to the lack of a sufficient number of Feniks-Z rockets for testing, the team created their own rocket of similar size (only slightly shorter) called Orion for testing purposes. It was produced in a number of dozens. In addition to these, a suitable launcher was built. Mesko was a great support here, providing rocket engines for testing and lending a dynamometer for testing. Field tests took place in Toruń, among other places.

An interesting feature is the possibility of extending the 122mm calibre rocket, which, despite its increased dimensions, is expected to fit in the same launcher as before. This will give the possibility of adding, for example, the aforementioned inertial navigation module to the combat agent, but without reducing the fuel supply or the size of the warhead. A team from the University of Technology has developed its own licence-free optical gyroscope based on infrared and ultraviolet sensors. Thanks to the use of many types of sensors and a not inconsiderable number of tests , the Polytechnic staff collected a great deal of data on the rocket’s behaviour, which made it possible to develop new solutions and knowledge for simulation studies and aerodynamic calculations.

At the end of the presentation, Dr Głębocki mentioned the Hardware In The Loop Laboratory, which was established thanks to the offset for theWisła programme and belongs to the Polish Armaments Group (to be more precise, to Wojskowy Zakłady Elektroniczne in Zielonka). This research unit gives our industrial and research centres an extraordinary capacity to conduct experimental programmes. Among the benefits, the speaker mentioned the reduction of development costs, fault detection, reduced R&D time, the ability to perform the same tests thousands of times or increased reliability and safety of developed devices. This is a key new competence in the area of rocket artillery. It is important to use the Laboratory so as not to waste the considerable potential that lies within it.

The work carried out by the Defence and Security Research Centre could significantly increase the effectiveness of 122mm calibre rocket with little impact on production costs. As Homar, Homar-K and most likely Homar-A are or will be integrated with the Feniks-Z family of munitions, it seems logical to continue the development of these munitions and to support this type of work. At stake is a clear improvement in the missile rocket of the Rocket and Artillery Forces, as well as the creation of a starting point for the development of larger calibre munitions. It should be remembered that BM-21 system rocket launchers and derivatives are widely used around the world, and the 122 mm calibre will remain with us for many decades to come. The export potential of a guided rocket of this class is therefore very substantial.