Annotation: The article presents the experience of the first liquid rocket engine parts developing and manufacturing by means of additive technologies. Application of these technologies imposes new constraints on parts configuration, which are necessary to be considered by a designer. At the same time, application of additive technologies provides new opportunities to a developer, which are absent at traditional method of manufacturing. The article presents the results of manufacturing in Yuzhnoye SDO the first commodity parts, manufactured by additive technologies – selective laser melting, using SLM280HL 3D- printer with building volume dimensions of 280x280x350 mm. The obtained experience in the first liquid rocket engine parts developing and manufacturing by means of additive technologies has shown, that application of this technology allows manufacturing the parts having high characteristics at minimum terms and cost of preproduction, however for all potential opportunities realization, especially at implementation phase, it is necessary to change designing philosophy, which will require more working hours at designing. The obtained first results conclusively prove efficiency and expediency of additive technologies application at certain segment of liquid rocket engine parts manufacturing, at that it is clear, that manufacturing equipment improvement and design methods evolution will lead to steady expansion of this segment.

Annotation: The Ukrainian companies Yuzhnoye SDO and SE PA YMZ supply VG143 main engine assembly for Vega LV AVUM upper stage, which is a one-chamber LRE of 250 kg thrust with five ignitions in flight. By the present, 11 successful launches of Vega LV have been made. In the process of flight operation, there were no critical comments on engines operation. This LRE has a combination of attractive characteristics, such as high specific pulse, low mass, multiple ignitions in flight, high reliability confirmed by good results of flight test of the prototype engines. The reserve of this engine from the viewpoint of further modernization is far from being exhausted. Enhancing the capabilities of payload injection by launch vehicles into various orbits of artificial Earth satellites is the main task for the developers of ILV as a whole and for the developers of separate assemblies and systems, such as LRE being part of ILV. With consideration for the experience of prototype engines testing, we should note the following ways of main engine assembly modernization: – increasing the specific pulse due to the increase of nozzle expansion ratio; – decreasing the volume of internal manifolds and mass of chamber; – increasing the operation time; – increasing the ignitions number; – increasing the duration of pauses between ignitions and orbital functioning time. Increasing the thrust and specific pulse of Vega LV VG143 main engine assembly and AVUM stage takes place due to the use of pneumopump propellant feeding system instead of standard pressure feeding. Besides, the information is presented on RD859, RD864, RD866 and RD869 prototype engines, the data on their basic characteristics, testing and operation. The below information is of interest to LRE and LV developers.