Abstract. The demand for launching satellites into the Earth’s orbit is constantly growing and becoming market-oriented. In 1985 only 37 out of 253 launched satellites were civilian, mainly owned by government institutions. Now more 2 700 satellites operate on the Earth’s orbit, and over 60% of them are privately owned. About 70% of newly launched satellites are light vehicles below 1 200 kg, which are launched to LEO, and the proportion of this group tends to grow, while the average mass of a spacecraft tends to decrease. The orbit launch cost is the main brake to the commercial exploration of near-Earth space. The cost of the launching of a small satellite weighing up to 100 kg may exceed 100 000 EUR per kg. Presently only 9 countries in the world, except ESA member countries, own carriers capable of delivering payload into the Earth’s orbit: USA, Russia, Ukraine, Japan, India, PRC, Israel, North Korea, and Iran. Attempts to create low-cost carriers are being made by private companies in the USA and Japan: RocketLab (Electron) and SpaceX (various modifications of Falcon); IHI Aerospace (Epsilon, SS-520) and Mitsubishi Heavy Industry N-II. However, in terms of conceptual approaches and main structural solutions, the proposed carriers do not differ fundamentally from those developed in the 1960s-1970s. The Institute of Aeronautics (AERTI) of the Riga Technical University MSTF is developing a LatLaunch aerospace system for launching small satellites into LEO. The project aims to create a commercial launch system to deliver a payload to LEO at the lowest possible cost per kilogram. The research shows that the declared aim can be achieved by discarding the first and probably the second stage of the conventional launch vehicle, substituting them with reusable aircraft and aircraft-rocket stages. The study analyses the existing launch systems and proposes some new conceptual principles for their development.