DESIGNING THE MULTIPLE SPACECRAFT SEPARATION SYSTEMS WITH THE SYSTEM ANALYSIS METHODS APPLICATION

摘要

The opportunity of multiple Spacecraft (SC) launch is one of the possible ways decreasing the total cost for deployment of SC orbital constellations. Currently the approach of creation mini- and micro-satellites to operate in Low Earth Orbits, High-Elliptical Orbits and even in Geo-Synchronous orbit is constantly extending, in this, such SCs are mainly oriented towards the launch in a group (as a piggyback also) by a single Launch Vehicle (LV). These tendencies allow for assuming that the multiple SC launch mission and associated optimization of the SCs separation schemes can be of the interest but the solution methods should incorporate widely used theoretical methodic jointly with contemporary technical measures providing for implementation of the requirements applied. This paper reports, as follows: a) possible schemes of accommodation on the LV and SCs separation taking into account SCs' typical structural features, mating conditions and loads application requirements, b) advantages and disadvantages for each of the schemes, preference criteria with the corresponding weight factors, c) comparative analysis of the described schemes and recommendations for the use in practice. The following schemes of SCs accommodation and separation are described: 1. SCs single level installation, mating at the lower edge and further separation by the LV upper stage spin-up, 2. SCs single level installation, mating at the lower edge and separation by deviation from the LV upper stage longitudinal axis with the further repulsion from the LV, 3. SCs single level installation, mating at the lower edge and separation by repulsion from the LV longitudinal axis in a side (lateral) direction, 4. SCs single level installation, mating at the lower edge and separation by the plane-parallel moving aside from the LV upper stage longitudinal axis. Schemes for separation of the SCs installed in a single level can be used for the multi-level layout of the Payload Unit. In result of the study conducted for a number of existing and prospective SCs (including Iridium, Globalstar, ECCO, Skybridge, Celestri, etc.), the conclusion was made that if the requirement is applied of SCs mating and loads application at the lower edge only, it is reasonable to use the scheme that foresees the SCs deviation from the LV longitudinal axis at a specified angle without fixing with the further repulsion and angular rate damping. Such a scheme provides for required initial parameters of the SCs motion (minimum disturbances due to the separation process), minimum mass and simplicity of the structure for the SC mating and separation.