ESA GNC Conference Papers Repository
Multi-Payload Injection Conception
Actually the cost of injection of the Payload to Low-Earth Orbit (LEO) became an important part and it has significant impact on the design of the mission strategy. One of the most efficient ways to reduce the injection cost is a multi-payload injection, i.e. the injection of a group of the spacecrafts to the one or few LEO by the same launcher. Nowadays there is no common (unified) conception of multi-payload release. Every time, for every mission, this problem is being solved individually, without respect to the experience of previous (or parallel) solutions. That leads to considerable costs for developing, modification and testing of the GNC algorithms and on-board software with respect to requirements of customer. Evidently, that the development of the modern unified conception of multi-payload release is necessary. This paper performs an attempt to propose a conception of multi-payload release that can be considered as an unification try. The proposed approach is based on the decomposition of the orbital phase timeline into the closed standard phases - basic activities. Each basic activity contains unique maximally full set of flight operations like: rotation around of axis of Body-fixed reference frame or the main engine ignition/cutoff. Review of feasible cases of payload assembly and its separation was performed. The quite complete list of basic activities has been designed. It includes: ? attitude pointing maneuver; ? activation of the engine for transfer to the other orbit; ? separation of the one payload (PL) or group of PLs; ? contamination/collision avoidance maneuver. Finally, basing on the set of basic activities of flight, the multi payload release logic was developed. Assembling the basic activities of flight timeline in accordance to multi-payload release logic, we can build the orbital phase of PL pointing of any degree of complexity. The method of additional flight timeline was developed providing flexible multi-payload release logic at the orbital phase of PL pointing. The method allows injection of any number of spacecrafts to the different LEOs assuming their feasibility by LV energetic performances. The important point of this approach is that the assembling of the orbital phase of flight is provided by tuning of the mission data flags without change of the onboard SW source code.