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The SSMS (Small Spacecraft Mission Service) program is a new multi-launch concept for the Vega and Vega C launchers, thanks to a new modular dispenser for the Small Satellites Market. The Vega Proof of Concept (POC) flight using the SSMS hardware was developed to provide solutions and services for the 1-400 kg mass class. The SSMS POC mission has successfully flown on VEGA VV16 flight on September 3rd, 2020. The paper describes the lesson learned after this first rideshare mission flight. Vega SSMS first Mission carried 43 different satellites ranging from 1 to 150 Kg from more than 10 different operators. Several challenges had to be dealt with. The missionization process had to be standardized and with increased genericity (ad-hoc margin policy) to cover the continuous changes (of satellites or at least of locations in the dispensers). To simplify and shorten the mission preparation time, from customer side, the satellites designers have tried to adapt to the standardized SSMS interfaces. The trajectory profile is more complex than a standard VEGA single mission. Several main engine boosts are designed to release the satellites in a sequence of separations and collision avoidance maneuvers. The paper presents the outcomes of the successful flight and the information collected from the different measurements. The accelerometers located in the upper part show that the random and shock environment, as well as the low frequency environment, sensed at the levels of the different structures including the satellites, are compatible with the predictions and the specifications. The same good consistency between measurements, predictions and specifications has been found on the thermal properties sensed by the satellites. The separation of the satellites has been observed thanks to different measurements. The inertial navigation system (INS) outputs, which are standard in the telemetry, provide good observation of the separation sequences in terms of direction and norm of the impulses generated by the various separation devices. In addition, dedicated cameras were present to film the satellites immediately after the separation and to check their good respective disposals in terms of attitude and position. The orbital accuracy has also been verified as normal work (by using not only the Navigation information but also the GNSS outputs). It is very good thanks to Guidance algorithms and Navigation performances. In the last chapter of the paper, we also couple the lessons learnt after VV16 flight with the on-going missionization of VV18 (to be flown on April 2021) and VV19 (to be flown on June 2021). They are not strictly speaking full SSMS missions, but they share strong commonalities with VV16 in terms of dispensers for CubeSats separations. |
