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Objectives
In order to foster the market share and to ensure the platform permanence, evolutions of the Attitude and Orbit Control System (AOCS) have been identified. After a first step of AOCS evolutions (so called AOCS Mk1.5), focused on the on-station pointing performances improvement with implementation of a Star tracker (STR) on-board and all associated algorithms, the next step is the development of STR-based AOCS (so called AOCS Mk2). This AOCS Mk2 evolution fully takes advantage of the STR features, all along the spacecraft lifetime from transfer phase, EOR (Electric Orbit Raising), Earth Acquisition to on-station mode, including recovery mode. Associated with deployable arm (mechanism to orient electric thrusters), this new AOCS ensures a full electric way to manage the Electric Orbit Raising and the On Station mode.
Challenges
The challenges of AOCS Mk2 was the development of a new full-STR-based AOCS, with new gyroscope and new wheel configuration, compatible with Electric Orbit Raising and ensuring a full-electric capability for transfer and on-station mode.
This development had also strict schedule constraints to ensure delivery of this new product, qualified in time for integration of first E3000 EOR spacecraft (first launch foreseen in 2017).
Plan
The project has been carried out with the following milestones:
- KO: December 2012
- PDR: February 2014
- CDR & TRR: July 2015
- TRB & FR: May 2016
Current Status
The AOCS Mk2 Final Review was held in May 2016.
The AOCS Mk2 product is now qualified, in time to be embarked on the first Eurostar 3000 spacecraft which will use Electric Orbit Raising.
The first 3 AOCS Mk2-based satellites are in AIT with launch foreseen in 2017.
