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SpaceOps Conferencespower system has more margin but eclipse seasons are an almost constant feature of the routine mission (albeit with varying duration eclipses). In addition, the satellite flies in a non-sun-synchronous orbit, which makes the assessment of the expected state of battery charge more difficult. An overview of the techniques used on other flying ESOC missions will also be presented (Herschel, Planck, GOCE, Venus Express and Rosetta).The paper will describe new operations that have been introduced to manage the degradation of the batteries, including specially designed settings that, while respecting the allowed usage profile of the battery, modify the charge and discharge management strategies and other flight operations to almost halve the rate of degradation compared with the worst-case design assumption. In addition, the methods used by each mission to assess absolute and/or relative battery degradation in flight will be discussed.The paper will conclude with an overview of the lessons that have been learnt so far at ESOC from missions flying Lithium Ion batteries. These lessons could be used as a model for current and future operators of spacecraft with Lithium Ion batteries on how to best manage their batteries for longevity, mission reliability and success.

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In October 2005, a launcher failure ended the CryoSat mission before that a single bit could be processed by the Ground Segment. Since the future of the mission was not known a formal close-down of the activities, including the documentation and all systems was performed, ensuring consolidation of pending issues and configuration control of all the available systems. The overwhelming interest from the science community supported the idea to rebuild the satellite, now called CryoSat-2, to fulfill the mission with exactly the same objectives, and to be in orbit as soon as possible. With the assumption that all of the systems would be the same, the estimated costs for the new mission assumed also the maximum reuse. In spite of the good intentions, a number of changes were enforced dictated by different drivers either on the ground or space segment. The paper will describe how the mission redevelopment could be achieved within the estimated budget, even including the unavoidable changes. Although the mission operations would theoretically be the same, at least 80% of the team changed since the launch failure, requiring therefore a high level of training. A complete test validation campaign had to be executed, as if it was a new mission, from unit level right up to the end-to-end system tests. Some further details will be given about the impact of the differences on the already available systems and it will explain the strategy adopted to avoid unreasonable increase in costs. The flexibility of ESOC with respect to the people and mission data systems will be emphasized as a key factor in this situation. The paper will conclude describing how the motivation and strong commitment of a few key personnel made it possible to resuscitate the mission at such a minimal cost and also mentioning whether any of the methodologies could be applied to the lifecycle of a nominal mission.

CryoSat-2, the ice mission of the ESA Earth Explorer program, was launched in April 2010. Although the platform and payload excellent status and the availability of the consumables led to the extension of the mission, the progressive loss of performance of the 3 Star Trackers used for Attitude determination could have prevented the continuation of the mission with the same profile. Therefore, software patches of both Initial Acquisition and Attitude Update Star Tracker software were studied, validated, uplinked and implemented, with excellent results. This paper introduces the symptoms, the technical analysis and the content of the software updates, focusing on the analysis of the On-Board Software Management cycle and the operations, including in-orbit validation and final performance analysis, in order to understand why such operations were so challenging for the mission.