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Promising on-orbit servicing tasks for spacecraft life extension

At present in near-Earth space, there are more than two thousand operating spacecraft and more than five thousand non-functioning satellites, which have failed or run out of fuel. The last ones are not only satellites that do not carry out their functions but are also space debris. And launching new satellites to replace the failed ones is an expensive process. Therefore, the concept of a serviced space and the development of service satellites to extend the life of existing spacecraft are becoming expedient. On-orbit satellite servicing tasks can include inspection of the target satellite, replacement of failed units and repair work, correction of the satellite orbit, or putting into a disposal orbit, refueling satellites. The work reviewed service satellites and the space experiments carried out, presented the main service stages, analyzed the operations conducted during the experiments, and identified the key critical service technologies.