General Conceptual Design Of Servicing Satellite For Space Maintenance

There has been an increasing interest to satellite on-orbit servicing in the space industry in the past few years. Benefits of autonomous satellite servicing include satellite repositioning, service life extension, debris removal, repair and salvage, cargo transportation and replenishment, technology refresh and on-orbit assembly. But there are still several top technical challenges for future development of on-orbit satellite servicing systems that requires detailed research and design. The survey of past international satellite servicing projects and technologies shows that there is a lack of universality in servicing functions that are supposed to be provided for a wide range of on-orbit customer satellites. Some of the potential client’s spacecraft remain stated as non-cooperative, so docking to un-cooperative spacecrafts is still one of the most challenging tasks in on-orbit satellite servicing field. Nowadays all of the previous on-orbit servicing missions focus only on the capture of a cooperative satellite which is supposed to move smoothly in its orbit without rapid attitude changes. In reality, a malfunctioning satellite may have spinning or tumbling motions. Thus, the development of technology for grappling and anchoring tumbling objects with no pre-existing docking interface is necessary. It will allow repairing of malfunctioning satellite on geosynchronous orbit(or small scientific satellites on low circular orbit which have no thermal control system and are designed to tumble during operation), and will also bring benefit for future projects of space debris reuse and grappling meteoroids.The research reported in this paper focuses on design on-orbit servicing satellite, which is capable to perform docking with a wide range of space objects, including arbitrarily rotating space objects, by the means of high dexterous robotic arms with universal capturing end effectors. This solution allows connection to every satellite(with the future possibility to capture not artificial objects in scientific aims), dislocation of the servicing satellite to the most convenient position relative to the customer satellite, possibility to withhold tumbling objects.Another important requirement of the on-orbit servicing is the ability of servicing spacecraft to perform wide range of recovering and servicing operations. General idea the repairing several satellites or repairing of a malfunctioning satellite with unknown failure will require servicing satellite to bring on-broad number of repairing materials and units, which is difficult to predict and implement. One servicing spacecraft can hardly satisfy all the various demand needs, so the system of complementary products should be organized on orbit. The base-warehouse is needed to store materials and units may be needed for recovering the custom satellites and dealing with unforeseen defects. According to this conception, it is suggested to develop an orbital servicing system, consisting of servicing spacecraft itself, base-warehouse, placed in LEO in order to receive customized payload from the ground, and the courier microsatellite with fine capability to transfer payload from one spacecraft to another. Creation of on-orbital servicing system of several spacecrafts requires a serious investment and comprehensive design, thus the system must be as effective as possible: providing wide range of servicing operations, universal to all potential customers and reusable – with the capability to be resupplied from the ground, with the ability of the technology to be upgraded and customized with the means of uploaded payload.