# Design and Testing of Torveastro: An Outer Space Service Robot
## 1 Introduction  
In the past decade, statistics data indicate that an average of one hundred satellites were launched annually. Most of them accomplished their missions without substantial impediments. Nevertheless, a small number of them experienced irregularities and even failures of varying severity [1]. Launcher failure was the most typical reason for failure in the past. In recent years, however, on-orbit failures have, for the first-time, overtaken launch failures [2], resulting in cumulative billions of dollars in damages [3]. In addition, all launched satellites eventually run out of fuel, necessitating their retirement [4]. Several investigations [5; 6; 7] have shown that repairing damaged spacecraft in flight is cost-effective, and [PERSON] et al. [8; 9] have given a model that integrates risk and uncertainty analysis. NASA realized as early as the 1980s [10] the significance of robotics in orbit servicing activities to protect their assets in space. On-orbit servicing (OOS) involves the maintenance of deployed space systems in orbit, including the repair, assembling, refueling, and/or upgrading of spacecraft. Notably, such difficult space missions have spurred the development of novel space robotics technologies and a number of manned and unmanned experimental demonstration missions [10]. A typical space robotic system (sometimes referred to as a space manipulator or space robot) for an OOS mission is comprised of the following three key components: The servicing system consists of a base spacecraft or servicing satellite, an n-DOF robot manipulator coupled to the servicing satellite, and a target spacecraft to be serviced. 'Servicing system' is also used to describe a vehicle designed to service the manipulators of spacecraft. Since the inaugural deployment of the Shuttle Remote Manipulator System (SRMS) from the Space Shuttle Columbia's cargo area in 1981, numerous space missions, including the International Space Station (ISS), have included robotic systems [11]. SRMS is a 15.2 m long, six-degrees-of-freedom (DOF) robotic manipulator known as Canadarm that was developed by the Canadian Space Agency (CSA) and has performed multiple on-orbit servicing missions [12]. As a result of advancements in robotics technology, some of today's space manipulators can move with incredible dexterity, allowing them to help or even replace astronauts in completing precise, complex, or potentially hazardous jobs. Multiple experimental space manipulators, for instance, have been tested successfully in space. Later, DLR devisedthe robotics experiment ROKVISS (Robotics Component Verification on the International Space Station) [13]. NASA and General Motors constructed the second Robonaut, R2, for flight testing aboard the International Space Station. This advanced, agile, humanoid robot offers significant technical advances over its predecessor, making it a far more valuable tool for astronauts. Increases in force sensing, range of motion, bandwidth, and dexterity are among the enhancements [14]. Therefore, the development of astronaut space robots for space exploration and utilization of space resources is essential for the evolution of space automation technology. Space robots are one of the most promising alternatives for on-orbit servicing (OOS) operations such as docking, berthing, refueling, repairing, upgrading, transporting, rescuing, and orbital trash cleanup. In the previous two decades, numerous enabling techniques and technology demonstration missions have been created and implemented. There have been a number of successful manned service missions in orbit, but unmanned service missions have not yet been completed. The investigation of robotic maintenance continues to be a dynamic topic with a variety of technical challenges, and robot mobility is crucial as it enables operations outside of a space station.