Autonomous Rail Transportation Network for Spacecraft Servicing and Inspection 

About ISAM

The Aerospace Corporation has established the In-Space Servicing and Manufacturing (ISAM) design challenge with the intent to develop technologies to make orbital production of satellites possible. Seeking to address the costs of structural overdesign, volumetric constraints, and long lead times imposed on satellites manufactured on Earth, our team set out to develop a concept for a technology that will help progress towards the goal of a fully autonomous in-orbit satellite factory, pushing the industry towards a future where in-space satellite production is standard practice.

Explored Problem 

Where past iterations of the design challenge focused on manufacturing and assembly processes, our team decided to propose a servicing process that has implications beyond only orbital manufacturing. After research and discussion with our Professor and sponsors, autonomous access to all locations on a satellite for servicing was identified as an underdeveloped capability. As a consequence of the current lack of a viable solution, small malfunctions in satellite hardware can have severe effects on system performance, compromising the ability to complete a mission.

Our Solution

Over a 15-week period, our team brainstormed, designed, animated, and tested a modular rail system to provide access to all parts of a host satellite for operations including inspection, manipulation, and transportation. We designed the system to be highly modular and customizable, incorporating 3D-printed beams that are recyclable at end-of-life. The system functions by using an assembly robot to extend a rail to a point of interest, transporting single-function robots along this rail to the point of interest to perform an operation, then disassembling the rail using the assembly robot, leaving the system back in its original configuration. The system provides reconfigurable access to all points on the host satellite without the need for attachment points beyond a central location, allowing rapid integration on diverse host vehicles.

The proof-of-concept system packs into a payload size of 40 x 43 x 61 cm, and can be assembled to a length of 3 m by the assembly robot to reach vital areas on the host satellite. The module contains everything it needs to function, including rail unit storage, multiple functional robots, cable spools for power and data transmission, and a carousel for robot orientation on the rails. By fitting everything in the module, this system can be attached to any satellite, extending host lifetimes significantly. 

Our sponsor requested conceptual work, with the deliverables for this project being CAD animations of the system in operation and a Concept of Operations to explain the process. Below are animations which show the module's layout and operation.

To support our conceptual design work, our team developed a prototype drivetrain system capable of driving along prototyped rails. The drivetrain incorporates spring-loaded T-sliders that ensure mechanical connection with the rail at all times. 

The rail connection mechanism was also prototyped and iterated on, yielding a mechanism with consistent assembly characteristics.