Assessing the Flexibility Provided by Fractionated Spacecraft

This paper introduces the concept of spacecraft fractionation, which transforms a traditional monolithic spacecraft into a network of elements where a free-flying payload module is supported by nearby free-flying infrastructure modules supplying communications, data handling, power, etc. Models were developed from a customercentric perspective to assess different fractionated spacecraft architectures relative to traditional spacecraft architectures using multi-attribute analysis. Along with traditional attributes of mass and cost, non-traditional attributes of maintainability, scalability, flexibility, and responsiveness were included in the assessment. A framework was created to clearly define and evaluate these non-traditional attributes, and appropriate metrics were constructed. This study demonstrates that if those non-traditional attributes are valued enough, customers would choose fractionated spacecraft rather than traditional ones. I. Introduction Traditional spacecraft are designed for one-time use. They are typically monolithic and have a tailored design. Because of the long development and manufacturing times, designers tend to increase the lifetime of traditional spacecraft and as a result spacecraft tend to grow larger and more complex. This tendency creates large costs and risks associated with a single mission and prevents use of most advanced technologies and reuse of launched elements. Moreover, these traditional architectures have a major drawback in that they limit the possible adaptations of spacecraft to the likely changes in their requirements or environment during their life cycle. The use of modular and standard components was a first step to reduce costs, risks, and development, manufacturing, and testing times. Reconfigurable spacecraft are now being developed to improve flexibility and decrease time constraints. Such new systems are based on standard modules that would be docked and undocked depending on the requirements. Taking modularity a step further means considering a spacecraft made of several smaller building blocks instead of a monolithic one. The technologies recently developed for distributed and cooperative space systems made conceivable this idea of fractionating spacecraft. The concept of fractionated spacecraft transforms a traditional monolithic spacecraft into a network of elements: a free-flying payload is supported by free-flying modules forming an on-orbit infrastructure. Those modules can be reconfigured, added, or exchanged independently from the others, and be reused over several missions. The lifetime of space assets would be extended by building those reusable and smaller components, which would be a first step toward sustainable space utilization.