Parametric Mass Estimating Relationships for Earth Imaging Monolithic and Fractionated Spacecraft

Abstract

Fractionated spacecraft consist of physically independent, “free-flying” modules composed of various subsystems. For example, a fractionated spacecraft might consist of one module providing communications, another module providing the payload functions, and so on. Fractionated spacecraft can therefore effectively distribute functionality among modules, which is called “sharing resources” and is the defining characteristic of fractionated spacecraft. Research has shown that, for Earth imaging missions, the ability of fractionated spacecraft to physically decouple the pointing-intensive payloads from subsystems not requiring such strict pointing can enable them to have a lower lifecycle cost and longer mission lifetime relative to a comparable monolithic spacecraft, for a given performance level. Existing theoretical models of fractionated spacecraft are either proprietary or not publicly available. The resulting key contribution of this research is a set of parametric mass estimating relationships that estimate the mass of fractionated spacecraft as a function of their architecture (i.e., number and configuration of modules), performance (i.e., Earth imaging resolution), and mission lifetime. Because fractionated spacecraft remain a hypothetical spacecraft concept, this research demonstrates a unique approach to validate monolith-based fractionated spacecraft models such as that developed in this research.