| Abstrakt: |
In terms of time and budget, integration is a significant time-consuming component of spacecraft development. While many useful COTS spacecraft components are available, interfacing and controlling these components in an integrated satellite system remains a complex engineering task. The Stan-ford/Cal Poly CubeSat and Poly-Picosatellite Orbital Dispenser (PPOD) standards have begun to standardize small satellite mechanical systems and revolutionize the way small satellites are deployed. NASA has recognized this as evident by their Educational Launch of Nanosatellites (ELaNa) program which recently selected 17 CubeSats for the ELaNa-4 launch in 2012 (including one high school). To capitalize on this momentum, the Air Force Research Lab (AFRL) has organized and supported a team of commercial and academic laboratories to develop and test an over-arching Space Plug-and-play Architecture (SPA) set of standards to support the rapid integration of independently developed satellite modular systems. SPA represents not only an electrical inter-connection and communication scheme, but a complete model for a self-organizing and self-configuring system to support the rapid assembly of mission-specific small satellites. Rather than forcing existing modules to be re-developed to a common messaging standard, SPA utilizes an XTEDS (eXtended Transducer Electronic Data Sheet) model. Each satellite module contains an electronic document describing its interface, capabilities, messages, data formats, etc. By reading a components XTEDS, other systems can quickly integrate and utilize a new module. While designed to initially take advantage of nanosatellites, everything developed can easily scale to larger spacecraft, UAVs or other aerospace and defense systems. This paper discusses our experience in developing the CubeSat Trailblazer, a 1U SPA-only spacecraft — launching in 2012 as a testbed for SPA technology. The mechanisms of self-organization for independent modules as a cooperating communications system are discussed. The simplifications associated with software development of a Command and Data Handler (CDH) is also presented. [ABSTRACT FROM PUBLISHER] |
