The *.Sat CubeSat Bus: When Three Cubes Meet

A collaborative effort between Stanford University and the National Aeronautics and Space Administration (NASA) begun in 2003 continues today with the primary objective of supporting a NASA Ames Research Center (ARC) biological payload scheduled for launch into orbit aboard a satellite conforming to the International CubeSat Specification authored in 2001. The Stanford portion of the program, named “StarDotSat” (*.Sat), seeks to put forth a standardized spacecraft bus adhering to the CubeSat Specification that provides all necessary services to one or more attached payload modules. The CubeSat specification was the result of a joint effort by the California Polytechnic University, San Luis Obispo (CalPoly SLO) and Stanford University to provide the basis for low-cost, rapid-turnaround access to space geared primarily towards the University audience. Leading to development of a standardized launcher known as the Poly- Picosatellite Orbital Deployer (P-POD) and subsequent launch service partnerships by the team at CalPoly, the CubeSat standard has grown to include over 70 universities worldwide. Based upon the CubeSat Specification, the *.Sat design implements a standardized set of mechanical, electrical, and software interfaces that allow the Bus Module, itself a single-sized CubeSat, to provide services such as electrical power, command and data handling, and communications to one or more Payload Modules. By defining the demarcation point between Bus and Payload(s), the *.Sat program allowed the interface itself to become the focal point for independent development of the Bus and Payload elements prior to integration. The initial mission, encompassing the use of the Stanford *.Sat Bus with a NASA ARC-designed biological payload has been named “GeneSat-1” (GS-1). The overall mission is a cooperative effort between NASA and various universities partnered at the Space Technology Center, managed by San Jose State University, including Santa Clara University, CalPoly, and Stanford. This paper will present the development and implementation of the *.Sat Bus from the perspective of the Stanford University development team, highlighting the successful cooperation between academia and industry expertise