CubeSat design for LEO-based Earth science missions

The 2001 University of Washington Space Design class designed and developed a CubeSat platform to accomplish science objectives related to ionospheric modeling. Small satellites (between 1 and 15 kg) show great promise as a low-cost option to perform limited LEO science missions. This paper describes a CubeSat bus that supports two mission architectures based on two instrument packages. Both architectures involve multiple CubeSats separated from each other to gather spatially and temporally distributed data. The first is a combined plasma impedance probe/DC probe system on two satellites, separated by a tether. The second is two separate CubeSats that perform GPS scintillation measurements. In addition to the common bus structure, unique design traits (such as tethered gravity gradient control) and extensive hardware and software prototyping are discussed in the paper.