DICE Mission Design, Development, and Implementation: Success and Challenges

Funded by the NSF CubeSat and NASA ELaNa programs, the Dynamic Ionosphere CubeSat Experiment (DICE) mission consists of two 1.5U CubeSats which were launched into an eccentric low Earth orbit on October 28, 2011. Each identical spacecraft carries two Langmuir probes to measure ionospheric in-situ plasma densities, electric field probes to measure in-situ DC and AC electric fields, and a magnetometer to measure in-situ DC and AC magnetic fields. Given the tight integration of these multiple sensors with the CubeSat platforms, each of the DICE spacecraft is effectively a “sensor-sat” capable of comprehensive ionospheric diagnostics. Over time, the sensor-sats will separate relative to each other due to differences in the ejection velocity and enable accurate identification of geospace storm-time features, such as the geomagnetic Storm Enhanced Density (SED) bulge and plume. The use of two identical sensor-sats permits the de-convolution of spatial and temporal ambiguities in the observations of the ionosphere from a moving platform. In addition to demonstrating nanosat constellation science, the DICE mission downlink communications system is operating at 3 Mbit/s. To our knowledge, this transmission rate is a factor of 100 or more greater than previous CubeSat missions to date. This paper will focus on the DICE mission design, implementation, and on-orbit operations successes as well as the challenges faced in implementing a high-return science mission with limited resources. Specifically, it will focus on the lessons learned in integrating, calibrating, and managing a small constellation of sensor-sats for global science measurements