The University of Hawaii (UH) is currently a funded participant in the AFOSR University Nanosat-6/Nanosat-7 Program (UNP-6/UNP-7), and is the only one of 11 awardees that has a CubeSat-based mission. Our mission is driven by current operational needs of US radar range facilities: the design, build, test, and operation of a very low-cost radar calibration nanosatellite. Currently, only two calibration satellites are in service, one of which has been operating well past its operational lifetime and has been degrading in power capacity. Our radar calibration mission is intended to supplement the two existing, aging spacecraft with a student-built CubeSat carrying a C-band transponder and high-accuracy GPS payload. This mission will demonstrate a university’s ability to satisfy an immediate operational need at very low cost while simultaneously providing immense educational value. Students will learn to operate under customer-driven design requirements, constraints, and schedules to offer a solution to an immediate, real-world need.

Compared to the existing RADCAL satellite, the primary innovation of UH’s UNP-6 effort is designing the RADCAL mission to fit within a CubeSat form factor, and of course, all the ancillary benefits that come with this platform: reduced cost, reduced development time, and reduced launch cost. UH has worked closely with the RADCAL Coordinator at Vandenberg Air Force Base (VAFB), as well as Northrop Grumman Aerospace Systems (Redondo Beach, CA) during the entire UNP-6 effort.

The original RADCAL satellite had a mass of 96 kg, while our 3U CubeSat implementation will fall between 3.0 and 3.4 kg. New battery chemistry results in a lighter energy storage system, and a smaller transponder reduces mass and lowers overall payload power requirements. New photovoltaic technologies offer higher efficiencies and improved radiation hardness, reducing the required surface area coverage and increasing the potential mission lifetime.