Science Goals and Objectives The Cusp Plasma Imaging Detector (CuPID) cubesat will answer longstanding questions regarding the macroscale properties of magnetic reconnection such as, (i) what is the longitudinal extent of the reconnecting magnetopause; (ii) under what conditions do multiple reconnection sites form; and (iii) under what conditions is reconnection continuous versus bursty? The process of magnetic reconnection changes magnetic topology and permits the flow of energy from the solar wind into the Earth's magnetosphere and ionosphere. This project has great relevance for goal #2 of the NRC Decadal Survey for Solar and Space Physics to "Determine the dynamics and coupling of Earth's magnetosphere, ionosphere, and atmosphere and their response to solar and terrestrial inputs." It can be difficult to determine the global nature of magnetopause reconnection from isolated in-situ spacecraft measurements. Even clusters of spacecraft with inter-spacecraft separations ranging from 10's of kilometers (MMS) or even 1-2 RE (Cluster) cannot determine the extent (and therefore significance) of processes that may span 10's of RE. However, the magnetic field lines on which reconnection occurs converges in the cusps, where observations of cusp ion dispersions provide a rich source of information on the characteristics of reconnection. However inherent ambiguity between spatial and temporal features in in-situ measurements hinders our ability to interpret these observations. The CuPID observatory will overcome the spatial/temporal ambiguity by innovatively imaging ion dispersions in soft X-rays. Soft X-rays are emitted from charge-exchange between high-charge-state solar wind and neutral hydrogen atoms in the Earth's geocorona. By imaging ion dispersions, one can map and understand the full spatial and temporal features of ion injections and therefore the macroscale nature of magnetopause reconnection. Methodology The CuPID mission is designed around an autonomous, magnetorquer-controlled 3U cubesat carrying an X-ray telescope. The wide field-of-view soft X-ray telescope will focus 0.1-2keV photons with slumped micropore optics onto a position sensitive anode/microchannel plate assembly. In an inclined, low-Earth orbit, CuPID will look up the throat of the cusp and monitor X-rays emitted from ion injections. The science instrument and much of the flight subsystems come with significant flight heritage. A previous generation of CuPID's X-ray telescope was successfully flown on the DXL sounding rocket in 2012. An identical X-ray telescope to the one planned for CuPID has been developed and will fly on the DXL II launch in December 2015. Many of the flight subsystems such as the flight radio, magnetorquer, power system, and flight computer will be leveraged from the highly successful FireFly cubesat, constructed and operated by team members on proposed project. The communication will implement a UHF radio for both uplink and downlink with the ground station at the NASA Wallops Flight Facility.