The University of Southern Indiana's Engineering Department began its efforts to conceive, design, build, and operate a spacecraft to be flown in Low Earth Orbit (LEO) after NASA's Project Initiation Conference in September 2016. USI's student lead multidisciplinary team embarked on an 18-month CubeSat project, fully funded through NASA's Undergraduate Student Instrument Project (USIP), to deliver a flight-ready nanosatellite by March 15, 2018. USI's CubeSat was dubbed the Undergraduate Nano Ionospheric Temperature Explorer (UNITE), as its mission will primarily be conducted in the lower ionosphere, a region rarely explored by spacecraft. The science objectives of the UNITE 3U CubeSat mission are to: 1) conduct space weather measurements in the lower ionosphere using a Langmuir plasma probe, 2) measure exterior and interior temperatures of the spacecraft for comparison to a thermal model, and 3) track orbital decay of the spacecraft in the lower ionosphere and during final hours of reentry. This senior design project entails the design and fabrication of an attitude determination and control system, which will correctly orient the spacecraft to achieve its science objectives. Complete mission success depends on the correct orientation of the science payload. Work entails a design that uses aerodynamic, magnetic, and hysteresis environmental torques to passively orient the spacecraft and dampen the angular velocities of the spacecraft. Orbital simulations were performed to verify design.