Helmholtz Cage

CubeSats are small satellites with a standardized size of 10 cm x 10 cm x 10 cm (1U). The satellites are routinely made larger as multiples of this 1U are stacked together (common sizes being 2U, 3U, and 6U). Embry-Riddle Aeronautical University (ERAU) Daytona Beach campus has plans to launch CubeSats in the near future; however, historically about 40% of university built CubeSats have failed due to a malfunction in one of the satellite subsystems [1]. ERAU’s first CubeSat built at the Prescott campus was launched in November 2017 and has not been heard from. To try and prevent mission failure arising from subsystem problems, students working in ERAU’s Space and Atmospheric Instrumentation Lab (SAIL) are building test facilities for the CubeSats. The first testing facility that has been built are a pair of Helmholtz Cages that test magnetically actuated attitude determination and control subsystems (ADCS) of small satellites. Most CubeSats use either a passive or active ADCS that depend on interactions with the Earth’s magnetic field, and if this system does not work properly then satellites will not know where they are pointing. This can result in either failed communications (antenna not pointing in the right direction), failed power subsystem (solar panels not pointing to the Sun), or failed science mission (instruments not oriented correctly). SAIL has designed, built, and commissioned two different sized Helmholtz Cages, the smaller one specifically for a 1U CubeSat and the larger one capable of testing up to 6U CubeSats. Both cages are capable of producing magnetic fields to within 10% of the Earth’s magnetic field, simulating an orbital path (latitude, longitude, altitude) with a one second cadence. The larger Helmholtz Cage can also house an air bearing table to allow for testing the ADCS of CubeSats that are equipped with torquer rods or coils. This will allow for thorough testing of the ADCS of the CubeSat, simulating continuous operations over multiple orbits