Testing

FlatSat Testing
As Hermes is just under one year from its delivery date, the team is on the eve of a series of comprehensive testing known as FlatSat. FlatSat is the first time that each subsystem of the satellite will come together and work as one unit. Essentially FlatSat is a full electrical model of the CubeSat. However, rather than interfacing with the structure, the components are laid out on a workbench, hence the name, FlatSat. This is a major milestone in the development schedule of Hermes; once the FlatSat testing is complete and all systems are functioning as expected, final satellite construction will begin.
 

Day in the Life Testing
Once the satellite is fully constructed, integrated testing can begin. One very important test that will occur is known as Day in the Life (DITL) testing. DITL testing involves simulating a day of activities for the satellite and analyzing how the satellite functions. Different scenarios from normal operation to error modes to critical emergency functionality will all be vigorously tested. This series of tests will also offer MOPs the ability to gain understanding of how the satellite functions, which will help with diagnosing errors during the actual mission.


Vibration Testing
As specified by CalPoly, the CubeSat must undergo a vibration test to ensure that it will survive the launch environment. In particular, the test will ensure that the natural frequency of the satellite structure is greater than the frequency of launch (approximately 30 Hz). If the structural natural frequency is below this value, the satellite will literally vibrate apart during launch due to resonance. This testing will occur in several stages so that the structural properties can be best understood. The structure will be vibrated alone first and then the components or mass dummies will be integrated into the structure and it will be vibrated again.
 

Thermal Vacuum Testing
CalPoly also specifies that Thermal Vacuum (TVAC) Testing must be completed on the CubeSat. This involves placing the satellite in a thermally controlled vacuum chamber and lowering the pressure and temperature to the expected values in Low Earth Orbit (LEO). This will ensure that the chosen components can survive the low pressure and extreme temperatures of space.

 

Links & Downloads

CubeSat Design Specifications (CDS) Document

Testing Requirements for the Dnepr IV