We’re deep in the process of testing for our upcoming SSO-A mission at our Auburn integration facility. Adam Hadaller, our lead integration engineer, gave us a run down of some of the preparations. To support the requirements of this mission, we actually built out a new facility, which includes a new certified ISO 8 cleanroom (<100,000 0.5µm particles/ft3), a 3-ton bridge crane to move manipulate hardware and integrate dozens of discrete spacecraft. The cleanroom has an airlock for moving hardware in and out, a gowning room, and an electrostatic dissipative floor. The air is constantly being scrubbed by filters and its conditions are controlled to keep humidity and temperature within required levels. At our facility we also have a portable cleanroom tent capable of ISO 7 (<10,000 0.5µm particles/ft3) for smaller integration work, such as CubeSat-to-dispenser integration . We’ve also built a lab for bench testing, so we can test new software/firmware on non-flight hardware before we test it on the flight hardware in the cleanroom environment.
We conduct many layers of avionics testing, over the life of the program, from bench-level testing to full system-level, to make sure our on-orbit deployment platforms, which we call Upper Free Flyer and Lower Free Flyer, are ready for customer payload integration, flight, and eventual operations. Initially, we check out all hardware received from vendors, to make sure it was built up to specifications. Then we bring in our software, getting more complicated at each step, until we are finally running the actual mission scripts that will run during launch. The final tests look at the entire mission duration, from going to internal power on the launch pad, the moment of separation from the launch vehicle, through our on-orbit passes over our ground stations. The Mission Simulation Tests can last as much as 16 hours. During those tests we simulate data collection and dissemination, sending those data to our mission management team who will eventually send those data to our customers, so they can locate and communicate with their spacecraft.
Thorough testing keeps us on our toes. Sometimes, we get a part that isn’t manufactured up to our specifications, and we need to send it back. Often times with a mission as large as this, our customer manifest changes, because a customer is no longer ready to launch. Luckily we have a large backlog of customers ready to take their place, and we can move someone else up because Spaceflight works to have a large and diverse launch capacity. However, customer manifest changes mean potential changes to harnesses, mission sequences, etc., which we must rigorously test.
All our tests are geared to incrementally build on previous tests to give us the most confidence we can have in the Upper and Lower Free Flyers to operate successfully on orbit. We’re looking forward to finishing up this phase before we move on to spacecraft integration.