Shepard Test Stand

I've made some changes to the Requirements Document based on our latest findings in our dev logs and conversations with one of our partners.

https://opendesignengine.net/projects/shepard-ts/wiki/Requirements_document

I'd appreciate it if at least one person could check all the requirements, but for everyone else, the following requirements were the ones that changed the most.

STSR 4.5.1 and STSR 4.5.2 were added back in from the version 1.0 requirements document. This is because it's now practical for us to meet those requirements. 4.5.1 has been reworded so that you can choose whether or not you want to spend the money on a NIST traceable weight set. To be in full NAR compliance when testing motors you'll have to calibrate using NIST traceable weights though.

STSR 4.8 and STSR 4.9 have been changed based on the types of sensors that we're migrating toward for this version and 2.0.

STSR 3.3 has been added based on a very recent conversation with our educational partner, CCSSC.

STSR 5.5 and STSR 5.6 have been added based on recent general conversations about test stands beyond the Shepard class.

We also need to discuss requirements STSR 5.7 through STSR 5.12. When we first started Shepard, I think the plan was to just keep scaling Shepard up as needed to larger thrusts and more advanced motors. Now, we're banking on the Glenn test stand and it's successors to handle these later motors. My suggestion would be that we remove all the future motor requirements other than STSR 5.7 and set them aside for Glenn+. Along with that, we should also discuss doing the same thing with STSR 5.5 and STSR 5.6 if those are only ever going to make it into Glenn and beyond.