Monday, June 15, 2020

Google continues to educate me - this time about the ISS

I was aware that the International Space Station used gyros to adjust its position in orbit, but I never understood how complex maintaining the space station is.   You certainly don't get to put one in orbit and just let it continue on its way without lots of monitoring.    

This video gives a good explanation:



I also liked this little detail about the computer that monitors it:
The attitude control computer (GNC MDM) contains the software that does all of the necessary calculations for attitude control. It takes in the actual attitude and subtracts the commanded attitude to determine the error it needs to correct. It knows the rates of the ISS. That is very sensitive, so sensitive that we can tell when the crew wake up by watching the behavior of the CMGs as the crew start to move around the vehicle. The software also needs a set of user provided parameters such as the vehicle mass properties and inertia tensors. These are located in data slots called CCDBs (controller configuration databases). We have a stockpile of these CCDBs for different vehicle configurations. For example, if a Progress cargo vehicle arrives and docks to the Russian Segment, we will have a CCDB slot designed for that configuration. When it leaves, we will swap to another one.

1 comment:

GMB said...

Two large bodies never conform to heritage formulae. But a large body and small one pretty much do. Hence the normal tendency for a satellite orbit is to degrade. Now they will give you a lot of bullshit about gyroscopic propulsion. Thats all lies. What a gyroscope does is that it partially neutralises gravity and inertia since it interferes with the aether. So to maintain the orbit the space station will need to harness solar energy and turn it into gravity/inertia neutralisation.