Today Anton, Terry and I had our first training event together in Houston as the Soyuz 41S crew. The occasion was a simulation in which we had to deal with a Loss of Attitude Control on ISS. We call that LOAC for short.
If you think about it, that’s pretty bad. We need to have the Space Station in a known, controllable attitude in order to make sure that we have good pointing for the antennas, the solar arrays, the radiators, etc. without attitude control the Station will continue spinning with whatever (little or big) rotation rate it had when attitude control was lost.
Both the US Lab and the Russian segment Guidance and Navigation Computers can provide attitude control, with one big difference: the US segment has Control Moment Gyroscopes, the Russian segment has actual thrusters. In one of our scenarios today the Control Moment Gyroscopes saturated and that caused the LOAC. To recover from that, we had to transfer control of the Station to the Russian segment, so that attitude control could be reestablished with the help of the thrusters.
However, thrusters impulses can be significant and they could potentially damage the huge solar arrays that provide power to the Station. That’s why we first need to bring the solar arrays to a safe angle and lock them there. Only then can we safely go to thrusters control.
Thanks +Josh Matthew for the photo!
(Trad IT) Traduzione in italiano a cura di +AstronautiNEWS qui:
https://www.astronautinews.it/tag/logbook/
(Trad ES) Tradducción en español aquí:
https://www.intervidia.com/category/bitacora/
(Trad FR) Traduction en français par +Anne Cpamoa ici:
https://anne.cpamoa.free.fr/blog/index.php/category/logbook-samantha
24/10/2013