Today we finally had our first real Soyuz sim with our complete crew! Terry joined Anton and myself for a pretty adventurous afternoon in which we had to practice fighting for our life when smoke started to fill up the small volume of our descent module just after our simulated injection into orbit.
In situations like this, your best friends are good crew coordination and your pressure suit!
Normally air from the cabin is circulated through the suit. In case of smoke, however, we would immediately close the helmets, turn off the ventilation and start instead pure oxygen flow into the suit from the oxygen tanks. The continuous flow of fresh oxygen prevents fogging of the helmet, but it also means that we’re introducing oxygen into the cabin via the suit relief valve.
As the oxygen concentration in the descent module grows, so does the flammability of the atmosphere. Latest at a concentration of 40% we want to fully depressurize, venting all the atmosphere to space. At that point we rely fully on the suits to keep us alive: they are designed to maintain an internal pressure of 0,4 atm, enough to avoid symptoms of decompression sickness, but also to make the suit very rigid.
In a fire scenario we need to act very quickly: before we can depressurize we need to leak check the suits to make sure we’re not going to kill a crewmember when we vent the atmosphere. And in parallel we need to initiate the sequence that will lead us to a timely deorbit burn and a safe reentry. It was a very busy and very fun sim! And also, as we like to joke, a free sauna: with the helmet closed, the ventilation off and only the (smaller) oxygen flow, it gets quickly warm in the Sokol!
(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
10/12/2013