As I have mentioned, yesterday Anton, Terry and I had a chance to repeat the fire evacuation simulation as part of our proficiency training as prime crew. I had talked about our first sim last December.
One of the things that changed, for the better, since we did this in our backup flow, is that we now have an improved oxygen mask on the Russian segment. To understand how it got better, it’s useful to know how it actually works. Please refer to the picture. The Russian ИПК mask is a self-contained system, so no filtering involved here. The greenish container connected to the mask itself via a tube contains a substance that will chemically react with your exhaled breath to remove CO2 and add oxygen.
When you are ready to put on the gas mask, you need to take a deep breath and hold it during donning. Then you exhale into the mask to get the reaction in the container started. The exhaled air goes through the chemically active substance into the bag, when you inhale you will pull that back into your lungs. You’ll know that somebody is breathing properly through the mask because you’ll see the bag inflating and collapsing with exhalations and inhalations.
If you happen to squeeze the air out of the bag, you’ll not be able to take the next breath. Most likely you’ve pushed that air into the hood, so you need to lift the mask off your mouth, breath that air back in from the hood volume and exhale it back into the bag to get back to your normal cycle.
The chemical reaction is exothermic, so the air gets quite warm. And here’s the big improvement since the previous model: there is a heat exchanger (the little metal element half way down the tube) that cools the air down to about 37°C, a lot cooler than it user to be. Impressive what a difference it made in our comfort level yesterday!
The Russian mask is supposed to last between 20 and 140 min, a wide range that considers different people’s size and different activity levels. On average, it will last about 40 min.
As a comparison, in the USOS segments we have masks that come with their own small oxygen tank. They’re are a lot quicker to don and more practical to wean and do work in, but you will run out of oxygen in about 7 min. If needed, you could connect them via a cable to the Station oxygen ports, although that does limit mobility. I’m wearing one of those masks in this picture: https://www.flickr.com/photos/astrosamantha/14526249749/in/set-72157637728544633
Picture: donning the Sokol suit while wearing the gas mask. Simulating contaminated atmosphere and evacuation of ISS due to ongoing fire.
Futura mission website (Italian): Avamposto42
avamposto42.esa.int
(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://spacetux.org/cpamoa/category/traductions/logbook-samantha/
01/10/2014