I certainly couldn’t miss today’s logbook… today is L-42 for Expedition 42!
As I am starting to write this, it’s 6 pm in Baikonur, Kazakhstan, where our voyage to space will start in six weeks. At exactly this time, 6 pm, on Nov 23rd, we will wake up after an afternoon nap of 5 hours to start our preparations for launch. Nine final hours on the planet, before the Soyuz engines will light up the night at exactly at 02:59:06 local time (that’s 20:59:06 GMT).
But today, let’s go back in time a few weeks to my vacuum chamber run in Houston, final event required for spacewalk certification in the NASA EMU suit. Life has been so busy recently, I haven’t had time yet to tell you about it.
As you might remember, back in July I did the dry-run, going through all the operations but without actually going to vacuum. I talked about it here.
The next day a technical issue caused us to abort the altitude run, which was postponed to September and moved to a different chamber. This time I was finally able to go to vacuum in the EMU!
That is… at around 2pm, although the day did start at 7:30. As you probably know by now, you can’t go to vacuum just like that: the suit will keep you at 4,3 PSI and at that low pressure decompression sickness could be an issue. Therefore, we need to perform a carefully designed pre-breath protocol to get rid of nitrogen which is in solution in our blood.
The way to do that is to breath pure oxygen for a while, which means that we need to replace all the air inside the suit with oxygen. We do that by opening a purge valve, basically a hole in the suit: the regulator keeps supplying oxygen from the tanks into the suit to keep the overpressure up and, after about 12 min, we consider that all air has been replaced by oxygen. Then, we wait… and breath.
In space we actually tend to use the faster In-Suit-Light-Exercise protocol, which we practice in Prep&Post classes, as I have described here.
In the chamber we just breath pure oxygen for four hours, instead. We do have the chance to watch a movie while we wait – I chose Princess Bride, which was a lot of fun! And after the four hours, the chamber pressure was lowered to a very low value – for practical purposes, vacuum.
Compared to the experience in the Orlan vacuum chamber (see here: https://blogs.esa.int/astronauts/2012/11/05/a-trip-into-vacuum/) I got the additional treat of watching a fun vacuum effect: a pot with some water was left on the floor where I could observe it and, sure enough, I could watch the water boil away!
What we didn’t do, which is usually done in the nominal chamber, is to drop two very different objects and observe them reach the floor at the same time… well, I guess this will be something to look forward to for next time!
You can find more pictures of the chamber run here:
https://www.flickr.com/photos/astrosamantha/sets/72157645822082702/
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 FR) Traduction en français par +Anne Cpamoa ici:
https://spacetux.org/cpamoa/category/traductions/logbook-samantha/
(Trad ES – Currently not updated) Tradducción en español aquí:
https://www.intervidia.com/category/bitacora/
12/10/2014