

Live: ISS Spacewalk - ra
http://www.nasa.gov/multimedia/nasatv/index.html

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k_infinite
Just thinking about how sometimes an approaching deadline makes me piss my
pants, I have the utmost respect for these people, who live and work under the
highest pressure, out there, alone in the void helpless, if something goes
really wrong. Only one small piece of their gear malfunctions and they are
done. And then I'm thinking about the complexity of all the systems they are
supported and kept alive by. I couldn't probably help but constantly be
thinking that with a huge human-designed system like that, something is always
bound to go wrong and that I would probably die in a few minutes because of
some obscure equipment failure. And yet, there he is, floating around, keeping
it cool, just doing his stuff in that floating cable jungle, swinging that
razor sharp knife around like he isn't a knife cut away from eternity. I will
try to keep this image in mind next time when my cables get tangled.

~~~
bargl
Actually if I were up there I'd be more worried about the lack of pressure, I
saw the opportunity and couldn't resists on a more serious note though.

Agreed, I know a couple submariners who told me they'd tie a string from one
side of the room to the other. As they dove the string would begin to droop
and loose tension, a lot of tension.

Makes my head spin just thinking about the possibilities, which I'd be doing
if I were down there...

~~~
jlgreco
> _Actually if I were up there I'd be more worried about the lack of pressure_

Interesting you should mention that. I learned a few days ago that while the
ISS at large is kept at 1ATM, the spacesuits they use for spacewalks are only
pressurized to a fraction of that (if you pressurize a suit too much, it
becomes too balloon-like to easily move). Because of this
astronauts/cosmonauts have to spend several hours before each space-walk
breathing pure oxygen so that they don't get the bends.

That degree of preparation before every spacewalk would disturb me to some
extra degree I think. If there was a problem, it's not like somebody else
could just hop into another suit and come help you.

~~~
jamesmontalvo3
There are several different "pre-breathe protocols" used prior to US
spacewalks to avoid the bends. Some involve taking the airlock down to 10.2
psi (as opposed to 14.7 psi for 1 ATM) and sleeping there overnight. Also the
crew may hang out in the suit while still in the space station for several
hours before the spacewalk. The suit is pressurized with pure oxygen and is at
a 4.3 psi.

All of this does make for a long day. Even though the spacewalk may _only_ be
6 or 7 hours, entire day with preparations and clean up afterwards is
exhausting.

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prawks
Are nighttime space-walks common? I'd imagine you'd want to schedule them when
you have sunlight to avoid any unnecessary complications. I mean their
schedule each day is jam packed, but I'd imagine it wouldn't be too much
trouble to schedule around nighttime?

EDIT: Duh, orbit is much faster than a 24-hour day...

~~~
Diederich
The ISS orbits every 90 minutes. Any non-trivial space-walk will be in
darkness at least part of the time.

~~~
jamesmontalvo3
Depending upon the Beta Angle [1], the spacewalk could be in sunlight the
entire time (though that's rare). It could be in darkness up to about 50% of
the time.

[1] <http://en.wikipedia.org/wiki/Beta_angle>

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jameswyse
Awesome. The other ISS thread [1] posted today had me lost on youtube watching
related videos for nearly 2 hours.

I really want to experience zero-gravity!

[1] <http://news.ycombinator.com/item?id=5575469>

~~~
lisper
> I really want to experience zero-gravity!

You can.

<http://www.gozerog.com/>

Or if you don't want to drop $5k, go to your local flying school. You can get
~5 seconds of zero G in a Cessna.

~~~
jameswyse
Thanks, I'm in Australia though and I can't find a similar company.

I'm not talking about the weightless feeling you get when you're in free fall
(or on a roller coaster) either, I want to float around!

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davidbrent
I never realized how time consuming it was to deal with all your cables. I'd
love to know the purpose of the color coding scheme on their different cables,
but couldn't find anything with a quick search. I'm assuming different
weights?

~~~
viame
Well they seem to be hooked to the ISS rails with a blue cable. The orange one
seems to be hooked to one of their blue ones and also the the rail. This looks
amazing!

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purplelobster
Looks about as much fun as building Lego with mittens. Must be frustrating as
hell.

~~~
jamesmontalvo3
The Russian Orlan suit [1] is pressurized higher than the US EMU [2], and
gloves are not as dexterous. I don't know a lot about Russian spacewalks, but
US gloves have caused fingernail delamination in many people, including myself
(I'm not an astronaut, but I work with this hardware a lot).

[1] <http://en.wikipedia.org/wiki/Orlan_space_suits>

[2] <http://en.wikipedia.org/wiki/Extravehicular_Mobility_Unit>

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ArikBe
Is it possible to receive a Russian transmission? I speak Russian and so the
interpreter is only ruining it for me because I hear too many people talking.

~~~
viame
Lots of voices. Are the instructions given in English and translated to him?

~~~
ArikBe
I turned off the feed, but I kept hearing a lady with a distinctive Russian
accent speaking English, so I suppose that it's the other way around. Although
maybe that's just for the spectator feed.

Edit: I listened to it again. The Russian communications are between two
cosmonauts. One is most likely inside the ISS and the other is walking. The
interpreter is translating their Russian communication to English.

~~~
viame
Sweet, that's for doing this and clarifying.

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bagosm
Is there any info on what is happening? Why are they out of the station?

~~~
gldnspud
I just heard a voice-over mention: "...setting up all their hardware for the
beginning of the installation of the Obstanovka experiment that will study
plasma waves".

Found more detail here:
[http://www.nasa.gov/home/hqnews/2013/apr/HQ_M13-060_Russian_...](http://www.nasa.gov/home/hqnews/2013/apr/HQ_M13-060_Russian_Spacewalk.html)

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ricardobeat
Watching that gives me chills:

    
    
        What is that?
        I don't know what that is attached to..
    

All those strings and cables and ties look like a huge mess.

~~~
codenapper

      singing...

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brador
How many things need to go wrong for an astronaut to float away into space?
Just how safe are they?

~~~
jamesmontalvo3
I can't speak for Russian EVAs [1], but in US EVAs we always have a long
tether reel attaching us to station. If we need to get further than that
tether reel allows, we attach another tether reel before releasing the first.
Additionally, we have a sort of jetpack called a SAFER [2] in case a tether
(or the user) fails.

[1] <http://en.wikipedia.org/wiki/Extra-vehicular_activity>

[2] <http://en.wikipedia.org/wiki/Simplified_Aid_for_EVA_Rescue>

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mrb
I am shocked to see that NASA still uses _analog_ video transmission systems!
(I can tell because of the type of visible video artifacts: discoloration,
etc).

Elon Musk is right when he says government-funded space research programs are
stuck using decades old technologies due to inertia, conservatism, and lack of
competition.

~~~
ucr
I'm shocked at how high quality the video is. It's being beamed from outer
space, and I can watch in practically real time. Who cares if it's analog or
digital? It works, and it's awesome.

I don't want NASA messing with the latest technology just for shits and
giggles. Don't fix what ain't broken.

~~~
mrb
Well, let me do a comparison:

I can watch much higher quality videos streamed over the Internet, from
servers thousands of miles away, around the world, through many routers, fiber
optics, and complex technological stacks (DOCSIS, TCP/IP, fiber optics signal
modulation, video codecs, etc).

Yet the ISS has a _clear line of sight to ground receiving stations_ 230-1000
miles away (or to satellites which are perfectly able to transmit digital
data), yet the video signal quality is that bad?

Don't get me wrong. As a space enthusiast I love being able to watch live
spacewalks. But as an engineer I sigh at certain technical aspects...

~~~
jamesmontalvo3
Both you and the servers you're pulling the content from are stationary on the
ground, and any satellites used are in geosynchronous orbit. ISS is travelling
17000 mph. So while it may have clear line of sight to a ground station in New
Mexico one minute, the next minute that same line of sight is in Texas.

Also, for a spacewalk the video source is from a space suit, so the video
signal is sent wirelessly from the spacesuit to ISS, then sent to a TDRS
satellite, then to the ground. The spacesuit camera is admittedly not as good
as I'd like it to be, but considering all the architecture supporting it
started being put in orbit over 10 years ago, and was designed before that,
it's pretty good.

~~~
TheLegace
That's cool did you directly work on any of the systems? I have been poking
around the NSTS 07700 Volume X Book 1 Flight and Ground Specification. The
EVA, and Video subsystems are highlighted there.

Crazy stuff.

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lukeholder
He is using a knife really UNcarefully?!?

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neilmiddleton
Too many people talking...

