News article on step by step Soyuz reentry

[Soda Popinski]

This article has a video with a relatively detailed procedure for Soyuz disembarkation from the ISS and re-entry. Even has diagrams showing the orbital velocity changes. Favorite line is "Soft landing really isn't that soft."

http://www.wptv.com/dpp/news/science_tech/video-soyuz-reentry-ride-back-to-earth-from-inside-the-capsule

[rpayne88]

"Soft Landing." Makes me wonder if anyone's ever been knocked unconscious upon touchdown.

[Kryten]

There was one guy who had the misfortune of landing in a Soyuz with dud retrorockets. I don't think he lost consciousness, but he did break most of his teeth.

[Godot]

Well, I guess Komarow (Soyuz 1) on the other hand would had been glad if with his capsule only he retrorockets had failed ...

unfortunately in his case the Retrorockets were almost the only thing working

[rdfox]

Alan Bean was knocked out on splashdown of Apollo 12, but that was because he'd left a camera in its mounting bracket in the window directly above his head, instead of removing it as the checklist said to, and when splashdown came (at about 20 miles per hour, as per normal), the shock knocked the camera out of the bracket and it whacked him on the forehead to knock him out for a few seconds.

[K^2]

I don't think he lost consciousness, but he did break most of his teeth.

That's the sort of thing that would make me wish I lost consciousness.

[Kerbart]

According the documentary "Gravitity" it's really not that hard. Even when it's in a Chinese clone, with buttons labeled in Chinese icons. And if you hit the wrong button, just try another one.

[TheBedla]

I was just going to post this video

What surprised me however, before the undocking of a "belly-mounted" Soyuz, ISS rotates 90 degrees so that the Soyuz detaches forward, to a higher orbit.

How is it worth the energy of rotating the entire ISS? Why do they not just separate the Soyuz underneath, rotate it and fire the retro rockets in parallel to the ISS?

Thanks to anyone who can enlighten me!

[czokletmuss]

The gases and dust from the retro rockets could damage the ISS I suppose.

And ISS is rotated using gyros as far as I remember, so it's like SAS - only energy is needed and we have solar panels for this.

[TheBedla]

The gases and dust from the retro rockets could damage the ISS I suppose.

I would think that if you rotate the soyuz after it is sprung back from ISS, the gases would go _below_ the ISS (and on a lower orbit), so I can't see how that would be an issue.

And ISS is rotated using gyros as far as I remember, so it's like SAS - only energy is needed and we have solar panels for this.

I know rotating the ISS should only consume electricity, but it would also put some strain on the structure, and the upright position would probably also increase the stations's drag (remember, it's not KSP, so ISS is always continuously aerobraking a little).

I am sure there are good reasons why they do it that way, I just can't wrap my head a

[Godot]

Btw. that´s the other way round ... flying with the Soyuz to the ISS .. as a diary of one of the astronauts:

http://www.nasa.gov/mission_pages/station/expeditions/expedition13/journals_williams_1.html

I was surprised that they spend such a long time on the Soyuz for the orbital rendesvouz with the ISS ... so much time that they even get out of their spacesuits and eat and sleep in the Soyuz

Another interesting thing is, how ascent and separation of stages feels for the Astro-/Kosmonauts inside Soyuz ... now we will understand how our Kerbals feel

Edited November 14, 2013 by Godot

[PlasmaticInc]

I would everyone shut up about Gravity already. It's a freaking movie, they had to take a few creative liberties. The director said that himself

[brdavis]

What surprised me however, before the undocking of a "belly-mounted" Soyuz, ISS rotates 90 degrees so that the Soyuz detaches forward, to a higher orbit… How is it worth the energy of rotating the entire ISS?

That's a really good question, and I hadn't realized that - got to watch the video I guess. In principle, rotating the ISS doesn't "cost" even any electricity - yes, you might need to "spin up" a reaction wheel, but you can recover that energy by "spinning down" (electromagnetically braking it) when you approach your desired attitude. I'm not sure if the ISS CMG (control moment gyroscopes… similar to reaction wheels, but used in a slightly different way) systems do that or not, but they could in principle. And it's not like you need to turn the ISS fast (nor could you… i'm actually surprised they turn it at all for reasons of microgravity experiments). Interesting.

[brdavis]

Hmm… addendum, dealing with how "real" SAS is done… failure modes of space hardware on the ISS (with lots of details about why certain positionings were done on the ISS, how the system functions, etc):

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100021932_2010023824.pdf

[nhnifong]

I think the reason they want to keep residual gas away from the station is that it clouds the view of cameras and telescopes.

[Outlander4]

B I was surprised that they spend such a long time on the Soyuz for the orbital rendesvouz with the ISS ... so much time that they even get out of their spacesuits and eat and sleep in the Soyuz

That's how it was done most of the time. Soyuz was designed as a multi-purpose craft; it can even withstand aerobraking from the lunar return trajectory (using the same techniques as Apollo). And while the capsule itself is very small ('criminally small', as one of the first Soyuz cosmonauts told in an interview), the rest of the ship provides more pressurised and habitable volume than the huge Apollo capsule. And long approach to the station has its advantages - it allows for a wider launch window, doesn't require very high launch precision and generally makes things simpler. And Russians absolutely love their technology to be simple and reliable, even at cost of some inconvenience to the crew.

[Motokid600]

Sorry if this is off topic, but the Soyuz is so small and cramped simply because they have to launch it. Every pound counts. So let's say in a future manned Mars mission where most of the craft is built in orbit. Could the astronauts not have a roomy, comfortable space craft? Because in my opinion the best way to solve range anxiety is just that.. make the space craft comfortable. A flying appartment if you will. Would that one day be possible? Or are astronauts forever doomed to stuffy tin cans?

[Motokid600]

Even if the entire structure is assembled in orbit? Yea its more resources you have to spend, but if your going to be sending humans to Mars and beyond I'd imagine you wouldn't wanna do it as cheap as possible. A comfy spacecraft would solve some major psychological issues. Such as home sickness for one. I'm basically imagining a spacecraft with a large, spinning cylindrical habitat with individual rooms.... Ever see Europa report or Mission to Mars? ( just the spacecraft in the movies, nothing else )

Either that or we develop and perfect a stasis pod. Or just not send humans farther then Mars..

Edited November 28, 2013 by Motokid600

[nhnifong]

Small living quarters are not inherently "uncomfortable". I personally love small living quarters, I find them cozy and protective, not to mention easier to clean. Making a small place comfortable is an architectural and interior design problem and there are many people who have already produced impressive solutions on Earth.

What's uncomfortable in my opinion is the lack of variety. One can increase the visual variety of a room without significantly increasing it's volume or mass by using deeper structures and designing the paths throughout the space such that the room is experienced from a wider variety of angles and situations. This technique could be exploited to an even greater extent in 0G because of the lack of limitations on orientation Lighting levels and colors can be made available to the astronauts so they can find a comfortable "new" place to work if they so choose.

However the largest problem facing long-term astronaut heath is probably insufficient exercise. Exercise is the most important factor in mental health, as well as bone and muscle health in space.

Edited November 28, 2013 by nhnifong