ISS Jan 14, 2009 vibration incident.

[OrbitalConfusion]

https://www.youtube.com/watch?v=CF_hRKqFicQ


This got me thinking a little bit. I remember listening to how they mitigate this from their gym equipment for example. Its kinda cool, yet scary to see this i think if I were there.

Regardless, I have some questions to ask. I know how to use google, but its more fun to ask and listen to peoples opinions on things.


Like in this video, they were apparently doing some maneuvers. How long would it take for the ISS to settle back down? Could an astro-cosmonaut, bouncing off the walls in play cause this to happen? It really looked like a lot of flexing, a breaking seal and super-space-grade-explosive-decompression comes to mind.


When they use a soyuz or other craft to boost their orbit which I presume is what we are seeing in this video... I would imagine it would be a very long and tough task to accomplish. How fragile the solar panels are and everything else. How would you keep it from spinning out of control...

 

[steph]

Wanted to mention something about love in space, but I think I'll let it go :lol:.
Quite some hardcore vibration there. I guess the whole structrue vibrates a bit even when an astronaut goes from A to B inside the station, though not too much.
I was thinking...maybe a small ion thruster constantly firing with just enough force to counter atmospheric drag or slightly more might work? I suppose it's not in the plans.

 

[DaveS]

Like in this video, they were apparently doing some maneuvers.

This was a reboost of ISS using the SM main engines. The cause of the vibrations were later determined to be have been caused by the optimum control system set of parameters had not been loaded into the SM computers.

When they use a soyuz or other craft to boost their orbit which I presume is what we are seeing in this video...

Soyuz'es are not used for reboost. After docking and hath opening the Soyuz is powered down completely and fed power from the station. Reboosts are done with whatever Visiting Vehicle (VV) that is docked to the aft docking port of the SM (Progress/ATV).

When the shuttle was still flying, occasionally they provided a reboost using the RCS.

 

[Izack]

Could an astro-cosmonaut, bouncing off the walls in play cause this to happen?

I would say no to this. Remember, the station weighs about 450 metric tonnes, so it has considerable inertia.

It really looked like a lot of flexing, a breaking seal and super-space-grade-explosive-decompression comes to mind.

I recall one late Shuttle mission (sadly I can't remember which) in which there was some serious flexing of the station at docking. IIRC it took quite some time to dampen the oscillations, yet there was no concern about the stress on the ISS structure.

When they use a soyuz or other craft to boost their orbit which I presume is what we are seeing in this video... I would imagine it would be a very long and tough task to accomplish. How fragile the solar panels are and everything else. How would you keep it from spinning out of control...

The acceleration is very low - within the tolerances of the attitude control system to compensate for, and the station structure to survive. Also, note that Zvezda's (or whatever craft's) engines are roughly on the centreline of the station.

 

[OrbitalConfusion]

Its to my understanding that the ISS is controlled by gyroscopic wheels. Is there an RCS system in place if more control is needed? I guess why this fundamental subject is so interesting is because there isnt a lot of video footage out there. I saw a video of the shuttle firing off its orbital engines and some astronaut reacting to it.

being a kid in the 80's I always imagined the space station would look like a huge square shape of lattice work. Everything is structurally dependent on the core structure like in the kid-goes-to-space-movie that I cant name that came in the late 80's early 90's. Im sure most you of know what im talking about.

I wonder how in the future using inflatable modules will work out. I watched a few documentaries on it and the tech looks so cool.

 

[Izack]

As I understand it (which is far from perfectly) it is primarily the control moment gyroscopes that maintain the station's attitude. Even when those need to be desaturated, the station uses the natural gravity gradient torque as a practically free method of doing so. However, it can use the attitude thrusters on Zarya and Zvezda, as well as those of docked spacecraft.

While googling around, I came across this article, which is interesting, if not necessarily related.