Comments on: Space Station Astronauts Could Get Stranded in Kibo

By: T. A. Radiant

T. A. Radiant — Tue, 17 Jun 2008 01:09:52 +0000

Didn't Skylab have a larger interior than Kibo? I don't remember any astronaut getting stuck in the middle of Skylab.

By: Jason

Jason — Sat, 14 Jun 2008 09:43:59 +0000

I think they should use electro magnet active clothing so they can drift toward preset metal handrails around the cabin.,It would also be cool to have objects drift to you like inkpens and clipboards.

By: Quantum_Flux

Quantum_Flux — Thu, 12 Jun 2008 19:41:43 +0000

Hehehe, or they could use silly string as a projectile.

By: Aodhhan

Aodhhan — Thu, 12 Jun 2008 12:05:09 +0000

They could carry collapsable pointers (like a collapsable antenna; just modify so it locks when extended so it doesn't collapse easily), in a pocket, and use it in case of emergency.

Extend it when needed and use it to push against a stationary object to get going again. Simple $2.50 solution.

By: Pete

Pete — Thu, 12 Jun 2008 03:14:35 +0000

A simple device with a rare earth magnet and a retractable cord – like vaccum cleaner cords, or a tiny mouse for laptops.

It could fit into a very small and unobtrusive pouch on the belt, or around the ankle with velcro.

Pull out a length, set the spring to lock, and toss it to something magnetic.

If aluminium and other non-magnetic synthetics are used throughout, it would be simple to glue brightly coloured, very thin steel targets in strategic locations.

By: Kevin M.

Kevin M. — Wed, 11 Jun 2008 23:13:01 +0000

Kibo is huge…so overnight the Japs will have the biggest, and most scientifically significant, component of the station? Very impressive, or ambitious…sounds like they may have a controlling interest from now on…

By: Quantum_Flux

Quantum_Flux — Wed, 11 Jun 2008 21:11:52 +0000

I wonder what might happen if somebody gets into a fast spin in the middle.

By: Frank Glover

Frank Glover — Wed, 11 Jun 2008 20:45:10 +0000

"I'm not sure how one could get stuck in the middle. If you floated to the middle somehow, you wouldn't just stop. You would continue floating to the other side."

It's not like moving through vacuum. If you started out slowly enough, air friction could well bring you to a stop, out of reach of anything to grab. The larger the pressurized volume, the mor easily this could happen.

'Swimming' through air is possible, of course, but with your hands alone, it would be less efficent than in water.

One of the things I imagine trying, had I the opprotunity, is to see if those little battery powered, hand-held fans could be effective personal propeller engines inside a pressurized, weightless enclosure.

That could also evolve into a weightless sport, much as Heinlein and Ruzic have already said about wings in a Lunar habitat…

By: Connie Drummond

Connie Drummond — Wed, 11 Jun 2008 19:18:17 +0000

I have seen no mention of the orbiting of the shuttle and the space station orbiting while be docked together. A local radio station announced on Monday ( 6/9/08) that It was seen on Sunday evening and could been seen again on the 9th. over the Arizona skies traveling from NW toward SE. I live in central Arizona and did observe at the approx, time and the direction he had stated. We have heard nothing on TV nor can we find ref. on the web. Can you help?

Drummeo

By: Peter

Peter — Wed, 11 Jun 2008 19:17:33 +0000

A few years back, we had the opportunity to talk to Canadian astronaut Chris Hadfield about a related question. Check out his response at

canadainspace.ca/qa.php?sectionName=qa§ionID=1#q48

Peter

By: GBendt

GBendt — Wed, 11 Jun 2008 18:36:52 +0000

If you get into the centre of the KIBO coming in from any side, you will continue to move to the opposite side, due to the conservation of momentum.
And if some curious fate happens to bring your momentum to zero just as you reach the centre of the lab, Alex has given the right solution to solve that problem: blow for a few times, and then wait a half a minute.

Regards

GÃ¼nther

By: Alex

Alex — Wed, 11 Jun 2008 17:57:30 +0000

Ahh just blow a few times or flap your arms as if swimming.

Sure it wont be fast, but you would get to the other side.

By: Bryan

Bryan — Wed, 11 Jun 2008 17:29:19 +0000

I'm not sure if anyone watched the first opening of the KIBO lab last week on NASA TV…but for a few minutes after it was first opened, the astronauts were just kinda lounging around inside of the lab…Garrett Reisman demonstrated what we're talking about here perfectly! he was literally stuck in the middle, out of reach of anything to help him to the side…

he did eventually reach something…after a series of flips and stretches…it was actually kind of funny to watch! im sure its not on youtube, but i still have it on my DVR…i suppose i should try to get it here to show everyone, even if its not top quality…

By: Kris

Kris — Wed, 11 Jun 2008 17:00:56 +0000

Well, yes, Hemal, I can imagine if you sneeze you make a firm tumble in 0-grav! So a firm "blowing at full force through puckered lips" with your head held upwards should put your feet on the other wall in a sec.
Can you confirm that, Cecil?

By: Hemal Shah

Hemal Shah — Wed, 11 Jun 2008 15:23:59 +0000

Tickle your nose…

By: Kris

Kris — Wed, 11 Jun 2008 15:22:30 +0000

Thank you, Cecil!
You said "Each exhale would accelerate you by 1.6 m/s." Does that mean that with one exhale (along the length axis of the body) would move the astronaut 1.6 m in one second? One blow would do the trick quite well, wouldn't it?

By: joe

joe — Wed, 11 Jun 2008 14:30:22 +0000

don't they put velcro in appropriate locations so you can hang without floating off?

By: joe

joe — Wed, 11 Jun 2008 14:26:17 +0000

small battery operated personal cooling fans would do the trick

By: Cecil

Cecil — Wed, 11 Jun 2008 14:17:27 +0000

Let's try this – hopefully someone can check my reasoning. The human lungs can expel 4.8 litres from maximal inspiration to maximal expiration. We'll use 4L to be safe. When repeated I can do about one maximal exhale every 4 seconds without fainting. That makes an average flow of 1 L/sec.

The article at http://lib.bioinfo.pl/pmid:17542834 makes reference to the air velocity of a cough being 10 m/sec and a sneeze being 50 m/sec. Let's say a maximal exhale through puckered lips is about midway between those at 30 m/sec(that's about what it feels like to me).

A few different sites give the weight of 1 L of air at about 1.2 g. So repeatedly, maximally blowing at full force through puckered lips provides a constant force of about (0.0012g/s)(30m/s) = 0.036 N.

That's enough to accelerate a 90kg (200lb) astronaut at 0.4mm/s^2. Each exhale would accelerate you by 1.6 m/s.

Really when you think about it air doesn't have much mass, and you're only accelerating a small amount with each breath. You can push far more air around (and thus moving you faster) by flapping a clipboard.

By: Kris

Kris — Wed, 11 Jun 2008 13:07:36 +0000

**Would just blowing air out of your mouth actually provide enough force to move a 90kg person faster than a hundredth of a millimeter per hour?**

Apart from starting to spin head over feet if blowing straight forward, one could blow upwards toward a wall and move to the opposite wal. Can somebody do the math here? How fast can a 90 kg person propel himself by blowing as hard as he can?

By: RL

RL — Wed, 11 Jun 2008 12:53:52 +0000

One can safely assume that if you deliberately attempt to get stuck in the middle, you can never do it. But its also a sure thing that it can and will happen without trying! Sort of like bouncing a golf ball off of a tree for a hole in one, throwing a balled up piece of paper into the trash can after bouncing it off of everything/anything and having it go in, or any number of fluke happenings that are sure things only when NOT attempting to do such a thing. (I usually claim I planned it anyway).

Not very scientific – but very true anyway.

By: Mick

Mick — Wed, 11 Jun 2008 12:08:53 +0000

How about a kids sucker gun. Ie Spring power.

By: Adam

Adam — Wed, 11 Jun 2008 06:56:55 +0000

Oh, c'mon! You just "swim" like in the water. Not as efficient but works basically just the same as the air does exert some drag. It would require a lot more flapping and swinging with the arms then in water so you would probably get a bit sweaty. It *could* be a problem in vacuum but that is unlikely to happen inside Kibo.

By: Sci-Fi Si

Sci-Fi Si — Wed, 11 Jun 2008 02:56:37 +0000

Also, once one's natural gas supply has expired (as it inevitably will) the time/cost ratio of an Astronaut suspended in zero 'G' although moving toward one's destination at minimal velocity, might justify the ignition of a secondary stage 'solid rocket booster' or firework to expediate the process.

By: Sci-Fi Si

Sci-Fi Si — Wed, 11 Jun 2008 02:33:29 +0000

You forget to mention fart power!

In this instance one couldn't use the formula:

V(0)=V^2-2as

As the acceleration wouldn't be a constant, unless of course one was extremely windy.

Newton's Third Law does however apply.

Also assuming one didn't pass out due to Oxygen depletion in the Kibo module, or suffer from toxic fume inhalation in the form of Methane.

One might also need to consider using after burner technology for extra thrust by igniting the gas with a lighter.

According to my calculations a sustained blast could carry one quite some distance – much like an ion drive.

Who said scientists didn't have a sence of humour?