Shenzhou 7?

[Peter B]

• Purchase flag from http://www.miniatureflagshop.com/china.html
• Locate clean pool
• Experiment
• Post results here
• Bask in the admiration of this forum AND become established as a major force in the space industry because you found out what those godless communists where getting up to

Not that you're going to do any of stuff as, like the last four time, you'll come up with an excuse.

Well, thanks to a kind lady at the local hardware store and one of my sons behaving angelically, I've been able to try the experiment.

We picked up an Australian flag (being handed out in large numbers for no particular reason I could see, except that in our case my son was being helpful to me and polite to the shop staff) of about the same size as the one being waved by the Chinese astronaut on the space walk.

I filled up the kitchen sink with hot water (later used to warm a couple of bowls for dinner) and waved the flag around in a variety of ways.

Results:

1. As a general rule, the flag always trailed wherever the flagpole led. That is, the part of the flag adjacent to the pole was always parallel with the direction the flag pole was travelling. The remainder of the flag simply trailed along like a snake's body. The water very obviously constrainted the motion of the flag. This compared most notably with the space walk flag which often remained perpendicular to the direction of the flag pole's motion.

2. The flag fluttered in the water. I assume this was due to a combination of (a) random motions generated in the flagpole by its passage through the water being transmitted to the flag, and (b) random lateral motions of the water against the flag as it passed by. This compared most notably with the constant smooth appearance of the space walk flag.

3. When the flagpole was moved in a circular fashion, the flag wrapped around the flagpole and remained in place, trapped by the water. This is simply a consequence of 1. above, whereby the flag simply trailed the movement of the flagpole.

Summary:

The flag moved through water in a fashion entirely unlike that of the space walk flag.

Conclusion:

The space walk flag was not submerged in water at the time the space walk footage was recorded.

[twik]

Very nice experiment and summary, Peter B.!

[Donnie B.]

Now try it with a lead feather :-)

[Inanimate Carbon Rod]

It's a shame that Vincent no longer hangs around these parts, as I'd be interested to see what he makes of China's plans for super a heavy load lifter, the Long March 5/CZ-5 heavy rocket:

http://www.americaspace.org/?p=22881

I suspect that he'd think this is faked as well, since the space walk was faked there's no possible way the Chinese could build anything this complex.

[ChrLz]

So, Vincent, how about having the cojones to return and withdraw your claim?  Or are you still looking for a flag and a pool?


Hmm.  I have an underwater camera, so perhaps I should do his work for him..?  But I won't bother if he hasn't the intestinal fortitude to return and face the results.

[Noldi400]

I don't know how much time an Apollo astronaut would have had to activate his OPS were his PLSS to suddenly expire, but it couldn't have been very long.

That's one of those questions that can only be answered "It depends."

If we're talking about a catastrophic loss of pressure, what little experience we have seems to indicate that he would have about 15 seconds before becoming unconscious. Depending on the cause, though, the OPS may not be much help. If it was a tear in the TLSA, the OPS probably couldn't supply O² fast enough to compensate for the leak.

If the oxygen system in the PLSS just suddenly stopped working, he would get audible alarms and RCS flags. I would guesstimate that he would have at least one to two minutes of clear-headed consciousness to pull the apple and open the purge valve.

On a related question, am I correct in thinking the spacesuits used for Gemini EVAs didn't have the convolute joints like the Apollo suits - just a "flexible" pressure layer, sort of like a very tight wet suit?  If so, I'm amazed they were able to move at all (I'm reading Collins' and Cernan's books and it sounds like either of them could have died as a result of their Gemini EVAs, basically from exhaustion).

[George Tirebiter]

The Gemini suits had a pressure bladder (more like a loose wetsuit) surrounded by a human-shaped woven mesh.  The mesh layer both forms constant-volume joints and keeps the bladder from inflating like a balloon.  This design has been the basis for the USAF's high-altitude pressure suits for the past 50 years, but, as I understand it, is much stiffer than the Apollo suits.

[Noldi400]

This design has been the basis for the USAF's high-altitude pressure suits for the past 50 years, but, as I understand it, is much stiffer than the Apollo suits.

Yes, evidently crawling around on the exterior of a spacecraft turned out to require more flexibility that sitting in a cockpit or gondola. Amazing how clear things are in hindsight, isn't it?

[ka9q]

IIRC, the OPS actually had quite a bit more oxygen than the PLSS, but it would be used up very quickly in a once-through mode. The buddy system hose introduced with Apollo 15 was only to share cooling water so the purge rate could be decreased, extending OPS lifetime from 30 to 60 min.

The irony is that on the moon something like 1/2 of the mass of the crust is chemically-bound oxygen, and there's plenty of solar energy to extract it. Someday they'll do just that.

[bobdude11]

And the tether and straps?

you know, I was thinking - with the relation of the ship to the Earth in the video (Earth 'above' the Astronaut), wouldn't the pull of Earth's gravity cause these items to 'float up'?

[bobdude11]

Here is a video of Ed White's Gemini 4 spacewalk.

Notice how at 0.47 there is a strap and a loop visible, both of which are 'floating' upwards of their own volition. Notice how as he sets up the camera at about 1.16 the coiled tether is floating upwards rather than sitting against the spacecraft.
Violating the laws of physics? Filmed underwater? Or just the natural tendency of the things in question?

How many times do I have to clear this up??
Ed White used a NITROGEN GUN to maneuver. That causes him to develop relative velocity and motion to the tether and strap... Inertia dictates they must move. On the Chinese video, however, it's clear that they float up without any kind of force throughout the video.

If I recall correctly, he did NOT use the gun to get out of the spacecraft - he talked about a physical maneuver he did, but not with the gun.

EDIT (I stand corrected): I apparently did not have the sound on - he did use the gun. I was certain that the comms during the mission he stated he didn't need it, but I must be misremembering.

[bobdude11]

They could patent it and make nothing but scifi films better than 2001!  Instead of Hollywood or Bollywood, it would have to be Chinese... hmm... Chinawood?  That sounds weird.

Chollywood! (ok that is just more sillier than the other ...)

[Jason Thompson]

you know, I was thinking - with the relation of the ship to the Earth in the video (Earth 'above' the Astronaut), wouldn't the pull of Earth's gravity cause these items to 'float up'?

No. All the items in the spacecraft are in freefall around the Earth, and are no more subject to being pulled 'up' by Earth's gravity than any other object, the spacecraft included. It is true that objects with one long axis tend to orient themselves with the long axis pointing towards Earth due to the gravity gradient, but this takes some time to occur.

In short, you can't think of these things as 'hanging' towards the Earth due to its gravity.

[bobdude11]

you know, I was thinking - with the relation of the ship to the Earth in the video (Earth 'above' the Astronaut), wouldn't the pull of Earth's gravity cause these items to 'float up'?

No. All the items in the spacecraft are in freefall around the Earth, and are no more subject to being pulled 'up' by Earth's gravity than any other object, the spacecraft included. It is true that objects with one long axis tend to orient themselves with the long axis pointing towards Earth due to the gravity gradient, but this takes some time to occur.

In short, you can't think of these things as 'hanging' towards the Earth due to its gravity.

Fair enough. I think I may have actually surmised this as I was reading last night, but needed the clarification. Having never been in space, I was clearly guessing, wrongly, at what happened. Thanks for keeping me on the right path. When I can find the time, I think I am going to read up on LEO 0g physics so I can at least talk intelligently here ... 

[gillianren]

The thing to remember--the problem that Vincent has--is that space does not work the way you expect.  Your expectations of how things act are based on your life experience, which involves things like air and gravity.  When things look wrong to you in space travel, it's almost certainly your expectations which are the issue.