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CJSF
2002-Feb-11, 05:08 PM
Space.com has this article about a Canadian microgravity drop tower:

http://space.com/SpaceReportersNetworkAstronomyDiscoveries/Brooks_Microgravity_0201.html

At least the Bush administration's decision to cripple ISS hasn't killed all the proposed research.

CJSF

Chip
2002-Feb-11, 05:27 PM
Thanks for the post. I wonder if they reduce the air inside the tower (to reduce friction,) - or does it matter for the kind of research they do?

On the lighter side (pun?) -- at the bottom of the micro-gravity drop tower they could install the "crater impact" room! /phpBB/images/smiles/icon_wink.gif

CJSF
2002-Feb-11, 05:36 PM
I don't know about how friction from the air might affect such experiments.

I love this sort of thing, though! Coming up with cheaper earth bound ways of doing things we thought we HAD to do in space.

I love the data we get from HST, for example, and I am sure there are lots of things it will always be better at than ground based telescopes. But the fact that we can now get ground based 'scopes to the same angular resolution as HST is GREAT!

http://www.space.com/scienceastronomy/astronomy/vlt_saturn_images_020204.html

Sorry for using Space.com so much, but they have a convenient URL. It's not really a great site any more... IMHO - any suggestions for better space news sources?

It's all groovy!

/phpBB/images/smiles/icon_cool.gif



_________________
"Be very, very careful what you put into that head, because you will never,
ever get it out."
--Thomas Cardinal Wolsey (1471-1530)

<font size=-1>[ This Message was edited by: Christopher Ferro on 2002-02-11 12:40 ]</font>

Bob
2002-Feb-11, 05:57 PM
The data given (265 mph after a 12 second drop) indicates the tower is evacuated.

Timm
2002-Feb-11, 06:48 PM
I once saw the drop tower in Bremen, really nice building. No possibility to visit it, though.

But why is there only micro-gravity inside an airplane in parrabel (sp?) flight?

As long as the test - container does not hit the Plane's fuselage, the should be not force acting on it besides the gravity of Earth. (Like in free fall)

With Hi-Tech plane steering systems it should also be possible to eliminate the problem of air friction. (You just have to make sure that the plane has a sinking speed of 9.81 ms^2, right?)

Silas
2002-Feb-11, 11:18 PM
On 2002-02-11 13:48, Timm wrote:
But why is there only micro-gravity inside an airplane in parrabel (sp?) flight?


Parabolic (I said, misspelling it twice myself in the attempt!)

I think that the problem with airplanes in the zero-g dive is vibration: the engines are roaring, the wind is hammering, and thus the air inside is also vibrating like crazy. There's almost no *gravity* acting on your experiments, but there's still quite a bit of *force* on them.

Or...I could be wrong...

Silas

Timm
2002-Feb-15, 11:52 PM
Parabolic (I said, misspelling it twice myself in the attempt!)



Ah, thanks. English is still a little confusing to me, sometimes.




I think that the problem with airplanes in the zero-g dive is vibration: the engines are roaring, the wind is hammering, and thus the air inside is also vibrating like crazy. There's almost no *gravity* acting on your experiments, but there's still quite a bit of *force* on them.

Or...I could be wrong...


That makes sense. I just wondered about the "micro gravity" in a plane vs. the "zero gravity" in the tower.

SiriMurthy
2002-Feb-18, 07:37 PM
On 2002-02-11 12:27, Chip wrote:
Thanks for the post. I wonder if they reduce the air inside the tower (to reduce friction,) - or does it matter for the kind of research they do?

On the lighter side (pun?) -- at the bottom of the micro-gravity drop tower they could install the "crater impact" room! /phpBB/images/smiles/icon_wink.gif


Yes, they do consider the air drag during the micro-g simulation experiments in drop towers. Typically, a drop tower yields about 2 - 2.5 seconds of microgravity. I have had an opportunity of working on these simulations - both theoricical and experimental.

We used a "Drag Sheid" and an "Experimental Package". Drag Shield (DS for short) simply encases the Experimental Package (EP for short). We calculated the relative travel between the EP and the DS. We didn't create vacuum inside the DS, even though ideally this is desired. But, given the humidity, ambient temperature, barometric pressure and so on, we can precisely calculate the relative travel and safely cushion the EP inside DS just when DS hits the ground. We used Spikes on DS and specally formulated foam on ground to reduce the impact. Specially designed springs inside DS protected the EP from getting damaged.

Chip
2002-Feb-19, 01:45 AM
On 2002-02-18 14:37, SiriMurthy wrote:

"Yes, they do consider the air drag during the micro-g simulation experiments in drop towers. Typically, a drop tower yields about 2 - 2.5 seconds of microgravity. I have had an opportunity of working on these simulations - both theoretical and experimental..." -- etc...(see post above.)

Thanks for the information. Fascinating work. Must yield some interesting results pointing perhaps to experiments already on the list for work on the ISS.


<font size=-1>[ This Message was edited by: Chip on 2002-02-18 20:47 ]</font>