Boomerang works in space: Japanese astronaut

[seriousstan]

TOKYO (AFP) - In an unprecedented experiment, a Japanese astronaut has thrown a boomerang in space and confirmed it flies back much like on Earth.

Astronaut Takao Doi "threw a boomerang and saw it come back" during his free time on March 18 at the International Space Station, a spokeswoman at the Japan Aerospace Exploration Agency said on Friday.

Doi threw the boomerang after a request from compatriot Yasuhiro Togai, a world boomerang champion.

"I was very surprised and moved to see that it flew the same way it does on Earth," the Mainichi Shimbun daily quoted the 53-year-old astronaut as telling his wife in a chat from space.

The space agency said a videotape of the experiment would likely be released later.

Doi travelled on US shuttle Endeavour on the March 11 blast-off and successfully delivered the first piece of a Japanese laboratory to the International Space Station.

OK. I'll admit to cluelessness.......WHY? Why did it return?

[Fridays Child]

1. Here's why it returns when thrown on earth...

But this doesn't explain boomerang physics in a vacuum. :shrug:

http://tinyurl.com/yo5xe9

[TexasProgresive]

7. 'Twasn't in a vacuum - just weightless

He wasn't on a space walk but inside the space station.

[Fridays Child]

9. Ah.

Silly me. :blush:

[eShirl]

2. something to do with its spinning, odd shape/center of gravity, centrifugal force?

no idea!

[Laughing Mirror]

3. Is the field of space in which the boomerang moves ...

the same on earth as it is in outer space? Do they maybe need to examine not the dynamics of the boomerang, but the field of space in which it operates to find out why.

[fasttense]

4. It has to be the way it is spinning.

Since, obviously there is no air to affect lift, it has to be the momentum of the spin. I don't know. But I would like to see the videotape.

[PetrusMonsFormicarum]

5. Yes spinning

I remember reading something years back that said that astronauts are trained to spin their bodies if they are left floating and have no mechanical propulsion.

All the same, half of me thinks the story is bogus--even if a boomerang would act the same as in atmosphere/gravity, don't you think that at least its outward flight would be considerably greater distance, like maybe a couple of miles?

[muriel_volestrangler]

6. I don't think he threw it outside the station, in a vacuum

Because he's not out there "during his free time". I think he threw it inside - so in an atmosphere, but while 'weightless'. But, given the explanation here doesn't involve gravity as a relevant force (just aerodynamic lift, and gyroscopic precession), I suppose it's not that surprising.

Here he is holding the boomerang, inside:

[RC]

8. I guess science is not a long suit with most people anymore.

There is no possible way the boomerang could have returned in airless space. The fact that it did means that it had to have been thrown in an environment with air and therefore was thrown inside the space station. Jeez people, shut off the TV and get some common sense.

[Thor_MN]

16. I'm thinking that if you were willing to wait long enough and could throw accurately enough

the boomerang could "return", but it would be due to intersecting orbits...

[krispos42]

10. It was stapled to the chicken!

:hide:

[Bonobo]

11. Kaeru shika nakatta.

[Johonny]

12. Wow I'm so happy

we are spending so much on man spaced flight. Now we have the answer if ants can sort tiny screws in space.

[Orrex]

13. I for one salute our kangaroo masters

:scared:

[FogerRox]

14. Coriolis force

induced by the earths spin, the space station orbits the earth, also inducing the same effect on the boomerang.

[caraher]

15. Coriolis force is irrelevant here

it's just plain aerodynamic forces. As the rotating 'rang moves forward, there's a lift force from that acts (at least in part) perpendicular to its direction of motion. That's pretty much the recipe for circular motion, which is what you want to get it to return.

If Coriolis force were relevant boomerangs would return when thrown on moons/planets with no atmosphere (since the Coriolis force is strictly a consequence of "apparent" forces that appear in accelerated reference frames).

In addition, if the Coriolis force were at all relevant, a lot of very peculiar results would follow. First, the latitude of the thrower would affect its flight. Would boomerangs cease to work at the poles? Would they change direction of flight depending on which hemisphere they were tossed in? Second, there could only be one "handedness" of boomerangs - they would all circle in the same direction thrown from a given location on Earth. You will find that virtually every boomerang circles counterclockwise (as seen from above). This is simply because boomerangs are designed for right-handed throwers; boomerangs designed for lefties circle in the opposite direction. And they do the same thing in Arizona as in Australia.

A decent explanation is in New Scientist's article. I look forward to seeing the video. I expect that the the plane of the circle will be pretty much perpendicular to the axis of rotation; the big difference is that for a long flight on Earth you need most of the lift to stay airborne and only a little to go in a "circle." If you watch a typical boomerang throw it starts with a nearly horizontal axis of rotation and returns with a nearly vertical rotation axis.

[crikkett]

17. Yikes I'm glad it didn't hit anything important.

[HiFructosePronSyrup]

18. It's an airfoil.

It's like little toy glider planes. Or jumbo jets, for that matter. You've got the Bernoulli principle providing lift, and presumably angle of attack plays a part as well. It's like those little toy helicopter things where you pull the ripcord and it goes flying up in the air as long as it's spinning.

[Ready4Change]

19. Well, in zero-g, it's not really 'lift.'

I suppose it would be called a vector change? Operating in a direction perpendicular to the wing, so long as the wings position and motion through the air is correct for the effect. (I'm sure someone can word that better/more accurately.)

Oh heck. Yah, it was lift. :)