Posted on 02/07/2008 8:36:23 PM PST by TigerLikesRooster
February 7, 2008
Japan to launch origami planes into outer space
Leo Lewis, Asia Business Correspondent
Video: how to create the perfct paper plane
In a bold bid to take the traditional art of origami beyond the Final Frontier, Japan is planning to release a huge squadron of paper aeroplanes in outer space.
The trailblazing experiment, slated for launch later this year, could see around 100 paper planes raining down on the planet as they are captured by the Earth’s gravitational pull and sucked down towards the surface.
Astronomers and star-gazers should have plenty of warning of the planes’ arrival, though: Shinichi Suzuki, the University of Tokyo professor behind the scheme, believes the paper flotilla will take several months to complete its gentle, gliding descent from upper atmosphere to the planet’s surface.
The origami planes, which will measure around 20cm each and weigh just 30 grams, are to be hurled into the void by a Japanese astronaut scheduled to visit the International Space Station this summer.
The experiment would, if successful, qualify for the longest ever flight by a paper plane: if one of the fleet should miraculously make it to earth, its journey will have been around 400km.
If any do make it back, the planes are statistically most likely to land in the sea - performing the same “splashdown” as the Apollo space missions. In the unlikely event that one floats down to solid ground, the lucky finder will be able to unfold the plane and discover the return address at the Japan Space Agency.
“It’s going to be the space version of a message in a bottle. It will be great if someone picks one up,” said Prof. Suzuki, “We are thinking of writing messages on the planes saying ’if found, please contact us’ in a couple of languages.” The idea comes as Japan is desperately trying to generate interest in its conventional space programme. Many Japanese have lost interest in the exploits of the nation’s Space Agency (JAXA) because of a string of embarrassing rocket launch failures.
Recent media reports have also cast doubt on the prospects of the GX rocket - a project that has encountered acrimonious wrangling over which government ministry should be in charge of which section of the fuselage.
The paper aircraft, meanwhile, are to be constructed from a specially heat-proofed paper able to withstand the astonishing temperatures liable to be experienced upon re-entry. The paper will also be chemically fortified to survive the enormous speeds that the planes will be travelling at as they are pulled into the earth’s orbit and breach the outer atmosphere.
In recent experiments by the Japan Origami Airplane Association, the prototypes have withstood speeds of Mach 7 and temperatures of 300C before disintegrating. The design of the planes - not unlike the United States Space Shuttle - is also calculated to minimise the destructive effects of re-entry.
There is serious scientific intent behind the plan. Japan believes that if the paper planes are successful, they may open possibilities of using softer, lighter materials for constructing space craft.
Japan’s recent relationship with outer space has been controversial. In December, the Japanese Government was asked in parliament to produce a position paper on the existence of UFOs, prompting the chief cabinet secretary, Nobutaka Machimura, to declare his belief that aliens are “definitely” out there.
Later the same day, Yasuo Fukuda, the Prime Minister, separately told reporters, ”I have not yet confirmed” the existence of UFOs.
This is form of art is reaching new heights.
That's my first thought, but presumably they are doing their homework on this. Small objects have the advantage in reentry, since the kinetic energy is carried away ( or left behind ) by a layer of heated ( very thin ) air. For a large object, the size of this layer is comparatively small and the rate of energy loss requires a very high temperature. For a small object, not so much. You would have to do the math, which as I say, I have to believe they are doing.
Also, the planes will have a high surface area to weight ratio, so they should descend less rapidly. Interesting experiment...
With a higher surface area to weight ratio, you should expect more rapid deceleration, and hence a more rapid descent, at least initially. It's only when it becomes a glider that it can "float to the earth" in the familiar paper airplane glide.
Interesting experiment...
It's got my attention.
Well, it will descend more rapidly at first, because more of the rarified atmosphere will be striking it, and because of its low mass, it will have less momentum. However, once it enters the atmospheric regime, it will descend less rapidly because of the surface area. So basically its characteristics produce opposite results in the two different environments.
Oh, did you mean vertical speed not airspeed? Well maybe. Would have to plot it out to see if there is much difference there.
Agree?
Right it will start to fall out of orbit faster at first so it’s trajectory will be much steeper. It might be that it will loose speed enough to trade off that steeper entry angle, but yeah, I see what you mean now.
Orbital decay is kind of tricky. Paradoxically, an object in a lower circular orbit has a higher velocity than one in a higher circular orbit. How then can a frictional force acting antiparallel to the velocity move an object from a higher circular orbit to a lower one?
To solve this paradox, you have to account for the deviation of the direction of the velocity. If it tilts downward, then a component of the gravitational force acts parallel to the velocity, and this must be greater than the frictional force. Now the lower total energy, kinetic plus potential, is accounted for by the work done on the atmosphere by friction, even as the object moves faster in the lower orbit due to the net force, frictional plus gravitational, acting with a component parallel to the velocity.
It’ll take a long time for each reentry; it’ll be somewhat akin to Rutan’s “shuttlecock” model for reentry. But anyway, reminds me of the Japanese balloon bombs during WWII.
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