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## Origami Plane to Fly From the Int. Space Station217

SK writes "The University of Tokyo and the Japan folded paper (origami) plane society hopes to fly a paper airplane from the International Space Station to Earth. The plane will be 30-40cm long and weigh about 30 grams. A University of Tokyo research group has successfully designed a special paper plane model that was able to withstand a Mach 7 high velocity stream for 10 seconds. The experimental plane was about one-fifth the size and withstood temperatures as high as 300C without burning up." Unfortunately for most of us reading this, the original source is all in japanese.
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## Origami Plane to Fly From the Int. Space Station

• #### Hey guys! (Score:5, Funny)

on Monday January 21, 2008 @11:33AM (#22126776) Homepage Journal
"Ha, that's sweet! You know what we should do with it?"
*Airlock Sounds*
• #### flip? (Score:5, Interesting)

<info@EULERdevinmoore.com minus math_god> on Monday January 21, 2008 @11:42AM (#22126870) Homepage Journal
won't the paper flip when it starts to hit air, and burn up? How do you get a paper airplane to get to mach anything? I know how to make a very fast paper airplane for hand throwing, but it only goes maybe into the low 100 range... I never clocked it, though. Still, I think it would flip before getting that fast.
• #### Re:flip? (Score:5, Funny)

on Monday January 21, 2008 @11:46AM (#22126904) Homepage
Simple... use carbon nanotube paper!
• #### Re:flip? (Score:5, Informative)

on Monday January 21, 2008 @11:58AM (#22127034) Homepage

Remember that the speed of sound changes with the properties of the air through which an object is travelling. The absolute speed of an object (i.e. in m/s) corresponding to a high Mach number deep in our atmosphere (say in the troposphere or stratosphere) would actually be much, much slower than the speed of sound in the mid-thermosphere (where the ISS is located).

Its a similar reason to why de-orbiting objects can travel faster than terminal velocity; they accelerated to that speed before the air resistance built up.

Aikon-

• #### Re: (Score:2, Interesting)

The summary says the mini model was able to withstand 300 degrees C. And what's wrong with flipping? Paper airplanes that I make usually orient themselves that way, and they do quite well.
• #### Re:flip? (Score:5, Interesting)

on Monday January 21, 2008 @12:16PM (#22127214)
But your paper airplaines don't encounter strong temperature gradients or supersonic shock waves. In such conditions, even having the sun illuminate one side of the plane and not the other one could significantly alter the trajectory of the plane, and I believe is what makes the experiment interesting: will the real course match the planned one?
• #### Re: (Score:2)

If you drop the plane out of orbit it'll accelerate at 9.8 m/s/s or so until it hits atmosphere dense enough to appreciably slow it by friction. By then it'll probably be going pretty fast. After reaching this point in the atmosphere it will quickly deccelerate to terminal velocity for a paper airplane. So ten seconds at mach 7 is probably good enough.
• #### Orbital mechanics, not magic... (Score:2, Insightful)

No, it won't. You're assuming it'll somehow magically come to a dead stop when released, then start to fall straight down. What will really happen is that it'll just get shoved into a slightly lower orbit, so it will hit the atmosphere at pretty much orbital velocity, just like the shuttle does.
• #### I'm chargin' mah lazer! (Score:4, Funny)

on Monday January 21, 2008 @11:43AM (#22126872)
China will probably vaporize it, just out of spite.
• #### On the contrary... (Score:5, Funny)

on Monday January 21, 2008 @12:00PM (#22127044) Journal
This is the Librarian wing of the JSA testing new paper for books. This paper, obviously with embedded copy protection coatings, will prove that books are better than websites, and gloriously launch the Japanese people to a state of technological superiority over western libraries. This is just stage one of the Paper Ninja Warriors contest.

Stage two involves plasma thrusters and a "paper moon" orbiter. When you can afford to launch 14 million orbital vehicles, one of them is bound to accomplish the job. Besides, what better building material to use if you want to send a message to aliens in other galaxies?
• #### Translated (Score:3, Informative)

on Monday January 21, 2008 @11:46AM (#22126906) Homepage
Even though it's in Japanese, just use Google Translate [64.233.179.104] to read it.
• #### Re:Translated (Score:5, Funny)

by Anonymous Coward on Monday January 21, 2008 @11:53AM (#22126976)

Suzuki professor at Tokyo University (aerospace engineering) is a "message of peace from the space station to skip it. Land in the world where you do not know the fairy who could deliver" a dream said.

uh, Fascinating!
• #### Re:Translated (Score:5, Funny)

on Monday January 21, 2008 @11:55AM (#22126998) Journal
Hmm, I think something was lost in the translation:

Down to Earth from space station by this vision of creating a paper airplane, Japan Origami Association HIKOKI and Tokyo are working on a large group. 17, the university's wind tunnel using a validated test.

8 centimeters in length experiment, the space shuttle heat-resistant form of folded paper airplane use by the process. Tokyo campus Ookashiwa (Kashiwa, Chiba Prefecture), a super high-speed wind tunnel tests of the high-speed stream of Mach 7 in the heat resistance and strength to find out.

When the space shuttle and other spacecraft will return to the speed of Mach 20, and the friction in the air and high temperatures for the heat-resistant surface is a special twist. Paper airplane is so light, slowing down from the thin air, landing in slow. Coming back without burnout might be.

Suzuki professor at Tokyo University (aerospace engineering) is a "message of peace from the space station to skip it. Land in the world where you do not know the fairy who could deliver" a dream said.

• #### Re:Translated (Score:4, Funny)

<phillipsam@@@gmail...com> on Monday January 21, 2008 @12:07PM (#22127122) Journal
I have to wonder: is this better or worse than the cell phone text message novels?
• #### Re:Translated (Score:5, Funny)

on Monday January 21, 2008 @02:01PM (#22128582) Homepage Journal
Now I know how the manual for my DVD player was translated.
• #### Re: (Score:2)

8 centimeters in length experiment,

Hey! I saw that movie, too!

It wasn't that great.
• #### Re:Translated (Score:5, Informative)

<goughnourc.gmail@com> on Monday January 21, 2008 @06:33PM (#22131472)
Here's a human translation, if it helps.

In order to make a paper airplane that can fall back to Earth from a space station, the Japan Origami Paper Airplane Group and Tokyo University have been brought together. Using the University's wind tunnel, testing was performed on the 17th.

In the experiment an 8 cm long paper airplane, folded into the shape of the space shuttle, was made of material that had been treated for heat resistance. It was tested for heat resistance and strength in a Mach 7 airflow generated by the ultra high speed wind tunnel located at Todai's Kashiwa Campus (Kashiwa City, Chiba Prefecture).

Space vehicles such as the Space Shuttle can reach speeds of Mach 20 on reentry and due to the high temperatures caused friction with the atomosphere, their surfaces require special heat resistance devices. Because of the low weight of the paper airplane, it will begin deceleration from where the atmosphere is thin and be able to land slowly. It is said that it may be able to return to Earth without burning up.

Shinji Suzuki, professor of aerospace engineering at Tokyo University, shared his dream. "I want to fly it from the Space Station with a message of peace. I don't know where in the world it will land, but hopefully the person who finds it report it."
• #### origami book (Score:4, Funny)

on Monday January 21, 2008 @11:48AM (#22126922)
Somebody gave me an origami book once. I never read it - I couldn't, it was all creased seven ways to Sunday.
• #### English language link (Score:5, Informative)

on Monday January 21, 2008 @11:51AM (#22126964)
Japan wants to fly paper plane from International Space Station to earth:
http://mdn.mainichi.jp/national/news/20080118p2a00m0na025000c.html [mainichi.jp]
• #### More likely ... (Score:5, Funny)

on Monday January 21, 2008 @11:51AM (#22126966) Homepage

"We hope the space station crew will write a message of peace on the plane before they launch it," says Suzuki.
As it enter the atmosphere above the United States and promptly got "neutralised" by some missiles.
• #### Re:More likely ... (Score:5, Funny)

on Monday January 21, 2008 @02:24PM (#22128872)
As it enter the atmosphere above the United States and promptly got "neutralised" by some missiles.

I doubt it. The Americans have always had a bit of a blind spot for incoming Japanese planes.

• #### Re: (Score:2)

Indeed, will they be able to follow it somehow ? Radar comes to mind if it's made out of aluminium. But then at sharp angles like this it will reflect radar like an F117 !
• #### why not metal foil? (Score:5, Interesting)

on Monday January 21, 2008 @11:52AM (#22126968)
I would think that a metal foil would provide a better "paper" for the plane. Not only would it resist higher temperatures, but it would conduct heat from the hot side to radiate heat on the upper side. Chemically etching the foil on the upper surface to make it black would also help radiate heat. Finally, a metal foil plane would have a higher radar cross-section so it might be possible to track the trajectory and recover the plane.

If purists insist on paper, the one could deposit a thin foil veneer on the leading edges or deposit a trace-work of metal to create a reflector of radar waves (extra credit for adding an RFID chip to the mix).
• #### Re:why not metal foil? (Score:5, Interesting)

on Monday January 21, 2008 @12:18PM (#22127230) Homepage Journal
People immediately wonder "why" they would do something like this. As far as has been reported, there won't even be an attempt to track the actual landing, and as we could expect, it would even be difficult to pinpoint which continent (if any) would receive the landing.

The point isn't what happens to the plane in ACTUAL freefall, the point is to do the materials and aerodynamics studies on the ground. Why not use foil? Because they have already tested foil in space and know quite a bit about it. Whether foil would work or not is not what this particular group wants to study. They haven't tested this kind of treated paper. Maybe there are some surprising benefits in heat-treated papers that could change the way we do satellites.

Of course, the final "experiment" is more like playing golf on the moon, if they even bother to do it at all. It's just a part of joie de vivre, which I think is sorely lacking in western society today. Stop griping needlessly. They won't spend a billion dollars to take a piece of scrap paper to space and chuck it into the big blue swirly spherical rubbish heap. However, thanks to this outlandish conversation-starter concept, they might be allowed to spend a significantly smaller budget on traditional material and aerodynamic science.

• #### joie de vivre + useful asteroid mining tech (Score:2)

I don't begrudge them the fun of launching a "paper" airplane in space but want to think long-term. How can we use "paper" airplanes in space?

I'd bet that foil airplanes might be an interesting way to de-orbit a stream from materials from LEO. Rather than build big expensive return vehicles (that require fuel for de-orbiting), one could build origami return vehicles that deorbit automatically due to thin atmosphere at LEO. Robotic machinery would create sheet metal (from nickel-iron asteroids), fold it,
• #### Re: (Score:2)

Since the ISS is already up there and is serviced by regular flights, and since the experimental plane is made of paper - if this project is running into the billions-of-dollars arena I would recommend a personnel change.
• #### Paper planes for planetary exploration (Score:4, Interesting)

on Monday January 21, 2008 @09:04PM (#22132806) Homepage

As far as has been reported, there won't even be an attempt to track the actual landing ...
New Scientist:

Suzuki says he would like to develop an ultra small tracking device to attach to the plane.

If you can track it, you can learn stuff about the reentry characteristics of ultra-light probes.

Now, think about the consequences of that for a moment. Most existing reentry vehicles are reentry vihicles designed to return personnel and equipment and data to ground level, but when you explore other planets the data flow goes the other way. There's also a lot of data that doesn't have to be collected from the ground. So, instead of an orbiter chucking two or three big chunky armored landers which attempt to survive crashing into the surface, and then trying to get a rover to crawl out of the lander and chug for miles to get somewhere interesting (without falling down a hole), why not release a cloud of ultralites and have them beam back picture info and data as they they drift earthwards? If you could insert an ultralite robotic aircraft into the atmosphere (of the type they currently use for weather sensing), it wouldn't have to land, and some of these designs might be able to stay aloft for years. Couple that with a microsatellite relay network and you potentially have a good system.

Alternatively you could go down the balloon path ... instead of a conventional balloon carrying a heavy heavy metal box with electronics in ... instead, stick your CCD chips to the balloon, print additional circuitry and perhaps solar cells directly onto the surface, perhaps use the upper and lower surfaces as charge carriers to avoid batteries, or have the lower surface metallised and the upper transparent, and use it as a solar collector.

With a whole bunch of these balloons drifting about in the upper atmosphere, you have an ad-hoc signal relay system. Hell, give em internet protocols. You won't be able to steer them, and you'd always be losing contact with a few, but a mission could carry along hundreds of them. The transponders would only have to be comparatively short-range, maybe you could even beam power from the orbiter. If you want random mapping plus a study of the atmosphere, bung 'em into a low orbit and wait for them to decay.

Perhaps a future Venus mission might well involve an orbiter repeatedly chucking a series of fifty cheap, disposable, "smart" transponder-equipped paper planes into the Venusian atmosphere and relaying that data back to Earth.

The first step is developing and testing materials. The second is using a tracking system to see how well they cope with reentry. The third is embedding smarter electronics.

• #### Re:why not metal foil? (Score:5, Funny)

on Monday January 21, 2008 @12:21PM (#22127270)
They dropped making it of tin foil due to the risk of blocking mind control satelites.
At normal altitude, a tin foil hat can block the ray for a single person, dropped in space however, the tin foil plane might block mind control of enough people, to actually affect the outcome of the upcoming elections.

Remember, if we're provided a proper tinfoil cover, we will no longer welcome our <insert pathetica> overlords.
• #### Re: (Score:3, Insightful)

Apparently you haven't read the study on tinfoil hats.....

http://people.csail.mit.edu/rahimi/helmet/ [mit.edu]

Tinfoil hats actually amplify frequencies controlled by the government (very likely the ones the government would choose to use for mind control). The tinfoil hat is a lie.

Unless, of course, this study was produced with government funding and is an attempt to dissuade people from wearing their hats........the conspiracy lives on.

Layne
• #### What if it crashes (Score:5, Funny)

on Monday January 21, 2008 @11:57AM (#22127026) Homepage Journal
What if it crashes? All the boffins are gathered, scratching their heads, and then one of them will say "But it looked fine on paper!" Then all the others will groan, and proceed to calculate the optimum method for beating the crap out of him.
• #### Re: (Score:3, Funny)

We'll just have see how it all unfolds.
• #### RTFA!! (Score:2, Funny)

Paper airplane? When I read the article, I read that the Japanese students wanted to recreate the finale from Final Fantasy VII where Sephiroth summons a meteor to destroy the planet! I've been taking Japanese class for almost 3 semesters, I should know what I'm talking about! :P
• #### How would you know if it "worked"? (Score:2)

I mean, it is not like you can easily track a "30-40cm" piece of paper at any distance.

And how can they not know if it is 30cm or 40cm? that's quite a range, haven't they picked the paper yet?

Anyhow, if they do it, I'd claim success! You won't be able to prove it didn't make it all the way down OK, unless you find its charred remains, but just in case, I would litter "seed" charred remains about, so that I could claim any found "were just a test model", thus ensuring victory!

• #### This is brilliant! (Score:5, Insightful)

on Monday January 21, 2008 @12:05PM (#22127106)
This is brilliant! The use is obvious. We need cheaper reentry vehicles. These vehicles would not be designed to bring back passengers, but there are times when you have 50 (harmless) samples and would like to get one of them to a lab earth-side.

First, for those who say they've never seen a paper airplane break 100MPH, that's at 1 atmosphere. Mach 7 is definitely not at 1 atmosphere.

Second, for those who say it would flip, try writing a stability proof sometime. do you know how to apply inverse kinematics? can you write an equation for the Jacobian of a human elbow joint?

Third, the first step is to try one small paper plane. It'll probably not work, and we'll have to try again. Eventually, we might get a working 8" plane. Some day, we might even have a meter long plane that can bring 3 ounces back to earth.

Imagine an astronaut who is sick, and we need to get some lab tests run. Sending a shuttle or Soyouz down is incredibly wasteful. OTOH, a paper airplane could be equipped with a tracking device (think 1-2oz GPS & transmitter) and a small sample case. We drop the plane, and it's got a 1-in-3 chance of getting the sample into the right hands, in a usable condition. So we drop 5 or 10 and hope for the best.

Think of the potential when we start building larger stations & craft in space. A line of bolts could shear off, and we might not have the ability to analyze it in space. We drop one on each of 5 paper planes, and get a good idea from 2 that we recover of what happened. Were the bolts defective? Was it a fatigue issue? Were they improperly installed?

Imagine a very low cost mission to a near Earth crossing object. Half a dozen paper planes could let us get a few ounces of samples on the cheap.

Andy
• #### Re: (Score:2)

Sorry to burst your bubble, but NASA and Russia have been doing this via considerably more "low-tech" methods since the 60s. Early spy satellites took their photographs on film, and sent capsules down containing the film exposures that were to be developed. They were then retrieved in mid-air by an aircraft.

Still... a cool idea nonetheless. I wonder if the ISS is fitted out with any sort of small-capacity cargo-return capsule... (But at the same time, the space agencies probably wouldn't risk the health o
• #### Re: (Score:2, Funny)

Date: the year 2250.
Scenario: Ship on re-entry orbit to earth.

Officer: "Captain, you're not going to believe this, but we were just passed by a paper airplane...."

(I know, I know, even if it ended up in orbit, the orbit would have degraded in that much time, but I'd still like to see the expression on the guy's face when he sees it fly by the viewscreen."
• #### Re: (Score:2)

The hard part is not going down on the cheap. It's going up on the cheap.
• #### Translation (Score:4, Informative)

on Monday January 21, 2008 @12:06PM (#22127114) Homepage
My quick translation:

Space -> Earth, Flying paper aeroplane. Hobbyists and Tokyo University to conduct tests.

A Tokyo University group and the Japan Origami Airplane Association are cooperating to create a paper aeroplane that can return to Earth from a space station. The wind tunnel tests will be conducted on the 17th. (This article is dated 14th.)

The tests will use an 8cm-long paper plane folded in the shape of the space shuttle that was given heat-resistance treatment. The tests include heat resistance and strength and will be conducted in Mach 7 wind speed in a wind tunnel located at Tokyo University's Kashiwa Campus. (Kashiwa City in Chiba Prefecture)

Due to the fact that space shuttles return to Earth at Mach 20, experiencing high temperature levels due to air friction, special heat-resisting measures have to be taken to protect their surface. Because paper aeroplanes are light, they can begin deceleration even in thin air, thus landing at a slower speed. It is speculated that the plane may be able to reach the ground safely without burning up.

An aeronautics professor at Tokyo University, Professor Shinji Suzuki, says, "I hope that this plane will be released from the space station with a message of peace attached to it. We don't know where it will land, but we hope that the person who finds it will send it back to us."
• #### Re: (Score:2)

"with a message of peace attached to it". I hope that would be in the form of some kind of radiotransmitter...
• #### Pink Tentacle? (Score:3, Funny)

<[moc.liamg] [ta] [vdalived]> on Monday January 21, 2008 @12:08PM (#22127136) Homepage
I mean... I can't say any more than that. A news source, dedicated to the more unusual aspects of Japanese culture... called Pink Tentacle.

I'm a total perv myself but I'm just having a hard time dealing with a news source with that name that has nothing to do with Hentai... maybe that's my problem... I must be too much of a perv.

But then again, I am on slashdot, there must be tons of us unable to process this ;)
• #### De-Orbit? (Score:5, Interesting)

on Monday January 21, 2008 @12:13PM (#22127182)
Since I can't read japanese and therefore can't RTFA, I have a few questions.

The ISS Orbits the Earth at around 7.400k/s at an altitude of 365k. You can't just throw something out of the ISS and hit the Earth's atmosphere for Re-entry. If you "throw" it out of the ISS, it'll orbit, just like the ISS. In order to intersect with the Earth's atmosphere for areo-braking, you are going to need to lower he perigee of your orbit to at least 50-60k. You'll need a delta V of about 100 m/sec to do this.

What gives? Have they built an oragami retrograde rocket as well?

• #### Re: (Score:3, Funny)

Surely if you throw it *down* it'll then have a velocity component in the earthward direction, and since Isaac Newton is in the pilot's seat, it'll carry on downwards...

• #### Re:De-Orbit? (Score:5, Informative)

on Monday January 21, 2008 @12:30PM (#22127402)
No. If you throw something from a satellite in a circular orbit, giving it a small 'downward' velocity component, the object will just end up in a slightly elliptical orbit.

One way of thinking about orbits is that a satellite is perpetually falling towards the earth, because of gravity, but also perpetually missing, because of the lateral velocity component.

To make the paper plane de-orbit, you could throw it in the opposite direction to the ISS at the same velocity as the ISS is travelling: 27 500 km/h. Then the plane won't have any lateral velocity component, and will fall straight down.

• #### Re: (Score:2)

Eliptical or not it will surely have its lowest point (of orbit) lower than ISS. Since ISS flys as low as reasonably possible without touching the detectable athmosphere it should be enough for the glider to touch the thin air and "spiral" down to surface from there.
• #### Re: (Score:2)

One way of thinking about orbits is that a satellite is perpetually falling towards the earth, because of gravity, but also perpetually missing, because of the lateral velocity component.

Wait ... so, orbiting really is the art of throwing yourself at the ground and missing? :-P

I must say though, I'm somewhat baffled by the whole "paper plan in space" thingy as I can't for the life of me figure out what it's going to accomplish.

Cheers

• #### Re: (Score:2)

No, not quite. Newton is in the pilot's seat, but he still has ~7.400 k/sec of tangent velocity along the orbital prograde vector to contend with. Yes if you throw it "down" it will move away from the ISS and towards the Earth. But all you've done is put the airplane in a slightly lower orbit than the ISS. You'd also put the ISS in a very slightly, almost imeasurable, higher orbit.

Remember that orbiting a planet is carrying a velocity that moves you tangent to the planet at a rate equal to the graviti

• #### Re: (Score:2)

I wondered the same thing. There are 2 pieces to an answer to this, though probably this isn't the answer.

The ISS isn't really above the atmosphere, it's above *most* of the atmosphere. Periodic reboosting is necessary. So if you just set the paper plane outside the lock (Perpendicular to the orbital direction) its orbit would decay faster, due to its higher surface-area/mass ratio. Beyond that, a retrograde through, while not 100m/s, would certainly decrease its orbital velocity. You still might have
• #### Re: (Score:2)

I'm really not up with my gravity understanding in space, so forgive me for sounding ignorant.

If you just placed the paper plane just outside the airlock of the space station, without any additional momentum added, would the space station's mass exert a small gravity well that would keep the plane alongside the station? Or is the Earth's gravity stronger at that point because of the space station's altitude that the plane would be pulled toward Earth?
• #### Re: (Score:3, Informative)

The force due to gravity of the ISS is so small it might as well be zero.
• #### Re: (Score:2)

You still might have to wait some months for reentry, however.

The ISS can last months and even years in a semi-stable orbit without re-boosting. The ISS also has gyro's that help it shift it's gravitional gradient around in order to help keep the orbit stable. The orbit will eventually decay, yes. Each shuttle mission does clean up the ISS orbit, but the orbit wouldn't decay for a few years. It only drops around 3km per month. But that effect would be exponential as the orbit decreases.

The ISS has a

• #### Re: (Score:2)

A back of the eyelide calculation would suggest the paper airplane would decelerate at around .05 m/s and drop about 2 meter a year taking it some 60 years to deorbit.

This can't be right. I'll admit it's not easy to find air density figures for those altitudes, but look at the decay rates of other small satellites. The SNOE reentered from a higher altitude than ISS after only 6 years, and it's mass/surface area ratio (the important factor here) was around 100 kg/m^2, much heavier (and thus likely to orbit
• #### Re: (Score:2)

Heck, all you need to do is look at how long the USS Enterprise (NCC1701 - not A, B, C, D, or E) took to decay from "standard orbit" when the power or engines went out. It was always going to happen within the 1 hour episode, unless Scotty worked his miracles. Kind of makes you wonder what the heck "standard orbit" really was. The only truly significant "standard orbit" I can think of is geosynchronous, and that doesn't decay at any sort of significant rate. You'd have to come up with some really odd pl
• #### Re: (Score:2)

Hmm - accellerating a paper plane to 250 mph in probably 0.1 seconds might not be too good for it staying in one piece...

You'd need to be very gradual about the acceleration. That means some kind of guidance system (even if it is just a wire) and propulsion that lasts for at least a few seconds.
• #### Re: (Score:2)

Not even Roger Clemens on roids (wait, was that redundant?) is able to throw it hard enough to break orbit.
• #### Re: (Score:2)

Rail or Light Gas Gun [wikipedia.org]
• #### A few more things... (Score:4, Insightful)

on Monday January 21, 2008 @12:14PM (#22127194)
I'm not associated with the project, but I do have common sense.

For those who think this is a high-risk project, risk is the chance of failure multiplied by the cost. The cost of throwing a paper plane from the ISS is low compared to other experiments, and we will learn quite a bit, not matter what happens.

For those who think this is a waste of money, I understand. You would have never funded the research into better clocks that eventually led to better navigation, which led to Columbus' voyages. The idea of opening a new frontier does not excite you. You would have us turn inward like the Chinese did at one point, burn your own ships, and never venture out again. You will accept a stagnant society. Based on my understanding of you, I offer one suggestion: Please commit suicide. We're better off without you.

Andy
• #### Re: origami deorbit (Score:4, Funny)

by Anonymous Coward on Monday January 21, 2008 @12:16PM (#22127210)
Go creased lighting! Go creased lighting!
• #### The full lyrics (Score:3, Funny)

We'll get some ISS launches and some wind tunnel tests
oh yeah
(Keep talking whoa keep talking)
A mach 10 liftoff and special coated paper oh yeah
(I'll get the money I'll kill to get the money)
With a paperclip on the tail, out the airlock it'll bail
To be completely fair, we'll be catchin lots of air
In Creased Lightning
Go, go, go, go, go, go, go, go, go, go
Go creased lightning you're burning up on reentry
(Creased lightning go creased lightning)
Go creased lightning you're coasting through the atmosphere
You are s
• #### Er... what is the point? (Score:3, Insightful)

<markt@NoSPaM.nerdflat.com> on Monday January 21, 2008 @12:22PM (#22127280) Journal
Even if it _doesn't_ burn up in the atmosphere, which I am willing to concede could possibly occur, as soon as this thing gets into the upper atmosphere of the earth, it will be whipped around by the high speed winds like a toothpick would be inside of a tornado. Heck, the winds could conceivably even shred the thing. I would be surprised if a paper plane that high up actually makes it to the ground at all any time within the next 5 years, assuming that it manages to stay in one piece the whole time.

So what is the point of this, exactly? I mean other than to launch a paper plane from what could be argued as a really cool place to throw one from?

• #### I have a cunning plan (Score:5, Funny)

on Monday January 21, 2008 @12:43PM (#22127588) Homepage
So, here's the thing. I've got a plane. And I have a window in the plane. The rules say (FAR 91.15) that I can chuck stuff out of the plane if I take reasonable precautions to avoid hurting anyone on the ground. So the answer here is simple:

A bunch of paper airplanes with japanese writing on them, air brushed lightly at the nose to look like it's re-entered.

Thrown out the window over the local university.

Playing the odds, at least one of them will be seen landing by someone who reads slashdot. "Holy crap!" he/she (just kidding, he) shouts.

Mua-ha-ha-ha.... I don't know what step 2 is, but #3 is profit.
• #### New crew escape vehicle... (Score:2)

NASA budget cuts inspire the design of the On-site Assembled Crew Escape Vehicle (OSASSCREV): Take twelve sheets of 50-lb A4 paper from storage locker, crease the first lengthwise and fold...
• #### Re: (Score:2)

The only problem is you have to be careful with the units conversion if your plans are in letter and you want to use A4.
• #### This isn't the best kind of PR (Score:2)

Critics of the space station, and a significant manned program in general, point out that the space station serves no scientific or engineering purpose. Unfortunately things like this, rich tourists, and hitting golf balls don't provide the best endorsement, at least from the scientific community. Then again, the scientific and engineering community has basically no input for the station, because if they did the station would either be scrapped, or filled with actual scientific experiments.
• #### Origami Meteor? (Score:2)

Sounds like a new business opportunity for the Origami Boulder guy:

http://www.origamiboulder.com/ [origamiboulder.com]

• #### Prior art (Score:2)

I think I know where the Japanese got their inspiration. Anyone see that MacGyver episode where he was stuck on the Mir space station with a ream of paper to work with?

Dan East
• #### Expensive paper airplane (Score:3, Insightful)

on Monday January 21, 2008 @01:18PM (#22128060) Journal
Back of the envelope time:

The cost to launch something to the ISS's orbit is something like \$10,000/lb. Let's say they make it from typical 20-lb bonded paper - the kind you'd pull from a copier.A 500-sheet ream of 20-lb actually weighs about 5 lbs [howstuffworks.com], or 1/100th of a pound per sheet. Do out the math, and it works out to about \$100/sheet of paper.

Ouch! That's an expensive paper airplane!
• #### Re: (Score:2, Insightful)

Avoid sending 1,377,000 of these sheets up there and you can buy an F-22 Raptor instead.
• #### Ha! (Score:5, Funny)

by Anonymous Coward on Monday January 21, 2008 @01:20PM (#22128082)
Fuck you, scissors and rock!
• #### Re: (Score:3, Funny)

Ooooh! Lets throw Rocks and Scissors from the Space station and see what happens!
• #### Some maths (Score:2, Interesting)

400km up 27700 km/h the energy loss required is about 117kJ potential and 888kJ kinetic to land. say 1MJ. This is slightly reduceded as to get to an eacth grazing orbit the plane must be thrown backwards fom the space station eith a relative velocity of about 700km/h.

If we assume a surface area of 1000 sq cm, not unreasonable for a length of 30-40 cm, then and a re-entry time of 1000 seconds the energy must be lost at about 1 watt/sq cm, which seems possible.

The launch from the space station would appear to
• #### If flying slow enough, why should it burn? (Score:3, Interesting)

on Monday January 21, 2008 @01:29PM (#22128210) Homepage
We always think of re-entry of a spacecraft as this fiery process, but would it be possible for a paper airplane to approach the atmosphere slowly and enter it gently without any high temperatures? Perhaps someone can explain how this is impossible.
• #### Re:If flying slow enough, why should it burn? (Score:5, Informative)

<aeroillini&gmail,com> on Monday January 21, 2008 @02:41PM (#22129060)
As a rocket scientist, I'll take the reins here.

From the altitude the ISS is orbiting, there's no such thing as approaching the atmosphere "slowly". The ISS is traveling at about 17000 mph around the circumference of its circular orbit. In order to enter the atmosphere, a body in that orbit would have to slow down in order to enter an elliptical orbit which intersects the atmosphere. This requires a velocity change (delta v) of about 200-250 mph. Even with that change, you're still traveling at 16,750 mph, so that when you finally do hit atmosphere, the friction from the air will be very high, even if the air is thin. As the friction slows you down, you drop farther into the atmosphere, where the air is thicker and there is more friction. These two changes (air pressure and velocity change) work together to reach a point of maximum heating, and then taper off again as you reach subsonic speeds. The steeper the dive, the faster you reach thicker air, and the higher the max heating point will be.

Let's say for argument's sake that you wanted to drop straight down from where the ISS is orbiting, with no horizontal velocity. (That would require an instantaneous delta v of the whole 17000 mph, which is nigh impossible, but we'll assume we can for our thought experiment.) Since the ISS is orbiting at an altitude of about 225 miles, and the atmosphere is generally considered to start at the 62 mile mark, that's still 163 miles of vacuum free fall to contend with. Leaving out the square-of-the-distance effects of gravity fall off (which are close to negligible at these distances), we get a fall time of sqrt((163 miles)/(32 feet per second squared)) = 164 seconds. That gives us a velocity of (32 feet per second squared)*(164 seconds) = 5248 feet per second, or 3578 mph at the moment we hit the upper fringes of the atmosphere. The heating will certainly be less than the standard deorbit, but it is still a decent force to be reckoned with. Any angle larger than the vertical will require a smaller delta v but will result in a higher entry velocity and higher heating.

Now you might be thinking to yourself, "but AeroIllini! You totally contradicted yourself there!" I did. Except that as you vary the angle of entry from shallow to vertical, the graph of max heating reaches a peak and then falls off again. So for a very shallow entry, your heating will be lower than a steeper entry, but going even steeper the heating will taper off again until you reach vertical entry, which will have the lowest heating of all. Vertical entry also has the highest delta v requirement of all, and a shallow entry has the least delta v required.

• #### Re: (Score:2)

For something with as low a mass/area number as a paper airplane, the calculation for "speed, friction, temperature, atmosphere-density" needs to be done for the complete deorbit process. The tail-off of the atmosphere is a continuum. I suspect that most of the speed will bleed off and the heat radiate away before the paper plane reaches what we normally consider atmosphere. Just a guess on my part; I lack the data and aerodynamic knowledge to do the work.
• #### Re: (Score:2)

So your saying they would be better off using the speed of the station and using it to produce a shallow entry.

• #### Re: (Score:2)

Theoretically, yes. I read about a single-man reentry design that was worked up in the 60's. It was like a giant snowflake. The idea was to create as much drag for as little mass as possible, slowing the structure down before friction heated the structure to melting. It was so high drag that it wouldn't even require a dedicated parachute, it would hit the ground at about the same speed as a proper chute, AND the bottom of the structure would crumple for additional braking.

I forget what materials they said w
• #### Not even a good joke (Score:2, Insightful)

Since there is no mention of instrumentation or tracking, I fail to see even the remotest point to this exercise. Who will know (or care) if this "plane" survives a Mach 7 reentry? It would take months or yers to deorbit if they just throw it out the shuttle. In the meantime, it joins all the orbiting debris as a hazard to near-Earth navigation. Even a paper airplane is a serious piece of debris if you are orbiting in the opposite direction. Kudos on the wind tunnel research, though. How about a study

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