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Origami Plane to Fly From the Int. Space Station
Posted by
CmdrTaco
on Mon Jan 21, 2008 11:32 AM
from the spitwads-are-next dept.
from the spitwads-are-next dept.
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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Firehose:Origami plane to fly from the Int. Space Station by Anonymous Coward
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Hey guys! (Score:5, Funny)
"Ha, that's sweet! You know what we should do with it?"
*Airlock Sounds*
flip? (Score:5, Interesting)
Re:flip? (Score:5, Funny)
Parent
Re:flip? (Score:5, Informative)
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-
Parent
Re:flip? (Score:5, Interesting)
Parent
I'm chargin' mah lazer! (Score:4, Funny)
On the contrary... (Score:5, Funny)
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?
Parent
English language link (Score:5, Informative)
http://mdn.mainichi.jp/national/news/20080118p2a00m0na025000c.html [mainichi.jp]
More likely ... (Score:5, Funny)
Re:More likely ... (Score:5, Funny)
I doubt it. The Americans have always had a bit of a blind spot for incoming Japanese planes.
Parent
why not metal foil? (Score:5, Interesting)
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)
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.
Parent
Re:why not metal foil? (Score:5, Funny)
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.
Parent
What if it crashes (Score:5, Funny)
This is brilliant! (Score:5, Insightful)
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
De-Orbit? (Score:5, Interesting)
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:De-Orbit? (Score:5, Informative)
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.
Parent
I have a cunning plan (Score:5, Funny)
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.
Ha! (Score:5, Funny)
Re:Translated (Score:5, Funny)
uh, Fascinating!
Parent
Re:Translated (Score:5, Funny)
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.
Parent
Re:Translated (Score:5, Funny)
Parent
Re:Translated (Score:5, Informative)
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."
Parent
Re:If flying slow enough, why should it burn? (Score:5, Informative)
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.
I hope this answers your question.
Parent
Re:Too Much Time?? (Score:5, Insightful)
Don't underestimate the power of pure curiosity. Maybe launching paper airplanes from a space station isn't directly going to contribute to anything great like curing cancer, but when that great thing does happen, I'm certain that the big leaps are going to be made by people that just followed their curiosity, instead of worrying about the significance of what they're doing.
As an example, Richard Feynman had sort of a breakdown early in his career. His inspiration had run out, everybody was waiting for the genius to do something brilliant, and he was feeling miserable. Then he decided that he wasn't going to care about people's expectations, about what kind of research was respectable, he was just going to follow up on the little things that interested him. He sat in a cafeteria, looked at a spinning plate (I don't remember the details, there was a spinning plate somehow) and he decided he would try to figure out the forces that made that plate spin like that. He did figure it out, proudly showed it to some senior, who said 'great, but what's the relevance'. There wasn't any, he'd just followed his nose, and solved a problem. Later that little solution turned into to the research that earned him a Nobel prize and became the most accurate scientific theory to date (or second most accurate, I'm no expert).
The point is that many scientists don't work well on something that is prescribed in any way. They need absolute freedom to just do stuff that interests them. If they really have to they can work on things that are more immediately relevant, but not with passion, and it'll never be as great as the stuff they do when just follow their instinct. And these scientists tend to be the ones that come up with the great breakthroughs.
So if these guys want to send up 30 grams with the next shuttle, and take up three minutes of the astronauts' time, I'm fine with that. It's important in a subtle way. It's also very cool.
Parent