So apparently I was right. I read this story on fark last night, and then tried to find info on it in the Japanese media. I found nothing but a 2chan entry about it.
This is the only thing I dislike about the internet. Pretty much everyone believes everything they read, just because it's about "insert nation X here".
Why Homeschool: The first Carnival of Space
Here's a cool thing to take a look at if you've got a few minutes.
The Carnival of Space puts a bunch of space bloggers in one spot, making it easier to get your daily space-geek fix. Some of them talk about NASA, some about propulsion and its associated engineering problems, and all of them are space geeks.
I've read through all the linked blogs, and they're interesting and well-written. Except mine, anyway, I had to pay to get in.
I love rocketships!
If you find any mistakes, please let me know. I will be updating this over the next few days to add pictures that I steal from the web. Thanks to Asuka for pointing out the incorrect bits.
Obstacles to Space Travel Part I: Propulsion.
Manned space exploration has three stages;
Most of these questions have simple answers, and we'll discuss them in future articles.
'How do we get to space?' and "How do we get to our destination once in space?" are the questions not so easily answered. In today’s article, we’ll talk about space propulsion.
To Boldly Go
The first goal for every space traveler is called Low Earth Orbit (LEO). LEO lies between 300km and 2000km above the surface of Earth, it's not too hard to get there as long as you have enough energy, and enough money to buy the energy. Of course, the big problem is finding enough energy.
What does “energy” mean? Energy is the word that scientists use to describe pretty much everything. In simple terms, if something has a lot of energy, it’s either moving really fast (kinetic energy), or it has the potential to move really fast (potential energy).
For example, if you throw a baseball, it has kinetic (moving) energy. If you stand on top of the Empire State Building with a baseball in your hand, the baseball has potential energy because if you drop the ball, it will go faster and faster until it hits the ground. All of the potential energy will change into kinetic energy as the ball speeds up.
It's exactly the same with spaceships. When you have a spaceship sitting on its launch pad, it has zero kinetic energy, because it’s not moving. But it has a lot of rocket fuel in its tanks, so it can be said that it has lots of potential energy. When you light the fuel, it will go fast.
Let’s look at how much energy the Space shuttle needs to get to LEO.
· The energy we need is almost the same as if we wanted the shuttle to go 32,000km/h. Look at the picture below. This cute little picture shows how orbit works. Isaac Newton drew it to show how gravity works. If you shoot a cannonball horizontally away from the Earth (from point V) with a certain speed, it will land at point D. If you shoot it with a slightly higher speed it will land at point E. Even higher and it lands at point F.
If this drawing belongs to anyone it belongs to Newton, but I don't know his email address so I can't confirm it.
He shows that if you shoot a cannonball fast enough, it will fall down to the Earth at the same rate as the Earth curves, and the cannonball will go all the way around the Earth. It will go right back to where it started, probably hurting the cannon shooter in the process. This is what orbit is.
TO stay at a certain height you have to be going a certain speed. In the case of a spacecraft travelind around the Earth at the same height as the Space Shuttle, the speed is about 25,000km/h. But, we lose some speed because of air resistance, so our guess is that we need to be going 32,000km/h.
· The shuttle weighs (masses) about 100 tonnes empty.
If you go to the Moon, your weight will be one-sixth what it normally is. But your mass does not change. Scientists always use mass when they talk about science, because saying "weight" is confusing. Non-geeks say weigh, so I'll use "weigh", and "weight" here, too. But I'll use the word "mass" as well just to be clear. Just remember that mass means kilograms, and not pounds (lbs) or Newtons, and it doesn't change in low gravity.
· Now that we have the speed we want to go, and the mass of the space shuttle, we use the kinetic energy equation to find out how much energy we need.Kinetic Energy = 1/2 x mass (weight) x velocity2
OR
(0.5) x (100,000kg) x (9,000m/s)2 = 4,050,000,000,000 Joules of energy
You would have to run a dishwasher for 24 hours a day, 365 days a year, for the next 1,991 years to use up that much energy.
Or eat 1,844,262,295 Big Mac hamburgers.
That is a lot of energy, but the cool thing is that once we get to orbit, we have a lot of kinetic energy, so we don’t need that much more to go to another planet. The problem is that although we only need a bit more speed to go to Mars, we need to carry fuel with us.
The faster we want a rocket to go, the more fuel we need to get it going. Makes sense?
Okay, but once more fuel has been added to make it go faster, the rocket gets heavier, right? So the rocket needs more fuel to lift the fuel that has just been added.
And then the rocket needs more fuel to lift the fuel that was added to lift the fuel that was added to make it go faster. This is where the problem starts to hurt normal brains.
Luckily, one of the more famous virgins in history, Sir Isaac Newton, designed more than just the gravity cannon. He helped to develop a new type of math, called calculus, and rocket engineers use it to find out how much fuel they need to go a certain speed. We won't use any calculus here, because it's too hard and only Math professors like it, but here is what the Rocket Equation looks like.
Thank you, NASA!
Heavy, eh?
'The Rocket Equation' is the calculus equation we use to find the answer. The Rocket Equation tells us that the full fuel tanks of Space Shuttle have to weigh 19 times more than the spaceship itself. To get higher we need a more fuel than that, and therefore bigger and heavier fuel tanks.
I love you, NASACan we lose weight?
The problem with losing weight is that there isn't much left to lose. Fuel can't be reduced, life support can't be reduced, scientific equipment can't be reduced or we lose our only convincing reason for playing about up there, and robots suck. I want to go to space, I don't want to send some stupid automatic satellite. We're talking about manned space travel here! We must look elsewhere.
Can we find a better fuel?
There is really no way to make conventional fuel more efficient without discovering a new exotic substance. Efficiency rates - how much energy we get from the fuel - are pretty much at a maximum. Making the rocket do more work by designing better nozzles and stuff helps a little bit, but the general consensus is that conventional fuel is a dead end.
So how do we lower costs?
One way to lower the cost of launches using conventional propulsion is to start launching rockets all the time. The more of something you make the cheaper it is to make each one. This is called “Economy of Scale”, and it’s the reason why McDonald’s is so cheap.
The big problem with this argument is that there are no motels in Space. There’s really no reason for anyone to go up there. And there isn't much to do up there except deal with motion sickness and take pictures of floating liquid.
So, until there is a reason for the general public to fly to space, there doesn't seem to be much chance of companies building more rockets to try to take advantage of lowered costs. Maybe we need to find a new technology?
There must be another way...
This was a really neat idea from the 1950's that involved dropping Hydrogen-bombs behind the ship, and then detonating them. The ship would then kind of surf on the energy from the hydrogen bombs. Of course, as you can see from the picture below, the whole idea is insane.
Stolen from NuclearSpace.com
This ship never flew, nor was it even built, but it's still theoretically the fastest and most efficient ship design anyone has come up with. Successful tests were done on the idea using small conventional bombs, but unfortunately, until people stop caring about unimportant things like nuclear fallout drifting into their Cheerios, this option will remain on the drawing board.
These are non-nuclear Cheerios.
· Ion Engines:
Take a few tiny little pieces of ionized Xenon, accelerate them to enormous speeds with a grid of opposite charge, et voila, an engine that exerts the same force as a piece of paper sitting on your hand.
It's not exactly powerful, and it can't be used to get off the planet.
There are two problems. First, on Earth, a spacecraft has to fight off gravity and air resistance to get into space. The force of this engine is so small that the spacecraft wouldn't move at all. And the second problem is that the engine wouldn't even start on Earth. It only works in a vacuum. In the atmosphere, particles in the air mix with the fuel and stop the engine from working.
In space though, there is nothing slowing the spacecraft down (like air resistance) so it eventually speeds up.
The Deep Space 1 (DS1) probe had an ion engine as its primary propulsion.
·VASIMR:This idea involves high temperature plasmas. It uses less fuel, has a low overall dry mass, and makes you go REALLY fast. Like the Ion Engine, it takes a while to build up speed, but it has a higher maximum velocity. Also, it can adjust the flow rate of the fuel so that when the ship is travelling at higher speeds it can use less fuel. Again, like the Ion Engine, VASIMR can only be used in space, but once up there, it rocks. Problems relating to funding seem to have stalled the development of this engine for now, but it also might be that it works really well and the US Government doesn't want anyone else getting their filthy hands on it.
· Solar Sails: Picture the HMS Bounty sailing across the Pacific Ocean in search of gold, spices, and women with no shirts on. Now, in your mind make the sails one million times greater in area, make the ship one tenth the size, lose the prospect of gold and spices, and make the women green with three heads and tentacles. That is the idea of the solar sail.
It works by unfurling a gigantic sail made of mylar (a fancy plastic) and uses the wind of particles that blows off the Sun. It is slow, but it is pretty cheap and looks absolutely fantastic. Beautiful even. Of course, because of something called the inverse square law, we can't use it when we get too far from a star. Yes, it is useful, and beautiful, but it has its limitations.
· The Space Elevator : The space elevator will come as soon as we work the kinks out of carbon nanotechnology. Unfortunately, that looks like it's going to take a while. The elevator basically climbs up a really long piece of burnt rope that hangs from space. It is just as fantastically difficult to realise as it seems, but it does offer an option. It is also fantastically expensive. It could cost hundreds of trillions of dollars. But man, it looks cool.
· The Rail Gun: If you were to put a high-speed Maglev train on the side of a mountain, have the end of the track curve upwards off the top of the mountain, and then strap a rocket engine to the back of the train, you would essentially have the general idea behind the rail gun.
The idea is that we can reduce the amount of fuel necessary to get a rocket off the ground by giving it a lot of speed before it even leaves the ground. Of course the energy requirements are still there, but instead of putting the fuel on the rocket, we can just tap into the local hydro utility. Oh, and spend billions of dollars building the tracks up the mountain.
So what's the conclusion?
This article isn't exactly a full treatment of the subject, but I think we covered the basic ideas.
The conclusion is that we don't really have a conclusion. Space research is a constantly changing field. Every year new rockets are developed, and every year new wierd and wonderful ideas are thought up to get us into space. Some are feasible, some are not, but all of them move the field a little bit further forward.
One answer that a lot of rocket engineers like is the hybrid space ship. Basically it is a space ship that has many different types of propulsion on it for the different environments it goes through.
For example, a space ship could launch like the Space Shuttle, use ion engines to get away from Earth, use a solar sail to get to Jupiter, and then use a VASIMR engine to get to Pluto. It would look pretty cool, though this kind of space ship has problems as well, mostly engineering ones. And engineering problems equal money problems, so I'm not sure a hybrid design is really much of an answer at all.
In regards to popularizing space travel, I can say one thing. Barring the complete destruction of humanity, manned spaceflight will one day become more commonplace. How much it will cost to go to the Moon Hotel, I have no idea, but one day, you will be able to stay there.
I'm trying to fix the layout of the site and am running into some HTML problems. The biggest problem being that I suck at HTML. If it looks wierd for you, please let me know by sending me an email. I'll fix it right away.
You will have questions about the grammar I used, and there will be many jokes that you don't understand. So don't hesitate to email me or comment in the section below.
Obstacles to Manned Space Exploration Part II: Life Support
There are five main items that we must address;
We will look at each of these in turn, discussing in each section three things;
Food: Where do we get it and what do we eat?
Sadly, the number of fast food restaurants and convenience stores in outer space has been dwindling since the Outer Space Nuclear Arms Treaty of January 27, 1967 and we are thereby required to find other food sources. The idea that food is an important aspect of manned space travel is essentially self-evident, but there are many problems associated with food, namely; where do we get it, what should we eat, how do we ensure that proper dietary requirements are met, what is the shelf-life of the food we take with us, and where do we store it?
If music be the food of life... (misquote, I know, but it works.)
It would be wonderful if the only thing one needed to survive was an old Led Zeppelin 4 cassette and a Sony Walkman, but sadly this is not true. Humans need food less ephemeral than rock and roll. For the sake of simplicity, let us assume that Earthly sustenance has two possible sources. The first is the friendly neighbourhood grocery store, where one can buy milk, bread, canned beans, and other items good for eating. The second is our garden, where we grow our vegetables, keep our chicken coops, and tie up the cow. We can make the same assumption about food in space. In essence, there are only two sources. We either have to bring our food with us after buying it in the shops, or grow it, breed it, and raise it on our ship. However, one item that allows for no debate about its source is water. We must bring water with us. There are no known intergalactic natural springs so we must take a good percentage of the water we will need with us. We will discuss the importance of this, and solutions to the problem, in a later article.
Packed sandwiches and a picnic cooler.
The great thing about bringing your own food with you is that you only need a microwave and water to prepare it. Freeze dried biscuits, ice cream, lasagna, and chow mein have all been created, most specifically for the space program. When one is hungry, one goes to the cupboard, takes out a package, opens the top and plunks it in the microwave with a few drops of water. Two minutes later, we can suck our beef bourgignon out of the convenient extra-wide straw in the top of the package. There are problems with this. Shelf-life, while incredibly long for freeze-dried items, is still limited. In the case of a trip longer than a year, this would become critical. The nutritional value of preserved foods drops off drastically after between six months and one year, while unpreserved foods are nutritious for even shorter periods. Nutritional supplements, like pills, creams, drinks, etc., can help but still will not supply everything the body needs.
While convenient in terms of what we will prepare for dinner each night, bringing our food with us is difficult because of the sheer mass of food required. On a short trip this is not a problem as you only need a few sandwiches, an apple, and a thermos of tea. On long trips, it becomes enormous.
Assume the average adult, in total, requires 2500 kilocalories of food and 2 litres of water a day.
Let's say that the 2500kCal makes up 2kg of food (not a bad guess).
That means that every day, for every person, we need 4kg of food and water (because 1L of water = 1kg).
For a 2.5 year mission, which is what some say is necessary for a Mars round trip, each person would require over 4 tonnes of food and water. Luckily, because half of that is water, which can be recycled (this will be discussed in the waste disposal article) with little loss, we can reduce the total required sustenance mass to, as a guess, 3 tonnes.
3 people X 3 tonnes = a lot of extra weight (otherwise known as 9 tonnes). How much space would that food take up? If the food was packed as densely as possible, and assuming the food had the same density as water (which isn't far off), we would need 9m3 of space to store all the food. That's a cube that's a little over 2m wide by 2m tall by 2m long. Doesn't sound like much, does it?
Consider that the volume of the Apollo capsule was about 7.7m3, one is better able to see why this is a problem.
As you can see from this picture, it would take the entire living volume of the Apollo capsule just to store the food for a Mars mission. And ours was a pretty liberal estimate that didn't include refrigeration systems, shelves, boxes, and silverware.
As mentioned in the previous installment of this series titled 'Propulsion', extra mass is a bad thing when designing space missions. The more mass you have, the more fuel you need, and the more fuel you have, the more mass you have. It's a vicious circle, and it requires a lot of math, so obviously we need a better solution.
Image courtesy http://homepage.mac.com/crmichaud/0504asma/0504asma.html, sorry for stealing it.
Grow-your-own
What seems to be the only other possibility is to grow our food as we go. The benefits of growing our own food are various and are laid out below.
Although the mass of a hydroponic growing system would be high, compared to the total mass of the food one would need for a three year trip, it's negligible. We would need more water for growing food which increases mass again, and everyone would essentially become vegetarian which has its own problems, but there are many subsidiary benefits.
Freeze dried ice cream may be fun the first 43 times one eats it, but once the novelty has worn off, a simple crunchy carrot could potentially go a long way to aiding crew morale. Image comes from howstuffworks.com
This, more importantly than morale or mass concerns, is probably the greatest argument against bringing all the necessary food from Earth. The importance of good nutrition cannot be overemphasized, especially for a group of people who will be millions of kilometres from home.
Far from "just" making one physically healthy, nutritional levels have been shown to influence mood, sexual desire and ability, and intellectual capabilities.Very little would be more dangerous to the crew than a grumpy, foolish, space engineer who can't get it up.
Naturally, there are downsides to carrying a farm around.
Limited Variety
No matter how good a farmer one is, there is always a limit to the number of different crops one can grow on one field. If that field happens to be a 5cm deep swimming pool with nutrient rich water under UV lamps in the cramped back corner of a space ship, the choices are even more limited.
Also, as mentioned above, the crew would have to eat a vegetarian diet. There is no simple way to raise animals for protein, because they need way too much living space (unless you like veal), and have their own food requirements. So, to get the necessary protein (primarily from meat), calcium (from milk) and other minerals like iron, we need easily grown vegetable replacements.
Limited Volume
While packaged food may be heavy and eventually tasteless, a small farm is much less efficient in terms of calories per cubic metre. We can pack billions of calories into a space only 2m cubed with pre-packaged food, but a farm requires dozens of square metres of area in order to grow enough food for an entire crew (the increase can be mitigated by stacking, but then we get into other issues.) The farm itself may mass less, but the corresponding increase in the volume of the ship could easily outbalance the loss in total food mass.
Gravity
Boxed food doesn't care which way is up, but water does. To grow food in a hydroponic setup, we need something that keeps the water in one place. We can get that in two ways.
First, we can set the ship up so that it spins on its axis.
Image courtesy of the person at http://www.visual-memory.co.uk who stole it first
When a space ship spins, it creates an artificial gravity field. It's not real gravity, but it sure feels like it, and that's all that matters. If we have something like in the above picture, we don't have to worry about water floating all over the place. Setting a ship spinning is a pretty complicated procedure though, so it's not perfect.
Solutions and Conclusions
With what we have discussed thus far, we must come to the conclusion that though packaged food is a poor solution in a number of ways, it is probably the best for both short-duration and long-duration missions.
In order to have a farm, a ship would by necessity by two or three times bigger in volume just to have room for it or the big structure necessary to keep the ship spinning. This sort of requirement is beyond our ability right now, when we already have a suitable, though flawed, alternative in freeze dried food. A large volume craft is a waste of resources. There would have to be a much more pressing reason for including a farm on board a ship.
Luckily for the hydroponics industry, there are two reasons why we should have a hydroponic farm, and we will discuss them both in the next two sections. (As soon as I get around to them.)
I'm going to write updates for the previous articles I have written. This is a quick update of one from May 2006.
Comics are a big part of Japanese literature, more so than in English-speaking countries, and they can be a great way to learn how people really speak English. Some of the comics below are difficult, but use the dictionaries on the right hand side of this page to help you out.
A big problem for learners is the difference between the English they learn, and the English that normal people speak. Humourous statements in one language don't translate easily to others, because verbal humour tends to be based upon cultural references. Of course, some things are the same no matter where you go. North American's love Takeshi's Castle, and Japanese enjoy American sitcoms. But when we speak, it's really difficult to get across humour without using an encyclopedia.
How do we fix this problem? There are a few options. You can watch movies, but in movies people usually speak too fast. Pausing the movie every two minutes to read the subtitles ruins it.
You can watch television cartoons, but the mouths of the characters rarely match the words they say, and we still have the problem with speed.
You could read novels, but novels predominantly use proper English for description. They will help you with grammar and vocabulary, but not with common English (except when characters are speaking). So what do we do?
One of the best ways to learn real English is online with webcomics. In webcomics, we have a large number of different styles, humour, and settings, and all you have to do is find the one that is right for you.
Our first site is Userfriendly. If you know the difference between a computer hard disk and a DVD drive, this is the comic for you.
Userfriendly is set in a small internet service provider in Vancouver, Canada. The characters are all neatly woven into an overall commentary on the internet, and on the computer industry in general.
The strip is populated with a sentient computer named Erwin, a beautiful and brilliant system technician, and a bevy of wierd and wonderful people.
Greg is the customer support person who has fits of anger every time he has to deal with a customer who uses his cd tray as a coffee cup holder.
The main software team, Pitr and Sid, are arch-rivals. Pitr speaks in a false Slavic accent to make himself seem evil, because he is trying to take over the world, and Sid is constantly trying to get Pitr thrown in jail. Pitr is also dating Sid's daughter, one of Pitr's few successes in his war against Sid.
Every Sunday there is a colour version of the strip that lampoons the heads of the industry, and discusses the biggest, and sometimes silliest, tech news of the week. If you are interested in the politics behind technology, this strip can be great for you.
Something Positive is sometimes dark, sometimes cynical, but almost always funny. The story is set in Boston, U.S.A., and the characters are as widely varied as those in Userfriendly. It tells the story of a (usually) single actor and his gang of wierd friends. His two best friends, a woman from Toronto and a woman from his hometown in Texas, are probably the most insane people you will ever read about and still like.
Something positive is somewhat auto-biographical. The author, with name changes and some significant story line changes, is trying to show his view of what the world is, and maybe should be.
Unlike Userfriendly, Something Positive also talks about some serious issues, but tries to make us laugh at the same time. The main character's mother passed away, his girlfriends leave him on a regular basis for silly reasons, his father has Alzheimer's Disease, and his friends have to deal with issues like first pregnancies, racism, sexism, and other problems.
For students who normally read manga, MegaTokyo is a great introduction to English comics. It tells the story of two American gamers who get stuck in Tokyo after the E3 game convention. The comic started in 2000, and has been popular ever since.
The comic focuses on the humourous antics of the main characters, Largo and Piro, while they try to get used to life in Tokyo, and of the two women they meet. Hayasaka Eriko is an ex-idol and hates Otaku, Nanasawa Kimiko is becoming popular as a voice actor, and she needs protection from the Otaku.
We also meet the Tokyo Police Cataclysm Division (TPCD). Their job is to protect Idols and also to clean up Tokyo whenever a monster attacks. The TPCD drive giant robots and hire Godzilla for special events (see example).
Why is MegaTokyo funny? Because everything is SO WIERD.
It appeals to me because of the silliness of the situations, and because the characters act like there is nothing un-ordinary happening. The leetspeak is sometimes difficult to understand (for me too!) but it adds atmosphere to the comic.
And finally, here are a few others you can check out:
Starslip Crisis - A spaceship that is also a museum. Wierd, often quite funny.
Questionable Content - This comic is great, and pretty realistic. Except for the robots.
Nine Planets Without Intelligent Life - A philosophical comic. It won't make you laugh, but it will make you smile and think about life.
Can you learn humour? Yes, but as usual when we are learning a new language, it will be difficult. Like everything else in life, have patience, and you will get there. And with webcomics, at least you'll be laughing on the way.
Good surfing.
