Reactionless EM drive

Recently, a Chinese physicist claimed to have invented something that was previously only science fiction. I'm going to have to explain. Most of our motion is thanks to Newton's 3rd law, which states that for every action, there is an equal but opposite reaction. In other words, to move forward, something else must be pushed backwards. When I walk, or drive, or take a train, my shoes or the vehicle are pushing the earth backward, to push me forward. The earth is pushed back a negligible amount. This is bad news for rocketry, as there is now a tyranny of fuel requirements. In order for the rocket to move, it must eject fuel. The fuel has weight. More weight means less thrust for any particular expenditure of fuel. The rocket must be super powerful to move both itself, and the fuel required to move it, which requires still more fuel (because the additional fuel has mass, causing additional inertia). So science fiction writers proposed the reactionless drive, in which no fuel is ejected. Instead, energy is inputted into the system, and somehow directly transferred into motion. This way any energy, such as solar power, nuclear power, or other systems that don't involve a constant stream of exhaust, could keep the rocket moving. The rocket would be much lighter, and thus easier to launch, maneuver, and power. The EM drive is, if the reporting about it is correct, exactly that reactionless drive. Microwaves are bounced around in a container, imparting their energy in the desired direction of motion. Microwaves have essentially zero mass, and can be produced by electrical activity. Since electricity can be generated by all kinds of systems, any of these systems can power the rocket. The drive as described now is not very efficient. Only 2% of the inputted energy becomes motion, the rest becomes heat, noise, and other wasted energy. This drive could not launch a rocket from the earth's surface, and would only really be useful for a rocket that is already in space. However, we can expect refinement of the device as time goes on. And someday, in the distant future, a spacecraft will launch, unfurl its solar panels, and use a reactionless drive like the EM drive to speed it on its way to a distant star. A laser system in solar orbit is tracking the system and providing a steady steam of power. The craft accelerates, going faster and faster until it is traveling at a large percentage of the speed of light. After years of accelerating, it then reverses the process, slowing down until it arrives at a planet, orbiting the distant star. It then deploys its payload. Perhaps this is a scientific probe, to bring data of this distant world to scientists on earth. Perhaps this is a colony constructor, bringing a human colony to a distant world. Perhaps it is something that I can't even conceive of yet. But whatever it is, it will be glorious.

Uranus

Our seventh planet from the sun has been known about since ancient times, but most of the ancients thought it was a star, as only a dim point of light is visible from earth.    In the 1970s, we got our first good look at it, and what we saw was a dull green-grey sphere.   However, this planet has a greater significance.

Uranus is one of the odder planets in the solar system.   It has a much greater axis of rotation, being either 96 or 106 degrees, depending on which of the two definitions you are using.   If you are basing it on the way the planet rotates, and assuming the rightwards based rotation  is the north pole, then it's 106 degrees.  It's the coldest planet in the solar system.  There is one planet further way, Neptune, and the numerous dwarf planets beyond like Pluto, but these have additional internal heat from radioactivity that warm them up.

But soon enough on geological time, Uranus will have to become our home.   In one billion years, our home star will become a red giant star.   The innermost planets will be incinerated, and if we can't move the earth in time, it will be charred into a lifeless glowing rock.   And we too would be baked if we can't move the earth in time.

When the red giant phase is complete, the habitable zone, currently in our orbit, will have moved to the Uranus orbit.   I'd like to believe that we'll move the earth into being a new moon, but in all practicality, we'll probably just abandon the earth and rebuild on the various moons that are already there.

We'll need energy, in greater quantities than I can readily imagine, and technology that I can't even dream of, but we have a billion years to do it.

Radiation Pigeons

When the Chernobyl nuclear plant near Pirpyat, in what is now the Ukraine, melted down in 1986, it was a worldwide disaster.   Radiation spread as far away as Kansas, and Pirpyat is now massively radioactive, and judged uninhabitable.  A few very stubborn people live there, and made an incredible discovery.  A type of yeast there developed the ability to eat gamma radiation.  As food.    This species of yeast is also universally found in pigeon feces.
Gamma radiation is the lowest-mass type of radiation produced from radioactive decay.   It takes several feet of lead to stop it due to its high energy,and it's absolutely hazardous to human health in the same way as touching a red hot stove would be.   Also, outer space is absolutely full of it, which is a hazard to would-be space travelers.  
These two facts can be combined to form two mad inventions, and I'm not sure which one is crazier.
One, we can clean up radioactive spills by spreading bread all over the affected area and then releasing some pigeons, which can easily be caught in most major cities in North America and Europe.   When these pigeons poop all over the place, the yeast will get right to work eating up all the radiation, making the area inhabitable years sooner than it would otherwise.
Two, we can keep a thin layer of pigeon poop in the outer hull of space going vehicles.   In the depths of space, the yeasts will absolutely feast on the radiation, and only very little would reach the astronauts.  Space travel would be lighter, cheaper, and safer.

Water Cloud Jovian

According to astronomers, one of the more commonly discovered planets that we've seen in the universe is the Water cloud Jovian -- imagine Jupiter, but in the earth's orbit. Under higher temperatures, the brown and orange stained ammonia clouds evaporate, and are replaced with fluffy white clouds, the kind seen in the earth's sky. The planet enjoys earth-like temperatures (based on radiation calculations), and if you could somehow visit one, you'd see sky above, and sky below, ending in a blue void. Artists have drawn, from the scientist's description of the conditions, what one would look like from the view of an air vehicle flying through the upper atmosphere, and it is remarkably beautiful.

Jovian planets would also be useful industrially. Although this beautiful air would choke you to death, plants could live in this environment without difficulty, and the strong magnetic field allows light in while shutting out much of the more harmful radiation of a star. A farm in such an environment would be a very useful thing, if you could get it on a floating, balloon hoisted platform. With effectively ten earths of space, you could grow quite a bit of stuff. The planet is also rich in chemicals like methane and ammonia, and hydrocarbon synthesis would also prove valuable as industries. Much of a Jovian planet's hydrogen is actually in the form of pure H₂, which is quite chemically valuable (as well as dangerously explosive, so it would have to be kept separate from the breathable air.)

These industries would be able to bootstrap from small balloon-hoisted platforms into larger platforms, into connecting the platforms. While getting the end-products out of the immense gravity well would prove challenging, a successful farm would also be a good place to start a colony -- independence and cheap food would prove a draw to quite a lot of people. The plants would, over time, terraform the planet and increase the industrial usability of the planet's remaining hydrocarbons. Although metal would be in short supply, there being effectively none other than what the colonists bring with them when they arrive, all the plastic you want could be synthesized out of, effectively the planetary air, farming will be super easy, Earth can't attack you, and you can never, ever leave. Anarco-primitivists would love it, as would the more agricultural sectors of French society.

Over time, I think these floating platforms would expand to cover the planet, with each new immigrant group bringing another platform, and extensions being woven from wood and plastic. In a few strategic spots, a hole is deliberately left for the view, but elsewhere, cities spring up, farms grow enough food to literally cover the entire surface of the earth, and people live their lives.

It'd be awesome. Also, impractically distant, as the closest known water cloud Jovian planet is about 41 light-years away, not to mention the usual preposterous costs of any space travel at all.

The Ugandan Space Program

Slashdot informs me today that a small group of Ugandans have an impressive dream: They intend to create their own space program with no help from the Ugandan government, and using only the local resources.
This is a big deal because Uganda is not the wealthiest country on earth, and so far space exploration has been the domain of large nations doing this for billion dollar science grants and military-industrial-complex testing of rocketry and other technology. Uganda has pretty much none of those things. At the moment, the team are designing airplanes, but they intend to move upwards as they gain more capability. (None of the team are professional engineers.)
Ideally, discoveries that this team makes will make space travel an order of magnitude less expensive, and thus more available to more people.

Engineering Apotheosis

Image by Ralph Buckley via Flickr

There are three inventions that might not even be possible, but given them in conjunction, would grant engineers absolute omnipotence. Given all three of these things, it's only a matter of time before I'm creating entire universes.
First, a zero point energy generator. This might not even be possible. Energy is like the money of physics, and there have been a few clues that it might be possible to have negative energy as well as the positive kind that we're familiar with. If so, then from a "zero point" of no energy, you could draw off and separate arbitrary amounts of negative and positive energy, which would have to be shuttled off in opposite directions, as they would nullify each other on contact. However, negative energy hasn't been shown to really exist, and might make about as much sense as making money by sending out checks for negative amounts of money and somehow collecting when the checks are cashed in.
The first thing I'd do with zero point energy would be the mundane energy use, running the air conditioning, refrigerator, and lights with the energy, and do experiments with the negative energy. Could I run my computer on anti-electricity, and if so, would it absorb heat instead of producing it?
The next thing would be a matter condenser, that would change energy into hydrogen. Since E=MC^2, this would ensure an unlimited supply of materials. Of course, this would not be worthwhile without the unlimited energy from the zero point system.
The third thing would be some sort of teleportation system to make arbitrary manufacturing. It would have to teleport together raw materials to make things, such as combining a few grams of carbon from charcoal, hydrogen and oxygen from water, and nitrogen from air to form a hot dog. It would also need to be able to scan new patterns and store them in a computer. This also might not be possible due to the Heisenberg uncertainty principle, in which knowing the exact position of an atom requires unpredictably altering its velocity and vice versa.
My power with these things would grow exponentially. First I'd use the teleporter/replicator to scan the three inventions and be able to arbitrarily produce more. Then I'd start scanning useful tools, which I now have in arbitrary amounts. Then, having proven its safety, I'll start handing them out because other people deserve this too. And next, I'd start designing entire star systems, which I teleport into existence. If I want to visit them, a matter-condenser rocket will take me there, accelerating to preposterous speeds with a zero-point-energy plus matter condenser, producing a stream of supercompressed hydrogen gas.
I'd send probes to go deep into the void, make a ring of trillions of matter condensers that was several AU in diameter, and spray hydrogen into the center to create stars. When the star grows enough, the welding on the ring fails and the matter condensers go flying outward into the universe. I'd recharge the sun by swapping out large amounts of it for a fresh cube of hydrogen. The heat death of the universe would never occur, because we would continuously rebuild it from scratch.

A Lunar Base

I constantly hear about how the moon has water in a crater on its south pole. This gives me an idea of building a base in the north pole.
The moon, unlike the Earth, is not tilted. The poles of the moon have perpetual sunlight...except that the south pole is a crater that lives in perpetual shadow. Hence the water. (With no atmosphere, the moon is burning hot where the sun shines and freezing cold where it doesn't. Ice remains in the shadows.) So my idea is to build a huge megastructure on the north pole (especially if there is a crater there), topped with a giant geodesic dome made of Plexiglas. I imagine this structure being many cubic kilometers in size, at least the size of Rhode Island. In the geodesic dome, there will be a park and a farm. Below, a living area and a laboratory and a huge storage area, and some sort of airlocked shaft to the lunar surface for resupplying.
I imagine the lab being used for fusion research, as the lunar surface is covered with helium, and the farm growing the food that the fusion scientists would eat. Also, it would grow tobacco. Why? Interesting reason for that.
On our third trip to the moon, one of the astronauts was a major conservationist and brought a collection of seeds with him. When he came back, these seeds were quite popular with people who desired the novelty of a "moon tree." There is nothing odd about the trees other than the fact that as seeds they were once on the moon. (This has not changed them in any perceivable way.) If people like "moon trees," I'll bet they'd go absolutely gaga for "moon tobacco." Now you can smoke something...that grew in the perpetual sunlight at the lunar pole. Holy crap!
One other project to develop would be to send astronauts to the far side and have them construct a telescope there. Communication wires would then be installed to link it to the moon base, and then to Earth-based radio link. This would be an excellent vantage point to observe the universe, and I imagine a major jockeying of astronomers for a share of time to use it. (Only really useful when the moon is full, and the telescope not facing the sun, unfortunately.)

Space Internet

People love the internet. Especially astronauts. You can get all kinds of practical information, keep in touch with family, and there are countless amusements for the boring parts. Just one problem: It's hard to get off-planet. It's really hard in high earth orbit, and past about the moon or so, just plain outright impossible. TCP/IP, the backbone of the internet, would literally time out before signals could reach, say, Mars, even when Mars is at its closest. To say nothing of the return trip. My Mars base is ruined!
NASA does have a solution that they call DTN, which they use in the space station and other orbital places. DTN has a much much much longer timeout. If you're patient, you could run signals as far as you need to. And this gives me an idea.
A DTN over radio link connects a caching computer to the Internet...by downloading all the pages it can get a hold of, transferring email, and uploading new pages and transmissions (such as, say, blog posts), and storing this. It would transmit once per day. Space stations or other planets now receive the internet via the caching computer. Admittedly, every page in it is, on average, a day old, but it is as it appeared on Earth yesterday, and it would work at area network speeds (100Mbs is cheap, and 10,000 Mbs is...available.)
This way, people in space can look up things on wikipedia, or write blog posts, or upload the Mars vacation photographs to their blog. From their perspective, the Internet just doesn't update very often, but it still works. And back on Earth, you might get notification late, but you will get it. It's the best I can think of without, you know, altering the speed of light.

Mining Space

NASA says that the solar system is rich in gold. (And some other things.) Meanwhile, demand for gold on earth has skyrocketed. If the other eight planets (and dwarf planets and meteors) are as rich in gold as the earth is, then there's quite a pretty penny in reaching it. I think the only reason why not is the immense cost of space travel. And there are ways of bringing that down.
A quick investigation into space fountains and railguns could, I think, cut the cost of space travel by a factor of ten. From $10,000/kg to $1,000/kg. Geologists would tell us the most likely locations to find gold, and automated probes would go mine and refine it. The immense cost of setting up this industry would be recouped within a year's operation.
If the price of gold collapses, other materials can be mined as well. Platinum, perhaps, or silver. Even bulk material like iron or lead could be mined in massive scale with no concern of environmental damage, as the non-earth planets of our solar system have no plants or animals to damage. Iron may sell for a mere 2c per pound, but when you can move a billion tons, that adds up to some serious money.
The cost of these materials dropping would be a boon to the manufacturers who make things from them, and and a disaster to the companies who mine it from the earth. (Though, if too many of them object, a change in focus would be doable, maybe even easy.)
Some places would be easier to mine than others. Mars would be easier than, say, pluto, which in turn would be easier than, say, Venus.

Space Railgun

The most efficient way I can think of to move a large amount of mass to space is to have a site with many solar panels, and many deep cycle batteries, and a massive railgun. In existing rockets, 91% of the weight must be dedicated to fuel. Fuel which will instead by in the batteries. We would launch something along the lines of a 10 ton cargo container. With some kind of docking port.
Randall Monroe's XKCD suddenly becomes terribly relevant here, as Mr. Monroe used to be a NASA consultant. Accordingly, he brings me a chart of how much force I need to apply to escape various planets in the solar system. Escaping Earth's gravity is essentially the same as moving 5,478 6,379 km straight up. From this, I can calculate energy.
10 tons * 6379km / .1 s ^2 = 5.87 x 10^11 newtons. Quite a lot of force, for sure, but only 9% of what would be needed if it were a traditional rocket. And, this can be used over and over. Every few months, we can launch another cargo container, until either the batteries or solar panels break down, and if we replace one of those after every launch, the system will run indefinitely. (Solar panels last for about 20 years before requiring replacement. Batteries depend on the manufacturing, but I give them 5 years. We can replace a component once a year, or if we're paranoid, once a month. More than enough capacity left, so every launch should succeed.)
The best part of this system is that it would bank sunlight until launch day. You can't launch every day: there are narrow windows when you can get to your destination with the most gravitational assistance from the other planets, and reach your actual destination in space rather than drifting forever into the void. In the meantime, the system is not idle so much as gathering energy. Energy it will use when the time is right.
I'm hoping that this will reduce space launches costs by a factor of ten. Not as good as a space elevator, but a definite improvement. Did I write this before? I feel the strangest deja vu....

Impractically Terraforming Venus

I think this plan is impractical, but the coolest possible way I could terraform Venus. As I mentioned before, Carl Sagan had a plan to have a city encased in a plexiglass bubble, filled with Earthlike air. Placed in Venus's atmosphere, this floats like a balloon, about six miles over Venus's inhospitable surface, where the temperature and pressure are Earthlike.
We deploy millions of these in a Dyson-like swarm. (Dyson's sphere, as described by Dr. Dyson, is not a solid object, but a swarm of satellites in clever orbits that never quite collide, and prove dense enough to capture 99% of a star's output.) The swarm orbits around Venus, and when they're close enough to each other, we connect them with steel rods, and then form "bowls" with metal plates in the area between the rods and the bubble cities. Venus now has a second "surface". Below, the supercritical carbon dioxide cools in the darkness, while above, a large planet with lots of room. We fill one bowl with imported soil, and grow plants in it. Preferably crop-plants. Any waste shucked off by the farming is put into the other bowls to compost. When the composting is done, they are super-fertile farming areas. The process accelerates until the entire surface is full of greenery. At that point, the plexiglass can be removed from the bubble cities, as human beings could now breathe this planet's air.
Down below, the carbon dioxide cools in the darkness until it is a liquid. It probably won't reach solid temperatures at this pressure. I can imagine the farmers above siphoning small amounts off on occasion. As this gets used up, the rocks below can become a second resource. Or, thirdly, the gap can be used for waste disposal, because no human being's ever going down there.
Now at the beginning, I said this was impractical. Even one sagan-bubble city would be a massively expensive trillion dollar undertaking, with some very difficult engineering in the process. This is talking about making millions, possibly even billions, of them. And as for the connecting stage, I'm not sure earth even has that much steel.

Potatoes

Solanum tuberosum is quite an amazing plant for agriculture. It's native to Chile/Peru (Inca lands), but can be grown in the wet marshlands of east Texas, the dry deserts of California, the high mountains of Japan, the hot African savannah, the freezing tundra of Siberia, and the grasslands of Ireland. Most other plants couldn't withstand that kind of climatic variation. It is nutritious and the natives describe its origins as a gift from their very gods. You could live for two weeks on it and a minor protein source like a swig of milk, albeit not well. And all but one part of it is utter poison.
I'm speaking, of course, of the common potato. Between it and milk, one would only be deficient in molybdenum, which can be supplemented back with a bit of oatmeal.
I think we should grow potatoes in space. Why? Practice. If we want to send a mission to Mars or farther, we'd either need three months of food packed and weighing down the whole mission (More weight needs more fuel), or we can grow our own en-route. And plants are an excellent absorber of carbon dioxide and other things we humans need filtered from the air.
I also think we should experiment with potato genetics. Potato blights have ruined many-a-harvest because the farmer was growing a monoculture that was all equally susceptible to the disease.

ComputerWorld

In the future, when we humans as a species have some project so massive that all the world's supercomputers aren't enough, I have an idea for a huge omni-computer.
We build a planet, of which one side is purely solar cells, and the other is all a massive supercomputer-complex, with a radio-array to send and receive instructions. The interior could be storage batteries, or maybe even is hollow. Due to the massive size of this, it would have to be constructed in space. We then move it to a very close orbit around the sun, where it becomes tidally locked with the solar-cell side always facing the sun, and the computer array always facing away. The solar cell side heats to over 500C, and provides Exawatts of power. The computer side is very cold when the machine is off, -300C. When the computer turns on, that will change.
This project would easily cost a quadrillion dollars, but it would solve every computation problem known to humankind in 30 minutes. Only a more complex problem would justify the massive expense.

Orbital Habitat

Long ago, the mathematician Joseph-Louis Lagrange found that for any three-body orbit (that is, three large objects, a la a solar system), There are five points where you could introduce a new object and its orbit would remain stable. The next paragraph will review this idea -- feel free to skip it if you are a mathematician, physicist, or computer scientist.
The points are numbered, L1 through L5. There are two existing bodies, one larger and one smaller. For the purpose of this exercise, we will call the larger body "the sun" and the smaller one "the earth," although this could easily be adapted to any solar system. L1 is directly between "the earth" at a short distance past where the moon orbits. A solar probe is in fact maintained at this position, because it's really useful for studying the sun. (It stays with the earth's orbit, has a direct, unobstructed view of the sun, and so on.) L2 is on the other, night side of the earth, and would be a great place for a deep-space telescope. It would move with the earth, and remain forever in the earth's shadow, seeing deep into the darkness for a great resolution. (Apparently, someone else beat me to that idea, because two probes are already there, and three more are planned.) L3, L4, and L5 are the most interesting ones for this. L3 is on the opposite side of the sun from the earth, in the earth's orbit. L4 is 60 degrees "ahead" of the earth, L5 is 60 degrees "behind." The Lagrangian points are maintained by gravitational balance, and will stay in relative position until pushed out by some other force. Math, it works.
I think we should build habitats in L3, L4 and L5. They could have polluting factories, dangerous crops, or just people who we don't want anywhere near the earth. (Like say, the chronically annoying.) The platforms wouldn't touch Earth, would have an excellent supply of solar energy to power industrial or agricultural activity, and would survive events that would destroy the human ecosystem. (Oops, we nuked ourselves out of existence? L4 can reseed....)
This would be insanely expensive. Cheaper than terraforming mars or venus, but still in the multiple billions, and up to trillions, especially if we make it a large, human habitable habitat, and not just a simple lightweight probe.

Project Orion

Way back in 1947, a rocket was designed that would be able to accelerate as fast as 80% of light speed, and worked better with larger masses (thus making space travel freakishly cheap) and would cost about the same as the smaller rockets we now favor. It was called Project Orion, and was only scrapped because of nuclear paranoia. For you see, Project Orion's main propulsion was essentially nuclear bombs.
Orion would now be illegal to build under the Partial Test Ban Treaty of 1963, which requires that all nuclear detonations be done in underground bunkers. Detonations in space would be right out, to say nothing of detonations in the open atmosphere. The safest possible launches would have been from the poles, where radiation would not have been magnetically drawn back to the earth.

Space Based Waste Disposal

When you never, ever, ever, ever want to see it again, take my railgun system and shoot it off into space. Time it so that it avoids big star systems, and accelerate it faster than 11km/s, and it's gone forever.
Trash is a problem because we have it sitting around in landfills. The landfills smell. The landfills require a lot of work so as not to seep toxins into the water supply. The landfills attract unwanted animals and hobos that want to eat the decaying sandwich and pizza crusts. Some of the more toxic waste requires more elaborate procedures to keep it contained. But if it were far enough away in space, it wouldn't be anyone's problem ever again.

Railgun Space Launch

Rail guns would greatly reduce the expense of launching items, vehicles, satellites, and so on, into space. Possibly down to the magic level that would allow privatization of space travel, finally putting advocates of such to put up or shut up. Allow me to explain.
A railgun is an engineered device that, using two electrically charged rails, exerts an enormous force on the object placed between those two rails. Aligning the currents with the right spin, this direction is "up." Yes, it uses a lot of energy to reliably produce a space launch, but less with this method because the energy will be provided at ground level. The launch vehicle will not require its own fuel, as the rail gun will be providing the energy. It can launch thousands of vehicles a day, if need be. (Though need will not be unless we're evacuating the Earth or something.)
Now space travel is expensive, because anything you want to get even into earth orbit must be sped to 11 km/s, or it will just fall back down again. 11 km/s is absurdly fast. To accelerate even, say, my car, to this kind of speed, some 19,958 Kilo-newtons must be applied. This would easily consume the entire output of a medium sized power plant, all charged in a bank of capacitors the size of a skyscraper.
Existing space travel uses massive hydrogen-oxygen bombs that, when
detonated, provide all that thrust and more. Of course, this means
carrying thousands of kilograms of those materials with you, which will further throw off calculations by being used up. Heavier thing, more fuel required. More fuel means even more weight. Any space mission will easily cost a billion dollars, leaving it solely in the reach of national governments.
With a rail gun setup, a very rich person could afford to send themselves and a Soyuz-type space station into orbit, for about $10 million. Plus maybe another $50 million in startup costs. Further advances might further reduce the expenses, bringing space travel to the masses.
Now at this time, there are people who complain that space travel is a misuse of government resources, and that space travel should be privatized. Very well. For $60 million, I offer you more material resources than the entire mining output of the earth. For $400 million, a consistent trade route could be developed, earning that sum back within 20 years time and employing a staff equal to the current population of Utah. I dare you to.

The world's farthest away greenhouse

20 light years from our own solar system is a red dwarf star, Gliese 581. Astronomers have confirmed the existence of 3 planets around it. The tradition of naming for planets around stars is to name them with the star's name followed by a letter, starting with 'b' for the first planet. (Because the star is 'a.')

Gliese 581b seems to be a gas giant around the size of Neptune. Gliese 581c seems to be similar to our planet Venus, but larger. Gliese 581d is in the habitable zone, and is speculated to be similar to earth, with liquid water and more. All three are likely to be tidally locked due to their proximity to their home star, meaning that they have a day side that always faces the star and is lit constantly, and a night side facing away from the star that is dark forever.

I think we should send a probe to Gliese 581d, which would broadcast video of circulating the planet when it arrived. It should then land, construct an airtight greenhouse, fill a tank with the local water, and plant the seeds of earth plants in the greenhouse. In the remote chance that Gliese 581d has native aliens, they would probably find this interesting (organisms from ANOTHER WORLD, sealed off so it won't harm us, holy crap!), and if they don't, then we've kick started terraforming the place in case something happens to earth. (Probably the greenhouse would, at some point, leak, and carbon dioxide and methane are gases likely to be common on other planets that plants can use)

Now since Gliese is 20 light years away, and the absolute maximum speed we could manage is about .8c, if we launched this probe tomorrow at top speed, the probe would land 25 years from now, and we'd get the video about it radio'd to us in 45 years. Also, this would cost multiple millions of dollars. Still, awesome, right?

Space Elevator

Many organizations would like to build an elevator to space. Such a structure would reduce the cost of space travel by a factor of 100. (It costs $10,000/kg now, this would reduce the cost to $100/kg.) Having done so, we humans could afford many more space missions including colonization missions.

To built it, we would orbit a large rock around the equator, and build a base directly under it. The rock would have a geosynchronous orbit in which the location it hovered over remains constant. Then, from both directions, cable would be built until connecting at the middle.

A strong enough cable could hoist things up and down for cheap. (Elevators take very little energy if a counterweight system is involved.)

A big problem is the necessary tensile strength. Most conventional materials would rip themselves in half under the strain. Plus, most things that we humans want to send into space are quite heavy. Voyager 2 weighs around 700 kg. A 70kg human would need a 40kg space suit (with air and so on) to survive. They will also need extensive thrusters to reach their destination in space. And the elevator will likely weigh in excess of 300kg all by itself.

In the unlikely event that the ribbon broke, under excessive strain, or by having a plane fly into it, the part of the ribbon nearest the bottom would fall eastward. Since this would have to be built at the equator, and most of the equator is ocean not claimed by any nation, the best place to build this would be in the middle of the pacific ocean. That way, even the highest flying plane crashing into it would only affect the bottommost part of the ribbon, which would fall into the ocean, scaring the hell out of any passing fish, but not harming any humans, buildings, or complex animals. The part above where the ribbon broke would be slowly ejected into space, with any cargo still attached. Seeing as that's where passengers on the elevator would want to go in the first place, no big loss. Should the elevator detach while trying to LOWER a passenger back to earth, the cargo can be detached from the ribbon and splash down in the ocean, where the earth's gravity will pull it.

Terraforming Mars

Perhaps you've heard in the news about the US (and perhaps other countries), trying to travel to Mars. One of the goals of the project is to finally either confirm or deny the existance of life on Mars, be it now or thousands of years ago.

Many people are complaining, as this mission is expensive and doesn't produce a material result. (It wouldn't be worth bringing back any materials that didn't have a large scientific interest, and mining is done in tons anyway.) Well, for material results, I've got something for you that I read in a magazine once.

Terraforming is a slow process that would make Mars more Earthlike, until we could build cities and wildlife reserves on it. It'd be like gaining another Eurasia for all of earthly life. (Mars is smaller than earth, and the lowest land on Mars would become flooded by the new ocean.)

The first step would be to crash Mars's two moons into the surface, as the moons aren't as scenic as ours and would be inside the Martian atmosphere by the time we finished, which would crash them anyway. Then have satellites release CFCs from the surface. This would not erode the Ozone layer as it does on earth, because Mars does not have an ozone layer. The thickening of the atmosphere would increase the temperature, which would allow for better options. At this point, we would release large amounts of methane and CO2 into the Martian atmosphere, which is useful to us as both of those are essentially waste in our atmosphere.

By this point, Mars is like the polar regions of earth: cold and miserable, but able to support some life. Lichens would be seeded at strategic points on the Martian surface. Mars has some water to sustain them, but probably not enough for, say, a penguin, or a polar bear. We would want to add more. NASA would find asteroids in the asteroid belt rich in water, and crash them into Mars. As it warms, small lakes would develop. More CO2 and methane would keep it from freezing back over.

In addition to providing oceans and life support, vaporized water is a greenhouse gas, further raising the temperatures. We're at the three quarters completed point, and now some regions of mars resemble Siberia. The wetter areas would support arboreal trees.

We continue to add CO2, but now we're planting more plants. The plants break down the CO2 with the power of the sun. The carbon becomes their food and bodies, the oxygen is released into the atmosphere. The original CFCs have probably decayed or escaped into space, so an ozone layer would form, protecting Martian life from the powerful radiation of the sun. Water would also need to be added. Contaminated earthly water could be used too, if bacteria are added to break down the pollution.

It would also be wise to find a way to reactivate the magnetic core of Mars. Earth's molten core provides a magnetic field that in addition to aiding in navigation through the use of compases, also reflects harmful radiation from space.

At the end of the project, mars has oceans, plants, and the deserts on which plants continue to expand into. We add animals now, including ourselves. Any humans there build cities, and run civilizations, be it as a colony of the sponsoring nation, or independantly. Space travel would connect the two planets economically, and I imagine the Martian population booming from the rich resources and lack of people to compete with the colonists.

All in all, this project would cost trillions of dollars and take over a thousand years to complete, and there is some risk of Mars slowly de-terraforming, returning to the lifeless husk it is today. I am absolutely convinced that it is worth doing