How about liquid hydrogen and oxygen?

Many unmanned spacecraft are nuclear powered. Plutonium or other highly radioactive materials are used as a steady and dependable heat source. This is somewhat controversial from a safety standpoint, because an explosion or crash during launch would scatter radioactive and toxic compounds.

FOSSIL FUELS to get a space craft into orbit? Gasoline and coal do NOT provide the raw power needed to put a space ship into orbit. They use liquid oxygen and other things. As far as I know Russia uses a solid rocket booster, but I don't think it's made of fossil fuels.

There have been demos of a ground based laser being used to heat material on a ship into plasma. The plasma creates thrust like a rocket engine. The big advantage is that the energy source is ground based.

Hydrogen maybe..but dangerous to work with.

I saw an article detailing using a huge rail gun to propel spaceships into space. The calculations are done and they say it would work.

hydrogen but you gotta be carefull with it cos one thing wrong and kaboom and ur dead.

Well, there are a number of technologies that have been proposed, but most have severe enough issues that they haven't been attempted yet. Rail guns have already been mentioned but there are two that haven't, and probably a few more I'm not aware of: 1) Construct a space elevator using extremely strong and light fibers (possibly carbon nanotubes) that reach to a counterweight that's in geosynchronous orbit. Then an "elevator car" would climb this cable, decreasing the cost-to-orbit per kilogram by perhaps a factor of 1000. 2) Use nuclear rockets. Use a sub-critical mass of plutonium or Uranium-235 to flash water into steam, and use that reaction mass as rocket thrust. 3) Use a matter/anti-matter reactor to perform a similar thing as 2). Of these, 1 seems the safest but is technically out of reach right now, and there may be some difficult problems with such a long cable that are not yet fully understood (resonances, micro-meteorite impact on the cable, etc.) 2 has some severe safety problems (what happens if the rocket blows up and scatters plutonium for a 200 mile radius?) 3 is essentially impossible right now. The world's GNP for 10 years could not produce enough anti-matter to lift even a single kilogram into orbit. Maybe someday we will find a way of making anti-matter more cheaply. But it too could have some severe safety problems.

bean dip?

Laser..Nevermind... Ninja beat me to it! Lol...

not being an educated scientist, i think that spacecraft is possible through solor technology. it may take awhile, though. what are your thoughts?

I saw an article in a magazine which described a magnetic sling system which would launch things into space. The track was like 5 miles in diameter, a half circle sort of looking thing. It looked like a big particle accelerator, but the end of it lifted off the ground and angled up. I could see this as being a feasable method of launching things into space without using fossil fuels. =) Here's a link: http://spacemonitor.blogspot.com/2007/03/magnetic-launch-system.html

you could heat anything up to extreme temperatures, the more you raise the temperature the more the exhaust velocity is. If you found a material (say even helium(cant burn at all)) and found properties of thermal expansion (it wants to push like your shower faucet) you could essentially use a gallon of it, (just a guess on temp.) raise the temp to 50000 degrees farenheit and you would have a real propulsion, however the problem you may have no rocket in a second or two. I believe that the highest temp material that can stay solid is Tungsten (8000deg F) in a vacuum but oxidizes at like 1200 (carbon doesn't burn but i dont know its stability at temps (but they use it on the leading edges of spaceshuttle so prob pretty good. the machine to bring temps up look up z machine highest man made temp is 6.6 billion deg F but just real quick (good luck) that would be an extreme pressure.

How about electro-gravitic propulsion ala the Searl Device?

but the biggest thing to be done is just dont take off from the ground.... like take a LARGE balloon or blimp or airplane up to a high altitude and then lauch.

If you build your spacecraft from an orbiting space station, you would have a choice of propulsion methods. The craft would not have to escape the earth's atmosphere, and could therefore use fuels that would last longer but provide less thrust, like nuclear propulsion, or an ion drive for long journeys.

I personally believe that a combination of a Magnetoplasmadynamic thruster (MPDT) combined with Laser based wireless power transmission would be the most efficient. http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster http://en.wikipedia.org/wiki/Wireless_energy_transfer#Laser

Im not a big time scientist or anything...but i think magnets are the future..don't ask me how but its energy without using energy its awesome

solar wind , anti gravity , mag sling ,

anti matter...theres your solution....its been made, it just cost sooo fucking much to make, for only about a millilitre of it...however a millilitre could run the states for at least a month...you think thatll launch your spacecraft?? the guy above said magnets are the future...pfffft antimatter is the fucking future