Sobaan Tali wrote: Getting people to Mars is more than just leaving Earth...you have to find a way to a) leave Earth, b) reach Mars, c) land on Mars, d) leave Mars, e) reach Earth, f) land on Earth. Each of those individually is a nightmare of planning, preping, coordinating, and exicuting to say the least.
Actually, most of that is pretty easy for us given out current technology. we have lots and lots of experience getting stuff off the earth and into orbit.
We have experience assembling things in space. A rocket to Mars would be like the international space station, with a motor and lots and lots of fuel.
Stopping when you get to mars is even pretty easy since you can air brake off it's thin atmosphere and do other tricks with elongated orbits.
Assuming you've brought enough fuel, getting back to earth is pie. And stopping once you get here? again, pie with the earth's atmosphere to orbit through.
The really tricky part is the landing on mars in something big enough, and having enough fuel in it, to get you back into orbit.
My dad is the rocket scientist, but as I recall the numbers, using a chemical rocket to accelerate 1 ton payload to earth escape velocity of 11km.sec, requires 5 tons of propellent. To lift that 5 tons of propellent out of the atmosphere, requires 20 tons of propellent. Add on the weight of the lifting body that hold the propellant, and you're talking 35-40 ton rocket to lift a 1 ton payload.
On Mars, with the lower escape velocity of 5km.sec, lifting that 1 ton payload would require 2.5 tons of propellant, and lifting that 2.5 tons of propellant would require only 6 tons of propellant. However..... landing that... 10 tons of space ship on Mars would require 25 tons of fuel to slow the ship from orbital velocity and overcome the acceleration due to gravity. So, you are back to something the size of the rocket needed to launch the 1 ton from earth.
Again, the moon, with 1/6th the gravity of the earth, an very low escape velocityi, would take less than a ton of fuel to accelerate a ton to orbit, and less than a ton to lift that propellant... then less than that to lower the ship to the moon in the first place.