What Makes it so Hard to Travel Through Space?
For us to travel through space, we would need some huge improvements in the ability of how fast we travel, what we use to fuel our travel, and a new source of propellant. We would need all of these things because of one thing, space takes up more space than any other thing that we know of [a LOT more]. So let's face it people, space takes up a lot of space!
New Speeds
Okay, we all know that to be able to travel through space we are going to have to be able to exceed the speed of light. How would it really be able to help us, though? It's obvious that it would help us get to other planets and star a lot quicker, but how correct are our thoughts? The speed of light travels about, what 182,000 miles per second, and at that speed it takes light over 4 YEARS to travel to the nearest star. That would be like if the sun and the nearest star were 210 miles (338 kilometers) away and light (the fastest traveling object that we know) could only travel at about 6 inches (15 centimeters) per minute.
New Fuel
A new fuel would be another big thing that would have to come for us to travel in space as we dream we will in the future. The fuels we use right now aren't common enough in space, and we would need too much of it to be able to travel long distances, or for a long amount of time in space.
A New Propellant
Why would we need a new form of propellant? Propelling yourself through space is different than on land or even in the water. On land, you would have the ground to push against, and in the water you would have the water, while in space, there is nothing. Even in spaceships, there is a large difficulty in learning how to propel yourself, because you can't "swim" through the air, you have to have something to push off of.
So, in space, you have to use a huge amount of propellant to propel the ship through space, because there is nothing to push off of. This will also mean you need to use even more fuel for the propellent, because we need it to propel the ship through space. What we need to do is find a way to propel something without using propellant. [Hope you weren't reading this paragraph out loud since it's tongue-twisting.]
