How is it that we engineer vehicles in space to travel for millions of miles at absurdly fast speeds? When we can only have vehicles on earth (jets) travel for thousands of miles at lower speeds? Why is the gap SO BIG?

Question

We can send vehicles/rovers to space and have them travel at very high speeds for millions of miles to other planets. But vehicles on earth (jets/planes) have significantly shorter range and speed. Why is this? ELI5

In: Physics

Answer 1

Things in space are much farther away, so going faster will get you there sooner.

You can go faster in space because there is much less stuff (like air) in the way. The air and other stuff floating around on Earth cause resistance and friction on moving things. This makes it harder to increase speed and can wear down parts of vehicles.