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

The atmosphere will absolutely mess you up. The faster you go the more the atmosphere pushes back on you. This makes it significantly harder to get up to the speeds spacecraft get to, and significantly harder maintaining these speeds without the craft breaking apart. Space crafts are a relatively simple affair in this regard. Burn fuel to go fast, burn more fuel to go faster.