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 is stuff and space isn’t. The shuttle Columbia didn’t get destroyed in space, but in the atmosphere because it was moving so fast. Remember they reentry heat is caused by compressing the air and not friction and is an issue with super fast planes as well. The SR-71pumoed fuel through the hot parts before the going to the engine to keep things cool and it ‘only’ went Mach 3.2.

Back to Columbia, the damaged insulation didn’t keep that heat away from parts of the structure and they failed. Now that it was unbalanced it tumbled, and the air tore it apart. None of that would happen in space.