If you wanted to get anywhere important in space (like Mars, Alpha Centauri, etc.), you’d have to go pretty fast, right? Otherwise, what would be the point? For example, if you wanted to go to Alpha Centauri it’s 4.3 light years away. For comparison, that’s about 25 trillion miles away. “Escape velocity”, the speed at which you’d have to go to escape Earth’s gravity, is approximately 25,000 miles per hour. Without boring you with the math, at that speed it would take 115,000 years to get to Alpha Centauri. You’d have to go a lot faster to make it to Alpha Centauri in any reasonable amount of time.

But here’s the real point. Let’s say that you’re in space going in excess of 25,000 miles per hour, on your way to Alpha Centauri. What if, somewhere along your way, you encounter a rock or dirt clod? It’s one thing to have something like that fracture your wind shield on the way to the next city. You probably know what kind of damage that can do. And on the way to the next city, you’re only going 60 miles per hour. Imagine what such a thing would do to a space craft going thousands of miles per hour.

If you guessed that a rock or meteor could cut through your hull like hot butter, you’re right.

Even going to Mars, which would take months at the speeds we can currently accomplish, anything of any significant size would more or less destroy the integrity of your well designed and engineered space craft. Of course, I suppose you could make your hull feet thick to avoid the problem. And that might work… maybe. But chances are, sooner or later you would encounter something which would puncture your hull and leave you leaking air. Space, as empty as it’s supposed to be, is still full of “stuff”.

So what’s the solution? There’s no way you can make a hull strong enough to shed everything you might run across. Answer: shields.

Don’t laugh. Star Trek ships had shields for a very good reason. Forget Romulan attacks. Big rocks were a larger threat.

And what about those less than bright idiots in science fiction who throw bodies and debris out the airlock? Imagine hitting a bolt at a million miles an hour.

And by the way– radiation is a very real threat as well. Earth has the Van Allen belts to protect it from the Sun’s radiation output. Scientists believe that without it, the Earth’s surface would be a waste land. Space ships, outside this natural shield, would receive many times the radiation we normally receive at the surface of the Earth. Shields would likewise protect the crew from that threat.

Here’s the problem, though. Shield technology is far beyond anything we’ve yet to develop, anywhere in science. There isn’t even any good theory to start with. It would require something akin to anti-gravity, which we obviously haven’t figured out.

But that’s not really the point. The point is that that’s going to have to be one of the crucial components to travel significant distances in space. So… somebody start working on the theory and get some engineers to make it happen.

I assume you don’t want to be stuck on Earth forever, right?