Could we build a starship using current technology?

[Mailanka]

Originally Posted by Dustin

For comparison, a proposed unmanned interstellar probe design (Project Longshot) using nuclear pulse propulsion and relatively few advances on current technology compared to other designs achieves an acceleration of .001g (.01 m/s2) after 70 years of flight, and twice that after 100 years of flight (when it reaches Alpha Centauri B).

There's no way that graph is correct. For one thing, an orion drive is going to accelerate you much faster than 0.01g. We have chemical rockets that accelerate you faster than that. Blowing nuclear bombs behind you (what a nuclear pulse drive is) will certainly kick you forward faster than that. Second, you'll never get to alpha centauri in 100 years at a speed of 0.01 m/s after seventy years.

You can actually read up on the Orion Drive in GURPS Spaceships. One engine gives 2g acceleration and each fuel tank (at TL 8) gives 3 mps, which is really, really good compared to everything else we can use. The main reason we don't use them is that people are very skeptical of the safety of blowing up tons of radioactive, weapons-grade bombs to get off the planet (and even if you get it up into orbit with more conventional means and then start blasting it around, what if the rocket crashes on the way up? We won't have people seriously considering an Orion Drive until we can construct it entirely in space with radioactive material collected IN space, and even then, there's a substantial anti-nuclear sentiment that has people freezing up at the very mention of the idea).

Also, Alpha Centauri is not THAT far away. Yes, it's very very very far away, but not insurmountable with modern technology. It's just that there's not much reason to spend billions of dollars building a ship powered by weapons of mass destruction that will get there in back in a couple of centuries. What would you do with something like that? What's the point?