# Time with current technology to reach nearest star? **URL:** \ **Category:** Factual Questions\ **Created:** [August 18, 2000, 4:50pm UTC](https://boards.straightdope.com/t/time-with-current-technology-to-reach-nearest-star/29867 "2000-08-18T16:50:01Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![douglips](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@douglips](https://boards.straightdope.com/u/douglips)\ **Post date:** [August 19, 2000, 3:42pm UTC](https://boards.straightdope.com/t/time-with-current-technology-to-reach-nearest-star/29867/21 "2000-08-19T15:42:20Z")
The movie _Deep Impact_ involved an Orion style spaceship built in orbit. The major implausibility in that movie was they were able to build it in 2 years, in secret. OK, one of the major implausibilities. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 19, 2000, 4:52pm UTC](https://boards.straightdope.com/t/time-with-current-technology-to-reach-nearest-star/29867/22 "2000-08-19T16:52:28Z")
Well, given enough funding, they probably could do it in two years, and the secrecy actually wouldn’t be too hard, if you painted all the parts matte black before launching them. At worst, folks would figure out that you’re building something, but they wouldn’t know what. ---
**Author:** ![Pigs\_in\_Space](https://avatars.discourse-cdn.com/v4/letter/p/9d8465/32.png) [@Pigs\_in\_Space](https://boards.straightdope.com/u/Pigs_in_Space)\ **Post date:** [August 19, 2000, 10:53pm UTC](https://boards.straightdope.com/t/time-with-current-technology-to-reach-nearest-star/29867/23 "2000-08-19T22:53:30Z")
> [@](#): > > \*Originally posted by friedo \* > \*\* > > > [@](#): > > > > \*Originally posted by iberii \* > > We _could_ build such a craft, although it would be enormously expensive, but we could never, by any feasible means, get it into orbit. > > Why not build it in orbit? That’s how they’re doing the international space station, and that thing is big. You could bring it up piece by piece, put it together, put some rocket engines on it and aim it away from the Earth. > > \*\* It’d be possible to assemble the spacecraft is orbit, but those steel/tungsten shields would be impossible to launch whole. It’d be hard as hell to weld those in space with anything approaching the quality you’d need. And I sure wouldn’t want to depend on a bolted structure as protection from a nuclear blast. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [August 20, 2000, 2:22am UTC](https://boards.straightdope.com/t/time-with-current-technology-to-reach-nearest-star/29867/24 "2000-08-20T02:22:21Z")
Seems to me the only fuel usable is antimatter although calling it off the shelf technology is pushing it a bit. While there is some antimatter sitting at Fermi Lab just outside Chicago as well as a variety of other accelerators they don’t have very much. IIRC someone said that if we increased antimatter production 1,000x over today’s levels it’d take several hundred years to get enough together to launch the space shuttle. However, the good part about antimatter is it goes a LONG way in comparison to its mass. Again, this is dug out of a dim memory, but I believe I heard that about 1 ounce would be sufficient to launch the space shuttle into orbit. ---
**Author:** ![Foggy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foggy/32/1082_2.png) [@Foggy](https://boards.straightdope.com/u/Foggy)\ **Post date:** [August 20, 2000, 5:28am UTC](https://boards.straightdope.com/t/time-with-current-technology-to-reach-nearest-star/29867/25 "2000-08-20T05:28:44Z")
> [@](#): > > \*Originally posted by Lemur866 \*\*\* > So most current ideas try to get around this by designing photon sails, or such. Of course, you can postulate reactionless thrusters or antigravity or hyperspace and get to Alpha Centauri any time you like. But I’m assuming we’ll stick to known physical laws for now. \*\* Why? I never let it stop me before. 😃 In fact I had lunch just today with Lady Deirdre Sky, at Gaia’s Landing, on Chiron. ---
**Author:** ![Ura-Maru](https://avatars.discourse-cdn.com/v4/letter/u/51bf81/32.png) [@Ura-Maru](https://boards.straightdope.com/u/Ura-Maru)\ **Post date:** [August 20, 2000, 7:09am UTC](https://boards.straightdope.com/t/time-with-current-technology-to-reach-nearest-star/29867/26 "2000-08-20T07:09:04Z")
Well, fogmage, you can tell her that if she dosn’t get away from Mount Planet, I’m going to fed-ex her a planet-buster. 🙂 Why did those smug Gaiens get to be the “default” faction, anyway? – “Brought to you by Vermont. The other, smaller Wisconson.” ---
**Author:** ![matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@matt](https://boards.straightdope.com/u/matt)\ **Post date:** [August 20, 2000, 7:26am UTC](https://boards.straightdope.com/t/time-with-current-technology-to-reach-nearest-star/29867/27 "2000-08-20T07:26:29Z")
A very good summary of the history and technology of the Orion project can be found at [Project Orion](http://www.islandone.org/Propulsion/ProjectOrion.html). What is interesting is that most of the problems involved with pulse-nuclear bomb propulsion seem to have been solved, and this was back in the 1960’s! We could almost certainly build an orion ship now. We could even build a really big one down here and launch it in mid-pacific - dirty, but no worse than a big nuclear test. **Pigs in Space** - check out the “small Orion” story, a ship which could be launched using three Saturn V’s. It included a small (33 ft) pusher plate. The small size of this plate cut the specific impulse dreadfully, but it could be done. “It’d be hard as hell to weld those in space with anything approaching the quality you’d need.” Agreed, using terrestial welding technology. But if we want to develop any kind of infrastructure in space, we’d damned well better _learn_ how to do this! Maybe you could plasma-ablate the pieces you wanted to weld to give a clean, extremely reactive surface (it’s a GOOD vacuum up there) and bang them into each other. Or maybe we could use a variation on friction or diffusional welding - you don’t _need_ to have a liquid phase to get a good weld. ---
**Author:** ![Pigs\_in\_Space](https://avatars.discourse-cdn.com/v4/letter/p/9d8465/32.png) [@Pigs\_in\_Space](https://boards.straightdope.com/u/Pigs_in_Space)\ **Post date:** [August 21, 2000, 7:11am UTC](https://boards.straightdope.com/t/time-with-current-technology-to-reach-nearest-star/29867/28 "2000-08-21T07:11:39Z")
> [@](#): > > \*Originally posted by matt \* > \*\* > But if we want to develop any kind of infrastructure in space, we’d damned well better _learn_ how to do this! > > \*\* Sure, but wasn’t the idea to use today’s technology? 🙂 And keep in mind, with regard to welds, you have to be able to do it consistently, with no voids, and you’d have to be able to inspect all of it, too. I’m not saying it can’t be done, just that there would be a long development and testing process, before you can even really design the hardware. [Previous page](https://boards.straightdope.com/t/time-with-current-technology-to-reach-nearest-star/29867.md?page=1)