Workable Fusion Starship Proposed

Adam Korbitz writes "A former colleague of Edward Teller — father of the hydrogen bomb — has published a new paper proposing a design for what could be the first practical fusion-powered spacecraft (PDF). As described at Centauri Dreams, the design has certain similarities to MagOrion, a 1990s-era proposal for a nuclear-powered spaceship with a magnetic sail and propelled by small-yield fission devices. The proposal's author also has links to the British Interplanetary Society's Project Daedalus, a 1970s proposal for an unmanned fusion-powered interstellar probe designed to reach 12% of the speed of light on its way to Barnard's Star."

Comments

Great idea but pie in the sky...

[Cheerio Boy]

I'm all for ideas like this but we won't be building things like this until we, as a planet, have a permanent manufacturing presence in space.

Moon colony, orbiting L5 colony, whatever it is it must be permanent and able to manufacture using locally sourced materials because building something like this from within the gravity well doesn't make economic sense.

Re:Great idea but pie in the sky...

[Cheerio Boy]

There's no way shipping ANYTHING up from the gravity well would allow us to build a ship of this nature within any reasonable time frame with the exception of using absolutely huge space elevators.

*THE* gravity well?

The moon has one too. Asteroids have a different but similar problem in being so far away and having such different orbital mechanics.

What exactly are you proposing?

For practical engineering purposes the gravity well of the moon is weak enough to not be a problem for the transportation of materials off it's surface.

Asteroids do have gravity obviously but almost nothing due to their size. Thus materials transported from them are again easy to move into open space.

What I'm proposing is this:

1) Establish a colony on the moon or at L5.

2) Use moon materials to build the manufacturing framework.

3) Construct mining ships for asteroid field work.

4) Mine asteroids and use the materials to construct the large-scale interplanetary transport.

Now while this is a workable plan it is _also_ pie-in-the-sky as we can't even get our collective butts to agree on how to get a primary established off planet.

My memories of Edward Teller

[MarkWatson]

Edward Teller hired my Dad into the Physics department at UC Berkeley and I remember him as a gentleman - he was occasionally at our house. Once my parents had a costume party and Teller was provided with a bird costume - he did not want to wear the mask so he had these big white wings on. The SF Chronicle columnist Herb Caen ran a story the next day saying that Teller was dressed as the angel of peace. Until Teller died a few years ago, my Dad would occasionally travel to Berkeley to visit with him.

Re:Ramscoop design?

[geckipede]

Yes, absolutely. It has been proposed as a part of laser-boosted lightsail missions to other stars. A full sized collector scoop would work in interstellar gas, but you only need a relatively small magnet if you are plowing through solar wind (er... stellar wind, since it isn't Sol?). A superconducting cable spooled out of a probe and given a current could be used as a braking system to decelerate at a destination star. I recall seeing an estimate somewhere that the peak deceleration of a relativistic craft like this hitting the heliopause would be about 12g, not comfortable but very effective and cheap way to slow down. Magnetic sails have also been proposed as a way to accelerate in the first place, but in that case you are limited to speeds less than that of the solar wind itself, so it is more suited to in-system missions.