Workable Fusion Starship Proposed 260
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."
Great idea but pie in the sky... (Score:5, Interesting)
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.
My memories of Edward Teller (Score:5, Interesting)
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.
I does not matter (Score:2, Interesting)
Re:In case anyone's wondering (Score:3, Interesting)
As far as the Nuclear drive, my brother ( who is a Nuclear Engineer ) and I have discussed it for over 30 years and though it might work, it could also end up buried somewhere with a message "Do not open until Christmas 40010".
Re:Great idea but pie in the sky... (Score:5, Interesting)
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.
Re:Ramscoop design? (Score:2, Interesting)
Really? Could a magnetic scoop then be used for braking on a ship that used a different type of propulsion? Because more than half your propellant on an interstellar journey is required due to the need for braking when you get to your destination.
Re:Ramscoop design? (Score:5, Interesting)
Re:Ramscoop design? (Score:1, Interesting)
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.
Is that really true? Many years ago, I read a fascinating book called "The Twenty Knot Sailboat". The author, strangely enough, was in the Air Force and stationed at a dry lake bed in southern California. He used to build models of fast sailboat designs and could only test them on rare occasions when there were flash floods and the lake bed would have a few inches of water for a few days a year.
His thesis was that the two things that limited the speed of a sailboat were the sail and the boat. He proposed to replace the conventional sail with a far more efficient airfoil and the boat with a hull on hydrofoils. Both methods were means to avoid drag so as to allow greater speed.
The relevant part was when he got into the theory of sailing and said that it had been proven that an iceboat (far more friction-free than any sailboat) could actually go downwind on a broad reach at a speed exceeding the speed of the wind driving it.
I'm not a sailor (or physicist) myself, but his explanation seemed reasonable to me. I do remember his sketch of the situation -- it had him standing near the stern, going downwind on a broad reach, moving forward with his pipe smoke trailing out behind him.
Any engineers out there want to evaluate the possibility?
Re:My memories of Edward Teller (Score:3, Interesting)
Here's an odd bit of confluence... My uncle was Harold Green (he died recently) - an attorney who worked for the US Government and who was responsible for figuring out how to "get" Oppenheimer when the government went after him. He mentioned feeling conflicted over his part in that - proud for coming up with a legal novelty, but ashamed for helping to ruin a great man.
It was a very odd experience for me reading a biography of Oppenheimer and seeing my uncle in it, reading about what he did.