Going Interstellar by Les Johnson & Jack McDevitt

Author:Les Johnson & Jack McDevitt [Johnson, Les & McDevitt, Jack]
Language: eng
Format: epub
Published: 2012-04-24T17:02:06+00:00

Figure 2. Artist concept of a Project Orion nuclear pulse spacecraft. (Image courtesy of NASA.)

Daedalus evolved as a kid brother to Orion. Instead of using the dramatic thermonuclear-pulse drive, it used a somewhat tamer approach—inertial fusion. Small micropellets of fusion fuel were to be ejected into a combustion chamber equipped with strong magnetic fields. Instead of ignition by a fission trigger, these pellets were to be heated to fusion temperatures and condensed to fusion densities by an array of focused laser or electron beams.

Researchers involved in the effort spent a good deal of time considering fusion fuel cycles. They rejected the deuterium-tritium (D-T) and deuterium-deuterium (D-D) fusion reactions under active consideration for terrestrial energy production. Although cleaner than fission, the copious thermal neutrons produced by these reactions would rapidly irradiate the spacecraft. Instead, they settled on a reaction between a low-mass form of helium (Helium-3) and deuterium. The products of this reaction are electrically charged particles—these are relatively easy to focus and expel with the aid of powerful magnetic fields.

Although the Helium-3/D reaction is the second easiest to ignite after D-T, it has one significant drawback. Helium-3 is very, very rare in the terrestrial environment. Starship designers were faced with four alternatives to obtain the necessary tens of millions of kilograms of this substance.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.