Although it’s been quite some time since I’ve written about Voyager, our two interstellar craft (and this is indeed what they are at present, the first to return data from beyond the heliosphere) are never far from my mind. That has been the case since 1989, when I stayed up all night for the Neptune encounter and was haunted by the idea that we were saying goodbye to these doughty travelers. Talk about naivete! Now that I know as many people in this business as I do, I should have realized...
The propulsion technology the human characters conceive in the Netflix version of Liu Cixin’s novel The Three Body Problem clearly has roots in the ideas we’ve been kicking around lately. I should clarify that I’m talking about the American version of the novel, which Netflix titles ‘3 Body Problem,’ and not the Chinese 30-part series, which is also becoming available. In the last two posts, I’ve gone through various runway concepts, in which a spacecraft is driven forward by nuclear explosions...
Fusion runways remind me of the propulsion methods using pellets that have been suggested over the years in the literature. Before the runway concept emerged, the idea of firing pellets at a departing spacecraft was developed by Clifford Singer. Aware of the limitations of chemical propulsion, Singer first studied charged particle beams but quickly realized that the spread of the beam as it travels bedevils the concept. A stream of macro-pellets, each several grams in size, would offer a better...