/sci/ - Science & Math

>>11418868

>>9533849
>>9533875
Neither fusion nor fission pulse is a viable interstellar propulsion device. Orion does make for a readily available way to do interplanetary within very acceptable timescales though.

If we're going to the stars it's gonna be by lasersail. Only pure antimatter rockets can even remotely compete but those come with a bunch of obvious... disadvantages.

>>9519869
>But without it, you're pretty much limited to;
>A) staying within the Solar System, or
>B) introducing some other improbable technology: Alastair Reynolds' "Cojoiner drives" (handwavium with time travel) or Bussard Ramjets which can pull 10 gee indefinitely in "Tau Zero" (more of an engineering problem than a physical impossibility, but...)
No. Look up the many different variations of laser sail propulsion. Interstellar travel is perfectly doable with no magic.

>>9433661
A great deal of work has been done on this problem, especially by the late Dr Robert Forward. The illustration gives you the idea.
Forward also wrote SF. His novel "Rocheworld" is fiction, but contains an appendix full of detailed calculations.
This is a MANNED interstellar mission. The 28 terawatt laser near Mercury is collimated by a monster (but thin) Fresnel lens on the outskirts of the Solar system and the beam drives the craft. At the far end, the central section is detached from the main, now ring shaped, body of the sail and reflected light decelerates the payload even as the ring is shoved away.

Everything could be scaled down for an unmanned prove. Microwaves could also be used. Since their wavelengths are longer than light, the transmitter array would need to be even larger to maintain the requisite focus.
http://www.niac.usra.edu/files/studies/final_report/4Landis.pdf

These references will tell you how big the various components would have to be. Converting into dollars and cents depends on progress in robotics, use of off-planet resources, and spaceflight in general. It would be a major undertaking any way you look at it.