←back to thread

93 points JPLeRouzic | 3 comments | | HN request time: 0.704s | source
Show context
d_silin ◴[] No.44380695[source]
Developing propulsion technology to reach 0.1c velocity will move the needle on interstellar propulsion from impossible to just barely feasible. Although that is at least 100-200 years away, we can absolutely start expanding into our Solar System, starting with nearby bodies, like Moon and Mars.
replies(2): >>44380811 #>>44382130 #
1. JumpCrisscross ◴[] No.44380811[source]
> Developing propulsion technology to reach 0.1c velocity will move the needle on interstellar propulsion from impossible to just barely feasible

More than barely. "A 40-year one-way interstellar flyby mission to the nearest stars will require a relativistic spacecraft speed in excess of 6000 AU/yr (i.e., > 0.1c)" [1].

That means, practically speaking, nuclear-fusion, antimatter-annihilation and directed-energy propulsion. All of which are TRL ≤ 2.

My bet would be on fusion propulsion. It's inherently easier than fusion power since you don't need to bother converting the energy to electricity. That said, solar sails [2] and directed-energy anti-drone weapons [3] are seeing quiet progress.

[1] https://ntrs.nasa.gov/api/citations/20200000759/downloads/20...

[2] https://www.nasa.gov/mission/acs3/

[3] https://en.wikipedia.org/wiki/Silent_Hunter_(laser_weapon)

replies(1): >>44380881 #
2. carpdiem ◴[] No.44380881[source]
1 AU is about 8.3 light minutes. So 6k AU is about 50k light minutes. with ~525k minutes in a year, that means that 6k AU/yr is almost exactly 0.1c.
replies(1): >>44380932 #
3. JumpCrisscross ◴[] No.44380932[source]
> that means that 6k AU/yr is almost exactly 0.1c

Nobody debates this. The point is that 0.1c propulsion is not necessarily 100+ years away. And its 40-year transit time is not "barely feasible," it's comparable to present deep-space mission timelines [1].

[1] https://science.nasa.gov/mission/voyager/