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It would only take ~50 years to reach Barnard's star with a theoretical fusion engine according to a research study named Project Daedalus. Someone shoot a prob

It would only take ~50 years to reach Barnard's star with a theoretical fusion engine according to a research study named Project Daedalus. Someone shoot a probe at the planet and maybe our kids can see some cool imagery!

m_mueller 8y ago
You could also do it with existing nuclear fission technology (Project Orion). 3% speed of light seems to be quite feasible with that. If there‘d be no other way to save humanity, a generation ship with that technology would probably be built today.
- Robotbeat 8y ago
  Project Orion, the one that can hypothetically do 3% light speed, is definitely fusion as well. And the very high Isp versions of it are incredibly challenging to build (as you need like a magnetic shield to deflect the nuclear plasma ball). The more modest Isp versions are more realistic, but won't get you there.
  - m_mueller 8y ago
    I see, but still, at least the energy source itself would be proven technology in the form of H-bombs right? As for the shielding, do you mean the pusher plate or the nuclear shape charge in the bombs themselves? Does going from fission to fission+fusion bomb make such a big difference that couldn’t be overcome just with more/stronger material and/or ablative shields?
rbanffy 8y ago
With 100 tons of propellant and the best imaginable VASIMR engine we could send a 10 ton payload (mostly nuclear reactor) there in... 2600 years. We need better engines. A Daedalus-class fusion drive would be a great option, but first we'd need to develop it.
- taf2 8y ago
  Minor details - let’s roll
  - simonh 8y ago
    Ok, I'll just nip off to Jupiter to mine 50,000 tones of deuterium/Helium-3 fuel from the atmosphere. I'll be back in a jiffy.
    - barrow-rider 8y ago
      Also just a minor detail - let's roll
cultus 8y ago
I think fission fragment rockets might be more promising. Doable with current tech, they can have exhaust velocities of a few percent the speed of light (specific impulse in the 6 figures), comparable or better than fusion engines. https://en.wikipedia.org/wiki/Fission-fragment_rocket https://en.wikipedia.org/wiki/Fission-fragment_rocket
craftyguy 8y ago
If we wait a few thousand years, it'll get just a little closer to us: > Barnard's Star will make its closest approach to the Sun around 11,800 AD, when it will approach to within about 3.75 light-year https://en.wikipedia.org/wiki/Barnard%27s_Star#Overview https://en.wikipedia.org/wiki/Barnard%27s_Star#Overview
comicjk 8y ago
The most realistic current proposal for an interstellar science mission is to avoid onboard propulsion altogether using a fleet of tiny laser-accelerated probes. Each one would be a very thin mirror, shot from orbit to the stars by a ground-based laser array. httpss://en.m.wikipedia.org/wiki/Breakthrough_Starshot
- ddalex 8y ago
  Something like this would look to the Barnard's star inhabitants a lot like 'Oumuamua
  - simonh 8y ago
    Except only a few tens of centimetres across. There might be thousands of them streaming past us all the time and we'd never know.
    - wnkrshm 8y ago
      It's a fascinating idea but I'm not clear on how you would get back data? Modulation of reflected laser light? Active antennas that powerful radio telescopes are looking at?
      - simonh 8y ago
        You send a chain of them and they beam the message back along the chain.

m_mueller 8y ago

You could also do it with existing nuclear fission technology (Project Orion). 3% speed of light seems to be quite feasible with that. If there‘d be no other way to save humanity, a generation ship with that technology would probably be built today.

Robotbeat 8y ago
Project Orion, the one that can hypothetically do 3% light speed, is definitely fusion as well. And the very high Isp versions of it are incredibly challenging to build (as you need like a magnetic shield to deflect the nuclear plasma ball). The more modest Isp versions are more realistic, but won't get you there.
- m_mueller 8y ago
  I see, but still, at least the energy source itself would be proven technology in the form of H-bombs right? As for the shielding, do you mean the pusher plate or the nuclear shape charge in the bombs themselves? Does going from fission to fission+fusion bomb make such a big difference that couldn’t be overcome just with more/stronger material and/or ablative shields?

rbanffy 8y ago

With 100 tons of propellant and the best imaginable VASIMR engine we could send a 10 ton payload (mostly nuclear reactor) there in... 2600 years. We need better engines. A Daedalus-class fusion drive would be a great option, but first we'd need to develop it.

taf2 8y ago
Minor details - let’s roll
- simonh 8y ago
  Ok, I'll just nip off to Jupiter to mine 50,000 tones of deuterium/Helium-3 fuel from the atmosphere. I'll be back in a jiffy.
  - barrow-rider 8y ago
    Also just a minor detail - let's roll

cultus 8y ago

I think fission fragment rockets might be more promising. Doable with current tech, they can have exhaust velocities of a few percent the speed of light (specific impulse in the 6 figures), comparable or better than fusion engines. https://en.wikipedia.org/wiki/Fission-fragment_rocket https://en.wikipedia.org/wiki/Fission-fragment_rocket

craftyguy 8y ago

If we wait a few thousand years, it'll get just a little closer to us: > Barnard's Star will make its closest approach to the Sun around 11,800 AD, when it will approach to within about 3.75 light-year https://en.wikipedia.org/wiki/Barnard%27s_Star#Overview https://en.wikipedia.org/wiki/Barnard%27s_Star#Overview

comicjk 8y ago

The most realistic current proposal for an interstellar science mission is to avoid onboard propulsion altogether using a fleet of tiny laser-accelerated probes. Each one would be a very thin mirror, shot from orbit to the stars by a ground-based laser array. httpss://en.m.wikipedia.org/wiki/Breakthrough_Starshot

ddalex 8y ago
Something like this would look to the Barnard's star inhabitants a lot like 'Oumuamua
- simonh 8y ago
  Except only a few tens of centimetres across. There might be thousands of them streaming past us all the time and we'd never know.
  - wnkrshm 8y ago
    It's a fascinating idea but I'm not clear on how you would get back data? Modulation of reflected laser light? Active antennas that powerful radio telescopes are looking at?
    - simonh 8y ago
      You send a chain of them and they beam the message back along the chain.