Ask HN: Disprove my idea to travel to the nearest star within a lifetime | Hacker News Reader

Ask HN: Disprove my idea to travel to the nearest star within a lifetime

3 pointsionwake3 comments

Proxima Centauri nearest star. Distance 40,208,000,000,00km = 0.425 light years. Rocket which uses 200 nukes to propel itself ( i believe this was based on an old research paper from ages ago - anyone know which one I am referring to?) Design ( Simple rocket + shield + nuke layout ) Speed is around 95% speed of light = roughly 1 light year.

Interesting note: Time dilation from earth for observers = 365 * 2 = 730 years.

Now I realise there is a big mistake somewhere, but I cant remember what it is, if someone smarter could tell me that will be great thank you. Please excuse the rudimentary math - thank you.

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I'm guessing once you get there, controlled deceleration and getting into an orbit might be a bit of a problem at that speed. If there are enough particles for the nukes to keep pushing the rocket along, the fact that they are extremely sparse isn't going to evade the extraordinary level of heat generated from the friction, and there would be lots of gamma rays (and more) from particle collisions at the leading edges of the rocket. Also, if you hit even a spec of dust on the way, it would obliterate the mission in a spectacular way.

Matter travelling anywhere near the speed of light has a lot to contend with.

The rocket was called Orion. You would probably need more than 200 nukes for it.

Proxima Centauri is ~4 light years away, not a half of a light year.

Project Rho is a good one-stop-shop for all things interstellar travel. Here's their page on the Orion:

http://www.projectrho.com/public_html/rocket/enginelist3.php...

The numbers there indicate that the Orion design doesn't have the sort of exhaust velocity you'd want to get up to 0.95c

That site's also useful reading for all the OTHER downsides: for instance, traveling at 0.95c through space means that everything in your way is hitting the ship at 0.95c. Even stray hydrogen atoms are no picnic when they're arriving at that energy...

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