I am looking for a form of propulsion to achieve a fraction of C that could send and retrieve mining robots to our solar system's asteroid belt. Does this type of propulsion even currently exist?


closed as off-topic by John Rennie, Emilio Pisanty, tpg2114, Brandon Enright, Qmechanic Nov 12 '13 at 23:38

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The distance to the asteroid belt is roughly 1.5 AU (1 AU $\sim$ 150 million km). To reach that distance in 1 year (one way trip), we'd need to travel at $$ \frac{1.5\cdot150\,{\rm million\,km}}{1\,{\rm year}} \simeq 26,000\,{\rm km/h}\simeq7\,{\rm km/s} $$

The shuttle that took Curiosity to Mars did the 563 million km trip in about 8 months, leading to about 27 km/s.

So the answer to the question in your title is: yes, it is possible. There really isn't any reason to "achieve a fraction of $c$" for this trip (not that we have such technology, AFAIK at least), just doing what we do normally would work.

  • $\begingroup$ @user33668: no problem. Note however that part of the reason we're not doing this is that it takes a lot of fuel to get off earth, stop, then come back. This is really the "tyranny of the rocket equation" (Google search that phrase): as we increase $\Delta v$, we exponentially increase the necessary mass in fuel. Another reason we don't go out there is that it's mostly carbon out there, nothing valuable, resource-wise to offset the cost of getting there. $\endgroup$ – Kyle Kanos Nov 12 '13 at 21:25

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