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Regular spaceship missions are effective but also incredibly expensive. The most discussed alternative of them would be the space elevator, but with our current technology, it isn't possible to construct it yet.

But what about fast acceleration, like shooting a satellite into orbit by a railgun?

Railguns use super strong electromagnetic fields to accelerate things to high speed. They have military application, but would it be possible to shoot satellites to an altitude and at velocity to achieve orbit?

Theoretically, if we can accelerate a body to Mach 23, that MAY be enough to get it into outer space orbit (since this is the lowest velocity to achieve it).

My questions are:

  • Can we reach required speeds with structures similar to railguns?

  • Do we know of any materials that can "survive" a quick acceleration to such velocities without disintegrating, melting or exploding into pieces due to atmospheric drag and acceleration forces involved?

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  • $\begingroup$ Good for delivering raw materials. Not good for delivering live people or complex devices in one piece. $\endgroup$
    – SF.
    Nov 7 '13 at 15:46
  • $\begingroup$ @SF. Of course it's impossible for humans, but for satellites, it would be good, isn't it? The may even get a protective shield that melts down instead of the device itself (like the shield of bullets) $\endgroup$
    – Zoltán Schmidt
    Nov 7 '13 at 15:51
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    $\begingroup$ It's not so simple. A railgun slug is a solid cylinder of metal. A satellite has a lot of (fragile) electronics, solar cells, piping to orbital engines, rather big antennas - things that don't take kindly to accelerations on the order of 100g. It can be made somewhat more durable than a human, but the more you harden it the more weight you add - and the railgun will be definitely limited in weight it can launch. OTOH launching canisters with fuel to the orbit, where a (traditionally delivered) craft would refuel would be quite viable. $\endgroup$
    – SF.
    Nov 7 '13 at 16:02
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Sure. See this paper. If the rail is long enough, the acceleration doesn't have to be that high, say 1000 Gs over a two-mile track. You can design and test spacecraft hardware to survive those Gs. That makes it much heavier, but with the incredibly low launch costs promised by such a rail, the mass doesn't matter. You can also use the launch capability simply for materials, e.g. water, propellants, which have no problem with the Gs.

You need a pretty slender, aerodynamic projectile shape with thermal protection to make it through the atmosphere. No matter what, you will need a rocket motor and some guidance in your projectile to circularize the orbit at apogee.

You can also imagine much longer, more expensive tracks to reduce the Gs. To get to human levels, you would something like a 400 to 700 mile track. Kind of a big order.

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