What would be the best way to launch space craft/get into space from a northern latitude? Canada, Scandinavia, UK, Russia, Alaska, those sorts of places. I understand that being closer to the equator gives benefits due to rotational speed etc, but what are the options for those not on the equator? Space elevator is out but what are the other options? Would a skyhook work? Space fountain? Just regular old rocket launches? Which would be more energy efficient: fountain or launches? Thanks!


3 Answers 3


The difference isn't large, rockets will work fine

Escape velocity is calculated from setting the potential energy and object has in earth's gravity well equal to the kinetic energy it would need to escape from it: $mgh = \frac{1}{2}mv^2$. Since the mass of the object is the same on both sides, we can drop it and solve to get $$v = \sqrt{2gh}.$$

The force of gravity is not constant at different heights. I did my calculations accounting for the differences, and accounted for them in each equation. The exact radius of the earth at the poles (modeled by WGS-84) is 6356.752 km. Plugging into the above equation, escape velocity at the north pole is $$v = \sqrt{2\cdot9.854\frac{\text{m}}{\text{s}^2}\cdot6356752 \text{m}} = 11193 \frac{\text{m}}{\text{s}}.$$

The radius at the equator is 6378.137 km, and lets assume we get a free 465 m/s boost from the earth's rotation. Plug those numbers in to get

$$v = \sqrt{2\cdot9.788\frac{\text{m}}{\text{s}^2}\cdot6378137 \text{m}} - 465 \frac{\text{m}}{\text{s}} = 10709 \frac{\text{m}}{\text{s}}.$$

If we convert those two numbers into kinetic energy terms, it takes $6.26\times10^7\frac{\text{J}}{\text{kg}}$ at the pole and $5.73\times10^7\frac{\text{J}}{\text{kg}}$ at the equator with a rotational boost.

So escape velocity is 4.5% higher at the pole and escape energy is 9.2% higher. Significant differences, for sure, but no reason that rockets won't work.


Well, given that places such as the Pacific Spaceport Complex exist in Alaska... I'd say rocket launches.

If you want to use other options like sky hooks or space fountains etc. you are welcome to do so, but for the amount of space traffic we have today rockets are pretty much the only thing that has proved economical/feasible.


Just to add to kingledion's answer.

Its useful to launch from a location close to the equator if you want an equatorial or geo-stationary orbit, since you don't have to waste delta-v changing the inclination of your orbit.

If you want a polar orbit you can launch in a roughly north or south direction from anyway on the planet.

Alternatively you can launch due east from anywhere on the planet to obtain a inclined orbit at a specific latitude for example the ISS's orbits at 51.6 inclination to make it easier to resupply it from Baikonur Cosmodrome (45.95N).

As kingledion points out an easterly launch, helps but its not a show stopper.


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