Why is a certain latitude the best place to launch rockets into LEO?

Question

My logic tells me that since the earth is rotating the equator must be travelling the fastest, so this should be the best latitude to launch rockets because you could take advantage of the speed of the earth in reaching escape speed.

According to some news website, about the launch site to be made at Cape breton "The company chose Cape Breton because it lies at approximately the same latitude as Russia's launch facility, the Baikonur Cosmodrome."

Why is this latitude so wonderful?

(PS: this isn't a part of the question, but the fact that there is going to be this launch pad in Cape Breton, answers my first question on Yahoo answers whichly was how the heck can you "win a sub orbital space flight" from entering a contest at Shoppers drug mart? because i assumed it was only the russians doing it then.)

Answer 1

Your logic is correct; the closer you are to the equator, the more boost you get from the speed of Earth's rotation. (It's why rockets usually launch to the East.)

One advantage of an off-equator launch site is you can use the natural rotation of the Earth, but the orbit (as viewed on a map) creates a sine-wave pattern across the Earth's surface. (This can also be done from a launch on the equator as well, but you must launch in a slight angle to Earth's motion.)

One reason that the latitude is so wonderful is that it's probably the maximum latitude for the Space Station's orbit, so any vehicle launched would be able to dock to it.

Answer 2

The equator is the best because, as you say, it gives you the advantage of the Earth's maximum rotational speed. However, the company using Cape Breton is Canadian, and Canada doesn't happen to have any land on the equator that it could use for a space launch facility.

The comparison with Russia's Baikonur cosmodrome is useful because it shows that a space launch facility at that latitude does work and it works well. Russia has been using that latitude since 1957 to get things into orbit, and it still uses it now to get to the ISS.