The Russian Soyuz launch system is now also operating from the European space launch facilities in French Guyana. To the Russians, this location offers a number of advantages.
Located close to the equator, the ESA spaceport can make better use of the Earth’s rotational speed, which is higher at the equator and translates into fuel savings (or performance gains). Secondly, Russia’s main launch sites were built during Soviet times and are now located outside of Russia. (As a result, Russia has been pressured into paying high rent for its continued use of the facilities). And finally, western lawmakers have been lobbied to impose export restrictions on the number of Western satellites shipped for launching from Soviet successor states and China. Although these restrictions and tariffs have been somewhat relaxed lately, commercial launches from the ESA spaceport might avoid the issue altogether.
What ESA and Arianespace stand to gain from the agreement with Russia is not completely clear to me. Certainly, Soyuz will compete against Europe’s Ariane 5 in some aspects. On the other hand, there can be no question that more competition and the removal of artificial trade barriers will be good for spaceflight in general. Perhaps the market will grow so fast that in the end, everyone gets to benefit.
Here is a fascinating time lapse video showing how the Soyuz system works. (It is very different to Western systems).
For a larger version of this video, click this link.