 By 1970, the French launch base in French Guiana had cost £45 million, and in that year France became the most important partner in the project, then planning to build two-thirds of the rocket as well as owning the launch site.Although only on paper, Britain's involvement in the project has been much reduced, after being largely responsible (with an Australian launch site) for getting the entire project going in the first place.However, all of the launchers, to the very end of the programme, were completely dependent on the British rocket used for the first stage.