Great power competition did not disappear with the end of the Cold War. Nowadays, tensions are rising between the USA with Trump’s zero-sum-gain policies, Russia with its aggressive behaviour toward its neighbours, and finally China with its restored military and economic status.

This competition takes many forms. Trade wars, alliances and propaganda campaigns are one. The military competition is also going strong, with each side trying to improve on its weapons and to introduce game-changing new capabilities. Among those capabilities is a new class of high-speed projectiles that these three countries are developing: hypersonic vehicles. They are also looking at ways to counter them, and that starts with detecting and tracking them, which is best done from space. While this last aspect is not strictly Earth observation, it still consists in sensors carried by satellites looking at the Earth or very close to it, so we will broaden a…