When human abuse of an ecosystem has changed it so much that the ecosystem can no longer return to its previous state, that ecosystem?

Has reached it's tipping point, I think. Your question was not very specific, so hope this helps.

The soviet union beat the us to the first successful launch, with the october 4, 1957, orbiting of sputnik 1, and later beat the us to have the first human in earth orbit, yuri gagarin, on april 12, 1961. the "race" peaked with the july 20, 1969, us landing of the first humans on the moon with apollo 11