3. How might polar bears population suddenly increase? How would this affect the ecosystem?

It depends on their population and their food source, if their food source suddenly got low and started to die then that should impact the polar bears population.

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