US reacted to the achievement of USSR with determination not to lose the space race.
Explanation:
The Space Race was in a sense a public portrayal of everything that the Cold war was happening for behind the curtains.
It was a war fought through science to establish which country had more technical prowess and could reach moon and beyond before another.
This would have proved their overall superiority over the other as a nation, and by extension the superiority of their form of governance which was the difference between communism and capitalism.
This is why USA reacted with more productivity when USA put Yuri Gagrin in space.
