Answer:
President Kennedy is making the claim that the nation of America needs to be a part of the 'space exploration party' and how this will enable it to become a leading power in the world.
Explanation:
In the speech he gave at Rice University in 1962, President John F. Kennedy emphasized on the need to be a part of the advanced nations to explore space. He talks of how new ventures, paces cannot be helped, and may even bring criticism from others. But "<em>it dispels old, new ignorance, new problems, new dangers</em>".
Considering the given passage about the "<em>exploration of space</em>", he states that the world will go on with it whether America joins or not. He then states how a "<em>nation which expects to be the leader of other nations can expect to stay behind in the race for space</em>", which is an indirect reference to America's need to join the race.