Investments in space programs are investments in sustainability, global cooperation. Knowing how to seal a person in a box for months tells us what a human actually consumes. working together on joint scientific ventures brings foriegn peoples closer. This leaves out all the other cool inventions like GPS that space travel has enable thus far that improve are ability to do everything better.
This is just a repackaging of the purely economic investment observation of space programs. The government spending dollars on space has resulted in a many more dollars (or the same dollar spent many more times) on related economic interests. For example: Improved ways to track weather lead to reduced costs of flights, lead to more airline tickets purchased, lead to more travel, lead to more business trips leads to business happening.
Each step in the thread of such and example the effect gets smaller but because there are so many hard problems and so much science gets done that there are many threads.
I used to have a bicycle that I rode to work that was made using an aluminum foam that NASA developed and licensed out to companies that wanted to make light but stiff metal frames. In this case Fuji a Japanese company making racing bikes. Without it for that 3 year period I didn't have a license I would not have had job.