As human and in human nature we are know to do exploits and that the advancement and achievements for what we have and use can use today.

If the billions spent in the exploration of space is of positive impact to the earth where u stay, then why not, i support the idea behind it. But if for any means the exploration of space will bring doom to us on earth as was as extend and contribute more to the degradation of the earth, then i suggest we stop.

There has to be a total research and evaluation on it before we go ahead. The earth is already suffering global warming and other Environmental pollution and we wouldn't want more added to it.

If it is a positive gain without causing, pains, injuries or future pollution i will support it.

Is the knowledge we gain worth the money we spend?

To my it depends on the type of knowledge we are talking about, because some knowledge are worth while some are not worth it.

For example, the amount spent in other to acquire ICT skills these days, cannot be tagged as a loss, because the world is going ITC. Infact in years to come you would have made double the price you paid to acquire it.

But before this works out, there must be that determination and zeal to actually learn from what ever you are spending.

There are a lot of people out there, who spend to acquire knowledge that doesn't worth it.

That is my humble submission, thanks.