I suggest you are taking a very narrow view of what you consider "helping" to cure the world's social and economic troubles. Yes---we could try to feed the hungry---but experience tells us that is a rat infested bottomless pit. The very origin of their hunger ultimately distributes (or more correctly disposes of) that relief.
In keeping with the world hunger issue---I can (and I suspect you can as well) connect yield gains in modern agriculture directly to outgrowths of the space program. One of the most obvious, is the use of GPS technology to selectively apply fertilizer and seed density based on previous yield maps.
We could go on all day with this debate, if time permitted, but I have other demands. I will leave you with the thought that world hunger has many causes and as many cures---handing a man a fish---or $10 is not always the most beneficial or long lasting.
As a side note, I have read dissertations on the use and misuse of research funding in many areas of medicine, including cancer research. My reading indicates that effective oversight and coordinated management could yield better results than more money.
"A pessimist sees the difficulty in every opportunity, an optimist sees the opportunity in every difficulty” ---Sir Winston Churchill
"Political extremism involves two prime ingredients: an excessively simple diagnosis of the world's ills, and a conviction that there are identifiable villains back of it all." ---John W. Gardner
“You can’t go back and change the beginning, but you can start where you are and change the ending.” ---C. S. Lewis