Out of the fifteen intelligence agencies, which cost the taxpayers $75,000,000,000, Steven Aftergood estimates the NSA's budget in 2012 was $10,000,000,000. Now this is just an estimate because the actual budget is of course classified. NASA's budget in 2012 was a little over $16,000,000,000 and they landed a rover on Mars. Now imagine the scientific feats NASA could achieve if their budget was $26,000,000,000, almost double their budget now.
The NSA spends this money by spying on the citizens of the United States in the name of safety but yet cannot prevent terrorist attacks like the Boston marathon bombing. NASA uses it's budget to broaden our scientific understanding and actually achieves what's promised. If NASA says we're putting a man on Mars by 2025, you damn well believe it.