We hardly spend anything on space exploration. Not to mention it has a lot of benefits and carryover to the rest of the economy. If we have to make cuts, there are many other places we can target instead of the .5% of the federal budget to NASA.
NASA's contributions are estimated to have a 2-3 to 1 fold revenue generation for NASA spending.
http://www.nationaljournal.com/njonline/no_20100827_1798.php
Investments in science can have huge payoffs.