The Administration’s proposed budget cuts include abandoning upcoming Mars robotic missions in 2016 and 2018. While it appears that NASA might be able to salvage a 2018 mission by extreme cost cutting and siphoning money from other programs, the damage could be irreparable. The US Mars exploration program is a pipeline of projects scheduled at approximate 2-year intervals. Cutting that pipeline could set back Mars exploration by decades, and is a betrayal of commitments to our international exploration partners.
Some cost cuts are certainly justified in the current climate, and the shift to private launch systems could pay off in the long run. However, there is no reason to expect private interests to take up purely scientific endeavors like Mars exploration, at least anytime soon. Planetary exploration is and should be a core function of NASA, and a setback of even a couple of years cannot be justified.