My definition of substainable in this context is being better able to cope with potential budget cuts. A smaller, lower cost, mission is more agile when it comes to avoiding the budget axe. If there are too many large missions going on at once, that’s where the hawks are going to look. I know there are quite a few people here we think that JWST deserved the axe more than ExoMars, but at this point I disagree with that notion. Sure, a sample return sounds cool, but if we intend to send humans to Mars and back someday can’t we just do a sample return as part of that mission? Yeah, it’s a loooong time to wait, but it CAN wait. The same sort of redundancy can not be said for JWST.

And as far as your comment about feeding the hungry and healing the sick, our tax dollars already do commit a great deal of money to those efforts, especially if you include Medicaid. To suggest that any portion of NASA’s budget, or even the whole thing(less than 1/2 of 1% of the federal budget) is the money we’re missing to allow us to do anything of significance in those areas is a straw man at best. Besides, give a man a fish he eats for a day, teach a man to fish he eats for a lifetime. Creating new industries and inspiring our children to join the next generation of scientists and engineers is, to me, a very good way to spend money vs. Food stamps.

SpaceColonizer what is your defination of “substainable”? It seems to be based on money. But who or what determines the amount of money that is available? Generally, people who are not interested in space development or events not directly related to space.

Commerical space development could also be considered unsubstainale by some peoplel. Yea, I know the commerical space supporters will said that commerical space is cheaper, better, etc but $800 million can feed a lot of hungry people or a lot of sick people

Regarding an LRO style MARS mission: LRO was a stunning success for a variety of reasons unique to that period of time. The team at GSFC had worked together on many small quick missions over the prior 15 years; Griffin wanted something, anything to launch before Bush left office, so LRO funding was always available when it was needed – which is never the case for other missions. They were also given a rocket very early in their life cycle. It was way to big for their requirements; hence AMES was allowed to add LCROSS. There are plenty of missions now in Phase B that do not know what their LV is going to be. Replicating LRO again will be tough.

Sadly, the legacy the JWST leaves in its wake is the death of the flag ship mission. And this means the end of Observatory class Science, which isn’t achievable via a string of small explorers.

Another ominous indicator of tough times ahead for SMD (listen up JPL, GSFC, and LaRC) is that notwithstanding a Helio Explorer and an Astrophysics Explorer, there does not appear to be any new missions that will be developed between now and 2018/post JWST time frame. Lots of low level pre formulation studies, but not a mission that will feed one of these Centers. Am I reading that wrong?

Ouch!