The next Mars mission, after the nuclear-powered Mars rover, is to be called MAVEN.
NASA has just selected it because?....

(a) Because they can't afford a Mars sample return mission in the next decade?

(b) The technology isn't mature enough to allow for a successful Mars sample return
mission before 2015?

That sucks!...I'm convinced the technology for a successful MSR mission already
exists...
So why is NASA putting off selecting a Mars Sample Return mission to reach Mars
before 2015?

I'm tired of waiting for a Mars sample return mission!
If NASA doesn't want to do it within the next seven years, I think ESA, the Russians and Japanese
should join forces and budgets to carry out such an ambitious project.
Agreed?