" The robotic Mars program is sort of a planetary Dead Man Walking these days, as scientists debate what missions should be next on the agenda and how Mars should compete for funding with other compelling destinations ranging from our own moon to potentially life-harboring moons in the outer solar system."
So begins an article by long time space journalist Leonard David. He reports on the on-going debate on how to restructure the Mars program following the delay and cost overrun of the Mars Science Laboratory (MSL). In addition to the delay to this Flagship-class mission, funding the overrun is draining NASA's advanced technology programs for future Mars missions. NASA had planned on having technologies to allow for ever more pinpoint landings, opening up new places on the surface to visit. It also planned to spend to develop technologies for a Mars Sample Return (MSR) mission. Now those capabilities will be delayed at least two years and perhaps more as teams need to be rebuilt when money becomes available.
David reports that one leading Mars scientist, Chris McKay of the Ames Research Center writes that three factors will lead to a substantial revamping of the Mars program: (1) the delay and cost overrun of MSL, (2) missions that go beyond the capabilities of past and planned missions will be in the Flagship ($2-3B) cost realm, and (3) other locations for searching for life such as Enceladus and Titan provide alternative destinations. McKay still believes the Mars deserves to be the focus of robotic planetary missions, but as a lead in to future manned exploration.
Another Mars Researcher is quoted by David, Bruce Jakosky of the University of Colorado at Boulder, as saying that the Mars program remains fundamentally sound. While the program needs to be replanned, there are many options for cheaper missions. (Jakosky's Mars Maven planned for launch in 2013 will cost around $450M.)
Editorial Thoughts: I feel that this debate feels like the glass half empty versus the glass half full discussion. Yes, the Mars and NASA's overall planetary programs will take a major hit from the MSL delay. Yes, other good missions could have been flown for what MSL will cost. However, there isn't a right answer to how much should be spent exploring Mars. It is a subjective question of balance between Mars and other destinations. The most critical decision of the upcoming Decadal Survey, in my opinion, will be on the balance between funding for future Mars missions versus those other destinations. A case could be made for devoting the entire budget to Mars [let's focus on exploring one world in depth], for devoting none of it to Mars [Mars has been the focus for the last 15 years and it's time to move one], to virtually any balance in between. If the Decadal Survey simply lists a number of good missions whose probable costs exceed probable funding, then in my opinion it will not have made the hard decision of how to set priorities.
I also don't feel that flying ever more complicated missions to Mars is the onlyway to expand our knowledge of the Red Planet. (I say this knowing that many more knowledgeable than I are likely to disagree.) We could have a strategy of flying a series of rovers more capable than Spirit and Opportunity but less capable than MSL to a number of locations to find the one most deserving of a future flagship-class mission (be it a rover, a deep driller, or a sample return). We could focus on exploring Mars as a system and spend a decade putting simple network landers across the surface and a series of orbiters to address questions left unanswered by past and planned missions. (The science team that debated the focus of the planned Mars Science Orbiter (which may fly in a reduced configuration in 2016) identified three core study areas that future orbiters could focus on.)
I'm not saying that this should be our goal at Mars -- they don't pay me the big bucks to make those decisions and nor do I feel well enough informed. I do think that there are a range of mission options and price tags that could continue our exploration of Mars.
Resources: Leonard David's article at Space.com