The total cost of NASA's Mars Science Laboratory (MSL) mission could reach $2 billion as the program races to surmount its developmental problems and make its scheduled 2009 launch, according to Associate Administrator for Science Alan Stern.

A surface rover the size of a small car, the flagship-level MSL mission originally was approved at a cost of $1.5 billion, Stern told a Feb. 20 meeting of the Mars Exploration Program Analysis Group (MEPAG) in Monrovia, Calif. The latest estimate for the program is $1.8 billion, but it continues to rise, Stern said.

MSL's problems began to surface last year, when NASA had to shift $62 million to the program and cost-cap its various instruments to keep it on track. Just a few months later, the program revealed it would not be able to make its September 2009 launch date without another infusion of cash, as it dealt with a costly change in its thermal protection scheme (DAILY, Feb. 14).

Following an evaluation by an independent cost team, NASA is bracing itself to shift an estimated $165 million to keep MSL going. That money will be taken from current appropriations, and will come from within the Science Mission Directorate's Planetary division, Stern said.

"From what we've been told by the independent cost review team, this is not the end," Stern said. "It's going to go up some more. We just don't know how much."

In December, NASA spent $53 million on MSL, then $56 million the following month. "They are going as hard as they can to make that launch window," Stern said. "We should know in the next roughly hundred days if that's going to be possible or not. Hopefully by June or July it'll be clear." If 2009 is impossible, the program can shoot for a 2010 or 2011 launch.

Stern defended NASA's overall budget request for Mars, which is expected to dip significantly once MSL winds down and NASA's next flagship science mission, at this point simply called the Outer Planets Flagship (OPF), ramps up. The Mars program also took a significant hit when NASA reprogrammed money to fund $910 million in new Earth Science mission starts over the next five years, in response to recommendations from the National Academies (DAILY, Feb. 1).

Although he conceded that he'd like to see the Mars topline "a little bit higher," Stern still called it "a very healthy program, and I think it's hard to argue otherwise. Every program everywhere in SMD, every nook and cranny, would like to have more resources. But I doubt that there are many programs that wouldn't trade for the resources that [the Mars program] has."

Following OPF, the next flagship will be the Mars Sample Return (MSR) mission, for which NASA has set aside about $3.3 billion for U.S. participation, on the expectation that roughly half that amount will be kicked in by foreign partners. Stern attempted to calm fears that there was no formal "line" in the budget yet for MSR. He said $68 million is slated to be spent on technology development and architecture studies for MSR, although that money is tucked away in the technology and programmatic studies lines.

"There's no 'line' for MSR yet because we haven't gotten to a point yet where we believe enough to put a new start on the map," Stern said. "We have to do those architecture studies to see if, on the available budget ... we can do an MSR mission that the community can stand behind and say it's worth that level of resources."

MSR is actually two missions. The first, tentatively slated to launch in 2018, would send a rover to the surface of Mars to gather samples. The second, to launch in 2020, would retrieve the samples and bring them back to Earth.