In August 2012, NASA’s $2.5 billion Mars Science Laboratory mission, well over budget and two years behind schedule, captivated the world when it deployed the Curiosity rover on the martian surface in a high-wire — literally — maneuver that entailed lowering the car-sized, nuclear-powered vehicle by cable from a rocketship hovering above.

As engineering feats go, the landing was nothing short of spectacular, a testimony to NASA’s boldness and ingenuity — so much so that the rover’s science potential was almost an afterthought.

Unfortunately, that’s just how it appears to a panel of distinguished scientists who recently reviewed proposals to extend the missions of Curiosity and several other planetary probes. The senior review panel characterized the Mars Science Laboratory as a budding underachiever with vague scientific objectives, even as it recommended that NASA fund another two years of Curiosity operations at a cost of $115 million.

In its first two years, Curiosity collected and analyzed five soil samples of the martian surface, “a poor science return for such a large investment in a flagship mission,” the 15-member panel said in its Sept. 3 report.

The report also noted that the mission’s lead scientist, John Grotzinger of NASA’s Jet Propulsion Laboratory, failed to show up to a Mars-focused meeting of the panel back in May. “This left the panel with the impression that the [Curiosity] team felt they were too big to fail,” the report said.

Even after two years of Curiosity operations, the panel said it did not have a clear understanding of the mission’s scientific objectives. Therefore, the report said, it was difficult to determine whether those objectives had been achieved.

One might reasonably conclude, based on the report, that the Curiosity science team took the extension of Curiosity operations for granted given the mission’s status as a flagship and a showcase of NASA’s technical chops.

In a Sept. 11 conference call with reporters, Jim Green, director of NASA’s Planetary Science Division, and Mr. Grotzinger pushed back against the report’s main criticisms. They pointed out that Mr. Grotzinger had an educational outreach meeting that conflicted with the senior review meeting and that he sent his deputy in his stead and also made himself available by phone. Fair enough, but one still can question whether Mr. Grotzinger and his superiors made the right choice about which meeting he should attend.

As for the criticism that Curiosity hasn’t collected enough soil samples, NASA said quality trumps quantity. Even so, Mr. Grotzinger thought it important to point out that those five samples generated “millions” of data points. 

Mr. Green went so far as to say that “within weeks, Curiosity fulfilled its goal” by discovering the key ingredients to life on the red planet. But that observation suggests there was a big mismatch between mission requirements and objectives — for example, why design the rover to last at least two years? — and hardly makes the case for another two years of operations. Moreover, one has to wonder now about NASA’s scientific ambitions for Curiosity’s twin rover, now being built for a 2020 launch at an estimated cost of some $2 billion.  

One thing that’s clear is there’s a disconnect between the Curiosity science team and the broader academic community. This is a problem: The senior review panel is drawn from the same pool of mostly university-based scientists that help set long-term agendas for NASA’s planetary program. These groups really need to be on the same page for the program to be successful. 

The Mars Science Laboratory will never be regarded as a failure, but the project team nonetheless owes it to the science community and to the taxpayer to get the maximum possible scientific return from the rover. This is vital not only to justify the Curiosity’s two-year extension but also to give the Mars 2020 rover mission something to build upon.

A failure to map out a more robust scientific agenda for Curiosity and Mars 2020 will give ammunition to critics who often accuse NASA of being enamored with technological stunts and of trying to relive past glories. The agency’s world-class Mars exploration program is better than that.