The abrupt resignation of Alan Stern as associate administrator of NASA’s Science Mission Directorate is a blow to the
space agency and its constituents in the scientific community. Dr. Stern, a planetary scientist, was highly responsive to the priorities of the broader community. Perhaps more importantly, he had waged a determined campaign to impose better management discipline on individual programs, something NASA desperately needs amid a budget crunch that promises to get worse before it gets better.

Unfortunately, it appears Dr. Stern was beginning to encounter institutional resistance, particularly from Mars exploration advocates and their supporters in Congress who have complained loudly in recent weeks about a decline in spending for their activities. There were no doubt other factors, including the normal frustrations associated with trying to get things done in
, but the controversy that erupted over a directive from the Science Mission Directorate to cut costs within the Mars Exploration Program appears to be the proverbial straw that broke the camel’s back.

The directive was intended to help offset some $200 million in recent cost growth on the Mars Science Laboratory (MSL), a large, nuclear-powered rover slated to launch toward the red planet next year. Dr. Stern was insistent – and rightfully so – that NASA look first within the Mars Exploration Program to cover cost growth on one of its component projects. The order would have affected a number of current missions, however, including the Spirit and Opportunity Mars Exploration Rovers; one of these craft likely would have had to cease operations as a result.

Amid the howls of protest that ensued, NASA Administrator Mike Griffin rescinded the order, saying it had not been properly coordinated at agency headquarters. Dr. Stern informed stunned colleagues of his decision to resign early the next morning.

Parking one of the immensely popular Mars rovers without first checking with the NASA administrator might not have been the best idea, politically or otherwise, but the notion that Mars exploration is being shortchanged is nonsense. NASA has dedicated substantial amounts of money to that activity over the past decade and a half, with an eye toward launching missions at every biennial opportunity. This effort has yielded some tremendous scientific successes, perhaps none more spectacular than Spirit and
, now in the fifth year of what originally were supposed to be three-month missions.

But NASA today faces a genuine budgetary crisis, and no program is immune. This includes Mars exploration, whose budget is slated to drop from $555 million this year to $387 million in 2009 as development of the flagship-class MSL winds down and decline further over the next several years.

Dr. Stern recently told lawmakers the plan is nevertheless adequate to fund the MSL, a Mars Scout mission slated to launch in 2013, an $850 million mission that would launch in 2016, and a sample-return mission that would launch in 2018 or 2020. The sample-return mission is a holy grail of sorts for Mars exploration; it is a huge undertaking that would cost billions of dollars but yield a scientific bonanza.

Dr. Stern has a professional interest in Mars – he is principal investigator on one of the candidate missions for the 2013 flight opportunity – but he also recognizes there are other places in the solar system worth visiting. These include some of the moons circling Saturn and Jupiter, which look more interesting with each new piece of data coming in from spacecraft like Cassini.

In recent weeks and months, both Dr. Stern and Administrator Griffin have pleaded with the individual NASA constituencies, whether their cause is human spaceflight, robotic exploration, astronomy or Earth science, to quit pushing their own narrow agendas and get with the larger program. Mars exploration advocates, like everyone else, need to take that message to heart. In the current budgetary environment, the last thing the agency needs is counterproductive infighting. Every constituency inside NASA would benefit far more from a unified front to convince the White House and Congress that it is past time for them to start adequately funding all of the activities they have put on NASA’s plate.

Credit Mr. Griffin for making the best of the current situation by selecting Ed Weiler to replace the departing Dr. Stern. He not only has the experience for the job he held it for six years before being tapped to take over as director of the Goddard Space Flight Center in 2004 he also shares many of Dr. Stern’s views regarding programmatic discipline and responsiveness to the scientific community. Dr. Weiler will do his part to navigate NASA’s science program through these tough times; the various elements of the space science community can do theirs by getting behind him.