Early this year, dark clouds hovered over NASA’s planetary science program. As the agency started its biennial senior review of ongoing missions, many in the science community feared there would not be enough money to keep all its extended missions operating beyond 2014. The Cassini Saturn orbiter, the Lunar Reconnaissance Orbiter and the Mars rover Opportunity were thought to be in jeopardy.

However, when NASA released the senior review report Sept. 3, it recommended continuing all of the missions it evaluated with only minimal changes. That outcome is the latest juggling act by Jim Green, director of NASA’s Planetary Sciences Division, who has led efforts to keep current missions on track and start new ones despite a budget significantly smaller than just a few years ago.

Green frequently identifies himself as the chief proponent for planetary science in the U.S. government. That effort has involved working not just with NASA, the White House and Capitol Hill, but also within the planetary science community. Green is a frequent participant at conferences and advisory group meetings, not just talking about the issues he’s dealing with but also highlighting NASA’s accomplishments and plans in planetary science: a pep talk of sorts for scientists frequently dismayed by the state of agency budgets.

Green, a space physicist who became director in 2006, has seen his job become more difficult since the fiscal year 2013 budget proposal recommended a 20 percent cut in funding for his division. While Congress has partially restored those cuts, it has also earmarked funding for a Europa mission not requested by the agency, complicating his efforts.

In his presentations with scientists, Green has emphasized following the guidance provided in the latest planetary science decadal survey, published in early 2011, when making decisions about the budget. “These are tough budgetary times,” he said at a January meeting of the Small Bodies Assessment Group. “We’ve had to use priorities, and from the planetary science perspective, these are decadal priorities.” Despite overall budget cuts, he has taken steps to implement recommendations in the decadal report, such as increasing funding for research grants.

He has not been able to satisfy everyone, though. Last fall, he canceled work on a new radioisotope power source his division was funding, citing a lack of missions planned that would be able to use it. He also ruled out the use of such power sources for missions proposed in the upcoming round of the Discovery program of low-cost planetary missions in order to preserve available supplies of plutonium-238 while production of that isotope restarts. That has dismayed some planetary scientists, as it effectively rules out missions to the outer solar system.

Green also helped salvage another NASA science mission outside of his division facing cancellation this year. In May, NASA’s Astrophysics Division, in its own senior review, recommended that the Spitzer Space Telescope be shut down because of its high operating cost relative to its scientific utility.

In July, though, NASA reversed that decision, partially because of Spitzer’s submission of a revised budget but also because of a commitment by Green to provide funding for the telescope in support of planetary science observations. Green told a NASA Advisory Council committee Sept. 3 that his division’s share of Spitzer’s costs will be several million dollars. It’s another small step he has taken to get more science out of a smaller budget.