SAN FRANCISCO — While 2011 is expected to be a banner year for NASA’s planetary science program with three missions scheduled for launch, future initiatives are threatened by budget uncertainties and a dramatic spike in the price of launch vehicles, according to an agency official.

“This is a really difficult financial environment,” Jim Green, NASA’s director of planetary science, said Dec. 15 at a meeting of the American Geophysical Union here.

Rides into orbit for NASA’s 2011 planetary missions, the Mars Science Laboratory (MSL), the Juno mission to Jupiter and the Moon-bound Gravity Recovery and Interior Laboratory (GRAIL), were purchased under the first NASA Launch Services contract. That contract, which does not include specific quantities of rockets to be purchased or delivery dates, sets prices for launch vehicles and related services for NASA’s planetary, Earth observing, exploration and scientific satellites.

In September, NASA awarded a second set of Launch Services contracts to Denver-based Lockheed Martin Space Systems, Orbital Sciences Corp. of Dulles, Va., Space Exploration Technologies (SpaceX) of Hawthorne, Calif., and United Launch Alliance of Littleton, Colo. Prices in the second NASA Launch Services contract round are “significantly higher” than the prices in the first, Green said. He declined to be specific.

“We are surprised at how extensive those cost increases are,” he said. “You start to wonder where we go from here. How do we get out of low Earth orbit on a regular basis?”

NASA planetary missions typically are launched aboard Atlas 5 and Delta 2 rockets built by United Launch Alliance, a Boeing-Lockheed Martin joint venture. The Delta 2 has been phased out of production, however, and only a few vehicles remain available.

One possibility for the future is to rely on emerging commercial vehicles like the SpaceX Falcon 9, a medium-lift rocket in roughly the same class as the Delta 2 that recently made its second successful launch. “They need several more [successful flights] before we will have the opportunity to look at that vehicle and its capacity,” Green said. In the meantime, NASA officials are conducting a thorough review of the second NASA Launch Services contract to make sure they understand the prices included and meeting with officials from the White House Office of Management and Budget to discuss the problem of rising launch costs, he added.

At the same time, NASA’s future planning efforts for planetary exploration are being hindered by budgetary uncertainty. Congress has yet to pass a spending bill for the full 2011 fiscal year; in December, lawmakers passed a so-called continuing resolution that funds most federal programs at 2010 spending rates through March 4.

NASA’s planetary science program had been slated to receive a 10 percent increase, to $1.49 billion, under the White House’s budget request for 2011, but that now appears uncertain at best.

Further budgetary uncertainty is being created by the cost growth on MSL, a mission scheduled for launch in November 2011 to send a small-truck-sized rover to explore the red planet. “MSL is pushing our budget envelope,” Green said. “To make sure the program has enough reserve, we probably will be adding some funding.”

One scientist said the program needed an additional infusion of $35 million to cover projected expenses. Green declined to confirm that figure but said the shortfall “is going to be several tens of millions of dollars.” That additional funding will need to be found in the 2011 and 2012 budgets, he added.

To find that money, NASA officials will work with the NASA Advisory Council’s Planetary Science Subcommittee, which is scheduled to meet in Washington Jan. 26-27. “We will talk to them about how to supply the right funds at the right time to give MSL the best chance of success without affecting the rest of our research program,” Green said.

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...