With the release of his fiscal year 2011 budget, President Barack Obama dramatically broke one of his campaign promises.

Obama had said during the campaign that he would "endorse the goal of sending human missions to the moon by 2020, as a precursor in an orderly progression to missions to more distant destinations, including Mars." But the proposed budget he presented to Congress would shift course significantly.

Obama's proposed budget would cancel Constellation, the successor system for the space shuttle, after NASA has already spent $9 billion on the program. And along with canceling Costellation, Obama offered an alternative road map for human space exploration over the next decade or more.

"NASA's Constellation program – based largely on existing technologies – was based on a vision of returning astronauts back to the moon by 2020," the president's budget says. "However, the program was over budget, behind schedule, and lacking in innovation due to a failure to invest in critical new technologies. Using a broad range of criteria, an independent review panel determined that even if fully funded, NASA's program to repeat many of the achievements of the Apollo era, 50 years later, was the least attractive approach to space exploration as compared to potential alternatives. Furthermore, NASA's attempts to pursue its moon goals, while inadequate to that task, had drawn funding away from other NASA programs, including robotic space exploration, science, and Earth observations."

The budget proposes swapping Constellation for reliance on the still-developing commercial space sector to carry cargo and crew into orbit "with significantly lower operations costs than current systems." Contrary to his campaign promise, the budget does not mention a 2020 target date, and it dismisses the idea of humans actually landing on the moon, in favor of robotic missions "to scout locations and demonstrate technologies to increase the safety and capability of future human missions and provide scientific dividends." The budget avoids specifics about the ultimate target for human missions; the robotic forays would help determine whether landing humans on Mars is a viable goal.

Of course, the president's budget is only a proposal, and the forces supporting Constellation are substantial. They include lawmakers from Alabama, Florida and Texas, the states most deeply involved in Constellation. So Obama's major shift in focus is far from a done deal.

However, the president has made clear his opposition to the idea of landing a human on the moon by 2020, which was the linchpin of Promise 339. So we are moving it from In the Works to Promise Broken.

The preliminary report by a blue-ribbon space policy panel on Sept. 8, 2009, nudged forward several promises made by Barack Obama during the presidential campaign. One of those was to "endorse the goal of sending human missions to the moon by 2020, as a precursor in an orderly progression to missions to more distant destinations, including Mars."

In a 12-page summary of findings, the U.S. Human Space Flight Plans Committee — more commonly known as the Augustine Committee after its chairman, Norman Augustine, the former CEO of Lockheed Martin — drew up a menu of options for future human space flight goals.

In the big picture, the panel called Mars "the ultimate destination for human exploration, but it is not the best first destination." The technical and human challenges involved in starting with a Mars landing are too difficult, the panel said. Instead, the panel urged one of two approaches — "moon first" and "flexible path."

Under "moon first," NASA would use experience operating on the moon's surface as preparation for the goal of exploring Mars later on. Through multiple missions, astronauts could build a base and live there for months in preparation for a trip to Mars, doing things like prospecting for fuel and conducting scientific work.

Under "flexible path," NASA would visit a wider variety of destinations, including lunar orbit, asteroids and the moons of Mars, followed by exploration of the surface of the moon or Mars. The missions would get longer and longer, providing experience in the long transit times required of a trip to Mars.

"The committee finds that both 'moon first' and 'flexible path' are viable exploration strategies," the panel wrote. "It also finds that they are not necessarily mutually exclusive; before traveling to Mars, we might be well served to both extend our presence in free space and gain experience working on the lunar surface."

As for the details of following either approach, the panel offered a number of options, but it said that the only viable ones would require more money than currently envisioned in NASA's budget. Specifically, the panel's proposed budget would phase in increases for NASA — up to $3 billion above the budget that is currently envisioned for fiscal year 2014 — and then expand spending by 2.4 percent per year thereafter.

The key question is whether a moon mission can be achieved by Obama's 2020 goal. The "moon first" or "flexible path" approaches are feasible, the panel concluded. The moon strategy could send a human to the lunar surface by the mid 2020s, while the flexible path option could permit either a human trip to a moon of Mars or the lunar surface by the mid to late 2020s.

Either option is slower than Obama's promise envisioned, but the Augustine Committee's goals for human exploration are generally about the same as Obama's. Officially, the Augustine Committee's findings are only options for the administration to consider. And as of this writing, the full report is not out. But the panel's deliberations are being taken very seriously in NASA, at the White House, in Congress and in the larger space community, so the discussion of the moon strategy is enough for us to rate this one In the Works.