U.S. President Barack Obama’s 2012 budget request for NASA, and the immediate reaction it drew from agency stakeholders, are a good indication that last year’s battle over the agency’s future, specifically in human spaceflight, is far from over.

Although the president in October signed legislation that reflects Congress’ human spaceflight priorities more so than the ones he laid out at the beginning of last year, the fiscal mood of the nation, as manifested in the 2010 elections that brought Republicans to power in the House on promises to rein in spending, has reopened the proceedings.

This, to put it mildly, is not a good thing.

Another year of uncertainty for NASA’s human spaceflight program means hundreds of millions if not billions of dollars will continue to be spent on development projects that may or may not have a future.

Industry, meanwhile, in the absence of clear direction from NASA, cannot size its infrastructure accordingly; companies are carrying excess capacity just in case it might be needed, thus incurring overhead costs that ultimately get passed onto NASA and other government customers, including the Pentagon, through existing programs. A good example is the U.S. Air Force’s Evolved Expendable Launch Vehicle program, which is absorbing overhead costs that previously were spread among several programs, particularly the soon-to-be retired space shuttle.

The situation would be untenable under any circumstances, let alone a fiscal environment in which spending money more wisely and efficiently is of paramount importance.

The 2010 NASA Authorization Act, which directs the agency to build a government-owned crew capsule and heavy-lift rocket — two items that were not in President Obama’s 2011 budget request — rests on funding assumptions that now have little basis in reality. The law authorizes $19 billion for NASA in 2011, $19.5 billion in 2012, and nearly $20 billion in 2013. President Obama’s budget proposal appears at best to freeze NASA funding at the 2010 level of $18.7 billion for the next five years. After accounting for inflation, NASA’s buying power will actually shrink.

But wait — it potentially gets worse. The flat outyear funding scenario is depicted in the charts distributed by NASA; the numbers released by the White House Office of Management and Budget (OMB) show NASA’s budget declining to the $18 billion level for 2013 and 2014  before finally climbing back above $18.7 billion in 2017.

Neither NASA nor the White House has clarified the discrepancy, but if the OMB numbers are correct, and NASA’s numbers merely notional, then the individual program budgets that add up to the top line will have to be adjusted accordingly, which raises questions about the analysis that went into preparing them in the first place.

On top of all that, the House is pushing a continuing resolution to fund the federal government for the remainder of 2011 that would cut NASA’s budget by $600 million from the 2010 level. Although that measure stands next to no chance of passage, NASA could well be in for a funding reduction in any compromise lawmakers might be able to reach.

The administration’s priorities are clear in the 2012 budget request: commercial human spaceflight, Earth science and exploration technology development would see big increases, with the funds coming largely from the $2.4 billion in savings NASA expects to reap from the space shuttle fleet’s retirement later this year. Funding for new NASA-owned human exploration capabilities would decline relative to 2010, although the programmatic content is a bit different in the latest request. In 2010 that account was dominated by the Ares 1 crew launch vehicle and the Orion crew capsule; in 2012, Ares 1 is essentially replaced by the heavy-lift Space Launch System, which per the NASA Authorization Act is to leverage investments in Ares 1 and space shuttle technology and infrastructure.

Sen. Bill Nelson (D-Fla.), who played a primary role in drafting the NASA authorizing legislation, signaled his displeasure with the latest White House budget plan, saying, “Congress will assert its priorities in the next six months.” There also likely will be stiff opposition from the House Science and Technology space and aeronautics subcommittee, where nearly half of the members come from Alabama, Florida, Mississippi and Texas, states that host major NASA human spaceflight facilities that are tied closely to the Space Launch System and Orion.

In short, it’s a recipe for another year of wasteful gridlock that could turn destructive if the stakeholders in NASA’s different enterprises — who got along nicely under fiscal scenarios that now look like pure fantasy — turn on one another as their pet projects bump up against the realities of a no-growth budget. An early and ominous sign of things to come was the letter from several House Republicans representing human spaceflight states asking the House Appropriations Committee leadership to shift funding from Earth science to exploration accounts. Such a move almost certainly would be fiercely resisted by Sen. Barbara Mikulski (D-Md.), chairwoman of the Senate Appropriations subcommittee with NASA oversight and a longtime supporter of human spaceflight. Sen. Mikulski’s home state hosts NASA’s Goddard Space Flight Center, the agency’s lead center for Earth observation.

When NASA in January provided Congress with so-called reference designs for a Space Launch System and Multi-Purpose Crew Vehicle — the latter being a deep-space version of Orion — that the agency said could not be built on the schedule and at the price spelled out in the NASA Authorization Act, lawmakers reacted with skepticism. Surely NASA knows a bit more than Congress about what it takes to build space vehicles, but even if that were not the case, lawmakers cannot ignore the new fiscal environment, which barring a miracle will not support all the things they have directed NASA to do.

It is time to quit pretending that NASA is going to send astronauts to an asteroid or carry out meaningful exploration of any other deep-space destination in the next two decades. The White House and Congress need to get serious about setting realistic — in other words, far more modest — human spaceflight goals and develop a fiscally sustainable plan for achieving them.

Throwing big money at flagship technology demonstrations is not the answer. These are bound to become dead-end flight projects that encounter the same kinds of delays and cost growth as missions with actual scientific objectives —  to the extent they survive the congressional appropriations process or a change of administrations.

But a heavy-lift rocket built to congressional specifications, a vehicle that would cost billions of dollars yet have nothing to launch — there’s no money for landers or other equipment needed to visit an asteroid, for example — doesn’t make much sense either. Still worse would be gutting NASA’s science program, which nonetheless is going to have to be scaled back like everything else.

A space program locked in stalemate between multiple armed camps, each determined not to cede any ground, is a grounded space program.