HOUSTON — NASA’s Mars Planning Program Group (MPPG), armed with an array of new ideas for exploring the red planet in the wake of budget cuts, is now preparing to send its recommendations forward to the murky realm of Washington politics, with its reputation for bold visions and vague follow-through.

“Budget is the driver. It’s not a matter of what you can do. It’s a matter of when you can do it,” says Doug McCuistion, NASA’s Mars Program director and co-host, along with the NASA-funded Lunar Planetary Institute, of a three-day MPPG workshop attended by dozens of engineers and scientists that concluded here June 14.

A quick verdict from Washington policymakers on a more affordable blueprint could be wishful thinking. A closely contested presidential election and Congressional politics could place NASA’s proposed 2013 spending plan, with its near 40% cut in Mars spending and prospects for deeper reductions to follow, under the thumb of a budgetary continuing resolution, preventing a meaningful, high-level restructuring of its exploration strategy until well into 2013. A change in administrations could snarl efforts to establish a new Mars strategy even longer.

“Frankly, global economies are not in very good shape and our national economy is not good,” McCuistion stressed in an interview on the next phase of NASA planning. “We don’t want to keep starting over, certainly. But the budget will drive how quickly we can accomplish things, and that will always be the case.”

Scientists and engineers from the U.S. and abroad made just over 170 invitation-only presentations before the workshop in three broad areas: technology and enabling capabilities; human exploration and precursors; and science mission concepts.

Stephen Mackwell, LPI’s director, will forward a summary report of the workshop proceedings to Orlando Figueroa, head of the MPPG, by early next week, with a more analytical effort to follow in July. Figueroa, who like McCuistion circulated through the Houston workshop sessions, will prepare options for top NASA administrators by the end of August.

“We’re walking away with a few nuggets for the near term and the long term,” Figueroa said as the workshop ended.

NASA’s Mars re-planning team is governed by John Grunsfeld, associate administrator for science; Bill Gerstenmaier, associate administrator for Human Operations and Exploration; Chief Technologist Mason Peck and Chief Scientist Waleed Abdalati.

The internal re-planning timeline accommodates NASA/White House deliberations that could place elements of a revised Mars strategy in the 2014 budget presented to Congress next February, in the most optimistic scenario, McCuistion says.

The budget slump precipitated NASA’s withdrawal from a joint effort with the European Space Agency, ExoMars, which comprised joint orbiter and lander missions in 2016 and 2018 to set up a multinational sample-return expedition as soon as 2022. NASA new starts for Mars, beyond the late 2013 launch of the Mars Atmosphere and Volatile Evolution Mission, are now uncertain.

What has not changed, however, are two overarching policy factors: the emphasis placed by the National Research Council (NRC) on sample return as part of its decadal survey of planetary mission priorities between 2013 and 2022, and President Obama’s 2010 directive to NASA that it prepare to send astronauts to the Mars environs by the mid-2030s.

“We are trying to satisfy both of these at the same time, and that is the challenge,” McCuistion says, emphasizing the perhaps not-so-apparent significance of the NRC’s assessment. “Without decadals, you just end up with chaos — communities arguing whose science is more important, whose mission is more important.”

Called for by the MPPG in April, the LPI workshop should provide a wealth of competing ideas for reaching and probing Mars with machines and humans to determine its suitability for past or present life. Aside from the budget, the efforts will be paced by the 26-month separation in favorable Mars launch windows and a daunting assortment of technology challenges, including heavy-lift rocket and entry, descent and landing strategies.