NASA's fortunes are more precarious now that billionare businessman Donald Trump is the presumptive Republican nominee. His rival, Texas Sen. Ted Cruz, is bullish about the space program's plans to visit Mars and asteroids, but Trump is skeptical about funding deep space missions, preferring to keep the money Earth-bound.

Trump has indicated that if elected president he would prioritize economic development over NASA funding, most recently in a questionnaire about space policy published this week by Aerospace America.

"Our first priority is to restore a strong economic base to this country," Trump said. "If we are growing with all of our people employed and our military readiness back to acceptable levels, then we can take a look at the timeline for sending more people into space."

This echoes statements Trump made during a campaign event in New Hampshire in November, when he told a 10-year-old that he loves NASA but "right now we have bigger problems, you understand that, we've got to fix our potholes."

"You know we don't have exactly a lot of money," Trump said at the event, according to Space Policy Online.

Trump also said in August during another rally in New Hampshire that the space agency's goal of sending people to Mars by the 2030s is "wonderful," but "I want to rebuild our infrastructure first."

The Trump campaign could not be reached for additional comment.

As the chairman of the Senate Subcommittee on Space, Science and Competitiveness, Cruz has been vocal about his support for funding NASA. A spokesman for Cruz cited his op-ed from last year in the Houston Chronicle when he said his "first priority" on the space program is "to refocus NASA's energies on its core priority of exploring space," supporting its capability to travel to the Mars or the moon as "critical." NASA's Mission Control is located in Houston.

In spite of his support, however, Cruz has provided few details on how he would support NASA's budget while also keeping his promises to lower taxes and balance the federal budget.

"We need to get back to the hard sciences, to manned space exploration, and to the innovation that has been integral to the mission of NASA," Cruz said.

NASA has its differences with Cruz, however, as his support for space exploration accompanies his scrutiny of the agency's Earth sciences programs, criticizing them in part because of the association with the Obama administration's research into climate change.

"Since the end of the last administration we have seen a disproportionate increase in the amount of federal funds that have been allocated to the earth science program at the expense of and in comparison to exploration and space operations," Cruz said during a hearing of his Senate committee in March. "I am concerned that NASA in the current environment has lost its full focus on that core mission."

NASA would likely fare best with the Democratic presidential candidates. Sen. Bernie Sanders, I-Vermont, told Aerospace America that he supports fully funding NASA because of its roles in exploration and technological development.

"I am not prepared to say what the appropriate funding level should be for NASA until we get a handle on the revenue side of the budget," Sanders said. "I will demand that the wealthy and large corporations pay their fair share in taxes, which will allow us to adequately fund the programs and services that bring widespread benefits to the American people — including NASA."

Democratic front-runner Hillary Clinton campaigned for president in 2008 vowing to boost NASA's funding, and in December during a town hall in New Hampshire she insisted, "I really, really do support the space program." Clinton also showed her space geek side by promising the Conway Daily Sun in New Hampshire that she would "get to the bottom" of questions about UFOs by reviewing and declassifying government information.

No matter who becomes president, though, the funding of NASA "is under great downward pressure due to growth of entitlement spending and interest on the debt," says Scott Pace, a former NASA official and the director of the Space Policy Institute at George Washington University. The Obama administration's plans for a manned expedition to Mars, or to redirect an asteroid near the moon for closer study "don't seem sustainable -- not due to funding limits alone, but a lack of relevance for immediate national interests," says Pace.

"A U.S.-led return to the Moon with commercial and international partners would make more sense in my view," he says.

Indeed, Sanders noted in the questionairre that NASA does "not have a single overarching goal like the one it had in the 1960s." If elected president, Sanders said, "In the short term, I would continue planning for human exploration of Mars" but would consult with stakeholders on the best priority for its resources.

Members of both parties in the House Committee on Science, Space and Technology have called on NASA to produce a more detailed timeline and budget for its deep space missions. Darrell West, director of the center for technology innovation at the Brookings Institution, says Trump would be the candidate least willing to fund manned space missions because he "has been skeptical of a lot of big government projects" and "NASA has been the object of his scrutiny."

"We need more continuity in space policy, the idea that every administration that comes along has a different priority is a great way to waste money," West says. "Space exploration has a long lead time so each administration should be building on the work of the previous one."