Several prominent astronauts clashed at a Senate hearing today over where NASA should go next: the moon, Mars, or asteroids. But without adequate funding the question is moot.

Former astronaut Buzz Aldrin

Steven Senne / AP / Via apimages.com

Buzz Aldrin, the second man to stand on the moon, and two other prominent astronauts clashed at a Senate hearing Tuesday over whether future NASA explorers should land on the moon, Mars, or asteroids.

Testifying at the first Senate space subcommittee hearing chaired by Sen. Ted Cruz, Aldrin, former Apollo pilot Walt Cunningham, and Hubble space telescope repairman Michael Massimino did agree on one thing: The $18.4 billion space agency needs much more money before heading for the stars.

Cruz called for NASA to focus its efforts on space exploration and the "hard sciences." He did not mention NASA's recently launched climate science missions, which some observers worry are in jeopardy. The U.S. should "remain a leader in space exploration," Cruz said.

"If we're going back to the moon, show me the money," quipped Sen. Bill Nelson, another former astronaut, who sat among the politicians questioning the retired space explorers.

The goal of the $1.25 billion Asteroid Retrieval Mission (ARM) will be to grab all or part of a small asteroid, less than 33 feet across. The plan has faced sniping from legislators more interested in a return to the moon. And it was critiqued by a summer National Research Council report that noted a lack of interest among other countries in NASA's proposed asteroid-grabbing plan, as well as a need to ramp up spending on a heavy rocket.

But whether establishing a moon base, favored by Cunningham, or colonizing Mars, favored by Aldrin, or keeping our options open to include an asteroid trip, favored by Massimino, was the right future for NASA appeared no closer to a resolution at the end of the hearing. "You can make an argument for almost any one of them," Massimino said.

Aldrin called for the most daring move: an astronaut landing on Mars by 2038 and establishing a permanent settlement. He suggested that this Mars settlement could be completed, pending further study, "without being a major budget buster for NASA."

Cunningham was more conservative, calling for "a return to the moon," which he said would cost up to three times as much as the Apollo landings, which The Space Review has estimated cost about $119 billion in current dollars.

"Space is always going to be expensive," Cunningham said. "Unless the country, which here is Congress, decides to put more money into NASA, this is all just talk."