The ARM spacecraft's cost cap, Lightfoot said, remains $1.25 billion—not including the launch vehicle. Funding for ARM is currently scattered between multiple NASA programs.

"I think there will be some (funding) increase that is specific to the mission," he said. "We will take advantage of solar electric propulsion, which is estimated roughly at $300 million, which is already in the runout for space technologies. There's some capture technique mecahnisms that were already in parts of the human exploration budget."

Will ARM be officially stamped into next year's budget request? "I hope so. That's my plan," he said.

While the main goal of ARM is demonstrating technologies useful for deep space human exploration missions, there are also expected to be science benefits. In addition to a sample return, the target asteroid will be mapped, and the captured boulder will be characterized by instruments aboard the ARM spacecraft. "There’s some cool science that we’ll get out of it," said Busch.

Alessondra Springmann, a graduate researcher for the OSIRIS-REx mission, said ARM also demonstrates the importance of planetary radar. In particular, Arecibo Observatory, where she once worked, is unique in its ability to team up with other dishes like Goldstone to characterize asteroids. And unlike Goldstone, Arecibo doesn't have to compete for scheduling time with NASA's Deep Space Network. However, the observatory has recently struggled to stay funded.

"Radar bridges the gap between optical observatories and space missions," Springmann said. "There’s no other way to see boulders on the surface of an asteroid."