Neil Armstrong, the first person to set foot on the Moon, thinks humanity should stop neglecting the space environment much closer to Earth.

The United States dropped most of its test flights in the stratosphere and suborbital space after figuring out how to send humans to low Earth orbit and the Moon, said Armstrong, who stepped onto the lunar surface during NASA’s Apollo 11 mission in July 1969. He thinks it is time for that to change.

“In the suborbital area, there are a lot of things to be done,” Armstrong said Feb. 27 during a presentation at the Next-Generation Suborbital Researchers Conference in Palo Alto, Calif. “This is an area that has been essentially absent for about four decades, since the X-15 finished its job.”

The X-15 was a rocket plane that took to the skies 199 times between 1959 and 1968, setting numerous speed and altitude records along the way. Armstrong was at the controls for some of those flights; before becoming an astronaut in 1962, he was a test pilot for NASA and its predecessor institution, the National Advisory Committee for Aeronautics.

“There’s a lot of opportunity,” he told a room full of roughly 400 people. “So I certainly hope that some of the approaches that you all are providing now will prove to be both profitable and useful.”

Multiple private spaceflight firms are aiming to take both scientific experiments and paying customers to suborbital space. Such trips would reach altitudes of about 100 kilometers and return back to the ground without making a complete orbit of the Earth.

These companies include XCOR Aerospace, which is developing a two-seat rocket plane called Lynx, and Virgin Galactic, whose SpaceShipTwo vehicle can seat up to six passengers, along with two pilots.

The presence of a spaceflight legend like Armstrong at the Next-Generation Suborbital Researchers Conference should help shine a light on the promise of commercial suborbital spaceflight, some researchers say.

“I think that this shows that commercial suborbital, while being leading-edge, is also becoming mainstream,” said Alan Stern, associate vice president of the nonprofit Southwest Research Institute, which has bought tickets for its scientists and experiments on both the Lynx and SpaceShipTwo.

“The fact that he wanted to travel across the country — he actually cancelled an overseas trip so he could speak at a suborbital conference — I think speaks volumes,” Stern added.