U.S. President Donald Trump has said he wants the U.S. military to create a new "space force" that would be separate from the Pentagon's current army, navy, and air force.
Trump told troops at the Miramar Marine Corps Air Station near San Diego on March 13 that the new group would incorporate the "tremendous amount" of work the military already is doing on space-related defense.
"My new national strategy for space recognizes that space is a war-fighting domain, just like the land, air, and sea," Trump said.
"We may even have a space force... We have the air force, we'll have the space force, we'll have the army, the navy... Maybe we'll have to do that. That could happen," he said.
Last year, some legislators pushed a bill in Congress that included a provision to establish a new branch of the military dubbed the Space Corps.
But the Pentagon itself has resisted, saying it does not need to create another bureaucracy.
"At a time when we are trying to integrate the department's joint war-fighting functions, I do not wish to add a separate service that would likely present a narrower and even parochial approach to space operations," Defense Secretary Jim Mattis told Representative Michael Turner in a letter in July.
It would be "premature to add additional organizational and administrative tail to the department at a time I am trying to reduce overhead," Mattis said.
The idea was dropped from the Pentagon's funding bill by the end of last year, but it retains some support in Congress, where advocates say the United States is facing significant strategic vulnerabilities in the face of Russian and Chinese ventures into space warfare.
Representative Mike Rogers told a February 28 conference in Washington that China and Russia have become "near peers" to the United States in space capabilities, and the United States is not pushing hard enough to stay ahead.
"That's unacceptable that we have allowed that to happen, particularly in a day and age when it is essential to have those space capabilities to fight and win wars," he said.
Rogers said that a separate space corps could be carved out from the air force within "three to five years."
Sean O'Keefe, who was both NASA administrator and navy secretary under President George W. Bush, said some people may argue that a space force would "compromise the sanctity of considering space to be off-limits from warfare."
Ever since the Space Age started with the Soviet Union's launch of Sputnik, there has been a military and national security aspect to space, even though there are treaties aimed at keeping space a place of peace.
In the 1950s, U.S. President Dwight Eisenhower established two separate space programs -- a civilian one that became NASA, and a military one. NASA is much more public, but the military program is just as big.
The military space program has mostly been led by the air force. For the past several years, the military has been flying an unmanned space plane that is a lot like the retired civilian space shuttle but smaller, U.S. officials said.