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President Donald Trump's call this week that to create a sixth branch of the U.S. military — which he called the "Space Force" — has reopened a wider debate about whether such a move is necessary to better manage military space activities. While the idea of a separate, space-focused military branch is not new, Trump's surprise announcement caused a buzz on social media and news outlets.

"When it comes to defending America, it is not enough to merely have an American presence in space. We must have American dominance in space," Trump said in a speech before a meeting of the National Space Council at the White House Monday (June 18). "I'm hereby directing the Department of Defense and Pentagon to immediately begin the process necessary to establish a Space Force as the sixth branch of the armed forces. That's a big statement.

"We are going to have the Air Force, and we are going to have the Space Force — separate but equal," he continued. "It is going to be something. So important." Trump then directed a comment at the chair of the Joint Chiefs of Staff, Gen. Joseph Dunford. "Gen. Dunford, if you would carry that assignment out, I would be very greatly honored, also." [Military Space - Spacecraft, Weapons and Tech]

Trump's remarks follow decades of discussion on a separate space branch, including a recent 2017 attempt to create a new U.S. Space Corps. At the time, the U.S. House Armed Services Committee drafted legislation for the new corps in the 2018 National Defense Authorization Act. While the U.S. secretary of the Air Force was supposed to oversee this new branch, the U.S. Space Corps would have had its own seat on the Joint Chiefs of Staff. Senior military officials did not universally approve the proposal, and it was ultimately withdrawn.

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But some space experts say Trump's announcement may at least spur more discussion about how to best manage space activities.

The United States has worried for many years about the security of its satellites and how to best protect them, said Barry Strauss, a military and naval historian who is a humanistic studies professor at Cornell University in Ithaca, New York. He told Space.com that it would be good to have a public debate about what to do.

"It's going to be very controversial," he said. "The logistical questions are controversial; the funding questions are controversial. Whenever you start a new department of anything, it's controversial. Our resources are limited, so they [new resources] have to come from somewhere else. But as you know, it's not as though the president can snap his fingers and make this happen. It's something that Congress will have to debate and discuss."

But it's hard to say how a Space Force would change things, because the U.S. Air Force already oversees the military's space asset procurement budget with participation from the other military branches, pointed out Joan Johnson-Freese, a professor of national security affairs at the U.S. Naval War College in Newport, Rhode Island. Also, there are concerns about how to protect satellites without breaking international treaties and, more pressingly, generating more space debris by firing offensive weapons at satellites.

"Why do we need a Space Force? What is a Space Force going to do which isn't currently being done by the Air Force?" she told Space.com. Trump's idea to "dominate" space also raises questions, she said, because in military terms ,"dominate" generally means to completely control a limited geography for a limited period of time. "How do you dominate space?" she asked. "How do you have control of everything indefinitely?"

Decades of military work

The United States' military activity in space dates back to the beginning of the Space Age, when the Corona reconnaissance satellite launched in 1959 under President Dwight Eisenhower's administration. In the 1960s, there were military astronauts who first participated in the Dyna-Soar program and then the Manned Orbiting Laboratory, or MOL (both of which were ultimately canceled, with the MOL never reaching orbit). The space shuttle flew military missions in the 1980s and early 1990s. And the past few decades have seen numerous space military programs: reconnaissance satellites, Defense Advanced Research Projects Agencyprograms and activities by the National Reconnaissance Office, to mention a few.

The Air Force is the procurement lead on space activities, regardless of the military branch in which the program originates. [The Most Destructive Space Weapons Concepts]

The idea of a separate Space Force goes all the way back to Eisenhower, said John Logsdon, a professor emeritus of political science and international affairs at The George Washington University specializing in space exploration. After the Soviet Union launched the first satellite, Sputnik, in 1957, the United States debated its response. There was concern at the time that Soviet rocket prowess in space could easily be redirected to intercontinental missiles targeting the United States.

"President Eisenhower's first impulse was to put all space activity into the Department of Defense [DoD], and the scientific community would tell DoD what to do when space science was concerned," Logsdon said. "He was talked out of that by his brand-new science adviser, James Killian, and by his vice president, Richard Nixon, who made the argument that the United States would be better off having a separate civilian agency openly engaged in international cooperation that it could talk about on the one hand, while it went about classified military space activity on the other hand."

Some in the national security committee were not happy with that decision, particularly the Air Force, Logsdon continued. When President John F. Kennedy was elected in 1960, some military observers thought that he would revisit the idea and approve a separate military space branch. Kennedy did consider the idea but ultimately rejected it.[Presidential Visions for Space: From Ike to Trump]

"He and the people close to him were early arms controllers. They did not want to see the potential for armed conflict spread to this domain of activity," Logsdon said. The Outer Space Treaty of 1967 — which the Kennedy administration helped work on — includes language advocating for a peaceful use of space and forbidding weapons in outer space or on celestial bodies, Logsdon said.

But Kennedy's administration had a subtle take on that prohibition. It was of the opinion that weapons for defensive capabilities only (such as protecting a satellite from anti-satellite missiles) would meet the requirements of the treaty — something that some other nations didn't agree with, Logsdon said.

The idea of more military space control reoccurs in U.S. space policy, such as in the failed "Star Wars" program of the 1980s, which included some anti-satellite components. One theme of these various attempts, Logsdon said, is worry (whether founded or not) about Air Force procurement control — the belief that space priorities come second in a military branch dominated by pilots who like buying airplanes.

But he warned that a new Space Force would have its own problems, since jurisdictional battles over which military branch controls what would likely erupt. "What would be incorporated in a new Space Force is a question with both substantive and bureaucratic implications of the first order," he said.

Johnson-Freese added that, in the decades of debate over a separate space branch, the discussion never got too far. That was because of bureaucratic objections and concerns about the time and money it would take to establish a new branch. Although Trump tasked the Joint Chiefs with making a report, it is difficult to foresee how his proposal will go much further, Johnson-Freese said.

"We already spend more [in military space] than the other major spacefaring countries put together — all of them," she said. "We already have more satellites in space than anybody else. Our technology is ahead. We certainly need to stay ahead, but do we need a new bureaucracy to stay ahead technologically? … This [idea] is not new, and it's been resisted for many legitimate reasons."

Original article on Space.com.