When Vice President Pence announced plans to create a “Space Force” military command by 2020 on Thursday, social media was flooded with Star Trek theme music, astronaut GIFs and suggestions for the Space Force’s future logo.

But to some space experts, Pence’s de facto call to arms was less of a laughing matter.

Long before Pence referred to space as a potential future “battlefield,” China attempted to extend its military might there, culminating in a 2007 military antisatellite test in the low Earth orbit — within 1,240 miles of our planet — that has the highest density of satellites. Analysts estimate that 25 percent of today’s space debris originated in this single 2007 test when the Chinese military blasted apart one of its own weather satellites with a missile at an altitude of 537 miles.

“What the Chinese did in 2007 had a dramatic impact,” said Manuel Metz, a space debris expert at the German Aerospace Center.

Now imagine a real space arms race or even a full-blown conflict.

More than 170 million pieces of space debris — including decades-old satellites or spent rockets — already orbit the Earth today, with 29,000 of them being bigger than four inches. According to the European Space Agency, a satellite colliding with one of the 29,000 larger objects would be “catastrophic,” while smaller fragments could still penetrate surfaces.

That’s one reason nations long agreed to treat space as a largely demilitarized region. After initial experiments during the Cold War, the fall of the Berlin War brought almost two decades in which attacks against satellites were considered a minor risk, if at all. After 2006, however, the Bush administration’s more aggressive approach and similar research activity by other nations resulted in a resurgence of concerns that space attacks could eventually become an element of conventional wars.

Neither China nor Russia have destroyed any satellites circling Earth since 2007, but that hasn’t stopped them from continuing to develop more precise weapons.

Experts hope that they — and Washington — have learned their lessons from the 2007 incident. “Any country conducting another test would hurt itself, too: In the end, the Chinese increased the likelihood of one of their own satellites being lost to space debris with their 2007 test,” said Metz.

There are still few specifics on what a U.S. Space Force would exactly focus on. But in his speech, Pence specifically referenced the decade-old Chinese antisatellite test, saying that it constituted “a highly provocative demonstration of China’s growing capability to militarize space.” To the United States, any threats to its military satellites are unnerving because they provide crucial intelligence during military missions back on Earth.

A space arms race would inevitably increase the likelihood of a debris disaster, but there might still be ways out. “The United States should develop effective but limitable forms of space attack, particularly non-kinetic ones that do not result in space debris,” Elbridge Colby, a senior fellow at the Center for a New American Security, told AFP back in 2016.

In fact, the U.S. military has headed some efforts in recent years to tackle the debris problem, after Washington and other countries treated the orbit as a waste site for more than half a century. NASA and the U.S. military now track objects that exceed the size of four inches to predict their flight paths and move active satellites out of their way.

Gen. William Shelton, a commander with the U.S. Air Force Space Command, acknowledged growing concerns at a conference in 2011 when he said the orbit “may be a pretty tough neighborhood . . . in the not too distant future.” But much of the damage may already be done, Shelton feared at the time.

Debris doesn’t simply disappear as it circles Earth. Instead, it collides with other objects — splitting up into even more, smaller parts that can cut into satellites faster than speeding bullets.

Humans appear well on track to turn the Earth’s lower orbit into a satellite kill zone even before any of their Space Forces have actually taken off.