All astronauts get high — about 240 miles (385 kilometers) higher than the planet's surface, if they're working aboard the International Space Station.

But no astronauts get stoned … at least, they're not supposed to. There are plenty of good reasons for that. Practically speaking, sparking up a fire in the oxygen-rich environment of a space station could result in hungry balls of flame spreading in every direction that there's fuel to burn. (Scientists and stoners can agree: That's a serious buzzkill.)

But spontaneous combustion aside, there are other health risks associated with getting high in a demanding microgravity environment — reasons that Neil deGrasse Tyson, the most famous mustache in astrophysics, recently explained in an interview with a tabloid reporter who asked what it would be like to smoke weed in space.

"The problem is, in space now, many things will kill you," Tyson told TMZ reporters in an interview. "So, if you do anything to alter your understanding of what is reality, that's not in the interest of your health. If you want to get high in space, lock yourself in your cabin, and don't come out. 'Cause you could break stuff inadvertently."

NASA, for one, has taken the risk of weed-induced "breaking stuff" seriously for several decades. Thanks to an executive order signed by then-President Ronald Reagan, NASA has been a drug-free workplace since 1986, meaning all employees are forbidden from using recreational drugs whether on or off duty. In addition to receiving pre-employment drug screenings for traces of marijuana, cocaine, amphetamines and various other illegal substances, astronauts undergo periodic random drug screenings to satisfy federal regulations and make sure they still have the proverbial right stuff.

The topic came up after the reporter asked Tyson his thoughts about billionaire space entrepreneur Elon Musk taking a hit of weed during a recorded interview with TV personality and podcast host Joe Rogan. Musk, whose spaceflight company SpaceX contracts with the U.S. Air Force, is reportedly being investigated by Air Force officials for his use of the drug.

"Let the man get high if he wants to get high," Tyson told TMZ. "He's the best thing we've had since Thomas Edison."

Originally published on Live Science.