A screenshot of astronaut Chris Hadfield’s “Space Oddity” video on YouTube. (YouTube)

If you are not one of the 22 million people to watch astronaut Chris Hadfield’s cover of “Space Oddity” — in space!!! — you have a mere 12 hours left to do so. The five-and-a-half-minute YouTube video/absolute cultural treasure will come offline today, when Hadfield’s copyright agreement with David Bowie expires.

Hadfield, a Canadian astronaut who manned the International Space Station from December 2012 to May 2013, filmed the cover on the ISS and had it edited by his son. It’s one of several viral films Hadfield made onboard the station — you might also recall his primer on brushing your teeth in space.

As aggrieved fans have pointed out on YouTube, however there was something particularly magical about the “Space Oddity” cover: something impossibly, unusually whimsical, like “those awe moments we have as kids.” Bowie recorded the song in 1969, the same year that man first walked on the moon. Forty years later, it was extraordinary — almost inconceivable — that an astronaut would not only play the song in space, but beam it back for replay all over the world.

Sadly, no matter the magic, the video can’t escape copyright law — which does indeed apply in space. As The Economist explained when the video went up last year, extraterrestrial copyright laws vary based on what part of the ISS you’re in: If you’re recording in the U.S.-owned Destiny module, for instance, American law applies, while you’re bound by Japanese law if you’re in the Japanese Experiment Module. On top of that, a rights-holder could theoretically sue in any country where the recording was played, even if said recording was made in space.

(YouTube) (YouTube)

The whole thing is enormously complicated — not rocket science, exactly, but something pretty close. It’s led some legal experts to fret over the day when private rocket launches and space tourism put more people in orbit. Even singing a protected song in front of fellow space-travelers theoretically constitutes a copyright violation.

That, of course, is why Hadfield spent months negotiating the one-year lease with Bowie, NASA and the Canadian and Russian space agencies before recording “Space Oddity.” But don’t despair: While Hadfield might do things by the books, count on other YouTube users to show a little less regard for the law.

“This video gonna pop up all over the internet!” foretold one commenter. “Im already download[ing] the backup!”