CHRIS HADFIELD has captured the world's heart, judging by the 14m YouTube views of his free-fall rendition of David Bowie's "Space Oddity", recorded on the International Space Station (ISS). The Canadian astronaut's clear voice and capable guitar-playing were complemented by his facility in moving around in the microgravity of low-earth orbit. But when the man fell to Earth in a neat and safe descent a few days ago, after a five-month stay in orbit, should he have been greeted by copyright police? Commander Hadfield was only 250 miles (400 km) up, so he was still subject to terrestrial intellectual-property regimes, which would have applied even if he had flown the "100,000 miles" mentioned in the song's lyrics, or millions of kilometres to Mars. His five-minute video had the potential to create a tangled web of intellectual-property issues. How does copyright work in space? The song "Space Oddity" is under copyright protection in most countries, and the rights to it belong to Mr Bowie. But compulsory-licensing rights in many nations mean that any composition that has been released to the public (free or commercially) as an audio recording may be recorded again and sold by others for a statutorily defined fee, although it must be substantively the same music and lyrics as the original. But with the ISS circling the globe, which jurisdiction was Commander Hadfield in when he recorded the song and video? Moreover, compulsory-licensing rights for covers of existing songs do not include permission for broadcast or video distribution. Commander Hadfield's song was loaded onto YouTube, which delivers video on demand to users in many countries around the world. The first time the video was streamed in each country constituted publication in that country, and with it the potential for copyright infringement under local laws. Commander Hadfield could have made matters even more complicated by broadcasting live as he sang to an assembled audience of fellow astronauts for an onboard public performance while floating from segment to segment of the ISS.

That is because the space station consists of multiple modules and other pieces (called "elements") under the registration of the United States, the European Space Agency (ESA) consortium, Russia and Japan. The agreement governing the ISS makes it clear (in Article 5) that the applicable laws, including those governing IP rights, depend on which part of it an astronaut is in. This is most relevant when astronauts conduct science or write accounts of their work, whether for public or private parties, although equally true during their off hours. The audio and video seem to have been recorded in the Destiny module, owned by America's space agency, NASA, the Cupola, which previously owned by the ESA (and would thus have been governed by European law) but was transferred to NASA in 2005, and the Japanese Experiment Module, developed by Japan's aerospace agency, JAXA. The video was transmitted to Canada (probably through ground stations around the globe), where Mr Bowie's former bandmate Emm Gryner added a piano accompaniment and others edited and produced the final product. But recording a private performance does not violate any laws; a violation only occurs if the material is publicly distributed. Had the song been broadcast from space, Mr Bowie's lawyers would have been entitled to seek redress in Canadian, American and Japanese courts, in addition to any objections they might have raised based on YouTube views elsewhere. If Commander Hadfield's employer, the Canadian Space Agency, had been deemed to authorise the recording, transmission and distribution of the song while he was on the clock, Commander Hadfield might be off the hook for damages. But he would also, under Canadian copyright and employment rules, retain ownership in the work unless he had specifically assigned it to the CSA.

In this particular case the matter is straightforward because Commander Hadfield had obtained permission to record and distribute the song, and production and distribution was entirely terrestrial. Commander Hadfield and his son Evan spent several months hammering out details with Mr Bowie's representatives, and with NASA, Russia's space agency ROSCOSMOS and the CSA. The copyright issue may seem trivial, but the emergence of privately funded rocket launches, space tourism and space exploration hold the potential for more substantive disputes. If an astronaut were to travel to the Moon, an asteroid or Mars on a privately funded spacecraft, the situation would become knottier still, because the United Nations Outer Space Treaty of 1967 applies to countries, not companies or private individuals. J.A.L. Sterling, a London-based expert on international copyright law, anticipated all this in a 2008 paper, "Space Copyright Law: the new dimension", in which he lists dozens more potentially problematic scenarios that could arise, some seemingly risible at first. He asks what would have happened if, on a moon landing broadcast live by NASA across the world, two astronauts were overcome by emotion and burst into song—one covered by copyright. NASA might still be engaged in litigation 40 years later. More prosaically and immediately plausibly, Sterling considers space travellers who put copyrighted material from Earth on a server reachable from space, or engage in rights-violating "public performances" for crewmates. If the first person to walk on Mars decides to launch into "A Whole New World", the rights will need to have been cleared with Disney first.

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Update: Commander Hadfield responds via Twitter.

Corrections: This piece initially stated that the Cupola was owned by the ESA. In fact, its ownership was transferred to NASA in 2005. This was corrected on May 23rd. A reference to the Japanese Experiment Module, where some of the video was filmed, was added on May 25th.