Russian cosmonaut Yury Malenchenko, orbiting the Earth, will marry his earthbound American sweetheart on Sunday.
But the ceremony -- to be performed during a live link-up with the International Space Station as it flies some 400km above the planet -- is likely to draw the wrath of Malenchenko's superiors in Russia.
When Malenchenko, 41, announced three weeks ago that he planned to marry Yekaterina Dmitriyeva, 26, during his ISS mission, Russia's space agency opposed the plans.
The reason? Colonel Malenchenko, an active-duty officer, is prohibited from marrying a foreigner.
But Malenchenko pressed ahead with his plans after the Russian authorities withdrew their objection.
Dmitriyeva, who emigrated from the Soviet Union at age four, is a US citizen and lives in Houston, Texas.
The couple met several years ago during Malenchenko's training in the US and started dating last year.