To motivate it to fire its harpoons hard enough, Rosetta's Philae lander has been programmed to believe it is trying to kill the comet.

"Harpoons", by Randall Munroe, licensed under Creative Commons Attribution-NonCommercial 2.5 License

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To motivate it to fire its harpoons hard enough, Rosetta's Philae lander has been programmed to believe it is trying to kill the comet.