The success of space missions hinges on nearly perfect execution, with even the smallest technological failure scuttling years of preparation. When the Rosetta spacecraft approached Comet 67P – after a decade-long journey – the European Space Agency depended on the Philae lander aboard to land gently to begin conducting its data-gathering mission.
The first-ever soft landing happened, but it was actually because the lander’s harpoon system failed, reports BetaWired. Researchers now believe the comet’s surface was much harder than they anticipated, and if the harpoon fired as expected, it would have bounced off the surface and sent the lander, which weighs about 100 kg, “right back into space.”
The harpoon system was supposed “to fire upon impact with surface, providing two anchor points as the barbed harpoon tips burrowed into the surface of 67P,” according to BetaWired. The system didn’t deploy and that researchers believe it was “the deciding factor” in the successful landing.
Philae bounced off 67P a few times but managed to land softly about two hours later – reaching a historic feat as a “soft landing.”
The Philae beamed a trove of data back to Earth but its location beside a cliff made it unable to recharge its batteries and it eventually powered down. Researchers are optimistic that as the Rosetta travels towards the sun, the sunlight may recharge the batteries enough to reactivate it.