For most companies, failure is a reason for staff to be depressed, not a reason for them to throw parties.

At Alphabet’s research arm X, formerly known as Google X, however, failures are something that can be celebrated. As one of X’s top executives Obi Felten explained Wednesday during Fortune’s Most Powerful Women Next Gen Summit in Laguna Niguel, Calif., X has instituted an annual ritual modeled after Día de los Muertos, the Mexican holiday when families honor their deceased relatives.

The point is to bring a feeling of closure for workers on projects that didn’t take off and to celebrate “letting go,” Felten said. Regarding the first such celebrations, she said, “It was an incredibly powerful moment.”

There were “a lot of tears and in the end a lot of drinking,” she added.

It’s all part of the process of creating so-called moonshots, Alphabet’s goog ambitious projects like self-driving cars that may be revolutionary if they ever turn into actual businesses. Or they may just flop.

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A grand project to create renewable fuel from sea water, for example, turned out to not make business sense after the price of oil fell, thus X shelved it.

People who work at X must get accustomed to failing, because you “can’t do moonshots if everything works, it’s almost kind of the opposite,” Felten said.

Still, the hope is that out of the many failures, a successful moonshot could lead to a big breakthrough. Self-driving cars, for example, is one such project Alphabet is excited about and is “just about to graduate” from an experiment to a business, she said.

“Our money comes from Ruth Porat,” Felten said about Alphabet’s CFO with a Wall Street pedigree. “She would like her money back with a good return on her investments.”