From Google Glass to self-driving cars, Google X is bringing our sci-fi fantasies to life. Recently, the lab admitted to trying to design a space elevator (and failing). And now, its leader says it also tried to build jetpacks.

At the recent TechCrunch Disrupt, Google X's "captain of moonshots" Astro Teller said the lab researched jetpacks and that "it turns out you can make a jetpack that's not a death trap."

"The problem isn't that," said Teller. "The real problem is that it was gonna be so power inefficient, it was gonna get like a fourth of the mile to the gallon." Teller added that he couldn't "live" with that.