The Defense Advanced Research Projects Agency (DARPA) and Arizona State University are teaming up to develop a jetpack that will allow almost any U.S. troop to run at the speed and rate of Olympian.

The project is called “4MM”, the name an abbreviation of its core goal: to get someone who normally couldn’t run a four-minute mile to run one, wearing the technology on their back.

Currently, the world record time for a mile run is 3:43.13, held by Morocco’s Hicham El Guerrouj. The United States’ record is 3:46.91 by Michigan native Alan Webb.

Not only are the engineers attempting to design an apparatus that decreases time, they’re also trying to lower the metabolic cost required for a person to run at high speeds.

Which, as you might’ve guessed, can get tricky.

“We’re incredibly engineered as is, and augmenting our abilities really becomes a difficult, challenging research project,” said Arizona State graduate engineer Jason Kerestes. “You don’t know what the answers are going to be.”