Customers of Delta Air Lines will soon be able to check in bags by scanning their faces at Minneapolis-St. Paul International Airport.

The Atlanta-based carrier is spending $600,000 to test a new self-service bag drop system at MSP this summer. If all goes well, the airline plans to roll it out nationwide.

Several U.S. airlines already use self-service bag drops, but this is the first time a U.S. airline has implemented biometrics for the process. Delta will install four self-service lanes for the pilot program, but only one will use the facial recognition technology.

The biometric scan will only work if a customer has a valid U.S. passport, according to Transportation Security Administration requirements.

Customers will need to stop at the check-in kiosk to print their bag tags. They will then move to the self-service bag drop machines where they will scan their boarding pass.

Customers in the biometric lane will not need an agent to verify their identity, but will instead scan their face, place their bag on the conveyor belt and dash to security. The other three self-service lanes will still require an agent's approval before accepting the bags.

Special items, like golf clubs, skis, car seats and oversized bags will require an agent's assistance.

"We expect this investment and new process to save customers time," Gareth Joyce, Delta's senior vice president of airport customer service, said in a release. "And, since customers can operate the biometric-based bag drop machine independently, we see a future where Delta agents will be freed up to seek out travelers and deliver more proactive and thoughtful customer service."

The move will coincide with MSP's plan to install new, faster security lanes that will hasten the screening process. These "innovation lanes" have been installed at several other airports in the U.S. and have increased the security speed of customers and their carry-on bags by as much as 40 percent. The Metropolitan Airports Commission (MAC) approved spending $1.6 million for four of these lanes.

Delta said it chose to test its self-service bag drop system at MSP, its second-largest hub, because of upcoming lobby renovations at the airport. One of the stated goals of the airport's lobby upgrades is to "provide a more efficient space for airlines to process passengers with their new, self-service check-in kiosks."

United and American already offer basic self-tagging for customers dropping off bags at MSP, said airport spokesman Pat Hogan.

Delta is taking it a step further by automating the drop-off process.

"This trial reflects our ongoing efforts to take an innovative approach to enhancing the travel experience for all Delta customers," the airline said in a statement.

Delta has recently made several investments in the customer experience as the airline seeks to distinguish itself from its competitors. Last year, Delta rolled out a new $50 million tracking system — called radio-frequency identification or RFID — that is aimed at reducing the number of lost bags. Customers can use the Delta phone app to see on a map where their luggage is located at any given time.