United Parcel Service Inc. has for decades been the company that delivers packages to your doorstep with its signature brown trucks, but the company has quietly begun expanding into drone delivery.

The UPS Foundation announced Monday it has entered into a partnership with drone startup Zipline and Gavi, the Vaccine Alliance, to deliver blood for transfusions by drone throughout Rwanda. UPS offered an $800,000 grant to kick off the deliveries.

While major corporations like Amazon.com Inc. AMZN, +0.84%  and Domino's Pizza Inc. DPZ, +2.01%  have theorized about drones delivering shoes and pizza to your doorstep, UPS UPS, +0.30%  has quietly been experimenting in the drone industry—and taking the humanitarian approach. UPS last April participated in a study with the American Red Cross on making deliveries to disaster areas. UPS's Director of Autonomous Systems Jerome Ferguson, whose purview includes everything from delivery messaging to robotic technologies, has expressed a particular interest in drones.

Drone delivery of blood has the potential to be a life-saving technology, particularly in Rwanda, where roads often wash out and it can be impossible to quickly get medical supplies to more rural areas. A drone can carry just over 3 pounds of weight over a distance of 75 miles round-trip.

Sally French, MarketWatch

With endorsement from the Rwandan government, Zipline is going to start making as many as 150 blood deliveries a day from its central base in western Rwanda to 21 transfusing facilities within about a 37-mile radius. Zipline aims to be within a 30-minute delivery radius of 11 million Rwandan citizens by the end of 2016.

"This is an elegant solution to a difficult problem," said Dr. Seth Berkley, CEO of Gavi, the Vaccine Alliance. "This would have been great in the Ebola outbreak, when we actually had a boat delivering vaccines because of the poor road infrastructure."