[Update 6/28: This article has been updated to show that the World View balloon launch is now scheduled for June 29. The launch window opens at 8 a.m EDT.]

A Kentucky Fried Chicken sandwich is scheduled to travel into the stratosphere today aboard a high-altitude balloon system. 

The balloon launch window will open at 8 a.m. ET (1200 GMT) today (June 29).The webcast will appear on the website kfcin.space, as well as on the company's as well as on Facebook and Twitter pages. 

The sandwich, called the Zinger for its spiciness, will fly on a Stratollite balloon system designed and built by World View Enterprises. During its four-day flight the balloon is expected to reach altitudes of up to 50,000 to 80,000 feet (18,300 to 22,900 meters). It will be the "longest controlled stratospheric balloon flight with a commercial payload in history and the first-ever multi-day mission of the World View Stratollite flight system," according to a statement from KFC. [World View's Near-Space Balloon Rides in Pictures

An animation from Kentucky Fried Chicken as part of its ad campaign that involves sending a chicken sandwich to the edge of space.
An animation from Kentucky Fried Chicken as part of its ad campaign that involves sending a chicken sandwich to the edge of space.
Credit: KFC/World View

The flight is part of an advertising campaign by KFC. The company will be conducting daily events during the flight, including a coupon drop (where coupons will be dropped from the balloon) and various events meant to engage the public on social media. The sandwich will also take its flight inside a container shaped like one of KFC's chicken buckets, topped with a clear dome. 

But for World View, the flight is a test mission or "shakedown cruise" for the Stratollite system, which until now has never made a flight longer than 12 hours. World View plans to build balloons that can remain in flight for months at a time, and be used for weather monitoring, Earth observation and various scientific endeavors. The company has already flown consumer payloads on shorter and, in some cases, lower-altitude missions. 

A World View Enterprises stratospheric balloon, similar to the one that is scheduled to send a chicken sandwich to the edge of space on June 22, 2017.
A World View Enterprises stratospheric balloon, similar to the one that is scheduled to send a chicken sandwich to the edge of space on June 22, 2017.
Credit: World View

"This is an R&D [research and development] shakedown mission, and as with all things R&D, there's a very real chance some of the new Stratollite systems won't operate nominally," Taber MacCallum, CTO for World View, said in a statement from the company. 

Eventually, the company plans to make vehicles designed to carry humans to altitudes of over 100,000 feet (30,480 m) above Earth's surface. The company plans to use those flights for space tourism and as an opportunity for scientists to conduct research in the stratosphere. 

"Sure, this whole chicken sandwich payload is a bit funny," MacCallum said. "But, KFC gets to embark upon a one-of-a-kind marketing experiment, while we get to pursue our first multi-day shakedown cruise in the stratosphere. It's a win for all."

Editor's Note: This article has been corrected to reflect that the vehicles would ultimately reach altitudes of over 30,480 meters, not kilometers.

Follow Calla Cofield @callacofield. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.