A Kentucky Fried Chicken sandwich cut short its journey in space after just 17 hours of what was supposed to be a four-day trip. The reason for the early evacuation was a leak in the high-altitude balloon carrying the precious cargo.

The publicity stunt was supposed to be a milestone for the high-altitude balloon company World View Enterprises: the vehicle used for the KFC launch, called the Stratollite, is designed to float about 100,000 feet in the air. Eventually, the company wants the Stratollite to stay up into the stratosphere for months to a year at a time, providing communication services or scanning the Earth’s surface. The KFC sandwich failure suggests the company isn’t yet ready for that lofty goal.

Before last week’s launch, the balloon had only flown between six and 12 hours. World View wanted to fly the balloon for four days to test how several parts of the Stratollite — like its altitude control system, communications systems, and solar power technology — would work together over a longer period. But the systems they wanted to test weren’t what went awry — the balloon was.

All the system tests were completed within the first few hours of flight, World View’s CEO Jane Poynter said in a statement. And even if the trip was cut disappointingly short, this is still the longest trip the Stratollite has ever flown. Now, the company plans to review the data from the launch to understand what went wrong, so that future missions to the stratosphere can last longer.

At least the KFC sandwich seems to have had a good time: “Our special payload passenger, KFC's Zinger Spicy Chicken Sandwich, performed flawlessly and experienced incredible views from the edge of space,” Poynter said.