A dramatic video shows a NASA research plane touching down and performing a “belly landing” without its landing gear. The footage shows the plane sliding down the runway, creating a trail of sparks, smoke, and fire. The incident occurred at Ellington Airport in Houston on Tuesday.

The airplane is one of NASA’s three large WB-57 research aircraft. When the plane came to a stop, two crew members could be seen exiting the aircraft with assistance from emergency responders. NASA confirmed that both were safe.

“Today, a mechanical issue with one of NASA’s WB-57s resulted in a gear-up landing at Ellington Field,” NASA spokesperson Bethany Stevens wrote on social media. “Response to the incident is ongoing, and all crew are safe at this time. As with any incident, a thorough investigation will be conducted by NASA into the cause. NASA will transparently update the public as we gather more information.”

Houston is the home of the NASA WB-57 High Altitude Research Program. They operate out of NASA’s Johnson Space Center (JSC) and are based at Ellington Field near JSC.

What is the WB-57, and how does NASA utilize it?

According to NASA, the WB-57 can fly for approximately 6.5 hours, has a range of approximately 2500 miles, and can carry up to 8,800 lbs of payload. It is also capable of operating for extended periods of time from sea level to altitudes exceeding 63,000 feet.

Each WB-57 utilizes two crew members. They position themselves at separate stations in the forward section of the fuselage. The pilot station contains all the equipment to fly the aircraft. The sensor equipment operator (SEO) station contains both navigational equipment and controls for operating the payloads located throughout the aircraft.

NASA has flown and maintained two WB-57 aircraft for high-altitude atmospheric research since the early 1970s. In August 2013, they returned a third to flight status after it sat unused for over 40 years at Davis-Monthan Air Force Base.