Caption: 
The flight path of the two NASA WB-57F research aircraft tracking the August 21 eclipse as part of the SwRI-led project spanned from Kansas City, Mo., to Chattanooga, Tenn., observing totality over parts of Missouri and Illinois and observing Mercury for the remainder of the flight. The aircraft, based in Houston, reached an altitude of 50,000 feet and the mission lasted more than five hours flying at an average speed of 420 miles per hour. 

Credit: 
Image courtesy of NASA Airborne Science