Like most other things of a technical/scientific nature, the flat earthers are ill-equipped to comment meaningfully on the Columbia disaster.
And, as a few examples as to why; they believe that NASA is a bogus organisation set up to rob US taxpayers, they don't accept the reality of satellites, they don't accept the principles of jet propulsion—especially in a vacuum, they believe that all the Apollo missions were staged here on earth in a secret film set in Area 51, they claim that the thousands of images and all the film footage are faked, they believe that all the Google Earth imagery was taken from low-flying aircraft, they claim that the curvature of the earth's horizon can't be perceived even from a 70,000 ft altitude, they believe that one cannot circumnavigate the earth without altering course, they claim the sun and moon are only 32 miles in diameter, they refute the theory of gravitational attraction, they rebut the basic principles of the Foucault Pendulum, they don't believe in the astrophysics of solar and/or lunar eclipses, they claim that the sun is perpetually above all of the earth's surface, they deny that the earth is orbiting the sun periodically etc.....
With such extremely bizarre views such as these, it's more than obvious why their opinions on serious topics such as the deaths of the Columbia astronauts is treated by them so lightheartedly—and disrespectfully.
Although most flat earthers are noted for their disdain of any established scientific theories they disagree with (which accounts for nearly all of them LOL) and their usual contempt for round earthers.