An Italian astronaut who’s been on two space flights says an incorrect angle of re-entry into the Earth’s atmosphere could have caused the space shuttle Columbia to disintegrate.

Falling space shuttle debris (Photo:

“It is too early to speculate on the precise causes of the accident but the images from Texas suggest that the Columbia broke up into at least three pieces due to an improper angle as it returned into the atmosphere,” Umberto Guidoni told Italy’s ANSA news agency.

NASA declared an emergency after losing all contact with Columbia 16 minutes before it was due to land at 9:16 a.m. Eastern. It was at an altitude of 200,700 feet at the time, traveling at 12,500 mph.

“Re-entry through the atmosphere is one of the most critical moments in the mission of the shuttle,” Guidoni said. “An error of several degrees could provoke a catastrophe similar to what happened today.”

“The angle of penetration should be at 40 degrees to the horizon. … The margin of error is at most three or four degrees. Beyond that range the shuttle becomes uncontrollable.”

Note: Read our discussion guidelines before commenting.