[Dirk McQuickly]

Heard that, too -- said there was a "heat spike" at about the same time of the breakup.

[mrs9x]

If there had been some sort of missile, the shuttle would have blown up right away. Instead, it looked like pieces just kind of started flying off of it and it disintegrated slowly.

[Movemout]

"Heard that, too -- said there was a "heat spike" at about the same time of the breakup. "

A heat spike in this instance may refer to the vehicle health monitoring systems that are an integral part of the shuttle. Thermal management is key to all space hardware.

[CyberAnt]

I heard on FOX that there was this "unusual" (10 degree higher than usual) heat factor in this shuttle.