[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.

[July 4th]

Not a heat spike within the shuttle - from the US spy sats. Our early warning satellites picked up an atmospheric "spike" where the shuttle was.