Nelda Rogers also headed up the special debriefing unit, which debriefed NASA engineers and other personnel after the Columbia shuttle blew apart. They have tape recordings and other evidence, which indicates that NASA was well aware of the existing problems with the spacecraft – and yet they chose not to install sensors which would have detected the problem early and allowed countermeasures to be taken. It was evidently all not done for reasons of cost.
From here
(June 16) The Department of Defense whistleblower continues with her information about the NASA Columbia Disaster Cover-up and more details on the Chandra Levy Murder Cover-up story.
From the same article!!! HERE AGAIN