suppose I should have just posted a link to the article. Sorry to have wasted your time.

[www.cnn.com]

Calculations by NASA experts showed that the protrusions could increase the re-entry temperature by 10 percent to 30 percent, possibly exceeding NASA's safety guidelines for how much heat the shuttle's thermal protection system should be allowed to endure, said Wayne Hale, NASA's deputy shuttle program manager.

While the protrusions might not pose any threat to Discovery, the "large uncertainty" about their possible effect on the aerodynamics of the shuttle convinced NASA officials to try to fix the problem in space, he said."