NASA has posted nearly 30 megabytes of internal email traffic and attachments regarding the potential threat of foam debris striking the shuttle Columbia's left wing; concerns about corrosion that could interfere with proper operation of the ship's body flap during entry; and discussions regarding Columbia's heavier-than-usual landing weight. NASA also posted charts and data used to clear Columbia for flight during a formal flight readiness review before launch. See the agency's site here.

The sheer volume of the material, posted Monday, precludes a quick analysis, but a cursory review turned up no significant departures from the tone and general context of concern found in emails released by NASA last month. Quite a few engineers were seriously concerned about the potential threat posed by the debris impact, saying it was the most significant such impact to date and one that was well outside NASA's previous experience. But most ultimately deferred to an analysis carried out by Boeing that concluded whatever damage might be present was a turnaround/repair issue and not a "safety of flight" concern.

One draft memo posted separately, however, did show a previously unseen level of concern about senior management's decision not to request spy satellite photography of Columbia's left wing to better characterize the potential damage. The memo was in draft form and never sent via email to 14 listed recipients. Instead, according to a hand-written note, the contents of the memo - drafted around Jan. 22, six days after Columbia's launch - were discussed verbally with an unknown number of engineers and managers.

"In my humble technical opinion, this is the wrong (and bordering on irresponsible) answer from the SSP [Editor's note: space shuttle program] and Orbiter not to request additional imaging help from any outside source," wrote Rodney Rocha, a chief engineer in the structural engineering division at the Johnson Space Center.

"I must emphasize (again) that severe enough damage (3 or 4 multiple tiles knocked out down to the densification layer) combined with the heating and resulting damage to the underlying structure at the most critical location (viz, MLG Door/wheels/tires/hydraulics or the X1191 spar cap) could present potentially grave hazards. The engineering team will admit it might not achieve definitive high confidence answers even with additional images, but, without action to request help (to) clarify the damage visually, we will guarantee it will not.

"Can we talk to Frank Benz before Friday's MMT [Editor's note: mission management team]? Remember the NASA safety posters everywhere around site stating 'if it's not safe, say so?' Yes, it's that serious."

A more detailed review of the newly posted emails and supporting documents will be posted here later this week as warranted.