Alan R. Rocha, in an e-mail released by the space agency on Monday, pleaded for officials at the National Aeronautics and Space Administration to seek photographs of possible damage to the shuttle's left wing. Without those photos, he said, "it will be very difficult" to analyze any problem that Columbia might have.
He said the pictures could give answers about the shuttle's problems "ranging from acceptable to not-acceptable to horrible" and could provide options that Mission Control could consider about finding a safer way for the spacecraft to return to Earth.
"Despite some nay-sayers," Rocha wrote Jan. 21 in his widely distributed e-mail, "there are some options for the team to talk about."
Among those options, he said, were thermal conditioning, which means flying the spacecraft in such a way that some parts of the craft are chilled or warmed before re-entry. Another option, said Rocha, included adjusting the angle and path Columbia would have used to return to Earth. He said there also could be constraints on the left or right turns that Columbia would have made once it was in the atmosphere.
In his plea for pictures, Rocha asked, "Can we petition (beg) for outside agency assistance?" This is an apparent reference to using U.S. spy telescopes or satellites to photograph the underside of Columbia.
"Some of the old timers here remember we got such help in the early 1980s when we had missing tile concerns," Rocha's e-mail said.
NASA on Monday released hundreds of pages of e-mail exchanges between Rocha and other NASA engineers after they learned that Columbia's left wing had been hit by chunks of foam insulation that peeled off the shuttle's external fuel tank during its Jan. 16 launch. Launch pictures showed the flying insulation, but were too fuzzy to show the precise damage to the wing, if any.
In a draft e-mail that he never sent but which was released by NASA, Rocha wrote on Jan. 22 that it was wrong and "bordering on irresponsible" not to request any outside source pictures that might show tile damage. Multiple broken tiles, particularly near Columbia's wheel compartment, "could present potentially grave hazards," he wrote.
In another e-mail, also Jan. 22, Rocha wrote: "We do not know yet the exact extent or nature of the damage without being provided better images, and without such all the high-powered analyses and assessments in work will retain significant uncertainties."
A later assessment, made without spy satellite pictures by engineers of the Boeing Co., a NASA contractor, concluded that although Columbia's wing may have been damaged by launch debris, the craft should be able to land safely. Columbia broke up during re-entry on Feb. 1, killing its seven-member crew. Investigators now say the most likely cause was broken tiles that allowed superheated gas to penetrate its left wing, melting aluminum supports.
In response to Rocha's request for pictures from other agencies, NASA's Paul Shack replied on Jan. 23 that NASA higher-ups had decided they were "not requesting any outside imaging help." Shack is an engineering executive at the Johnson Space Center in Houston where Rocha works.
In his draft e-mail, addressed to at least 14 NASA employees, Rocha noted safety posters throughout the agency imploring, "If it's not safe, say so." He concluded the message with a prophetic note about the need for seeking pictures of possible damage to Columbia: "It's that serious."
NASA officials have acknowledged they turned down an offer by the U.S. National Imagery and Mapping Agency to have its satellites take pictures of the shuttle in Earth orbit.
Last week, NASA announced the satellite agency has agreed to regularly capture detailed satellite images of space shuttles.