IT'S BEEN JUST a month since the space shuttle Columbia broke apart over Texas, killing its seven-member crew. The commission investigating the disaster, which held its first public meeting Thursday, is literally trying to piece together an explanation as it considers what the panel's chairman, retired Adm. Harold W. Gehman Jr., termed the various "detective stories" about possible causes. The focus remains on an early suspect: possible tile damage from the insulating foam or other debris that struck the orbiter's wing 81 seconds after launch. A chilling set of internal NASA e-mails released recently shows how shuttle engineers analyzing that risk came up with an eerily prescient scenario of what might happen to Columbia upon reentry.

Nearly 17 years after an investigation into the space shuttle Challenger explosion criticized what it described as NASA's "silent safety program," the e-mails once again raise disturbing questions. NASA Administrator Sean O'Keefe told The Post last month that the major technical glitch he recalled being briefed on during the mission was an uncomfortable rise in cabin temperature. But much farther down the chain of command, the e-mails show, engineers on the front lines expressed repeated concerns about the consequences of tile damage, including the grim prediction that this could produce an "LOC" -- loss of crew -- situation. NASA's contract engineers at Boeing concluded that despite worrisome data from their own computer program, enough coverage would remain to provide protection against burn-through on reentry. A number of engineers continued to worry about that analysis, pressing for a spacewalk during which the crew could examine possible damage, and for pictures of the craft to be taken by Defense Department satellites. Others at NASA seemed more concerned about bureaucratic niceties. One of the most disturbing e-mail exchanges involves the cancellation of the request for help from Defense. NASA official Roger D. Simpson, apologizing for the about-face, said that while tile damage "is not considered a major problem . . . the one problem that this has identified is the need for some additional coordination within NASA to assure that when a request is made it is done through official channels."

The chairman of the House Science Committee, Rep. Sherwood L. Boehlert (R-N.Y.), wisely noted the other day that it was "premature to do any finger-pointing." Part of the engineers' job is to worry; as Mr. Boehlert pointed out, investigators need to determine whether similarly alarmist e-mails could be dredged up after every shuttle flight. It's also too early to make easy comparisons to the Challenger tragedy. The Challenger commission found that NASA and its contractor ignored eight years of warnings about problems with the shuttle's O-rings, playing "a kind of Russian roulette" in order to keep to a demanding flight schedule. While there have long been difficulties with the shuttle's tiles, the handling of Columbia does not seem to involve a deliberate and high-level decision to discount a known flight risk. Rather, the questions concern whether NASA was too accepting of Boeing's conclusion that the remaining heat shield would be adequate, and whether this serious issue should have been vetted by senior managers. Mr. O'Keefe told Congress recently that it appeared to him that "the right discussions" were had "at the right levels." That remains to be seen.