A recently recovered flight data recorder from the space shuttle Columbia appears to contain information until up to a fraction of a second before the orbiter disintegrated over Texas, investigators said today.

Technicians at Kennedy Space Center viewed a "time tag" on the tape that confirms the existence of "some type of imprint" until 9:00:18 EST on Feb. 1, the day of the shuttle's doomed reentry to Earth's atmosphere, according to the Columbia Accident Investigation Board. A moment later, a military helicopter's video shows the orbiter coming apart.

It is too early to say whether the data has been corrupted or obscured by the heat and trauma of the crash, but "there is something on the tape," said Laura Brown, a spokesman for the board. "We're still cautiously optimistic."

Engineers and technicians on the launch processing team were making several copies, which will be reviewed at NASA's Johnson Space Center in Houston and other facilities over the weekend.

Investigators "are working around the clock. Everybody is eager to find out" what the tape will reveal, Brown said.

Search teams found the data recorder near Hemphill, Tex., on March 19. The teams focused their search there after learning that other material from the same part of the crew cabin had been found nearby.

The device was sent to a lab in Minnesota to be cleaned and then to the Kennedy Space Center for duplication. "The first thing the [investigation] board wanted to know was when did the data end," said Bill Johnson, a spokesman for the space center.

The recorder stores data from sensors that measure temperature, aerodynamic pressure, vibration and other variables. Turned on shortly before the shuttle began its reentry, the device carries 9,400 feet of 28-track magnetic tape.