CAPE CANAVERAL, Fla. -- An Atlas-Centaur rocket destroyed after launch in a rainstorm last month was hit by up to nine lightning bolts, and instrument readings before liftoff showed a high potential for electrical activity, NASA revealed Thursday.
And in a major breakthrough, the rocket's electronic brain, sealed and intact, was pulled from the ocean later in the day. Analysis should help investigators determine if the lightning scrambled the computer, causing it to point the rocket off course and into a destructive tumble.
Although weather conditions technically were acceptable for launch under Atlas-Centaur guidelines, the decision to proceed has been widely criticized, and the accident investigation, due to end May 25, is adding more fuel to the fire.
'The potential was high at the time of launch and evidence has been found that indicates (the rocket) got hit by lightning,' NASA spokesman Hugh Harris said. 'They believe the vehicle was probably struck by lightning a number of times.'
Martin Uman, a lightning expert at the University of Florida, said in a telephone interview that data Air Force meteorologists recorded before blastoff indicated 'there was a very highly charged cloud overhead,' which in turn showed a 'potential for the rocket initiating lightning and normal lightning.'
The $78 million Atlas-Centaur, carrying an $83 million military communications satellite, was launched at 4:22 p.m. March 26, despite thick cloud cover, heavy rain and lightning in the area.
Forty-eight seconds after liftoff, with the 137-foot rocket hidden behind heavy clouds, radio data indicated major malfunctions in the Atlas-Centaur's electrical system.
A loud noise was recorded by a microphone in the nose cone, battery voltages fluctuated and the Atlas first-stage engines swung to one side as far as they could go, pushing the speeding rocket into a destructive tumble. All data ceased 52 seconds after blastoff.
The engine-steering command was sent by the on-board 'digitial computer unit,' or DCU, which was recovered Thursday just off the coast of Cape Canaveral. The device is about the size of a breadbox.
'Engineers will attempt to read the memory of the computer to determine what caused it to send the faulty command as well as determine whether it was damaged by electrical currents which could have come from lightning striking the vehicle,' NASA said in a statement.
With the recovery of the flight computer, the Atlas-Centaur salvage operation was called off.
Reporters Thursday were allowed to view some of the wreckage that has been recovered and Harris said nine areas on the rocket's nose cone have been found 'which are consistent with damage normally caused by lightning.'
'Most of them exhibit scorch marks and some of them are not really holes,' Harris said, adding that it is not known how many separate lightning bolts may have caused the damage.
Harris said a network of electrical field sensors near the launch pad showed high readings prior to blastoff.
For the space shuttle, readings of minus 1,000 volts per meter are enough to force a launch delay, he said. At 4:22 p.m. on March 26, a sensor near the Atlas-Centaur pad recorded minus 7,360 volts per meter. Two minutes earlier it read minus 8,207 volts per meter.
'Basically, I guess what happened is they just forgot about lessons from the past,' Uman said.
But Harris emphasized that in the Atlas-Centaur program, the only electrical constraint is that launch is not permitted if lightning is spotted within 5 miles of the launch pad. None was on March 26.
Uman, however, questioned the training of the Air Force forecasters who told launch director James Womack conditions were acceptable for launch.
'They just rotate those guys in every couple of years,' Uman said. 'They don't give them classes or courses in atmospheric electricity.'
