A piece of the ill-fated space shuttle Columbia has surfaced in eastern Texas, where a severe drought has dried up a lake and exposed debris from the 2003 accident, NASA said Tuesday. The globe-shaped object that turned up in Lake Nacogdoches, north of Houston, was one of 18 tanks on Columbia that helped power the shuttle, said NASA spokeswoman Lisa Malone. \"Late last week, we were contacted by the Nacogdoches sheriff\'s office letting us know that they had found an item of what they thought was Columbia debris,\" Malone told AFP. \"The drought caused the lake to recede and the levels are down, which exposed the tank.\" Pictures were sent to NASA engineers at Kennedy Space Center, and experts quickly confirmed that the tank must have been part of Columbia, she said. Several of the tanks have already been recovered in past years. The shuttle disintegrated on its way back to Earth in 2003, killing all seven astronauts on board and leaving a trail of debris that spanned several hundred miles. The cause of the accident was later linked to a faulty heat shield that had been damaged by a piece of foam that broke fee shortly after liftoff. Malone said 38-40 percent of the shuttle has been recovered, and local communities throughout Texas and Louisiana still report discoveries of bits of the spacecraft several times every year. \"We are trying to make plans to get it shipped back to Florida,\" said Malone, who noted that it will soon join other parts of Columbia stored at Kennedy Space Center. \"The area where it is located is real soft and mushy, and we can\'t even get a vehicle over there. The tank is full of mud,\" she said. The space shuttle program formally ended last month after 30 years, with the final flight of Atlantis to the International Space Station. NASA\'s Challenger shuttle exploded shortly after liftoff in 1986 due to cold weather and a technical flaw, killing seven astronauts. The remaining shuttles -- Atlantis, Endeavour, Discovery and Enterprise -- will soon become museum pieces.