WASHINGTON (Reuters) - NASA teams headed to California and Arizona on Tuesday to check reports that bits of heat-shielding tiles or wings from the earliest moments of space shuttle Columbia's disintegration had been found. "We have had some e-mail correspondence that potentially looks like it could be either (tiles) or wing material," said Michael Kostelnik, NASA's deputy associate administrator for the shuttle and space station. "If it is wing material obviously that would be important to the investigation," Kostelnik said at a briefing at U.S. space agency headquarters. "The sources were credible enough to cause us to send a NASA...