As lawmakers direct the Pentagon to again pursue a space-based sensor layer for missile defense, a top general says developing such a system should not be expensive despite cost concerns quashing similar efforts in the past. Air Force Gen. John Hyten, the head of U.S. Strategic Command, said a space-based sensor capability has been a well-known requirement since the Reagan administration's Strategic Defense Initiative. Hyten was chief engineer on the Air Force's SDI program at the time. "The belief back...