During the 2000s, further efforts were made by UPS to expand its flight network. In 2000, the company acquired Challenge Air Cargo to expand its services in Latin America. In a new concept, UPS introduced several "around the world" flights; originating from Louisville, the long-distance flights have several intermediate stops in Europe, the Middle East, and Asia, before returning to Worldport. In April 2001, UPS Airlines launched its first direct flights to China, providing service six days a week. In 2004, parent company UPS acquired Menlo Worldwide Forwarding (the successor to Emery Worldwide) to expand its heavy-freight operations.