1. Spray a medium skillet with vegetable cooking spray. Heat skillet over medium heat. Add onion and beef to skillet. Cook, stirring constantly, until beef is browned and onion is tender, about 8 minutes. Drain off fat.
2. In a large saucepan, combine broth, beef mixture, tomato juice, carrots, corn, cayenne pepper, and black pepper. Cover and bring to boil over high heat.
3. Reduce heat to low; add noodles to broth mixture. Simmer, stirring occasionally, until noodles soften and vegetables are tender, about 10 minutes. Ladle soup into individual serving bowls.