Brown ground beef and onion; drain. Add salt, pepper, chili powder, soups and water; simmer 30 minutes. Place cooked spaghetti in an ungreased 13"x9" baking pan; top with beef mixture, stirring to combine. Spread catsup over top and sprinkle with cheese. Bake at 350 degrees for 20 to 30 minutes, until bubbly.