Cook spaghetti according to package directions. Meanwhile, in a blender, combine 1 tablespoon oil, basil, lemon juice, garlic and salt; cover and process until smooth. , In a large skillet, saute asparagus in remaining oil until crisp-tender. Add shrimp and pepper flakes. Cook and stir until shrimp turn pink. , Drain spaghetti; place in a large bowl. Add basil mixture; toss to coat. Add shrimp mixture and mix well.