Cook and drain pasta as directed on package. Rinse with cold water; drain.
Meanwhile, heat coals or gas grill for direct heat. Toss asparagus, fennel, onion, 2 teaspoons oil and 1/4 teaspoon salt until vegetables are coated.
Place in grill basket. Grill 5 to 6 inches from medium heat 10 to 15 minutes, stirring vegetables or shaking grill basket frequently, until vegetables are crisp-tender. Cool slightly.
Shake all Vinaigrette ingredients in tightly covered container.
In large bowl, toss vegetables, pasta, orange and vinaigrette.
Serve immediately, or cover and refrigerate up to 2 hours before serving.