Cut peel and white pith from oranges. Working over small bowl and using small sharp knife, cut between membranes to release segments. Squeeze membranes to release juice. Combine 1/4 cup orange juice and vinegar in small bowl (reserve remaining juice for another use). Whisk in olive oil. Season with salt and pepper.
Toss mâche, frisée, and radicchio in large bowl. Add orange segments, sliced red onion, and Kalamata olives. Drizzle orange dressing over salad and toss well to coat. Sprinkle with crumbled feta cheese and serve.