Preheat the oven to 350˚F.
Bring a pot of salted water to a rolling boil.
Add the pasta and cook according to the package directions for al dente.
Halfway through the cooking time, add the shredded carrots to the pot of water to cook as well.
In a large bowl, combine the soup, mayonnaise, milk, cheese, veggies, salmon, and onion.
Drain the pasta and carrots, and add to the soup mixture. Toss and pour into a large baking dish. Top with the crushed crackers. Bake for 30-40 minutes until nice and bubbly.