Preheat oven to 350 degrees. Cut the salmon into 1 inch cubes and place in a buttered baking dish. Add the lemon juice to the melted butter and drizzle over the salmon. Season the salmon with garlic powder, salt, and pepper. Bake for 15 minutes or until the salmon flakes easily with a fork. Do not let the salmon overcook. Remove immediately from the oven and keep warm.
While the salmon is cooking, add the pasta to a large pot of salted boiling water. Cook until al dente, about 8 to 10 minutes. Cut the asparagus into 1 inch pieces. Add the asparagus to the boiling water during the last three to five minutes of cooking. Drain and put in a large serving bowl.
While the salmon and pasta are cooking, combine the butter, cream cheese, parmesan cheese, and half-and-half in a saucepan. Season with garlic salt. Bring to a simmer over medium heat. Cook, stirring constantly, until slightly thickened. Remove from the heat. Add the pesto at this point. Go light with the pesto to ensure the sauce is lightly flavored.
Mix the artichoke hearts with the asparagus and penne pasta and pour the sauce over the pasta mixture. Mix lightly to coat everything. Add the salmon cubes to the top of the pasta. If desired, serve with extra parmesan cheese and freshly cracked black pepper.