1/2 teaspoon kosher salt, plus additional for cooking water
1 cup grape tomatoes, halved
Heat medium pot of salted water to boiling over high heat. Fill medium bowl with ice water. Add asparagus to boiling water and cook 1 minute, stirring frequently. Drain asparagus and immediately transfer to ice water.
Let asparagus fully cool in ice water, then transfer asparagus to small bowl and refrigerate.
Refill medium pot with salted water. Add pasta and cook according to package instructions.
Meanwhile, place 3 ounces goat cheese, lemon juice, oil, mustard, lemon zest and salt in large bowl and whisk until well combined.
At end of pasta cooking time, transfer 1/4 cup pasta cooking water to bowl with goat cheese mixture and whisk until smooth. Transfer half of dressing (about 1/2 cup) to small bowl and refrigerate.
Drain pasta and transfer to bowl with remaining dressing; toss until well combined. Refrigerate one hour or up to 3 days.
Just before serving, remove pasta from refrigerator and stir in tomatoes, asparagus, remaining 1 ounce goat cheese, and reserved dressing. Serve immediately.