Heat oven to 350°F. Arrange pancetta in a single layer on a large rimmed baking sheet. Bake until brown and crisp, 20-25 minutes. (Alternatively, place pancetta on folded layers of paper towels on a microwave-proof plate and microwave on high until brown and crisp, about 5 minutes.) Let pancetta stand until cool enough to handle, then break into bite-size pieces.
Meanwhile, cook pasta in a medium pot of boiling salted water, stirring occasionally, until al dente. Drain pasta; run under cold water to cool. Drain and set aside.
Whisk oil and vinegar in a large bowl. Add half of pancetta, cooked pasta, melon, half of mint, scallion, and red pepper flakes. Toss to coat. Season to taste with salt and pepper. Transfer to a serving dish and sprinkle remaining pancetta and mint over. Garnish with shaved ricotta salata.
