You can get a 2yr validity limited second US passport if you prove a need to submit a passport for visa application for 1 trip while traveling on a second trip. I have done so myself. However, you must do so at a Passport Office, and those are currently only giving appointments on Monday & Thursdays to medical emergencies of immediate family members. I have even been trying to help a Doctor get an appointment for a passport renewal to travel to a patient to no avail.