NASA's dreams of a quiet supersonic jet are one step closer to fruition. The agency tells Bloomberg that it'll start taking bids to build a larger (94-foot) real-world demo version of the aircraft that it tunnel-tested in June, and we now have a clearer sense of how well it'll perform in real life. The design is expected to reduce noise to no more than 65dBa, which is exceptionally quiet for an aircraft -- co-designer Lockheed Martin likens it to the inside of a luxury car. That would make it safe to fly just about anywhere. The Concorde, by contrast, was an assault on your ears at 90dBa and was limited to overseas flights.