NASA is funding early efforts to build a plane so fast it could whisk you to any city on the planet in six hours or less. NASA is giving Lockheed Martin about $20 million in a preliminary design contract to demonstrate a "low boom" aircraft, i.e. a plane that emits a quieter sonic boom, more like a subtle thump, because supersonic flight is prohibited over the United States. If supersonic flights were quiet enough to be allowed widely, the appeal of shorter flight times would probably draw travelers and make these planes a viable technology.
https://www.washingtonpost.com/busi...c6f608-dfcb-11e5-846c-10191d1fc4ec_story.html
https://www.washingtonpost.com/busi...c6f608-dfcb-11e5-846c-10191d1fc4ec_story.html