1. <sub id="zy88n"></sub>
        1. <blockquote id="zy88n"></blockquote>
          欧美黑人又大又粗xxxxx,人人爽久久久噜人人看,扒开双腿吃奶呻吟做受视频,中国少妇人妻xxxxx,2021国产在线视频,日韩福利片午夜免费观着,特黄aaaaaaa片免费视频,亚洲综合日韩av在线

          NASA to build supersonic manned plane without sonic boom

          Source: Xinhua| 2018-04-04 06:34:11|Editor: Shi Yinglun
          Video PlayerClose

          WASHINGTON, April 3 (Xinhua) -- The U.S. space agency NASA has started to create a supersonic manned aircraft that may cause no eardrum-battering sonic boom.

          It announced plans on Tuesday to grant a 247.5-million-U.S. dollar contract to Lockheed Martin, an American aerospace and defense group to design and build a new plane.

          In this Low-Boom Flight Demonstration contract, Lockheed Martin is obliged to completing the design and fabrication of an experimental aircraft, known as an X-plane.

          The plane is expected to cruise at an elevation of more than 16,700 meters, at a speed of more than 1,500 kilometers per hour, but create a sound about as loud as a car door closing instead of a sonic boom, according to NASA.

          Once NASA accepts the aircraft from its contractor in late 2021, the agency will perform additional flight tests to prove the quiet supersonic technology works as designed, aircraft performance is robust, and it's safe to operate in the country.

          According to its plan, beginning in mid-2022, NASA will fly the X-plane over select U.S. cities and collect data about community responses to the flights.

          The agency said this data set will be provided to U.S. and international regulators for their use in considering new sound-based rules regarding supersonic flight over land, which could enable new commercial cargo and passenger markets in faster-than-sound air travel.

          The X-plane's configuration will be based on a preliminary design developed by Lockheed Martin under a contract awarded in 2016. The proposed aircraft will be 28.65 meters long with a wingspan of nearly 9 meters, which have a fully-fueled takeoff weight of about 14,650 kilograms.

          The jet will be propelled by a single General Electric F414 engine, the powerplant used by F/A-18E/F fighters, according to NASA.

          "This is probably going to be a once-in-a-lifetime opportunity for me. We're all pretty excited," said Jim Less, a primary NASA pilots who will fly the X-plane after Lockheed Martin's pilots have completed initial test flights.

          TOP STORIES
          EDITOR’S CHOICE
          MOST VIEWED
          EXPLORE XINHUANET
          010020070750000000000000011100001370864441
          主站蜘蛛池模板: 婷婷午夜天| 又大又粗欧美成人网站| 91亚洲精品国产自在现线| 国产精品美女一区二区免费视频 | 欧美日本国产va高清cabal| 中文无码乱人伦中文视频在线| 免费看一级a女人自慰免费| 日本高清视频网站www| 男女后入视频免费观看| 欧美不卡视频一区发布| 国产又猛又爽又黄视频| 国产午夜精品一区二区三区极品| 精品一区二区三区波多野结衣 | 国产亚洲精品久久久久蜜臀| 国产成人精品无码专区| 日本精品中文字幕在线不卡| 成人欧美一区在线视频在线观看 | 亚洲a∨国产av综合av| 成人午夜福利视频一区二区| 蜜臀视频一区二区在线播放| 亚洲国产成人久久一区WWW| 国产高清视频一区三区| 亚洲中文字字幕精品乱码| 久久精品无码一区二区小草| 999福利激情视频| 国产韩国日本精品视频| 亚洲国语自产一区第二页| 亚洲永久中文字幕在线| 狠狠色婷婷久久综合频道日韩| 国产亚洲精| 色老头亚洲成人免费影院| 日本一区二区在线播放| 偷窥村妇洗澡毛毛多| 成人午夜av在线播放| 毛片在线播放网址| 久久爱在线视频在线观看| 男人的天堂av一二三区| 国产V亚洲V天堂A无码| 2021精品国产自在现线看| 人妻插B视频一区二区三区| 成年视频女人的天堂天天看片|