<address id="phfdn"></address>

        <address id="phfdn"><dfn id="phfdn"><menuitem id="phfdn"></menuitem></dfn></address>

        <form id="phfdn"><nobr id="phfdn"></nobr></form>

            <address id="phfdn"></address>
            4/9/2021 5:30AM     

            How NASA’s Ingenuity Helicopter Was Developed for Mars Here on Earth

            NASA's Ingenuity helicopter, which was carried to Mars by the Perseverance rover, is set for the first ever flight on the red planet. WSJ goes inside the company that partnered with NASA to design and build an aircraft for a completely different atmosphere from Earth. Photo: NASA/JPL

            正版资料大全全年2019小说