Invictus Hypersonic Space Plane Can Go From London to NYC in 1 Hour

After the NASA space shuttle was retired in 2011, it seemed like space planes might become relics. But they are on a comeback. U.S. companies Sierra Space Corp., Dawn Aerospace, and Radian Aerospace have all introduced their own versions of an aircraft that takes off like a plane, but soars like a rocket. Virgin Galactic soon plans to introduce the Delta version of its space plane. Among militaries, the U.S. Air Force operates a robotic orbital space plane called the X-37B, while China has…