NASA

In 1999, NASA lost a $327.6 million Mars probe to a measurement unit mix-up. Lockheed Martin sent data in pound-force seconds; NASA entered it into a newton-second program without converting. The orbiter drifted off course and burned up in Mars's atmosphere.

NASA's AD-1 was an oblique wing aircraft — one wing pointing forward, the other backward. At supersonic speeds, swept wings reduce drag, but sweeping both shifts the center of lift. The oblique wing solved this by rotating both wings on a single pivot.