Airbus isn't done trying to beat SpaceX... in fact, it's going for the jugular. The German aerospace firm has unveiled Adeline, a reusable first-stage rocket engine that aims to one-up the efforts from its American rival. Rather than try to return the entire first stage to Earth, Adeline carries just the most expensive bits, the engine and avionics. The machine has an aerodynamic shield that reduces engine stress on the way down, and two winglets with rotary motors to guide the craft safely to the ground -- Airbus envisions the rocket segment landing on runways, not launchpads. This approach reportedly requires much less fuel than SpaceX's approach, and would lop as much as 30 percent off routine launch costs.