Okay kiddo, have you ever seen a really fast airplane go zooming across the sky? Well, the Boeing X-51 Waverider is one of the fastest planes there is! It's like a superhero of airplanes.
The X-51 Waverider is called a "wave rider" because it rides on something called a "shock wave." When an airplane goes really fast, it makes a big whoosh of air called a "shock wave." Like when you blow a balloon really fast until it pops, that big boom it makes is kind of like a shock wave. The X-51 Waverider uses that shock wave to help it go even faster!
The X-51 Waverider is also a special kind of airplane called a "scramjet." That means it doesn't have any moving parts, like blades or fans, to help it go really fast. Instead, it uses the air coming in through the front of the plane to push the fuel through and make a flame that makes the plane go forward.
The X-51 Waverider is so fast that it can go from New York to Los Angeles in under an hour! That's like traveling from one side of your house to the other side super fast. But, the X-51 Waverider is not for people to ride in yet. It's just a test plane for scientists to make even faster airplanes in the future.
So there you have it, the X-51 Waverider is like a superhero airplane that rides on a shock wave and uses a special engine to go super duper fast!