August 15, 2013
The Grasshopper test is a big deal because there aren’t, at the moment, any rockets in use capable of the kind of lateral maneuvers SpaceX showed off Tuesday. Some smaller rockets have done it, but none of them even approaches Grasshopper’s size. The ability to make significant corrections to the trajectory is a key part of developing a reusable rocket, as the first stage will return to Earth at hypersonic speed. The only way to decrease its lateral speed, and guide it to a landing site, is through such moves.
“The test demonstrated the vehicle’s ability to perform more aggressive steering maneuvers than have been attempted in previous flights,” the company said in announcing the news. “Grasshopper is taller than a 10-story building, which makes the control problem particularly challenging.”
The braking and steering tests performed by Sierra Nevada Corporation are far less dramatic, though they are crucial to preparing its lifting body spacecraft for the company’s first glide flights in the coming months. After all, before you can fly to space, first you have to be sure you can come to a complete stop before unbuckling your seat belt.
The Dream Chaser is Sierra Nevada’s entry into the NASA competition for delivering astronauts to the International Space Station (and elsewhere in low Earth orbit). Unlike the entries from SpaceX and Boeing, the Dream Chaser is not a classic capsule. Instead, it’s a flying vehicle that would land like the space shuttle orbiters, rather than falling back to Earth under parachute.