SpaceX proved yesterday that their Grasshopper prototype Vertical Takeoff Vertical Landing (VTVL) vehicle can do more than just go straight up and down. The goal of the test, said SpaceX CEO Elon Musk on Twitter was, “hard lateral deviation, stabilize & hover, rapid descent back to pad.”
On August 13th, the Grasshopper did just that, completing a divert test, flying to a 250-meter altitude with a 100-meter lateral maneuver before returning to the center of the pad. SpaceX said the test demonstrated the vehicle’s ability to perform more aggressive steering maneuvers than have been attempted in previous flights.
While most rockets are designed to burn up in the atmosphere during reentry, SpaceX is looking to make their next generation of Falcon 9 rocket be able to return to the launch pad for a vertical landing.
This isn’t easy. The 10-story Grasshopper provides a challenge in controlling the structure. The Falcon 9 with a Dragon spacecraft is 48.1 meters (157 feet) tall, which equates to about 14 stories high. SpaceX said diverts like this are an important part of the trajectory in order to land the rocket precisely back at the launch site after reentering from space at hypersonic velocity.
Also on Twitter this morning, NASA’s Jon Cowert (who is now working with the Commercial Crew program) provided a look back at NASA’s foray into VTVL vehicles with the Delta Clipper Experimental vehicle,(DC-X). The video below is from July 7, 1995, and the Delta Clipper was billed as the world’s first fully reusable rocket vehicle. This eighth test flight proved that the vehicle could turn over into a re-entry profile and re-orient itself for landing. This flight took place at the White Sands Missile Range in southern New Mexico.
But after some problems (fires and the spacecraft actually fell over when a landing strut didn’t extend) NASA decided to try and focus on the X-33 VentureStar, which would land like an airplane…. and that didn’t work out very well either.
But that’s another story.