Grasshopper's latest test reaches 24 stories high
BY STEPHEN CLARK
Posted: March 11, 2013
SpaceX's reusable rocket testbed completed another brief hop at a Texas test facility last week, rising 24 stories into the air and landing on its launch pad.
The test Thursday demonstrated a guidance and landing algorithm to be used by SpaceX's Falcon 9 rocket, according to Elon Musk, the company's founder and CEO.
Multi-angle view of the Grasshopper test flight. Credit: SpaceX
"Reusability is extremely important if you think it's important that humanity extend beyond Earth and become a multi-planet species," Musk said Saturday in a keynote session at the South by Southwest festival in Austin, Texas.
The 106-foot-tall Grasshopper vehicle, powered by a single Merlin 1D rocket engine, lifted off and reached an altitude of 262.8 feet. The 34-second flight ended with a pinpoint landing back where the rocket took off.
The Grasshopper settled back on the launch pad using the Merlin engine's thrust to steer and control the speed of its descent.
Thursday's flight was the fourth in a series of Grasshopper test flights, which began in September with a brief hop that reached about 8 feet off the ground.
"Grasshopper touched down with its most accurate precision thus far on the centermost part of the launch pad," SpaceX said in a statement. "At touchdown, the thrust to weight ratio of the vehicle was greater than one, proving a key landing algorithm for Falcon 9."
Grasshopper testing occurs at SpaceX's rocket development facility in McGregor, Texas, located about midway between Dallas and Austin. The Grasshopper vehicle is a modified Falcon 9 rocket first stage with four steel and aluminum landing legs with hydraulic dampers and a steel support structure.
Single-angle view of the Grasshopper test flight. Credit: SpaceX
"That's been the goal since the beginning of the company," Musk said. "So far, I haven't been very successful in that regard. I think we kind of have a handle on it. We've got a design that, in the simulations and in the [computer] and so forth, it closes. It should work. If we can build that thing, it should work.
SpaceX's concept calls for the company's Falcon 9 rocket to lift off and drop its first stage a few minutes into flight. The nine-engine first stage would guide itself back to the launch site with leftover propellant in its fuel tanks, flying from the upper atmosphere to a vertical landing for reuse instead of falling into the ocean.
Engineers need more tests to prove the reusability technology before employing the concept on a real rocket launch.
"With each successive test, we want to higher and farther and improve the technology to the point where we'll be doing transitions all the way to hypersonic and back, hopefully later this year," Musk said.