A Grasshopper’s Leap

Contributed by
Dec 27, 2012
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On Dec. 24, 2012, the private space exploration company SpaceX gave its prototype Vertical Takeoff/Vertical Landing (VTVL) rocket called Grasshopper a chance to make a small hop: 40 meters straight up. During the test Grasshopper went up, hovered, and landed back on its tail successfully. Watch the test—and turn your speakers up for maximum effect!

That is so cool! It stayed aloft for a total of 29 seconds.

Grasshopper is actually the rocket tank from the first stage of a SpaceX Falcon 9 equipped with a single engine and landing legs. The idea is to be able to reuse rockets instead of dropping the used parts into the ocean when they’re done boosting the payload. The Space Shuttle did this with the solid rocket boosters, which fell into the Atlantic where they were recovered by boat. In the case of the Shuttle the financial savings of reusing the SRBs versus just building new ones was debatable. However, rocket design has improved since the SRBs were first built, and it’s possible reuse can save money as well as time.

This test of the Grasshopper was important because it used what’s called “closed loop thrust vector and throttle control”, which means the rocket engine was automatically pointed and thrust throttled as needed to compensate for things like changes in wind and fuel remaining (as the rocket burns fuel it gets lighter, so less thrust is needed to hover).

If you look carefully on the right hand side of the rocket in the picture above, you may notice what looks like a person riding on the landing leg platform. That's actually a cowboy mannequin the folks at SpaceX placed there as a lark. Elon Musk, SpaceX CEO, tweeted about it during the test flight. I suspect Wil Wheaton had something to do with this.

On Nov. 1, 2012, a test of Grasshopper had it going up less than 10 meters, so this test was pushing it harder. SpaceX plans on ramping up tests to the point where Grasshopper is traveling supersonically, to better mimic actual flight conditions of an orbital launch.

Other rocket companies have done similar tests, such as Armadillo Aerospace and Blue Origin. The idea is not new—the Apollo Lunar Modules were VTVL, after all. With improvements in onboard computers and mechanical techniques, though, the technology has come a long way. I’ll be very interested to see where this goes.

And a note: I am still hearing people grumbling that crewed space flight in the United States is dead with the Shuttle. That is simply ridiculous; they’re dead wrong. In fact, I’m excited for the next few years of putting humans into space. NASA is working on their Space Launch System (which just passed a major technology review), and there are several private companies working on taking people into space, into orbit, and beyond.

The future of humans in space looks pretty good to me right now. And I have a hope—a realistic one—that we’ll see a human walking on the Moon in the next fifteen to twenty years. Possibly sooner. We’ll see, but the idea is no longer a fantasy. It’ll be reality sooner or later. I’m hoping sooner.