Scientific Method —

Sustainable rocketry: SpaceX to cut launch costs with reusable rocket

Last week, the private venture SpaceX announced that it will modify its …

Reduce, reuse, recycle: Spacex concept of Falcon 9 main stage returning to Earth
Photograph by SpaceX

Privately-held SpaceX will attempt to build a re-usable rocket, founder Elon Musk announced last week. The effort marks a bold and refreshing attempt to change the technology and economics of reaching space.

Bold in comparison to the competition, at least. The Space Shuttle is now a museum piece, but its successors are also mostly relics of the past. NASA's just-revealed new rocket is essentially a large, Apollo-style rocket accessorized with solid-fuel boosters from the 1970s-era Shuttle. Although it’s planned to be the most powerful rocket ever, it has been saddled with the uncompelling, generic name of Space Launch System. President Obama cancelled a clean-sheet design called Ares saying it was too expensive and rehashed old ideas.

The use of old ideas reaches its apogee, however, in the Taurus II from Orbital Sciences. The first stage uses a Russian NK-33 engine built in the 1960s and '70s, intended for the Soviet lunar program but mothballed instead. Orbital Systems has a contract with NASA to use Taurus II for delivering cargos and crew to the International Space Station. So does a Lockheed-Martin/Boeing alliance—their Atlas V rocket will sit atop a (different) Russian first stage.

Clearly, Russia is doing most of the heavy lifting in the post-Shuttle era. And junkyard scavenging is now a kind of space technology strategy.

Elon Musk, having made a fortune with PayPal, founded SpaceX in 2002 with the ambition of finding a "Moore's Law of space" that would pound down the cost of escaping Earth. It has now been close to a decade, and large declines in the cost of reaching orbit are not in plain sight. SpaceX has claimed dramatic efficiencies compared to government programs (read: NASA) in reducing development costs. Ironically, in an era of specialization and outsourcing, SpaceX says its cost edge comes from keeping everything in-house. Vertical integration apparently makes sense for building rockets, even if it is passé as a management fashion.

Now Musk says that, despite intimidating technology hurdles, SpaceX will try to build a re-usable version of its Falcon-9 rocket. This means the expended main stage, having done its work, will kick-turn like a swimmer at pool’s end, return the way it came, and then arrest its descent with rockets, touching lightly down to Earth. Ditto for the second stage.

Rocket hardware, not fuel, is what makes space launch expensive. Reuse, the thinking goes, ought to make space launch cheaper. Of course, that same logic was what brought us the Space Shuttle.

For SpaceX, it will make the individual rockets heavier, more complicated, and more expensive. Whether the technology and economics pencil out can’t be determined without trying. But there has been remarkably little fundament advance in rocket technology for half a century. Maybe that will change.

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