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The world's first 3D-printed, battery powered rocket engine destined for space

New Zealand-based Rocket Lab has built a rocket engine that's not only 3D-printed -- it uses electric motors to drive the turbopumps.

Michelle Starr Science editor
Michelle Starr is CNET's science editor, and she hopes to get you as enthralled with the wonders of the universe as she is. When she's not daydreaming about flying through space, she's daydreaming about bats.
Michelle Starr
2 min read

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The Rutherford engine, named for New Zealand scientist Ernest Rutherford, undergoing testing. Rocket Lab

The cost of getting into space is -- pardon the pun -- astronomical, but New Zealand-based startup Rocket Lab believes it will be able to reduce average launch costs by 95 percent.

This is down to its lightweight satellite launcher, Electron -- and, partially, Electron's Rutherford engine, newly unveiled at the annual Space Symposium in Colorado, USA. According to the company, it has been able to reduce the amount of liquid fuel used -- and is able to get a satellite into orbit around the Earth using the same amount of fuel it takes a jet-liner to get from Los Angeles to San Francisco.

This is thanks to the 4,600lbf engine's system of turbopumps, which inject the propellant into the engine. While the engine still uses liquid rocket fuel as a propellant -- liquid oxygen and refined kerosene -- its turbopumps are powered differently.

Usually, turbopumps are driven by a turbine powered by fuel, such as liquid oxygen or gaseous hydrogen -- but Rutherford's turbopumps are driven by brushless DC electric motors powered by lithium-polymer batteries.

Moreover, the company said, Rutherford is the first LOX-RP-1 engine to use 3D printing for all its primary components -- including the regeneratively cooled thrust chamber, the injector, the pumps and the main propellant valves. These can all be printed from titanium alloys within around three days using a 3D printing technique called electron beam melting; traditionally, manufacturing the parts would take months.

This engine would then power both stages of the rocket -- nine Rutherfords in its tail end, and one in its nose.

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Rocket Lab

This helps optimise the Electron rocket for fast production -- which will be necessary with launches as often as once a week, especially if, as Rocket Lab CEO Peter Beck told Via Satellite in October 2014, the Electron rockets will not be reused.

"We did the trades and there is a lot of added mass and complexity to reusable systems. When your booster is worth $20 or $30 million, then to have the infrastructure required to retrieve, service and refurbish it makes sense. But when your booster is worth single-digit millions or less, the cost equation doesn't close. It's more cost effective to not reuse," he said.

Each launch is expected to cost around $4.9 million. According to Lockheed-Boeing, the average cost of a space rocket launch is around $225 million.

"Historically, the time and expense to launch small satellites have been prohibitive, costing many millions of dollars and requiring endless patience and flexibility waiting for months to 'hitch a ride' to space," said Beck.

"With Electron, companies can launch whenever they would like, at a substantially more affordable cost. This monumental advancement in space technology gives satellite-reliant businesses the freedom they have been waiting for, which will lead to vast improvements in how we use satellite technology in space."

Rocket Lab's commercial low-Earth orbit operations are scheduled to commence in 2016.