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Rocket Lab Unveils "Electric" Rocket Engine
New submitter Adrian Harvey writes The New Zealand based commercial space company Rocket Lab has unveiled their new rocket engine which the media is describing as battery-powered. It still uses rocket fuel, of course, but has an entirely new propulsion cycle which uses electric motors to drive its turbopumps.
To add to the interest over the design, it uses 3D printing for all its primary components. First launch is expected this year, with commercial operations commencing in 2016.
To add to the interest over the design, it uses 3D printing for all its primary components. First launch is expected this year, with commercial operations commencing in 2016.
About 10 years ago I worked on simulating a rocket with electric turbopumps for fun. The concept was the exact same as theirs - minimize the number of parts that have to operate in harsh environments to reduce cost, maintenance and risk of failure. You don't even need any penetrations of the propellant lines, the rotor of the electric motor is the compressor itself.
I have no clue whether the design will actually be practical. But it's certainly not new. I'm sure I'm not the first person that this concept occurred to.
*Kid Rock runs for Senate* Democrats: We must run Kid Scissors.
Big rocket engines use big propellant pumps. The pump on the F-1 (used on the Saturn V) ran about 55,000 horsepower.
Electric motors won't do that cheaper. And they'll sap the weight of the rocket, since even a dead battery is heavy. Fundamentally, a big rocket will be better served by a gas-generator or staged-combustion cycle.
That's fine for this rocket because it's so small. The payload is 110kg. For comparable rockets, turn to Iran's unflown Simorgh, Israel's Shavit, or North Korea's Unha, all in the 100-160kg range.
To put those numbers in comparison, let's look at SpaceX. The single-engined Falcon 1 put 670kg into orbit. A Falcon 9 runs 10,000-13,000kg. And the Falcon Heavy is supposed to lift 53,000kg.
Or for an older comparison, Sputnik 1 weighed 80kg, and Sputnik 2 weighed 500kg. So they're building a rocket that couldn't even lift the second satellite to ever fly. I'm not particularly impressed.
Maybe there's a niche for small payloads like this, but in all honesty, I expect you could fly several such payloads on one bigger rocket, or just hitchhike on the spare capacity on a big satellite launch. Still, worth a shot. Just don't pretend to be playing in the big leagues.