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Startup Develops First 3D Printed Battery Powered Rocket

The big question is whether or not that design scales up. Using a battery as a power source to allow something to get off the ground is nothing new, but how many batteries do you need to stack to keep the pump going? Are you going to get to a break even point of the thrust gained equalling the weight of the vehicle in which case you make a fancy fireworks display if you turn it upside down.
 
The turbo pumps are battery powered, not the rocket itself.

Still really cool.
 
cyclone3d said:
The turbo pumps are battery powered, not the rocket itself.

Still really cool.
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Yes I realize the turbo pumps are battery powered, but my question is whether or not that will scale up. More fuel movement, requires larger turbo pumps, larger pumps more batteries, longer duration of thrust means more batteries.

Not saying it won't work, I'm just wondering if it will once you scale it up to launch something.
 
weebling1 said:
Ever achieve orbit?
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Not yet, but I mean neither have they. I've likely reached higher velocities and altitude than they have though. From the looks of their testing that rocket isn't even moving, what newbs.
 
sfsuphysics said:
Yes I realize the turbo pumps are battery powered, but my question is whether or not that will scale up. More fuel movement, requires larger turbo pumps, larger pumps more batteries, longer duration of thrust means more batteries.

Not saying it won't work, I'm just wondering if it will once you scale it up to launch something.
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Right, and I wasn't really responding to your comment. The title was that the rocket was battery powered.
 
Let me know when it doesn't have to be charged every 200 miles.



Yes I read how it worked, the above was sarcasm.
 
sfsuphysics said:
Yes I realize the turbo pumps are battery powered, but my question is whether or not that will scale up. More fuel movement, requires larger turbo pumps, larger pumps more batteries, longer duration of thrust means more batteries.

Not saying it won't work, I'm just wondering if it will once you scale it up to launch something.
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In my experience, when pumps are scaled up they usually increase in efficiency rather than decrease.
 
Colecoman1982 said:
In my experience, when pumps are scaled up they usually increase in efficiency rather than decrease.
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Just as a follow-up, the same generally holds true of electric motors. I'd imagine that's also true of batteries if you increase the size of the individual cells. Even if you just use the same cells, the worst case is that the power density remains constant.
 
Yay! War just got a whole lot more profitable. Now the companies that make the rockets won't have to pay workers, they just have a machine print it, and then sell it to whichever government wants it at a slightly reduced cost but at a larger profit margin because this is a business afterall.
 
Colecoman1982 said:
Just as a follow-up, the same generally holds true of electric motors. I'd imagine that's also true of batteries if you increase the size of the individual cells. Even if you just use the same cells, the worst case is that the power density remains constant.
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Materials used determines voltage I believe, for example your standard AA alkaline battery puts out about 1.5v at full charge, whereas a Li-Ion cell phone battery puts out close to 3v i think. Only way to increase voltage is to use different materials or add more cells. Cell structure determines amp output and how long it can output those amps. The surface area of the metals exposed to the electrolyte determines maximum amperage draw, and how much electrolyte is in the cell will determine how long the battery can be used.

Scaling things up would imply a bigger motor, thus more resistance in the circuit therefore needing more voltage, so you would need more cells. A bigger motor also will require more amps to make it run, so you are going to need bigger batteries, unless you don't need it to run as long as they scaled down version. In the end it all equates to a whole lot more weight, and more weight requires more energy to make it move. Batteries don't scale very well in most applications, otherwise we would all be driving electric cars by now.
 
sfsuphysics said:
Yes I realize the turbo pumps are battery powered, but my question is whether or not that will scale up. More fuel movement, requires larger turbo pumps, larger pumps more batteries, longer duration of thrust means more batteries.

Not saying it won't work, I'm just wondering if it will once you scale it up to launch something.
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I would imagine you could put a small reactor on the spacecraft to provide the necessary electricity. The engine doesn't have to run constantly short bursts here and there...small reactor and/or solar panels could charge it in between firings.

Scale it up... not sure.

I imagine larger spacecraft in the future will have full nuclear reactors onboard just like today's modern day submarines. The reactors will power everything from the onboard electronics, to ion and plasma engines, to full blown nuclear engines. Despite concerns of nuclear thrust from older projects in the 60's and 70's, there is a renewed interest and advancement in the tech recently. Not much need for batteries at that point other than for backup power in the event of emergency. I seriously doubt the design this company in the news article is proposing will ever be used for anything more than a small booster.
 
TBH, I think the real amazing feat here is the 3d printed parts, not the electric turbopumps or the battery tech necessary. I am absolutely dumbfounded by the ability of 3d printers to make something with the kind of precision necessary and still have the structural integrity to be a rocket engine.

Any word on just how much of this engine is 3d printed? Does that include the nozzle too?
 
sfsuphysics said:
The big question is whether or not that design scales up.
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The short answer is 'no'.

Using an electric motor has only one benefit: an electric motor is easier to build than a turbopump. In every other way, this engine is inferior to a gas-generator, staged-combustion, or even pressure-fed cycle rocket. The motor and batteries are a big dead weight that needs to be carted around, and an electric motor that can produce the same power as a gas generator is going to be enormous.

Let's take the F-1 as our 'scaled up' engine. the F-1's gas generator pumps out 41 megawatts of shaft power, or 55000brake-horsepower. Given the turbopump is effectively a high-flow-rate compressor here's what a 55,000 HP compressor looks like. That's a heck of a low of metal to slap onto your rocket to do the same job, and ignores both the batteries needed to pump out 41MW for a few minutes, or that the gas generator gives you a bonus ~30,000lbs thrust.



That benefit of being easy to build is a big one for hobby rocketry though. Building a gas generator is non-trivial, and unlike an electric motor you can't just go and buy on off-the-shelf. Even converting an automotive Turbo into a turbine+turbopump combo (akin to conversion to a jet turbine) is a somewhat tricky endeavour due to the temperatures and power involved. A look through Copenhagen Suborbital's youtube channel will show plenty of videos of the building a turbo-based turbopump, testing it, then building and testing a from-scratch gas generator and turbopump.

TBH, I think the real amazing feat here is the 3d printed parts,
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Yep, EBM printing is neat. SpaceX use it to build their SuperDraco engines for the Dragon 2 our of Inconel, fully 3D printed.
 
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