ARCA

[Robotbeat]

Hydrogen rockets have steam as the exhaust… Don’t need to design it like the ARCA monstrosity to have low pollution.

[trimeta]

Hydrogen rockets have steam as the exhaust… Don’t need to design it like the ARCA monstrosity to have low pollution.

But crucially, you do need the competence to handle deep cryogens. That seems to be well beyond ARCA's capabilities, when they can't even handle "normal" cryogens (e.g., LOX).

[Nomadd]

 I'm working on a giant rocket shaped like a Coke bottle that you fill with freeze spray and put upside down in a giant coffee cup full of boiling water. Testing has already resulted in successful disassembly of several overhead panels.
 Send me your money.

[trimeta]

I'm working on a giant rocket shaped like a Coke bottle that you fill with freeze spray and put upside down in a giant coffee cup full of boiling water. Testing has already resulted in successful disassembly of several overhead panels.
 Send me your money.

If you're aiming for a sponsorship deal anyway, might as well make a monoprop rocket with Coke as the fuel, using a catalyst bed of Mentos.

[Mandella]

Hydrogen rockets have steam as the exhaust… Don’t need to design it like the ARCA monstrosity to have low pollution.

Hydrogen boosters have their own issues (gone over many, many times so no need to repeat), but the point is moot anyway since the bottom line is their steam rockets don't work with anything like the efficiency needed to get a meaningful payload to orbit, no matter how many you strap together.

So the issue isn't "regular rockets pollute (or not)," the issue is this system doesn't work. And once upon a time I would have given them the benefit of the doubt that they were reaching for what they might actually think was an attenable goal, at this point I really think that goal is "fleece the gullible."

[edzieba]

It's a real shame, as triggered boiling of supercritical water is a neat concept that could have practical applications if implemented sanely. But that's not what Arca are doing.

I'm working on a giant rocket shaped like a Coke bottle that you fill with freeze spray and put upside down in a giant coffee cup full of boiling water. Testing has already resulted in successful disassembly of several overhead panels.
 Send me your money.

Or you could fill your giant coke bottle with regular old coke, and hire SpaceX's giant arm to shake it up and down. Autogenous pressurisation, phase-change propulsion, nontoxic biodegradable propellants, it ticks all the buzzword boxes!

[matthewkantar]

I imagine an employee in a green head shade pulling on the crank of an adding machine: Sir, looks like 420 modules will do nicely for the first stage.

[SpaceCadet1980]

It's a real shame, as triggered boiling of supercritical water is a neat concept that could have practical applications if implemented sanely. But that's not what Arca are doing.

I'm working on a giant rocket shaped like a Coke bottle that you fill with freeze spray and put upside down in a giant coffee cup full of boiling water. Testing has already resulted in successful disassembly of several overhead panels.
 Send me your money.

Or you could fill your giant coke bottle with regular old coke, and hire SpaceX's giant arm to shake it up and down. Autogenous pressurisation, phase-change propulsion, nontoxic biodegradable propellants, it ticks all the buzzword boxes!

I think someone would probably quibble about whether nontoxic applies. (Not me, I drink it regularly, preferably with real sugar.)

[CameronD]

Let's continue the show...

AMi Exploration Mission Profile

No.. please, no.  They even have the audacity to quote "$85 million" as being the value of the material they'll recover?!??

I was willing to give them at least a few brownie points for coming up with something novel (their mega-sized bottle rocket), testing it with spectacular results and then convincing the Navy to help.. but this work of fiction does nothing for their credibility at all.

   

[libra]

Folks,

It has just dawned on me like an evidence. That ECO-rocket (ecology, my hasse) should be rebranded ESCROC-rocket. If you wonder, ESCROC is french slang for con man.

All hail the con man rocket !   Also known as scam-in-a-can.

I imagine an employee in a green head shade pulling on the crank of an adding machine: Sir, looks like 420 modules will do nicely for the first stage.

Also a propeller hat on his head, LMAO. One wonder whether they hired Wile E. Coyote as consultant rocket scientist.

I'm working on a giant rocket shaped like a Coke bottle that you fill with freeze spray and put upside down in a giant coffee cup full of boiling water. Testing has already resulted in successful disassembly of several overhead panels.
 Send me your money.

Look, if we build that large wooden badger... and then loaded it with some coconuts... using a dynamite rabbit drive for propulsion...

Those ARCA folks are  the living embodiment of South Park Gnomes underpants scheme, with a touch of Ponzi.

[Steven Pietrobon]

Latest ARCA video showing their AMi presentation. Seems to me like ARCA has a short attention span, never finishing their current project and always switching to something shiny and new.

[catdlr]

AMi - EcoRocket Heavy Design Philosophy

[Steven Pietrobon]

ARCA saying that the first Ecorocket couldn't be launched from the Black Sea due to the invasion of Ukraine, but that the rocket will now be launched from elsewhere in the EU this year. They are also planning sea trials of Ecorocket Heavy (EH) at the end of this year.

[trimeta]

Latest ARCA video showing their AMi presentation. Seems to me like ARCA has a short attention span, never finishing their current project and always switching to something shiny and new.

They hope that by changing plans before anything comes to completion, they can distract investors from the fact that none of their plans can in principle come to completion.

[launchwatcher]

My first reaction was - that wouldn't even work in Kerbal.

Here's evidence the shape worked in older versions (when aerodynamics was less of a factor).  An extreme example is depicted here:   

but note that unlike ARCA it's using engines with significantly higher I_sp.

I've seen this approach called "asparagus staging".   Besides a limited aerodynamic model, KSP also doesn't model the power requirements or propellant inertia effects of crossfeed, and its propellant crossfeed widget has unlimited flow rate.

[xyv]

Hilarious.  I amusingly stand corrected.  Maybe..."would only work in Kerbal..."

 

[PM3]

Omg, OTRAG is back. 

https://en.m.wikipedia.org/wiki/OTRAG
https://en.m.wikipedia.org/wiki/OTRAG_(rocket)

[rubicondsrv]

Omg, OTRAG is back. 

https://en.m.wikipedia.org/wiki/OTRAG
https://en.m.wikipedia.org/wiki/OTRAG_(rocket)

except with steam rockets. 

OTRAG at least worked on paper, this really doesn't. 

[FutureSpaceTourist]

[Lars-J]

One extra thing that adds to the non-believable-ness of this whole idea that few (if any) have commented on is the incredible amount of passive structures this ... thing ... would require to be able to fly.

Remember how SpaceX had to create a modified core stage design for FH to handle the extra loads? Now for the "Eco Heavy", the 2nd stage fully fueled would weight around 900 tonnes. (two F9's) The 3rd stage would weigh around 200 tonnes. So... The inner 36 'cores' of the first stage would need carry in excess of 1100 tonnes! Or 30.5 tonnes each. And then to be pulled/pushed by the outer cores, which are pulled/pushed by the next ring out, and so on. 

That would require them to be severely strengthened, or have a massive passive load bearing ring that holds the 2nd stage. And the outer 30 cores of the 2nd stage would be the lifting point to hold the weight of the 2nd and 3rd stage.

This is where are more typical on-top 2nd stage would simplify things since the loads could be more easily shared, and the 2nd stage also spread its load among its cores. But cranes are expensive!