sevenperforce

Amateur rocket to orbit

Recommended Posts

3 hours ago, Mad Rocket Scientist said:

I understand gasoline to be a bad fuel compared to alcohol. As to ITAR: what are the rules in other countries? Does copenhagen suborbitals have to deal with the local equivalent of ITAR there?

Alcohol is less energy dense and burn less hot than gasoline. Kerosene burns hotter still and is safer to handle because of lower flash point. 
V2 rocket used alcohol because it burned at lower temperature so it would not melt the engine. 

Copenhagen suborbitals launch from international water they still talk to their version of ITAR as nobody want to hit an plane or something. 
Note that Denmark is small an small and densely populated country, not sure even the military could test fire ballistic missiles there. 

Share this post


Link to post
Share on other sites

ITAR has nothing to do with hitting planes. It's about exporting technology, and it's a US-only thing.

Share this post


Link to post
Share on other sites
39 minutes ago, magnemoe said:

Alcohol is less energy dense and burn less hot than gasoline. Kerosene burns hotter still and is safer to handle because of lower flash point. 
V2 rocket used alcohol because it burned at lower temperature so it would not melt the engine. 

I recall reading that gasoline engines are hard to start. Especially if by gasoline you refer to what comes out of a gas (petrol) station pump, which varies quite a bit from batch to batch. On the other hand, Goddard had lots of successful flights with gasoline engines.

39 minutes ago, magnemoe said:

Copenhagen suborbitals launch from international water they still talk to their version of ITAR as nobody want to hit an plane or something. 
Note that Denmark is small an small and densely populated country, not sure even the military could test fire ballistic missiles there. 

 

25 minutes ago, Nibb31 said:

ITAR has nothing to do with hitting planes. It's about exporting technology, and it's a US-only thing.

Ah, so ITAR (or local equivalent) would frown on going to another country to develop rockets.

Share this post


Link to post
Share on other sites

I’m not in any way an expert in law, but I’d imagine that no, it does not apply to foreign countries. If we were to build it in, say, somewere in the equatorial regions of Africa, it might be legal (I might be wrong though). And actually, that reminds me, did we aggre on where we would be launching from? I live in Britain and there’s currently a vertical launch site being constructed in Scotland, although I think it’s only being used by Lockheed Martin right now. Or maybe we should take a more traditional approach, and launch it from the Nevada desert (where most high power amateur rockets are launched), though if that would be legally possible I’m not sure. Also for consideration is Australia since sounding rockets have been launched from there every now and again and even also orbital rockets (the black arrow). Plus Australia is outside the US (although if something like ITAR still apples I’m not sure). The problem with Australia is it’s not equatorial.  Of course we could always go with sea launch, although I’m not sure what regulations apply to that.  It’s possible that if we construct it in a country where these laws don’t apply and then ship it out to the middle of the Atlantic Ocean we might be able to launch it without getting in trouble.

Share this post


Link to post
Share on other sites

Also, on another topic, does anyone here know how to 3D model stuff? I just figure that now that we have a good understanding of how we’re going to have it work, we should now start creating digital mockups of it for simulations. Or really just start putting it an any sort of blueprint form.

I have an iPad Pro and an Apple Pencil, so I can draw 2D blueprints, but I simply don’t have the software or expertise for 3D design.

Edited by BillKerman1234

Share this post


Link to post
Share on other sites

There has been some talk recently of a launch facility being built by Equatorial Launch Australia in the Northern Territory (closer to the equator) that intends to provide services to commercial, research and government organizations.

https://www.news.com.au/technology/science/space/australias-first-commercial-space-base-to-launch-rockets-within-a-year/news-story/eb7841c5b39e04fd31302e8b1056e3ab

Share this post


Link to post
Share on other sites

Okay, so then for now let’s assume we’re launching from Australia. Does anyone know how much delta v that will take? LEO is usually 9.5km/s, so 10? Also, has anyone tried simulating this in KSP realism overhaul yet?

Share this post


Link to post
Share on other sites

Another question: does anyone know the mixture rato of jellied petrol / htp? I’m trying to calculate how big the rocket will need to be, but I need the volume of fuel & oxidiser, and in order to calculate that I need the mixture ratio.

For now I’ll assume it’s 1:1

Edited by BillKerman1234

Share this post


Link to post
Share on other sites
2 hours ago, BillKerman1234 said:

Another question: does anyone know the mixture rato of jellied petrol / htp? I’m trying to calculate how big the rocket will need to be, but I need the volume of fuel & oxidiser, and in order to calculate that I need the mixture ratio.

For now I’ll assume it’s 1:1

7:1 for H2O2/RP-1

Also, why jellied? 

Share this post


Link to post
Share on other sites
9 hours ago, Nibb31 said:

ITAR has nothing to do with hitting planes. It's about exporting technology, and it's a US-only thing.

I was googling about the safety of Finnish nuclear reactors and the results were primarily concerned about nuclear proliferation.  ITAR might be US specific laws, but I doubt that the EU is all that crazy about dangerous tech being sold to certain nations and likely has their own set of regulations with a different name.

2 hours ago, Steel said:

7:1 for H2O2/RP-1

Also, why jellied? 

I think that was the assumption that started this thread.  I really doubt you are going to get the high test peroxide unless things have changed a lot since the X-prize was a thing (granted we are talking  about right after 9/11 compared to 17 years later).  I'd have to assume that nitrous oxide would be wildly easier to procure (at least in the USA, down under I doubt it) and use, while LOX would be easier to procure and almost as easy to use (although I've never heard of pressure-fed LOX).

In the unlikely event that you can acquire HTP in Australia, that might change things (although I doubt I will ever be a big fan of HPT rocketry).

Edited by wumpus

Share this post


Link to post
Share on other sites

Well, we don’t have to get the HTP from Australia, we could import it. As for nitrous oxide, although I aggre about it being easier to get and safer, and while I’m not sure if the isp of nitrous oxide / jellied petrol, it is almost certainly lower than htp / jellied petrol. Assuming we’re going with jellied petrol of course. We could go with htpb / nitrous oxide, but the isp would be lower, and the density would drop dramatically. Also, for the record, here is a better diagram of the rocket that I came up with (using a diagram from earlier in the thread for the Hybids).2Z5Ig78.jpg

Edited by BillKerman1234

Share this post


Link to post
Share on other sites

I was the OP and yeah I'm still a little active active. Sometimes threads stay active for a while, sometimes not. This was def an interesting discussion.

I don't like HTP rocketry either but it beats the heck out of nitrous in both thrust and Isp, and it can be self-pressurizing with the right setup, and you can vent the pressure chamber as RCS.

26 minutes ago, wumpus said:
Quote

Why jellied?

I think that was the assumption that started this thread. 

The first ever "bipropellant" rocket used jellied petrol inside a mesh with pressure-fed GOX, which was basically a hybrid rocket.

My thought, though others questioned it, is that properly-jellied petrol may be able to "flow" from a non-burning region into a combustion region, which means you need lower amounts of inert binder and also allows for finer control.

26 minutes ago, wumpus said:

I really doubt you are going to get the high test peroxide unless things have changed a lot since the X-prize was a thing (granted we are talking  about right after 9/11 compared to 17 years later).  I'd have to assume that nitrous oxide would be wildly easier to procure (at least in the USA, down under I doubt it) and use, while LOX would be easier to procure and almost as easy to use (although I've never heard of pressure-fed LOX).

Never heard of pressure-fed LOX? Err...the Kestrel? You can even autogenously pressurize LOX if you heat it properly, though that gets into "hot oxygen gas" which is nasty on the best of days.

 

Share this post


Link to post
Share on other sites

We could get away with nitrous, but then the boosters would need 2.8 tonnes of propellent, instead of 2.0 (assuming nitrous / htpb has 260s of isp). Personally, I still like HTP / Jellied Petrol.

Edited by BillKerman1234

Share this post


Link to post
Share on other sites

Has anyone tried simulating the vehicle yet? We’ve basically finished the general design phase, the next step will be drawing blueprints, 3D modelling it, and doing CFD simulations on it. The first thing we should figure out is the optimum height to width ratio of the boosters and the core.

Share this post


Link to post
Share on other sites

I don't know for sure, but wouldn't LNG/LOX be safer?  It also gives much more performance, and i think those factors combined make up for the annoyance of cryogenics.  Amateur rockets aren't going to get close to the optimal performance of rocket engines, so you need all the base performance you can get.  Plus, the goal of this project is probably to prove yourself to some organization, and both SX and BO are doing Methalox.  Definitely do ablative nozzles, I don't know how exactly they work, and you might need to put some fuel next to the walls for cooling.  Electric pumps are probably easier and safer then pressurization, since both lox and lng can do pressurization relatively on their own and you don't need some high pressure helium container.  I think launching from a boat in the ocean is easier and cheaper, plus you can go out in the middle of nowhere so you don't hurt anything. 

Share this post


Link to post
Share on other sites
11 hours ago, Nibb31 said:

ITAR has nothing to do with hitting planes. It's about exporting technology, and it's a US-only thing.

Ok, I read it as ITA I think it is who handle safety in the air. 
Copenhagen suborbitals don't use restricted technology, engine is based on the V2 design. 
ITAR is an US organisation, you had an nato setup to limit technology transfer to the Soviet but that is history and would not apply here anyway. 
 

Share this post


Link to post
Share on other sites
2 hours ago, ment18 said:

I don't know for sure, but wouldn't LNG/LOX be safer?  It also gives much more performance, and i think those factors combined make up for the annoyance of cryogenics.  Amateur rockets aren't going to get close to the optimal performance of rocket engines, so you need all the base performance you can get.  Plus, the goal of this project is probably to prove yourself to some organization, and both SX and BO are doing Methalox.  Definitely do ablative nozzles, I don't know how exactly they work, and you might need to put some fuel next to the walls for cooling.  Electric pumps are probably easier and safer then pressurization, since both lox and lng can do pressurization relatively on their own and you don't need some high pressure helium container.  I think launching from a boat in the ocean is easier and cheaper, plus you can go out in the middle of nowhere so you don't hurt anything. 

We probably can’t do bipropellent liquids, but if we can then yes, that’s probably what we would go with. And indeed, sea launch is by far the best option.

Does anyone here know what it would take to build a biprop liquid engine? I’m curious how much more difficult it would be than a hybrid. In principle it should be easier to build a liquid motor, but in practice (from what I’ve heard) it’s far more difficult. Does anyone know why?

Maybe we could have a LNG/NTO or a LNG/LOX core with hybrid boosters?

Edit: I just realised liquid natural gas is also known as methane, in which case I would highly recommend a liquid core with hybrid boosters, as the core could have such a high isp that you wouldn’t need an upper stage.

Edited by BillKerman1234

Share this post


Link to post
Share on other sites
1 minute ago, BillKerman1234 said:

We probably can’t do bipropellent liquids, but if we can then yes, that’s probably what we would go with. And indeed, sea launch is by far the best option.

Does anyone here know what it would take to build a biprop liquid engine? I’m curious how much more difficult it would be than a hybrid. In principle it should be easier to build a liquid motor, but in practice (from what I’ve heard) it’s far more difficult. Does anyone know why?

I've built an extremely simple liquid fueled rocket engine.  From my experience and reading of rocket literature, the injector is a major sticking point, but I think a pintle would be relatively simple.  Pumping is hard, but electric gets rid of the really hard part in the pre-burner.  Liquids also have much higher standards than hydrid or solid.

Share this post


Link to post
Share on other sites
1 hour ago, BillKerman1234 said:

We could get away with nitrous, but then the boosters would need 2.8 tonnes of propellent, instead of 2.0 (assuming nitrous / htpb has 260s of isp). Personally, I still like HTP / Jellied Petrol.

Ever try sourcing multiple tons of HTP?  John Carmack claimed he did and found it to be impossible.  If you don't like nitrous I'd go straight to LOX.  I'd also be surprised if it is any less nasty than LOX.  If Copenhagen Suboritals uses it, it is probably simply copying the V2 system (LOX/Alcohol is a great propellant if you want to trade a little Isp for a  much lower temperature, but I suspect we want one solid/gel propellant and one pressurized one: see below about costs).

1 hour ago, BillKerman1234 said:

Has anyone tried simulating the vehicle yet? We’ve basically finished the general design phase, the next step will be drawing blueprints, 3D modelling it, and doing CFD simulations on it. The first thing we should figure out is the optimum height to width ratio of the boosters and the core.

 

I strongly doubt anyone is simulating it beyond Realism Overhaul  (the KSP mod). 

On 10/2/2017 at 2:52 AM, Riven said:
On 10/1/2017 at 2:25 PM, quasarrgames said:

Finally, i don't mean to beat a dead horse, but how much money would this "amateur" rocket be expected to cost? A few thousand? A few hundred thousand? A few million?

It would be at least in the high six figures, seven if you're going bipropellant with turbopumps. Be prepared to ask executives of companies in person to sponsor you.

Source: VP of operations for a space exploration org at my university. Our current flagship project is for the FAR-Mars competition. TL;DR for competition description: you fly an unguided liquid methane fueled rocket with 1 kilo payload to as close to 45,000 feet as possible, and we have until May 2018 to put something together that flies. We've done a lot of the theoretical calculations so far, and we have designed the engine already, but guess why we can't do testing and manufacturing yet? Money. We estimated that this rocket - including GSE, ground station electronics, custom fabricated test stands, test equipment - will cost us upwards of $60k. The engine itself would cost $15k to 3D print out of Inconel 716. It would be 3D printed because drilling extremely long and thin regenerative cooling channels into the thin, curved walls of a small methane fueled engine is probably impossible. While most of our efforts are focused on continuing to design, the president and I are organizing business majors to go to companies in person to attempt to get funding (or even spare rocket parts). We had limited success with Cryoquip, Inc. when we talked to them in person over the summer for example - they were extremely excited to design high pressure composite cryogenic tanks for us - but they got some LNG deal in South Korea recently and they dropped our project.

I skimmed through this thread and saw something about using turbopumps. If you can shell out tons of money for the manufacturing of it, then sure. We considered turbopumps over our helium pressure-fed system for a week, but after realizing the engineering required for the complexity of designing and manufacturing one, we elected to use a helium pressure fed system pressurized to 15Mpa.

We intend to apply what we learn building (and hopefully launching) this rocket to design an orbital cubesat launcher over the span of a few years because we need research, experience, and money/sponsors with operating something like this, and who knows, another university with extremely deep pockets (cough Purdue, USC, etc) could beat us to it by then.

1U cubesats - 10x10x10 cm. These can be as light as 1 kilo. If you have a highly directional VHF/UHF antenna and the right radio equipment, you can communicate with one in LEO.

If KSP:RO can get the price anywhere near the "high six figures" we can discuss just where to find said money.  That's basically the reason this is a necrothread.

2 minutes ago, BillKerman1234 said:

We probably can’t do bipropellent liquids, but if we can then yes, that’s probably what we would go with. And indeed, sea launch is by far the best option.

Does anyone here know what it would take to build a biprop liquid engine? I’m curious how much more difficult it would be than a hybrid. In principle it should be easier to build a liquid motor, but in practice (from what I’ve heard) it’s far more difficult. Does anyone know why?

It would take several hundred thousand dollars not including the specialized knowledge and huge number of unpaid hours to design said turbopumps.  Granted, this is simply what I've heard and I really don't know much about the process of designing said pumps.  I know that designing relatively simple circuit boards "costs millions of dollars" when done by pros, but nearly all of that is engineer time and could be done for this project.  I'm guessing that that the science of designing turbopumps is deliberately not published to limit "rogue nation" access and that a long design-test sequence will be needed.  While blowing up test turbopumps up might be wildly cheaper in the CNC age than in the Vostok-Mercury-Apollo era, it still isn't cheap.

5 minutes ago, ment18 said:

I've built an extremely simple liquid fueled rocket engine.  From my experience and reading of rocket literature, the injector is a major sticking point, but I think a pintle would be relatively simple.  Pumping is hard, but electric gets rid of the really hard part in the pre-burner.  Liquids also have much higher standards than hydrid or solid.

Electric might well be an option.

I'd also expect multiple (maybe just two) tiny solid stages at the very end, merely because you should be able to get the total stage at a much lower mass and a wet/dry ratio much higher (just don't expect to get more than a few grams into space this way).

Share this post


Link to post
Share on other sites

Wumpus, I aggre with everything you said, except for the bit about it costing 6 figures. If we do it right, we could probably do it for under 100k, maybe 50k. The main cost driver in rocketry is the cost of hiring designers, the testing equipment, and most of all, the paperwork. Everything in a rocket (conventionally) has to be checked 500 times and must be traceable back to the ore in the ground. We can get around this by having a small non-payed design team, and using off-the-shelf materials and tools. A good example would be cubesats, everyone says scratch building one takes thousands of dollars using standard space rated materials, but if you just take a metal box and stick a RPi with some foam insulation and a battery inside, your pretty much done! The same applys to rockets, take SpaceX for example, by making everything in house, they reduce the cost by something like 70%.

Think about it, what is a rocket? The fuel tanks are metal tubes with caps on the ends, the motor is a sphere with a funny shaped cone on the end, the fuel pumps are the same as you get in fire trucks (in fact there was a famous incident where von Brown was designing the V2 rocket and asked a bunch of pump engineers to design him a pump to some specifications only to have them all tell him that he was describing exactly a fire engine pump), and the guidance system can just be fins. Okay, I know this is vastly simplified, but when you think about it, there’s no real reason rockets have to be so expensive.

Edited by BillKerman1234

Share this post


Link to post
Share on other sites
50 minutes ago, wumpus said:

It would take several hundred thousand dollars not including the specialized knowledge and huge number of unpaid hours to design said turbopumps.  Granted, this is simply what I've heard and I really don't know much about the process of designing said pumps.  I know that designing relatively simple circuit boards "costs millions of dollars" when done by pros, but nearly all of that is engineer time and could be done for this project.  I'm guessing that that the science of designing turbopumps is deliberately not published to limit "rogue nation" access and that a long design-test sequence will be needed.  While blowing up test turbopumps up might be wildly cheaper in the CNC age than in the Vostok-Mercury-Apollo era, it still isn't cheap.

Pressure fed biprop engines are quite simple, and probably about as hard to design and build as a fancy model steam engine. Keeping them light is where it gets challenging, along with cooling.

But info on turbopump design isn't classified at all. I'm looking at a copy of Modern Engineering for Design of Liquid-Propellant Rocket Engines right now, and it has an entire chapter on turbopump design, with all the relevant formulas.

Share this post


Link to post
Share on other sites

Okay, so what if we use methane/lox with an electric turbo pump system, and strap on hybrid boosters? Sounds like a plan that could work! For guidance we could have static fins and mono prop RCS for higher up. The trick would be designing a biprop engine that actually works, and the hybrids could just be htpb and n2o.

Share this post


Link to post
Share on other sites
4 minutes ago, BillKerman1234 said:

Okay, so what if we use methane/lox with an electric turbo pump system, and strap on hybrid boosters? Sounds like a plan that could work! For guidance we could have static fins and mono prop RCS for higher up. The trick would be designing a biprop engine that actually works, and the hybrids could just be htpb and n2o.

Pressure fed is probably easier, which is more important than performance.  Why bother with trying to figure out hybrid rockets instead of just building more liquid cores?  Building gimbal would probably be the hardest part.

Edited by ment18

Share this post


Link to post
Share on other sites
21 minutes ago, ment18 said:

Pressure fed is probably easier, which is more important than performance.  Why bother with trying to figure out hybrid rockets instead of just building more liquid cores?  Building gimbal would probably be the hardest part.

Good point, pressure fed would be much simpler than electric pumps (although I’m still not sure why building a simple impeller is so difficult). As for more liquid cores, I was thinking that the materials in the hybrids would produce much more thrust which is very useful for launch. Also, I know that this is not  really a consideration in spaceflight, but liquid boosters have been done so many times that it would be very boring, sure we would be the first amateurs to launch a rocket into orbit, but it wouldn’t be that different from existing small-scale rockets like falcon 1 or electron (so much so that it might not be classified as a world record), however hybrids on the other hand have never been done before on an orbital scale (as far as I know). Not to mention that hybrids are (at least to my knowledge) cheaper than liquids, which is a major consideration if we want to ever use this to launch cubesats. 

Anyway, on another topic, have we fully decided how we’re going to reuse the stages?  I’m thinking chutes for the booster (be them hybrids or liquids) and ballots + chutes for the core (which will go into orbit, so it will also need a heat shield and retro motors, though de-orbiting only takes 150m/s of delta v, so it’s not too much to worry about). Of course we could make the core expendable, but that means we have to build a new one every time we launch, which could quickly get very expensive.

Edited by BillKerman1234

Share this post


Link to post
Share on other sites
6 hours ago, BillKerman1234 said:

Anyway, on another topic, have we fully decided how we’re going to reuse the stages?  I’m thinking chutes for the booster (be them hybrids or liquids) and ballots + chutes for the core (which will go into orbit, so it will also need a heat shield and retro motors, though de-orbiting only takes 150m/s of delta v, so it’s not too much to worry about). Of course we could make the core expendable, but that means we have to build a new one every time we launch, which could quickly get very expensive.

Wait you're already thinking about reusability? From a skeptical point of view, I doubt reuse is possible with at least the early designs. Any stage reuse means adding more equipment and weight to a design we want as light as possible. Even back in the early days, stage reuse was basically a thing that didn't happen because of the extra complexity.

The way I see the current project is that its an experimental prototype rocket, not a viable launch system. If it becomes expensive, so be it.

Share this post


Link to post
Share on other sites
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.