High altitude liquid rocket

[David Schwantz]

Time between some of his replies is 1 minute. Must just be sitting at PC waiting to answer.

 

[G_T]

Even if he is, it's irrelevant.

 

[jsdemar]

Even if he is, it's irrelevant.

It's at least a sign he's still alive.

 

[cbrarick]

hydrogen peroxide, at concentrations that are useful for rockets, is also very dangerous.
and really unhappy when in contact with a multitude of other materials.
Still not a walk in the park.....

at least the op hasn't killed himself with the fuels he wants to use, yet...

 

[Voyager1]

As for h2o2, it isn’t that difficult or scary to work with/make (at least compared to rfna). It’s just a vacuum distillation, or if you have a good heat plate you can heat water just under boiling so it rapidly evaporates (won’t decompose h2o2)

A belated welcome to the forum. However, statements like this don't fill us with any confidence that you know what you're doing! This dismissive attitude to good advice is, at best, naive; and at worst, very dangerous.

A number of members have asked about your level of knowledge and rocketry experience up to deciding that you wish to attempt an extremely challenging liquid-fuelled launch. So far, you have not responded with that information. It is hard for us to take dreams like this seriously when you don't take us on your journey.

Be smart, and be safe!

 

[Neutronium95]

I fly stuff at FAR a decent amount, so I've seen a good number of liquid rocket projects. I also hang out online with several people who work on liquids both in industry and as hobby projects.

Any spaceshot attempt is an extremely ambitious project. Adding on a liquid engine is also going to significantly increase complexity. The highest altitude achieved by an amateur group flying a liquid rocket engine that I know of is UCLA, and they only hit 22,000 feet, or about 6.7 km. There are other university groups with plans to fly higher, most notably Space Concordia with a 40 foot tall behemoth of a rocket intended to break the Karman line, but they have yet to fly.

I would strongly suggest that you do a lot more research before committing to any specific design requirements like final mass or propellant selection. Building some conventional high power rockets and getting your certs won't help too much with the liquid engine part, but will be a great way to learn about every other part of the rocket, from stability to recovery.

Ignition by John Clark has been mentioned a few times, but it it's an informal history of liquid propellant development in the 50s, not a textbook on engine design. From listening to people that know a lot more about liquids than me, Rocket Propulsion Elements by George Sutton and Design of Liquid Propellant Rocket Engines by Huzel and Huang are both well recommended books about engine design.

Finally, I'd strongly suggest taking a look at what's worked for amateur liquid rockets. Most groups are using LOX for their oxidizer, with several different fuels. Half Cat Rocketry has been doing some amazing work with low cost rockets using nitrous oxide and alcohol. You'll find very few people using RFNA or H2O2 in this day and age.

Please take things slowly and make realistic goals. A several hundred kilo rocket flying to several hundred kilometers is well outside the scope of anything I'd call amateur. Launching a liquid rocket to space is probably possible, but it would require a group that has significant experience with flying liquid engines on a smaller scale. Please stay safe and find someone who has experience to help you, I've seen some absolutely terrifying "liquid rocket engines" posted online built by teenagers who thought they knew everything.

 

[techrat]

I think the real question is: Does the OP have access to a machine shop and/or is a machinist? You cannot build a liquid fueled rocket with off the shelf parts, and unless his 3-D printer prints titanium, it's not happening. I believe the guy's name was Mark Pauline, who built fire-breathing robots back in the 1980's was building himself a rocket engine, and blew off many fingers from one of his hands. Currently, the OP hasn't even created a Sugar motor, which is fairly simplistic compared to liquid-fueled or even hybrid engines, so, he's a long way off. Mythbusters built a hybrid rocket for their "Civil War Rocket" myth, and that was two experienced professionals with a full safety team and they still ran into issues.

 

[rocket_troy]

I fly stuff at FAR a decent amount, ....

Excellent advice!

Only thing I would change is to list Huzel and Huang 1st. That's the go-to reference for liquids.

TP

 

[dhbarr]

Ignition by John Clark has been mentioned a few times, but it it's an informal history of liquid propellant development in the 50s, not a textbook on engine design. From listening to people that know a lot more about liquids than me, Rocket Propulsion Elements by George Sutton and Design of Liquid Propellant Rocket Engines by Huzel and Huang are both well recommended books about engine design.

Chiaverini & Kuo for hybrids, right? I've been looking for a similarly comprehensive treatment dedicated to solids, but no joy.

 

[techrat]

Of course, if you're really looking to get a start with liquid fueled rockets, right here is a good place to start:

 

[Neutronium95]

Of course, if you're really looking to get a start with liquid fueled rockets, right here is a good place to start:

Please don't replicate any of Goddard's early designs. Using boil off from your oxidizer tank to pressurize your fuel is more than a little bit sketchy...

 

[zburnt]

A belated welcome to the forum. However, statements like this don't fill us with any confidence that you know what you're doing! This dismissive attitude to good advice is, at best, naive; and at worst, very dangerous.

A number of members have asked about your level of knowledge and rocketry experience up to deciding that you wish to attempt an extremely challenging liquid-fuelled launch. So far, you have not responded with that information. It is hard for us to take dreams like this seriously when you don't take us on your journey.

Be smart, and be safe!

Thanks. I totally could be wrong, but I have done more research on high test h2o2 since I posted and I haven’t seen any evidence it is more or less dangerous than boiling water. Afaik as long as you don’t get it on you it should be fine. I know that storing it is a little more challenging because of not having it decompose and bubble. As for my experience, I think I have said this in other posts, with rocketry, none. However, my current goal (and the goal I would like this post to be about) is to just make a 500-1000 N total impulse engine. It would only be static fired. I also am working on other rocketry projects with commercial motors.

As for the reason I’m not using lox is I don’t want to have to do cryo. If anyone has a safer oxidizer then h2o2 that isn’t cryogenic, I would greatly appreciate recommendations

 

[BDB]

Check out these guys. They are methodically working on developing a reliable liquid motor for the amateur rocketeer community.

https://www.halfcatrocketry.com/
And please be very careful with concentrated H2O2 or fuming HNO3. I’m a PhD chemist (so is Terry, the professor who replied previously) and I would not feel comfortable handling either of those chemicals in my very well-equipped lab for a project like this.

 

[rocket_troy]

Chiaverini & Kuo for hybrids, right? I've been looking for a similarly comprehensive treatment dedicated to solids, but no joy.

Have you tried Fundamentals of Solid Propellant Combustion? Also Kuo, and similar layout.

TP

 

[rocket_troy]

Thanks. I totally could be wrong, but I have done more research on high test h2o2 since I posted and I haven’t seen any evidence it is more or less dangerous than boiling water. Afaik as long as you don’t get it on you it should be fine. I know that storing it is a little more challenging because of not having it decompose and bubble. As for my experience, I think I have said this in other posts, with rocketry, none. However, my current goal (and the goal I would like this post to be about) is to just make a 500-1000 N total impulse engine. It would only be static fired. I also am working on other rocketry projects with commercial motors.

As for the reason I’m not using lox is I don’t want to have to do cryo. If anyone has a safer oxidizer then h2o2 that isn’t cryogenic, I would greatly appreciate recommendations

As has been mentioned, you'll do well to find a commercial source of HTP.

50%, no probs, but you'll have to concentrate it and that can be dangerous if done incorrectly and/or without good care. And the stabilisers in there might need removal if you're passing through a catalyst pack you wish to reuse.

There have been incidents with it in concentrated form (aside from Subs and Torpedos). Gilmour's (probably the largest current users of it) experienced an incident a few year ago that resulted in no fatalities, but significant fire and damage. That (apparently) was a storage issue.

The other obvious oxidizer is N2O. Again, it has its issues too, but is perhaps the easiest to handle from the choice of it, NA and HTP. LOX is by far the safest to handle in large quantities, but there's the cryo thing.

TP

 

[bjphoenix]

Please don't replicate any of Goddard's early designs. Using boil off from your oxidizer tank to pressurize your fuel is more than a little bit sketchy...

Reading this thread I've been thinking that the OP will be repeating Goddard's work to some extent. He would have the benefit of knowing somewhat in general what the end result would be, it sounds like he is trying to build his own Aerobee-Hi. I can't imagine how long or how many millions of dollars this could take.

If worked through methodically, he would have to build a motor, build a test stand, build some instrumentation, then test it. Goddard ended up in the middle of nowhere in New Mexico because he couldn't test even small motors in the more populated area where he lived. That was 100 years ago, it would be even worse today. It would be a pretty monumental effort to build a working motor, that would have to go through numerous iterations. He couldn't build the actual rocket and start thinking about where to launch it and get permits and so forth.

While I think it would be fun to develop a real liquid fuel engine, I think it would be a lot more expeditious to build a large hybrid.

 

[zburnt]

As has been mentioned, you'll do well to find a commercial source of HTP.

50%, no probs, but you'll have to concentrate it and that can be dangerous if done incorrectly and/or without good care. And the stabilisers in there might need removal if you're passing through a catalyst pack you wish to reuse.

There have been incidents with it in concentrated form (aside from Subs and Torpedos). Gilmour's (probably the largest current users of it) experienced an incident a few year ago that resulted in no fatalities, but significant fire and damage. That (apparently) was a storage issue.

The other obvious oxidizer is N2O. Again, it has its issues too, but is perhaps the easiest to handle from the choice of it, NA and HTP. LOX is by far the safest to handle in large quantities, but there's the cryo thing.

TP

Thanks so much. I do have one oxidizer option that hasn’t been mentioned. On this site Here it mentions gaseous oxygen. Is this a viable option for non cryo needs, safety, and easiness to store

 

[dhbarr]

Thanks so much. I do have one oxidizer option that hasn’t been mentioned. On this site Here it mentions gaseous oxygen. Is this a viable option for non cryo needs, safety, and easiness to store

GOX is pretty normal for a benchtop demonstrator.

 

[zburnt]

Reading this thread I've been thinking that the OP will be repeating Goddard's work to some extent. He would have the benefit of knowing somewhat in general what the end result would be, it sounds like he is trying to build his own Aerobee-Hi. I can't imagine how long or how many millions of dollars this could take.

If worked through methodically, he would have to build a motor, build a test stand, build some instrumentation, then test it. Goddard ended up in the middle of nowhere in New Mexico because he couldn't test even small motors in the more populated area where he lived. That was 100 years ago, it would be even worse today. It would be a pretty monumental effort to build a working motor, that would have to go through numerous iterations. He couldn't build the actual rocket and start thinking about where to launch it and get permits and so forth.

While I think it would be fun to develop a real liquid fuel engine, I think it would be a lot more expeditious to build a large hybrid.

What is the reason I couldn’t do it at a large ish launch site. Especially if I do it remotely and with not large amounts of fuel. (So the tanks won’t explode). I definitely think at almost all to all sites it would be a no-no with even approaching explosive levels of fuel. But if I used small amounts to at least iterate designs over short periods of time before going through the long process of finding somewhere I could do a larger test. I am fairly sure I couldn’t even do this, but would like it confirmed.

 

[dhbarr]

Have you tried Fundamentals of Solid Propellant Combustion? Also Kuo, and similar layout.

Looks good, will have to keep an eye out for a copy.

 

[rocket_troy]

Thanks so much. I do have one oxidizer option that hasn’t been mentioned. On this site Here it mentions gaseous oxygen. Is this a viable option for non cryo needs, safety, and easiness to store

*For ground testing*: absolutely! It's not a practical oxidizer for flight due to its density, but for developing a feel for liquids and plumbing and chambers and maybe regen cooling - I would recommend it.

You're actually asking all the right questions, just doing it in the wrong place - and that's not a dig at the responders. No doubt there's a certain level of fatigue responding to the monthly "I wanna/gonna build a kewl liquid rocket" fad-boys that come and go like... well.. you know.

TP

 

[zburnt]

*For ground testing*: absolutely! It's not a practical oxidizer for flight due to its density, but for developing a feel for liquids and plumbing and chambers and maybe regen cooling - I would recommend it.

TP

That’s all my initial few iterations would be so I’ll look into that. Thanks for confirming.

 

[rocket_troy]

That’s all my initial few iterations would be so I’ll look into that. Thanks for confirming.

https://www.propulsionlabs.com.au/Gox_Methanol_Test/Sunday_Hot_Test1.mp4

Small GOX:Methanol engine test I assisted with years ago. Regen cooling using the methanol. The nozzle & engine were good to touch immediately post firing.

TP

 

[bjphoenix]

What is the reason I couldn’t do it at a large ish launch site.

I don't know what the practical limitations might be. Goddard's first rocket was relatively small but apparently loud enough that his neighbors didn't like it. There are parts of the US that have a whole lot of nothing and if you could find a landowner that would allow it you could do tests there. Public land such as BLM might be a different matter because they probably have regulations against it. To actually launch a big rocket would be even harder because now you have to get FAA clearance and apparently lots of deserts have restricted airspace above them.

 

[cls]

What is the reason I couldn’t do it at a large ish launch site. Especially if I do it remotely and with not large amounts of fuel.

No NAR club will let you anywhere near their site. The insurance doesn't cover this activity, for one thing.

TRA, depends on the club, I guess. But it seems unlikely.

You didn't say where you live?

Oh, by the way, learn the difference between explosion and deflagration, and use the proper term

 

[tsmith1315]

No NAR club will let you anywhere near their site. The insurance doesn't cover this activity, for one thing.

TRA, depends on the club, I guess. But it seems unlikely.

From the TRA Safety Code:

 

[zburnt]

Yeah. I would assume a static fire of a rocket engine may be ruled differently than a launch because there isn’t the risk of the engine failing. However, it could deflagrate on the ground which would be a large safety concern.

 

[tsmith1315]

I would assume a static fire of a rocket engine may be ruled differently than a launch because there isn’t the risk of the engine failing.

Not without satisfying 10-9 first.

 

[ksaves2]

I fly stuff at FAR a decent amount, so I've seen a good number of liquid rocket projects. I also hang out online with several people who work on liquids both in industry and as hobby projects.

Any spaceshot attempt is an extremely ambitious project. Adding on a liquid engine is also going to significantly increase complexity. The highest altitude achieved by an amateur group flying a liquid rocket engine that I know of is UCLA, and they only hit 22,000 feet, or about 6.7 km. There are other university groups with plans to fly higher, most notably Space Concordia with a 40 foot tall behemoth of a rocket intended to break the Karman line, but they have yet to fly.

I would strongly suggest that you do a lot more research before committing to any specific design requirements like final mass or propellant selection. Building some conventional high power rockets and getting your certs won't help too much with the liquid engine part, but will be a great way to learn about every other part of the rocket, from stability to recovery.

Ignition by John Clark has been mentioned a few times, but it it's an informal history of liquid propellant development in the 50s, not a textbook on engine design. From listening to people that know a lot more about liquids than me, Rocket Propulsion Elements by George Sutton and Design of Liquid Propellant Rocket Engines by Huzel and Huang are both well recommended books about engine design.

Finally, I'd strongly suggest taking a look at what's worked for amateur liquid rockets. Most groups are using LOX for their oxidizer, with several different fuels. Half Cat Rocketry has been doing some amazing work with low cost rockets using nitrous oxide and alcohol. You'll find very few people using RFNA or H2O2 in this day and age.

Please take things slowly and make realistic goals. A several hundred kilo rocket flying to several hundred kilometers is well outside the scope of anything I'd call amateur. Launching a liquid rocket to space is probably possible, but it would require a group that has significant experience with flying liquid engines on a smaller scale. Please stay safe and find someone who has experience to help you, I've seen some absolutely terrifying "liquid rocket engines" posted online built by teenagers who thought they knew everything.

At this point, I'm pretty sure we're getting trolled... no pics of what he's "working on".

Yup,
A troll. I wouldn't mind if it was a University or College based group of engineer students, Phd's or otherwise doing this as they would follow the rules to launch from an appropriate "gubbermint" site over the ocean into "no where". As such, this troll just started posting B.S. about a "liquid" motor that yanked a lot of legitimate fliers chains who follow established flying rules with APCP motors!!!
If legitimate, it would have listed the school(s), professor(s) and skilled rocketeers who were mentoring such students to achieve such a task with a liquid rocket propelled motor. Pure B.S. as far as I'm concerned. Kurt Savegnago

 

[Neutronium95]

Yup,
A troll. I wouldn't mind if it was a University or College based group of engineer students, Phd's or otherwise doing this as they would follow the rules to launch from an appropriate "gubbermint" site over the ocean into "no where". As such, this troll just started posting B.S. about a "liquid" motor that yanked a lot of legitimate fliers chains who follow established flying rules with APCP motors!!!
If legitimate, it would have listed the school(s), professor(s) and skilled rocketeers who were mentoring such students to achieve such a task with a liquid rocket propelled motor. Pure B.S. as far as I'm concerned. Kurt Savegnago

Not a troll, just someone who has an ambitious idea and no idea of the actual complexity involved. You see them a lot more in other rocketry communities that young people will tend to find before TRF. I typically see them either trying to build a TVC rocket, after seeing a few BPS.space videos, or making super sketchy sugar motors after seeing the a YouTube video with absolutely horrible instructions on how to build them.

Unless there is an imminent safety risk, like with a poorly designed and built sugar motor that they intend to light with a fuse and stand 10 feet away, I generally prefer to nudge them towards NAR and Tripoli clubs. I know of several teenagers who showed up in various online rocketry communities with various terrible motors who now have Jr. L1 certs and are working on interesting projects with experienced mentors.