Project Blacksky 200K two stage - Class 3 submitted!

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If you were to pull this off in time for flight by the end of this year I think the best launch event would be BALLS seeing as they have had 300kft+ waivers and that would save a lot of time and headaches with trying to get your own wavier.

Balls may also offer a larger radius than 10 miles. Here are a few thoughts on the approval process (your mileage may vary) ....

If I took this project for Tripoli approval at Balls, I would expect it to be rejected at some altitude point. I don't know if that altitude would be 150K, 200K or 250K, but it would happen somewhere within that range. That's the reason that I'm working on a stabilization approach - to get approval for a flight like this (plus it's a fun project!). If you took the project for approval at Balls, your chances of approval would be significantly lower than mine.

If I took this project for Tripoli approval at a different launch with a 10-mile radius, and we assume 200K, I would expect the flight to be rejected. The odds of landing outside of 10 miles are much higher than within 10 miles. My 118K project was pretty straight and I still landed 9 miles out. There is a slight chance that with stabilization, a flight could be approved, but I would expect to have to show proof of effectiveness and a very sound plan. If you took the project for approval (200K with 10 miles), your chances of approval would be zero.

I don't speak for Tripoli on this subject, but I'm sure they will do what's necessary to protect the venue. If there is another irresponsible flight there, we will likely lose access, and then we can all make plans to visit Bob's unambiguous splash zone at some Govt. facility.

Jim
 
I have to agree with Jim I the issue of approval. You need either active guidance like he is working on it spin stabilization.
 
Well that does suck and SW does not come cheap nor ANSYS. RAS for Cd is better than nothing, I suppose. If you were to pull this off in time for flight by the end of this year I think the best launch event would be BALLS seeing as they have had 300kft+ waivers and that would save a lot of time and headaches with trying to get your own wavier. That of course would require you to break your relationship with AeroPac launches but if everything else works out for you then this might be the best option to actually get it in the air.

I just read the ISC part of your write up and it appears your ISC design is to primarily minimize overall length of the vehicle. However I do think that to add ~3-6" to the overall length at the cost of saving thousands of dollars is a game changer. You can use the sustainer motor as the stack coupler and you will not gain much space over your current design as a result. Yes you will have some new design hurdles (stability one of them) but nothing to hard to design around. Any altitude losses due to this change would be "up in the air," with your predicted forecasts. Also if you want lightweight ( as you previously mentioned) go with composites for the material selection of the ISC, it can be done. On that note your sustainer fins do not need to be Ti and your booster fins are over designed being 0.157" thick plus the 10 layers (5 on each side) of tip-to-tip. My point? I think you have trade offs that you can do to save money, decrease time, and keep altitude to approximately the same but YOU will have to work harder with the changes.

Hmm, I was unaware of AHPRA's waiver standings, but I will look into them. This may prove useful indeed if they already have the ceiling, but per RocksimPro Monte Carlo distribution results (which I have asked for a few times from a friend and have yet to receive, Ill ask again today) I may very well need a cylinder expansion perhaps up to 20 miles instead of 10. TRA Class3 committee can most likely aid me in the logistics of that, I think. Not sure how easy it might be, though, given as Jim had stated, Black Rock is huge but not THAT huge. 20 miles puts Gerlach and Empire on the edge of the fall zone. No bueno. Ill have a look into it for sure.

Okay I think everyone who is trying to tell me to use the motor as a coupler is not fully understanding what Im trying to say- Yes, guys, I realize that using tongues is extremely expensive. BUT IT HAS BEEN DONE FOR CHEAP BEFORE. There ARE ways to design it to be very similar to what I have, and per the result of the step DMLS quote if I can get that in the next few days, I will be right back here on AutoCAD redrawing and redrawing and redrawing untill I find a shape that satisfies and is easy enough to produce. Again, it has been done before very similar to my design.

I really do NOT want to use the motor as a coupler. It wouldnt be a hard stability workaround, it would be a nearly IMPOSSIBLE stability workaround given the M2245's fast burn.
DOING SO DRASTICALLY SHIFTS CP FORWARD RELATIVE TO CG RANGE. This dramatically reduces stability unless fin size is increased. WITH FIN SIZE INCREASE comes lowered divergence and flutter velocitieis. Thus requiring STRONGER or thicker materials, aka more expensive, unless I were to use straight up steel, which is very heavy, and Im honestly not even sure if I could make that stay stable realistically. With using the motor as a coupler into the IST instead of using any sort of tongues, you basically let the motor hang 6 to 8 to 10 inches behind the fins. No. Bueno.
The M2245 simply pushes the sustainer TOO FAST for this to be a viable design method.
For the sake of discussion, if I were to do this method, I wouldnt even need a fincan sleeve. I could theoretically use carbon fins and t-t, bonded to airframe and friction fit those suckers on and hope they didnt come sliding off the back in flight. Why not do this? Carbon wouldnt survive the speed, and the vehicle wouldnt be stable at the speed. I would be forced to use a longburn motor. aka shorter motor with less impulse, go slower, and a lot lower. Aka, a whole new project essentially.

Why use .15 cores with 5 layers of bagged t-t for my booster? Because per simulation, that sucker is going to be doing upwards of mach 2.5 at the top of the boost, around 8,000ft MSL. This is a lot of aerodynamic stress on a 4 inch diameter's fins. Note how many 98mm rockets shredded from poor fin construction at these exact same conditions in the past. Overbuilt is under built in the case of a vehicle designed to go this fast. I am confident that this will suffice for booster tail construction.
Food for thought - my original Dragonplate quote came back at $600 for STANDARD 0/90 plate fins with a diamond airfoil added to them by Dragonplate. Needless to say, I will just be having them do quasi-isotropic cores and I will add the beveling myself on a 3 axis mill. It's really easy with a 5 degree jig you can cut on a table saw in 15 seconds.


Balls may also offer a larger radius than 10 miles. Here are a few thoughts on the approval process (your mileage may vary) ....

If I took this project for Tripoli approval at Balls, I would expect it to be rejected at some altitude point. I don't know if that altitude would be 150K, 200K or 250K, but it would happen somewhere within that range. That's the reason that I'm working on a stabilization approach - to get approval for a flight like this (plus it's a fun project!). If you took the project for approval at Balls, your chances of approval would be significantly lower than mine.

If I took this project for Tripoli approval at a different launch with a 10-mile radius, and we assume 200K, I would expect the flight to be rejected. The odds of landing outside of 10 miles are much higher than within 10 miles. My 118K project was pretty straight and I still landed 9 miles out. There is a slight chance that with stabilization, a flight could be approved, but I would expect to have to show proof of effectiveness and a very sound plan. If you took the project for approval (200K with 10 miles), your chances of approval would be zero.

I don't speak for Tripoli on this subject, but I'm sure they will do what's necessary to protect the venue. If there is another irresponsible flight there, we will likely lose access, and then we can all make plans to visit Bob's unambiguous splash zone at some Govt. facility.

Jim

Why would everyone agree that automated trajectory control is mandatory? Lets take a look at all the rockets that busted the waiver. What did they all have in common? Lack of tiltometers to stop them from staging at 5-10D off-vertical. Where did they apogee? At the edge or beyond the waiver.
Jim, where did FourCarbYen apogee in terms of distance to the edge of the waiver? Damn near the center, right? Am I mistaken to conclude that lateral distance was accumulated primarily during DESCENT, where said trajectory control devices would have no effect anyway?

Again, I am waiting on RSpro Monte Carlo distribution results from someone who has it, or my friend that I had asked a while ago, but I wouldnt doubt TRA will require more than a standard 10 mile waiver. This being said, I wouldnt go so far as to say theyre going to put a stop to my flight without the addition of trajectory control devices, given Im atleast flying a device which will actuate or inhibit staging based on trajectory at staging.
I just cant support the concept that it is necessary to add several inches and several pounds to the rocket to do something that it shouldn't need, if allowed to stage only at the proper angle. I can forsee tumbling once the air density gets close to nil, but i cannot forsee any sort of lateral distance gain as a result of this tumbling. The ONLY thing I can see making a difference here is whether or not I allow my sustainer to light when it is already beginning a gravity turn. The stability control devices you were mentioning would for sure make a difference up to this point, but after staging, it matters more the overall trajectory angle of flight, not the angle of attack. I could see how your canard project could indeed fix overall trajectory angle (provided enough atmo to be effective), but spin stabilization would only help to hold a fixed angle of attack... (right?)
This may sound like an elementary question, but is there a way to force OR to add a tilt angle to my sustainer upon ignition, for the sake of simulating lateral distance accumulation from there on? Perhaps as the result of a gust... I can tell you that OpenRocket predicts a ground hit over 45 miles away when launched starting 10 degrees from vertical on the ground. 25 miles when at 5 degrees, and 3 miles when at a perfect 0 degrees. We can assume with the use of levels that the launch rail can be made a perfect 0, but none of us can forecast exactly what the sustainer will do when it comes time to light the motor. The only thing we CAN do is establish what should be an ACCEPTABLE deviance from vertical, and install that as a gate to sustainer ignition in the telemega, OR install trajectory control devices which add space and weight to the rocket..... I hope you can see where Im trying to go with this.
So lets get down and dirty with it. How can we take a more in depth look at sustainer ignition angles and their results on lateral distance? How do we then factor this in to Monte Carlo distribution results to produce a reasonably accurate landing range?
 
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You need the software to do the distribution. You need to use the numbers for deviation setup used by TRA Class 3 committee. The software will run the sim based on those factors. You need to run at least a thousand iterations to get it to a the .999 that that the FAA runs. Considering the projected performance more is better.

Frankly, I would build your Rocksim of this and start talking to TRA class 3 committee before building. This is an extreme project, and they have tools and knowledge of simulation and regs you likely do not. So, I would contact Kent Newman sooner rather than later. Remember 90 days is a minimum and more is always appreciated by the committee.
 
I really do NOT want to use the motor as a coupler. It wouldnt be a hard stability workaround, it would be a nearly IMPOSSIBLE stability workaround given the M2245's fast burn.
DOING SO DRASTICALLY SHIFTS CP FORWARD RELATIVE TO CG RANGE. This dramatically reduces stability unless fin size is increased. WITH FIN SIZE INCREASE comes lowered divergence and flutter velocitieis. Thus requiring STRONGER or thicker materials, aka more expensive, unless I were to use straight up steel, which is very heavy, and Im honestly not even sure if I could make that stay stable realistically. With using the motor as a coupler into the IST instead of using any sort of tongues, you basically let the motor hang 6 to 8 to 10 inches behind the fins. No. Bueno.

The M2245 simply pushes the sustainer TOO FAST for this to be a viable design method.

False. I am further along on a similar project than you are, N5800 -> M2245. I have actually gotten passed the computer phase and it is with the sustainer motor acting as the coupler. All sims agree it was viable with +1 calibers of stability at max velocity. You do not need it to hang as far as you have quoted. My sims were maxing out at 190kft altitude (not saying I thought that is what it would of done) and that was without "tweaking it," for the record. I have since abandoned this project in favor of a single stage attempt. I only bring this is up because you seem to be making a lot of misinformed decisions, when in reality you do have viable alternative options. But of course design it how you want just giving you a alternative method to bring costs and time down to make this even a possible project. If you end up being able to go the prong route it will be very interesting as that was something I had originally looked into about 2 years ago. Best of luck.


Carbon wouldnt survive the speed, and the vehicle wouldnt be stable at the speed. I would be forced to use a longburn motor. aka shorter motor with less impulse, go slower, and a lot lower. Aka, a whole new project essentially.

That is also false, maybe you mean you cannot build composite fins to survive. You have not ran any FEA or CFD's to make that call, fin sim alone should not be the basis for that decision. It appears that you are in part basing your opinions on others failed attempts, most of which did not understand what they were really attempting. Composite fins have experienced similar loads at lower altitudes and survived. Furthermore I do not think USCRPL would use composite fins on their vehicle expected to go M5-M6 if there was any doubt to their survival. I bring them up because they have access to more "intellectual," and design capabilities than most of us on here. There is more to flutter and divergence than geometries and btw I would be more worried about dealing with the heating and keeping them on properly.


Why use .15 cores with 5 layers of t-t for my booster? Because per simulation, that sucker is going to be doing upwards of mach 2.5 at the top of the boost, around 8,000ft MSL. This is a lot of aerodynamic stress on a 4 inch diameter's fins. Note how many 98mm rockets shredded from poor fin construction at these exact same conditions in the past. Overbuilt is under built in the case of a vehicle designed to go this fast. I am confident that this will suffice for booster tail construction.
Food for thought - my original Dragonplate quote came back at $600 for STANDARD 0/90 plate fins with a diamond airfoil added to them by Dragonplate. Needless to say, I will just be having them do quasi-isotropic cores and I will add the beveling myself on a 3 axis mill. It's really easy with a 5 degree jig you can cut on a table saw in 15 seconds.

So you do not know what the loads will be and therefore are over building it to "fingers crossed," survive. Prophecy and I, recently launched a 4 inch all composite rocket with 3 swept back fins to ~M2.5 at about the same altitude... it survived without any tip-to-tip or carbon just fillets! The fins were all fiberglass. Last year we also flew a 3 mammoth sized FG core fin on a 4" vehicle with 3 layers of tip-to-tip to ~ Mach 2.8 at a lower altitude, survived. Thinner composite fins have survived much more extreme flights than your booster will ever see. You can make the fins yourself for a fraction of the cost. Why is most of your project out sourced? You can save a considerable amount by doing some of the work yourself.



Why would everyone agree that trajectory control is mandatory? Lets take a look at all the rockets that busted the waiver. What did they all have in common? Lack of tiltometers to stop them from staging at 5-10D off-vertical. Where did they apogee? At the edge or beyond the waiver.
Jim, where did FourCarbYen apogee in terms of distance to the edge of the waiver? Damn near the center, right? Am I mistaken to conclude that lateral distance was accumulated primarily during DESCENT, where said trajectory control devices would have no effect anyway?

Again, I am waiting on RSpro Monte Carlo distribution results from someone who has it, or my friend that I had asked a while ago, but I wouldnt doubt TRA will require more than a standard 10 mile waiver. This being said, I wouldnt go so far as to say theyre going to put a stop to my flight without the addition of trajectory control devices, given Im atleast flying a device which will actuate or inhibit staging based on trajectory at staging.


18095467081_a1e722b0fb.jpg

Here is Jim's GPS KML screen shot. Without going into detail and analyzing it, looks like ~half the lateral distance was accumulated during the descent, meaning there was quite a bit of lateral distance travelled during ascent.

Monte Carlo dispersion analysis is key to approval; you are aware that TRA will do this themselves when you apply? Get in touch with Kent. I know BALLS has had a 15 mile radius and altitude wavier to 491kft. You are not going to have a 90 degree flight. When and if your sustainer lights it will not be at 90 degrees. During the action and coast phase it will go further down range (most likely). During the whole descent you will drift further. You made a assumption that Jim's flight was relatively straight and yet he splashed down ~9 miles out.... you are expecting 100kft more than him! So maybe the reason people think it is necessary to have a method of trajectory control is for a more predictable and accurate splash zone. Even though you will be able to prohibit sustainer ignition if it goes over x degrees from vertical you will still have to show that it will not drift outside of the wavier (even if it is only during the descent), which is something that a device that inhibits staging based on trajectory cannot do.
 
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Why would everyone agree that automated trajectory control is mandatory? Lets take a look at all the rockets that busted the waiver. What did they all have in common? Lack of tiltometers to stop them from staging at 5-10D off-vertical. Where did they apogee? At the edge or beyond the waiver.
Jim, where did FourCarbYen apogee in terms of distance to the edge of the waiver? Damn near the center, right? Am I mistaken to conclude that lateral distance was accumulated primarily during DESCENT, where said trajectory control devices would have no effect anyway?

I believe apogee on my flight was about 6 miles out.

Tilt detection is helpful in keeping things from getting too out of hand. However, like everything else in rocketry, you need to understand how the instrumentation works. At the moment, you are assuming everything will work as it appears at face value. It is not that simple.

Jim
 
info only.

AeroPac's 2015 waiver is a standing 150k 9Nm radius (site B).

We also have 2 hour windows to 200k 17 Nm (site B+) at 9-11am on the following days June 20, Aug 1 and September 15, 17, and 19.

Tony Alcocer
AeroPac
 
Hmm, I was unaware of AHPRA's waiver standings, but I will look into them. This may prove useful indeed if they already have the ceiling, but per RocksimPro Monte Carlo distribution results (which I have asked for a few times from a friend and have yet to receive, Ill ask again today) I may very well need a cylinder expansion perhaps up to 20 miles instead of 10. TRA Class3 committee can most likely aid me in the logistics of that, I think. Not sure how easy it might be, though, given as Jim had stated, Black Rock is huge but not THAT huge. 20 miles puts Gerlach and Empire on the edge of the fall zone. No bueno. Ill have a look into it for sure.

Okay I think everyone who is trying to tell me to use the motor as a coupler is not fully understanding what Im trying to say- Yes, guys, I realize that using tongues is extremely expensive. BUT IT HAS BEEN DONE FOR CHEAP BEFORE. There ARE ways to design it to be very similar to what I have, and per the result of the step DMLS quote if I can get that in the next few days, I will be right back here on AutoCAD redrawing and redrawing and redrawing untill I find a shape that satisfies and is easy enough to produce. Again, it has been done before very similar to my design.

I really do NOT want to use the motor as a coupler. It wouldnt be a hard stability workaround, it would be a nearly IMPOSSIBLE stability workaround given the M2245's fast burn.
DOING SO DRASTICALLY SHIFTS CP FORWARD RELATIVE TO CG RANGE. This dramatically reduces stability unless fin size is increased. WITH FIN SIZE INCREASE comes lowered divergence and flutter velocitieis. Thus requiring STRONGER or thicker materials, aka more expensive, unless I were to use straight up steel, which is very heavy, and Im honestly not even sure if I could make that stay stable realistically. With using the motor as a coupler into the IST instead of using any sort of tongues, you basically let the motor hang 6 to 8 to 10 inches behind the fins. No. Bueno.
The M2245 simply pushes the sustainer TOO FAST for this to be a viable design method.
For the sake of discussion, if I were to do this method, I wouldnt even need a fincan sleeve. I could theoretically use carbon fins and t-t, bonded to airframe and friction fit those suckers on and hope they didnt come sliding off the back in flight. Why not do this? Carbon wouldnt survive the speed, and the vehicle wouldnt be stable at the speed. I would be forced to use a longburn motor. aka shorter motor with less impulse, go slower, and a lot lower. Aka, a whole new project essentially.

Why use .15 cores with 5 layers of bagged t-t for my booster? Because per simulation, that sucker is going to be doing upwards of mach 2.5 at the top of the boost, around 8,000ft MSL. This is a lot of aerodynamic stress on a 4 inch diameter's fins. Note how many 98mm rockets shredded from poor fin construction at these exact same conditions in the past. Overbuilt is under built in the case of a vehicle designed to go this fast. I am confident that this will suffice for booster tail construction.
Food for thought - my original Dragonplate quote came back at $600 for STANDARD 0/90 plate fins with a diamond airfoil added to them by Dragonplate. Needless to say, I will just be having them do quasi-isotropic cores and I will add the beveling myself on a 3 axis mill. It's really easy with a 5 degree jig you can cut on a table saw in 15 seconds.




Why would everyone agree that automated trajectory control is mandatory? Lets take a look at all the rockets that busted the waiver. What did they all have in common? Lack of tiltometers to stop them from staging at 5-10D off-vertical. Where did they apogee? At the edge or beyond the waiver.
Jim, where did FourCarbYen apogee in terms of distance to the edge of the waiver? Damn near the center, right? Am I mistaken to conclude that lateral distance was accumulated primarily during DESCENT, where said trajectory control devices would have no effect anyway?

Again, I am waiting on RSpro Monte Carlo distribution results from someone who has it, or my friend that I had asked a while ago, but I wouldnt doubt TRA will require more than a standard 10 mile waiver. This being said, I wouldnt go so far as to say theyre going to put a stop to my flight without the addition of trajectory control devices, given Im atleast flying a device which will actuate or inhibit staging based on trajectory at staging.
I just cant support the concept that it is necessary to add several inches and several pounds to the rocket to do something that it shouldn't need, if allowed to stage only at the proper angle. I can forsee tumbling once the air density gets close to nil, but i cannot forsee any sort of lateral distance gain as a result of this tumbling. The ONLY thing I can see making a difference here is whether or not I allow my sustainer to light when it is already beginning a gravity turn. The stability control devices you were mentioning would for sure make a difference up to this point, but after staging, it matters more the overall trajectory angle of flight, not the angle of attack. I could see how your canard project could indeed fix overall trajectory angle (provided enough atmo to be effective), but spin stabilization would only help to hold a fixed angle of attack... (right?)
This may sound like an elementary question, but is there a way to force OR to add a tilt angle to my sustainer upon ignition, for the sake of simulating lateral distance accumulation from there on? Perhaps as the result of a gust... I can tell you that OpenRocket predicts a ground hit over 45 miles away when launched starting 10 degrees from vertical on the ground. 25 miles when at 5 degrees, and 3 miles when at a perfect 0 degrees. We can assume with the use of levels that the launch rail can be made a perfect 0, but none of us can forecast exactly what the sustainer will do when it comes time to light the motor. The only thing we CAN do is establish what should be an ACCEPTABLE deviance from vertical, and install that as a gate to sustainer ignition in the telemega, OR install trajectory control devices which add space and weight to the rocket..... I hope you can see where Im trying to go with this.
So lets get down and dirty with it. How can we take a more in depth look at sustainer ignition angles and their results on lateral distance? How do we then factor this in to Monte Carlo distribution results to produce a reasonably accurate landing range?
Even though AHPRA can obtain Class 3 rocket waivers, it is not a blanket waiver and every Class 3 Rocket flight waiver request requires separate FAA approval, and a significant work effort is required for each individual Class 3 rocket application.

You need to read the regulations for Class 3 rocket flights from https://www.ecfr.gov/cgi-bin/text-idx?rgn=div5&node=14:2.0.1.3.15#se14.2.101_125 so that you will understand explicitly the minimum information that must be supplied before a Class 3 waiver request can be submitted.

(b) Class 3—Advanced High-Power Rockets. When a Class 3—Advanced High-Power Rocket requires a certificate of waiver or authorization the person planning the operation must provide the information below for each type of rocket to the FAA at least 45 days before the proposed operation. The FAA may request additional information if necessary to ensure the proposed operations can be safely conducted. The information shall include for each type of Class 3 rocket expected to be flown:(1) The information requirements of paragraph (a) of this section,
(2) Maximum possible range,
(3) The dynamic stability characteristics for the entire flight profile,
(4) A description of all major rocket systems, including structural, pneumatic, propellant, propulsion, ignition, electrical, avionics, recovery, wind-weighting, flight control, and tracking,
(5) A description of other support equipment necessary for a safe operation,
(6) The planned flight profile and sequence of events,
(7) All nominal impact areas, including those for any spent motors and other discarded hardware, within three standard deviations of the mean impact point,
(8) Launch commit criteria,
(9) Countdown procedures, and
(10) Mishap procedures.
[Doc. No. FAA-2007-27390, 73 FR 73781, Dec. 4, 2008, as amended at Doc. No. FAA-2007-27390, 74 FR 31843, July 6, 2009

The above is the minimum information that must be supplied to the FAA before they will consider a waiver request as each flight is decided on its own merits. The FAA could care less about how much money you have or don't have for your project. All they are concerned about is public safety. They need to know where you rocket will land if the flight is successful, and where it will crash if it isn't. They also need the dynamic stability calculations for the entire rocket flight.

https://en.wikipedia.org/wiki/Office_of_Commercial_Space_Transportation provides some further details on who you have to satisfy. If you go to the AST website you can download the exact details.

You don't need CFD or anything fancy to do a few simple calculation on the required strength of you rocket. There is not need to guess. And there is also no reason not to use composite fins for this flight. Properly constructed, they will perform just fine. You are simply not going that fast.

Bob
 
Even though AHPRA can obtain Class 3 rocket waivers, it is not a blanket waiver and every Class 3 Rocket flight waiver request requires separate FAA approval, and a significant work effort is required for each individual Class 3 rocket application.

I believe his project is Class 2. It still requires review by Tripoli but not FAA, and the process is a bit simpler.

Jim
 
Even though AHPRA can obtain Class 3 rocket waivers, it is not a blanket waiver and every Class 3 Rocket flight waiver request requires separate FAA approval, and a significant work effort is required for each individual Class 3 rocket application.

They also need the dynamic stability calculations for the entire rocket flight.

You don't need CFD or anything fancy to do a few simple calculation on the required strength of you rocket. There is not need to guess. And there is also no reason not to use composite fins for this flight. Properly constructed, they will perform just fine. You are simply not going that fast.

Bob


Except his rocket is a class 2 rocket since the sum of his motors is less than 40,960 Newton-seconds as per the the FAA Code of Federal Regulations (CFR), Title 14 Aeronautics and Space, Part 101, Subpart C, 101.22. No? He will however have to go through the internal Tripoli class 3 rocket wavier process (C3RC - which is for class 2 & 3 rockets) seeing as his simulations are over 50kft but he shouldn't have to have a separate FAA approval because per the FAA he is still a class 2 rocket. Is my understanding of the regs not accurate?

How would you go about calculating the temperature of the solid (outside rocket body) and pressure at elevated Mach numbers and then take into account the thermal conduction of the solids and by what margin that can weaken structural components? I am being vague but you get my drift. Not to mention using CFD to accurately calculate Cp and Cd throughout the entire flight and being able to use that to justify spending more money on parts that are "out of the way," and knowing with higher certainty that you will not go unstable. Sure you can come up with some rough rounded numbers... but to do all that and more by hand, no thanks, especially if optimization is goal. You are right though CFD is not required for a FAA class 3 rocket wavier. Anyways CFD will allow someone to make sure their vehicle will be likely to survive and further optimize their vehicle for such a aforementioned flight. Maybe I am just odd but I would like to be able to fine tune all the details on this realm of flight. All I know is that if someone came up to me with their hands out for ~$12k they better know these things with better values than OR, especially since they referenced CFD in their write up.


EDIT: Jim beat me to it.
 
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You are both correct on the Class 2 versus Class 3 however the scrutiny due to the altitude should be similar. I confused that part of this project with another one.

However I've actually looked at the trade-offs required for similar trajectories for SugarShot about 10 years ago, and I know that the 100+ full blown flight simulations the were conducted before a detailed design was developed. Our simulations for sugar propellant indicated that we wanted to accelerate the first stage moderately up to over 5 kft and M~1.5-1.7, and then coast to ~25 kft or so, and then ignite the second motor phase. I also know we wanted spin fins to control the trajectory and minimize the trajectory uncertainty on a high altitude attempt.

From my training and experience I know that the aerodynamic heating is proportional to the product of the atmospheric density and the Mach Number cubed. That's half the reason why you don't want to go to fast too low as the motor power required to attain a given Mach number also is proportional the same product so if you go too fast too low, for all practical purposes you're converting much of the propellant energy into rocket heating....which is the other half of the reason to avoid going too fast too low because excessively heating does not get the altitude you desire if you want to do this project...... The aerodynamic heating at M = 2.5 is 4.6 time more than Mach 1.5, and the heating at Mach 3 is 8 time greater at the same altitude.

So I would first calculate the heat load versus time for the ascent profile of the flight and then determine how much heating the stagnation regions would encounter as all other heat loads are lower. For the SugarShot trajectory, this was about 450 J/cm2 IIRC with a maximum velocity of Mach 5 at ~39 kft. which is nothing for a properly made CF composite. I know CF can handle this because I've conducted wind tunnel tests on commercial aerospace grade CF composites at much higher heating rates......under aerodynamic and compressive loading.......

What I'm suggesting that if the OP wants to attempt to conduct this type of flight, he should do a number of sims to find the optimum flight profile, then develop his design based on the predicted thermal and mechanical strength requirements derived from the flight profile.

Bob
 
I believe apogee on my flight was about 6 miles out.

Tilt detection is helpful in keeping things from getting too out of hand. However, like everything else in rocketry, you need to understand how the instrumentation works. At the moment, you are assuming everything will work as it appears at face value. It is not that simple.

Jim

That's why I like to read these threads. Interesting as all get out even though I don't understand everything. Best regards all, Kurt
 
In regards to the rocket having the most lateral movement on it's decent... I remember seeing a video a while back of a suborbital rocket, perhaps from Up Aerospace or Armadillo Aerospace, that had active guidance on the parachute recovery. From what I remember reading, they had to make sure they set the target GPS location as a slightly away from the launch pad as the guidance was so good it could actually hit the rail as it landed. Now, I do not know anything about the cost or whether it could be miniaturized to fit in this platform. But it may be something worth looking into for attempts this high.

Phil
 
If you lanching at BALLS you will need to go through the TRA Class 3 Committee. If you require a waiver higher than the BALLS waiver they will assist in getting it. We have had waivers to 493k (150km)with a 19 mile radius. For really high stuff. The center of the circle is not the launch site, launch towers are angled to the far edge to give a distance greater than the radius.
If you get your own waiver without the assistance of the TRA C3 committee you will not be allowed to launch.
I am not good with active stabilization in very high performance rockets that has not been tested and flight proven.
Recovery velocity at landing must be 40f/s or less.

Mark Clark
Prefect AHPRA
BALLS Launch Director
TRA 414, Life Member, L3
 
In regards to the rocket having the most lateral movement on it's decent... I remember seeing a video a while back of a suborbital rocket, perhaps from Up Aerospace or Armadillo Aerospace, that had active guidance on the parachute recovery. From what I remember reading, they had to make sure they set the target GPS location as a slightly away from the launch pad as the guidance was so good it could actually hit the rail as it landed. Now, I do not know anything about the cost or whether it could be miniaturized to fit in this platform. But it may be something worth looking into for attempts this high.

Phil

Armadillo Aerospace had active parachute recovery.
 
Armadillo Aerospace had active parachute recovery.

That was it. Just found the youtube video of the recovery. It looks like the company that made the system was Wamore, they included info on who to contact in the description.

[video=youtube;UV7zL07Tof8]https://www.youtube.com/watch?v=UV7zL07Tof8[/video]
 
Armadillo Aerospace had active parachute recovery.

Active recovery or no, I believe they would still want a comprehensive dispersion analysis to assess for less than nominal recovery system performance? I don't believe it's of any use to try and subvert the existing protocols.
I suspect there are "active" guidance rule weenies out there who say it violates active guidance of rockets but I say if it allows for recovery in a defined area, go for it. Kurt
 
I work for SolidWorks and would be interested and available in helping you with any modeling and CFD analysis of the design. Let me know if I can help.
 
False. I am further along on a similar project than you are, N5800 -> M2245. I have actually gotten passed the computer phase and it is with the sustainer motor acting as the coupler. All sims agree it was viable with +1 calibers of stability at max velocity. You do not need it to hang as far as you have quoted. My sims were maxing out at 190kft altitude (not saying I thought that is what it would of done) and that was without "tweaking it," for the record. I have since abandoned this project in favor of a single stage attempt. I only bring this is up because you seem to be making a lot of misinformed decisions, when in reality you do have viable alternative options. But of course design it how you want just giving you a alternative method to bring costs and time down to make this even a possible project. If you end up being able to go the prong route it will be very interesting as that was something I had originally looked into about 2 years ago. Best of luck.

Might I be able to take a glance just to see what the main differences are? Attached is a few >200K capable versions of my original design using the motor as a coupler, carbon fins, and a traditional interstage that could be made easily and on the cheap. They both have a span bump .25 inch, which is deadly in terms of flutter, and the only viable one needs 5 fins.
Notice the 4 finned sustainer's Cp and Cg at high mach. About 0.25 body calibers of stability. No bueno. That will cone, and put all kinds of stress on the fins. I realize that the tongue method is expensive and not what everybody wants, but for now I would like to continue to explore that route of doing it, as I truly think it is a superior coupling method. With an M2245 going this fast, you simply cannot have the fins 6" forward of the ass and still hope to have any sort of stability.

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That is also false, maybe you mean you cannot build composite fins to survive. You have not ran any FEA or CFD's to make that call, fin sim alone should not be the basis for that decision. It appears that you are in part basing your opinions on others failed attempts, most of which did not understand what they were really attempting. Composite fins have experienced similar loads at lower altitudes and survived. Furthermore I do not think USCRPL would use composite fins on their vehicle expected to go M5-M6 if there was any doubt to their survival. I bring them up because they have access to more "intellectual," and design capabilities than most of us on here. There is more to flutter and divergence than geometries and btw I would be more worried about dealing with the heating and keeping them on properly.

So you do not know what the loads will be and therefore are over building it to "fingers crossed," survive. Prophecy and I, recently launched a 4 inch all composite rocket with 3 swept back fins to ~M2.5 at about the same altitude... it survived without any tip-to-tip or carbon just fillets! The fins were all fiberglass. Last year we also flew a 3 mammoth sized FG core fin on a 4" vehicle with 3 layers of tip-to-tip to ~ Mach 2.8 at a lower altitude, survived. Thinner composite fins have survived much more extreme flights than your booster will ever see. You can make the fins yourself for a fraction of the cost. Why is most of your project out sourced? You can save a considerable amount by doing some of the work yourself.

No, I do not know what the loads will be as I was not able to obtain any sort of load testing from SW before I lost access to it. You know of any way I could possibly arrange to have it simulated out for me? Maybe Mattrece can help :)

I have a feeling that my composite fins would not survive. Yes, I know theyve gone faster, like with the HoneyBadger going way fast before a mile. But Ive only pushed 54mm stuff that fast thus far. I was playing around with coremat in the past and it seems pretty promising. I'd think a nice thick carbon core with some coremat and 6K carbon t-t vacuumed with cotronics 4461 oughta hold up. Use 4525 on all the edges and the fillets. Sure, sounds doable (and pricey still) but I just dont want to go experimenting on this particular project. Titanium fins surely will hold up.

I believe apogee on my flight was about 6 miles out.

Tilt detection is helpful in keeping things from getting too out of hand. However, like everything else in rocketry, you need to understand how the instrumentation works. At the moment, you are assuming everything will work as it appears at face value. It is not that simple.

Jim

I suppose, but part of the problem is that I lack access to wind tunnels, endless supplies of carbon to practice with, etc. I just have what I can get, and see online. As it is im real lucky to have CAD, and OR honestly. I dont see how this project could veer too far off as long as it staged, and then burned out going straight, and not coning too hard. I suppose spin stabilization or active canards or gyro would indeed resist it deviating from vertical in the first place, but say we have a stable enough vehicle that we dont need that? What do you think?

I would really love to see some of RsPro’s Monte Carlo distribution, indeed! But I dont have it. Does anyone reading this? Would you be so kind as to run a quick few sims maybe? I know the Class 3 committee can, I just wanted to have a better idea before I even approached them.

What I'm suggesting that if the OP wants to attempt to conduct this type of flight, he should do a number of sims to find the optimum flight profile, then develop his design based on the predicted thermal and mechanical strength requirements derived from the flight profile.

Bob

Why yes thats exactly what I want to do. But I am very limited in what I can do on my own without the appropriate softwares. Referring specifically to thermodynamics and to answer Astro’s question, you would examine the dynamic pressure on the nosecone. Like Bob said, it’s a matter of how fast the vehicle is moving and the density of the air it is moving through. CFD software can give you an energy value, such as Joules over an area, and this can be then plugged in to a model of the intumescence of the material. If the surface temperature is expected to rise and stay high, you can count on the low(er) temp epoxies in the FG nosecone below to begin to reach Tg and weaken. Can this be calculated exactly out and simulated reliably? Probably, but I sure dont know how or how difficult that process would be. All I know is that stagnation temperatures will reach nearly 2000 degrees on my nosecone, so Im going to put a coat of Rx2390 on there, and indeed ‘hope for the best’ . If any of you care to get more down and dirty with the details than that, Im all ears! I just dont know what much else to do on my own. Im no physics or math major.

If you lanching at BALLS you will need to go through the TRA Class 3 Committee. If you require a waiver higher than the BALLS waiver they will assist in getting it. We have had waivers to 493k (150km)with a 19 mile radius. For really high stuff. The center of the circle is not the launch site, launch towers are angled to the far edge to give a distance greater than the radius.
If you get your own waiver without the assistance of the TRA C3 committee you will not be allowed to launch.
I am not good with active stabilization in very high performance rockets that has not been tested and flight proven.
Recovery velocity at landing must be 40f/s or less.

I will go through the class 3 committee as that has been the plan from day1. I am not yet sure exactly when I will launch, as has been stated I would prefer to launch at (previously Aeronaut) XPRS so I dont have to haul a launch rail out, unless someone out at BALLS would be kind enough to let me borrow a 1515 over 16ft tall. I will contact you around the time that I prepare the package for C3 committee and we will chat more about those details. But for now, would I have to prepare the package any differently than I would per the instructions listed on TRA’s website? (Also what Bob was trying to point out. - I havent assembled all of that stuff just yet )

That was it. Just found the youtube video of the recovery. It looks like the company that made the system was Wamore, they included info on who to contact in the description.

VERY VERY COOL!!! That might be something to look into for main, actually, yeah. Ill check it out. My biggest concern though is currently drogue, and finding a small enough one yet durable enough to survive what Im about to put it through..

I work for SolidWorks and would be interested and available in helping you with any modeling and CFD analysis of the design. Let me know if I can help.

Yes! I will for sure hit you up in the next day or two when I get some free time, thanks!
 
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Hello All!

I have been able to successfully secure a reasonable quote for a job of the single piece interstage-transition part from a cool company called Nextline. I will be working closely with them for the next few days to secure quotes for the fincan as well, as they have assured me they can work with 6al-4v Ti.

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Moving forward, this weekend I will finalize the models for the 3D printed components. I need to take a trip to an electronics store and get dimensions of the smallest pull-type solenoid I can find. This is for the port system.

Another thing I need a better model of is a Rouse-Tech CD3 Unit as would be attatched to a shock cord. I have a general model of one, but it lacks a few true and accurate dimensions. Recovery space is on my mind. I would be fine with a drogueless setup, but the extreme descent velocity indeed requires it, as many of you have suggested. But the inclusion of a drogue calls for more space, especially given the thickness of the material required.
I had asked around before but... does anyone know these dimensions?

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Drogue? Well.. A few things come to mind. It must be small to be packed into that avbay, also so that the rocket may not drift upon descent. Tis very light on the way down. It must be durable, so as to survive the harsh operating environment, and it must have minimal shroud lines to prevent tangling.
A 6-8" Kevlar or nomex chute comes to mind... But who makes those?
I am going to give Ky Michaelson a call in the morning (as I believe he's an East Coast timer) And ask if he could custom sew me a chute. I had an idea for a shape that might offer only 1 shroud line, and a good ammount of drag for minimal packing profile... What do you guys think about this? Could this perhaps induce a spin that would promote tangling?


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So once these last things are complete, Ill launch my fundraising and send a package in for C3 Review. Thats another thing that I was considering lately. What perhaps might be the best method of fundraising for the project? As others have noted, Kickstarters usually are for product generation. But consider also that some people have used it for music production purposes (usually in smaller amounts albeit) . So if they can produce an album, cant I produce a video? :)
 
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If using titanium you need to contact the TRA board and make sure it meets the definition of 'ductile metal'.
Better to do it now rather than an issue in the field.

Mark
 
If using titanium you need to contact the TRA board and make sure it meets the definition of 'ductile metal'.
Better to do it now rather than an issue in the field.

Mark

Ofcourse! I will include it in the notes when submitting for the Class 3 Bor. I believe others have used it for fins before, but I want to get the go-ahead for everything anyway :)
 

MUCH too large. Would never fit. Even if it could, the rocket would drift like 30 miles.
I need 8" cannopy at absolute max. Packing volume about 38mmx38mm with cord if possible. There is not a lot of extra room in there. Alternatives to your standard ol' parachute must be considered as well. A pop-open mini-frisbee sparks my interest... Lets keep thinking!
 
Why would you use a CD3 system when Aeropac had all of theirs fail despite having the manufacturer of the device on their team?
 
Why would you use a CD3 system when Aeropac had all of theirs fail despite having the manufacturer of the device on their team?

Maximum redundancy. AeroPac was not operating in the same environments temperature wise. But other than that, you are correct, what worked for them will probably work for me. When somebody supplies me with the dimensions I need for the CD3 unit, I will make the call on it being included.

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I am very close to ditching it. I mean... Think about it. If airtight BP wont work in the T charge (or inline tube charge), or in the surgical charge, why would it work in a BP actuated device?
Ditching it would save money and space, and a few more pyro wires into the avionics lid. I am debating on using terminals or just sealing a pass through hole with hot candlewax before flight or something. Superglue perhaps. or even 30 second epoxy.
 
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If airtight BP wont work in the T charge (or inline tube charge), or in the surgical charge, why would it work in a BP actuated device?

When I used the CD3, I sealed and filled the ematch wells with epoxy. That completely contains the BP and minimizes the amount of air in the BP cavity. Years ago, I asked Tom if the plunger would move as a result of the decrease in pressure outside of the device (and the effect of G forces due to the orientation of the device was also discussed). We concluded that it would not move, or move very much, particularly if the air volume was minimized. So, I think the BP part of the CD3 will work just fine. I have stopped using mine because CO2 deployment is anemic at best and I have a simpler, more reliable method to replace it.

Jim
 
When I used the CD3, I sealed and filled the ematch wells with epoxy. That completely contains the BP and minimizes the amount of air in the BP cavity. Years ago, I asked Tom if the plunger would move as a result of the decrease in pressure outside of the device (and the effect of G forces due to the orientation of the device was also discussed). We concluded that it would not move, or move very much, particularly if the air volume was minimized. So, I think the BP part of the CD3 will work just fine. I have stopped using mine because CO2 deployment is anemic at best and I have a simpler, more reliable method to replace it.

Jim

Right.... But if I'm using two alternative air-tight methods, why would they act differently? You see where Im getting at? The BP itself will be in the same operating conditions in all three devices.

Okay so Ive received more quotes from Nextline and, we have ourselves a new problem. Nextline was able to quote me a fantastic IST price, but a less than good fin set price. The fins, needing to be 6Al-4v will be quite expensive indeed, but NextLine has me quoted at $1330 PER FIN. ($5320 for the set of four) . This is in addition to the $1770 quote for the fin can sleeve.

I have decided at this point to ditch the thermal methods of joining the fins as it would barely be viable with parts coming from multiple sources. I will just JB weld them together. They will still have dowel pins to lock them in place.

So, with that being said, does anyone know good shops that can not only supply, but MACHINE titanium? Does TitaniumJoe do mill work?

With a $5000 set of fins, the project comes out at $20,000 neatly rounded from its raw subtotal. My original goal was $15,000 or less....
Again, I wont skimp on materials just to cut cost. It will be done right, not cheap. But the higher the cost, the more people would have to contribute to make it achievable, so lowering costs is indeed desirable where possible.
Now... to make that parachute call..

**UPDATED**

Per an email back to NextLine they mentioned this:

" With regards to the fin, for qty 4 you will see a lower piece price from quantity 1, as the material and setup costs begin to be amortized somewhat. I'll also see what I can do on Monday as far as finding a better material source for the titanium sheet. Hopefully we can meet your price needs. "

So I will see where I can go with that.... Lets hope we can maybe make it under $2K for all four... $17,000 is still a bit high, though.

I also just spoke with Ky about parachutes, and he seemed interested in helping me find a chute suitable. We will speak again on Monday and I will know more at that time.
 
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