Attempt towards an amateur orbital rocket.

[jsdemar]

from that page

Note to paragraph (h)(1):

A guidance set integrates the process of measuring and computing a vehicle's position and velocity (i.e., navigation) with that of computing and sending commands to the vehicle's flight control systems to correct the trajectory.

Which I don't think applies here.

That clip is exactly what is needed for orbital insertion. ITAR applies here. Again, read the ITAR thread here on TRF for the detailed arguments and justification. The existence of similar projects and information online does not negate an infringement due to a new discussion elsewhere.

 

[plugger]

no offense John, but I'd prefer to not read other people's interpretations of ITAR found here. so often ITAR discussions here are hand wavy at best. This system relies solely on an IMU, which IIRC is exactly what people are using for canard based active stability systems. I'm happy to be proven wrong, but I'm uninterested in reading second hand interpretations on a a hobby forum as a basis for determining legality of such systems.

 

[jsdemar]

no offense John, but I'd prefer to not read other people's interpretations of ITAR found here. so often ITAR discussions here are hand wavy at best. This system relies solely on an IMU, which IIRC is exactly what people are using for canard based active stability systems. I'm happy to be proven wrong, but I'm uninterested in reading second hand interpretations on a a hobby forum as a basis for determining legality of such systems.

The previous itar thread included specific examples by those here who have experience with ITAR training, held high gov clearances, and had long careers in related fields. Like myself.
As I said in my initial post, I mention this issue for those who may be concerned. And I do not wish to go into a detailed discussion here again.
You are not concerned, so that’s fine with me!

 

[PayLoad]

I say go for a moon landing

 

[Adrian A]

The previous itar thread included specific examples by those here who have experience with ITAR training, held high gov clearances, and had long careers in related fields. Like myself.
As I said in my initial post, I mention this issue for those who may be concerned. And I do not wish to go into a detailed discussion here again.
You are not concerned, so that’s fine with me!

I looked for it but didn’t find it. Do you have a link?

 

[jsdemar]

I looked for it but didn’t find it. Do you have a link?

Thread 'ITAR and Research Access'
https://www.rocketryforum.com/threads/itar-and-research-access.169808/

 

[OverTheTop]

Thread 'ITAR and Research Access'
https://www.rocketryforum.com/threads/itar-and-research-access.169808/

It resides in an inaccessible area of the forum for me .

 

[wclaybaugh2]

There are several people in the hobby who have designed small electronics around modern chip-scale commercial gyros and successfully propagated attitude knowledge from them. That's as far as I have gotten so far. Some are rocketry electronics manufacturers but others are just people doing it for their own hobby enjoyment. Adding a control loop isn't a big leap from there, and a smaller number have done it with canards for atmospheric flight. To work in a vacuum, the control actuator needs to be a thrust vector controller and/or reaction control jets. A couple of hobbyists have successfully controlled motor thrust direction, but not in a minimum-diameter rocket yet as far as I know.


Were you looking at TVC?

Isn't comm loss over certain parts of the world still the norm even for professional launch vehicles? For the radio, I was being pretty hand-wavy with the link to the Featherweight GPS tracker. Something that size is possible, but it needs a GPS receiver that does not have altitude or velocity lockouts. I haven't spent a lot of time looking into those options. The Multitronix Kate has an unlocked GPS, but I don't know if it's driving the larger size for that unit.


For me this thread isn't about making a launch vehicle (that delivers a payload) but instead, just poking at what it would take to extend the boundary of amateur rocketry from its current location at the suborbital edge of space, to having part of a rocket orbit at least once around the world. I've always assumed that it's a huge leap, and I don't expect anyone to even make a serious attempt (I'm certainly not planning to myself), but it's interesting to me to do the math and think about what the limiting factors really are, and think if there are ways around them. Yes, getting approval is a real problem and would need to be part of the plan up front for a serious attempt, but since I'm not trying to make a serious attempt I'm content not to worry about it.

Regarding the thruster data sheet, I wouldn't want to use any of them for an amateur shot if I didn't have to. Using only TVC wouldn't control the roll, and a small reaction control system (RCS) for roll might be needed to keep the roll rate low enough for the TVC to keep up. A 3-axis RCS would probably be needed if getting to orbit requires a coast period and a circularization burn. But maybe a minimal orbit might just be able to get away with TVC-only.

Adrian:

A small quibble but the FAA is pretty clear that “amateur” rockets cannot exceed 150 km. If it goes higher, a full up professional launch license is required.

There accordingly isn’t any “amateur” effort (within FAA jurisdiction) that goes much beyond current high end amateur capabilities.

No reason not to discuss such things, but flying them is a rather different matter….

Bill

 

[RocketPro]

Were you looking at TVC?

Oh yes, for the MAV both TVC and RCS are required, but TVC is very mass efficient. The RCS is required to put you in the correct attitude for the required second burn (1/2 way around the planet) to get into a known orbit. Of course you also have to have an IMU, a good clock, and a computer to determine what that attitude should be. For the MAV, the point was to get the sample canister into an orbit that the return S/C could locate and then maneuver into in order to do the handoff capture.

Another consideration is that to get into orbit, any orbit, you normally burn, coast, burn. In order to do that, you need some sort of timing/control circuit. On Explorer I, they tracked the vehicle as it coasted and then radio controlled the start of the second burn. The timing of the burn and the variability of the 4th stage motor was that they “lost” the S/C for a while as it wasn’t where they thought it would be when it came back around to the ground station.

If you don’t want to do the burn, coast, burn, then the delta-v required is actually higher since as soon as the motor shuts off, the orbit trajectory will want to pass directly through that point (perigee) on the next go around. If your motor shuts off low, then drag will take over and you’ll de-orbit without actually getting into orbit. Normally, a second burn is done at apogee to raise the perigee out of the atmosphere.

As for radio requirements, you don’t have to have continuous coverage, but you have to have enough to get a good orbit track. You can do that tracking with an ground station or with TDRSS.

If the discussion is limited to just obtaining enough delta-v to get into orbit, then these factors don’t have to be considered, but if you really want to orbit something, even a brick, then there’s a lot of stuff other than propellant that’s required.

 

[Tim51]

I say go for a moon landing

On its own, or with an airstart and dual deploy..?

 

[plugger]

The previous itar thread included specific examples by those here who have experience with ITAR training, held high gov clearances, and had long careers in related fields. Like myself.
As I said in my initial post, I mention this issue for those who may be concerned. And I do not wish to go into a detailed discussion here again.
You are not concerned, so that’s fine with me!

Hi John, firstly apologies. I've been travelling, jet lag hit me hard, and I've only just come back to this. I've read the ITAR thread from the link you provided, I don't see any specific examples of anything about ITAR, other than Gerald's comments, which are high level and vague. And back to my earlier post, you called out orbital insertion. But there is no code or capability for orbital insertion in the project I linked to. Sure, it might be possible to modify the software to do that, but that isn't what we're discussing. But I did find Gerald's comments about educational exemptions interesting as they might be applicable here.

 

[RGClark]

I think this thread is interesting. You do not have to do solids though. Individuals have demonstrated the ability to make regeneratively cooled liquids. http://watzlavick.com/robert/rocket/

I also worked at a company in the Mojave desert that was very good at regeneratively cooled small rocket engines. Once you get that under control, you will have a big piece of the propulsion system ready for orbit.

Solids can still work, but amateurs can certainly branch into other options as well.

Amateurs have launched liquid-fueled rockets but their performance has been limited, as for example measured by their altitude reached. I get from that they are technically more difficult than solids. But they can get higher Isp than solids. For instance an upper stage kerosene rocket might be able get ca. 360s vacuum Isp with a long, vacuum optimized nozzle.

An amateur team might use for example a solid rocket to get to the altitude for space of 100 km or so, and then use the higher performance of a liquid to get a higher payload to orbit rather than using all solid stages. For such a pressure-fed liquid stage you would also want to minimize the tank mass by using composites.

Bob Clark

 

[AlexBruccoleri]

Amateurs have launched liquid-fueled rockets but their performance has been limited, as for example measured by their altitude reached. I get from that they are technically more difficult than solids. But they can get higher Isp than solids. For instance an upper stage kerosene rocket might be able get ca. 360s vacuum Isp with a long, vacuum optimized nozzle.

An amateur team might use for example a solid rocket to get to the altitude for space of 100 km or so, and then use the higher performance of a liquid to get a higher payload to orbit rather than using all solid stages. For such a pressure-fed liquid stage you would also want to minimize the tank mass by using composites.

Bob Clark

Hi Bob, Liquids are certainly more technically difficult; however, they are still a viable option for someone determined enough to try this. Anyway I have some questions for you. Are you a NAR/Tripoli member? If so, what level certified? If not, I would encourage you to build a fly a few rockets just to see what it is like. Theoretical discussions are fun, but it is always prudent to have some practical experience to intuitively understand the practical challenges.

 

[FredA]

I get from that they are technically more difficult than solids.

Yep - easy to write about in dreamland - hard to do in reality. Glad you finally figured that out.

 

[James Owen]

Theoretical discussions are fun, but it is always prudent to have some practical experience to intuitively understand the practical challenges.

Well said. I think amateur orbital insertion would be super cool, but RGClark here would need tons of experience and/or lots of help from people who have tons of experience in high performance rocketry. And also someone with experience on liquid engines would be very helpful.

Is this project possible? Maybe… with a team of very smart people and a lot of budget.

RGClark, I’d say work the way up to this orbital attempt slowly. Do some high power rocket flights, eventually a sub orbital spaceshot, and then you can start trying to go orbital. The space shot going to be a several year project at least, and orbital is going to take probably even longer.

 

[Ez2cDave]

An amateur team might use for example a solid rocket to get to the altitude for space of 100 km or so, and then use the higher performance of a liquid to get a higher payload to orbit rather than using all solid stages. For such a pressure-fed liquid stage you would also want to minimize the tank mass by using composites.

Bob Clark

Bob,

Let me ask the "unasked questions" . . .

(1) What is the projected cost for your orbital rocket project ?

(2) What percentage of this funding have you already acquired ?

(3) What are your plans to obtain the additional required assets ?

Dave F.

 

[Handeman]

Amateurs have launched liquid-fueled rockets but their performance has been limited, as for example measured by their altitude reached. I get from that they are technically more difficult than solids. But they can get higher Isp than solids. For instance an upper stage kerosene rocket might be able get ca. 360s vacuum Isp with a long, vacuum optimized nozzle.

An amateur team might use for example a solid rocket to get to the altitude for space of 100 km or so, and then use the higher performance of a liquid to get a higher payload to orbit rather than using all solid stages. For such a pressure-fed liquid stage you would also want to minimize the tank mass by using composites.

Bob Clark

Liquids are much, much, more technically difficult than solids. Also magnitudes more expensive.

Amateurs getting something into orbit, if that's even allowed, is a nice thought, but I really don't see that happening any time soon. Mostly because of the cost, regulations, and technical requirements. These are amateurs after all, not commercial, or university backed endeavors.

The Go-Fast team got an amateur rocket into space by going straight up at a vertical speed of just over Mach 5. Adding a horizontal speed of Mach 24+ to that to achieve orbit is magnitudes more difficult and expensive.

 

[jsdemar]

Amateurs getting something into orbit, if that's even allowed, is a nice thought, but I really don't see that happening any time soon.

FAA's definition of an Amateur Rocket:
To qualify as an amateur rocket, the launch must be suborbital, not have any humans onboard, remain under 150 km (93.2 statute miles), and have a total impulse under 200,000 lb-sec (889,600 Newton seconds).

 

[bad_idea]

FAA's definition of an Amateur Rocket:
To qualify as an amateur rocket, the launch must be suborbital, not have any humans onboard, remain under 150 km (93.2 statute miles), and have a total impulse under 200,000 lb-sec (889,600 Newton seconds).

That passage describes the rocket, not the people launching it. Nothing forbids amateurs from launching rockets that are not Amateur Rockets*, but those launching such rockets must be licensed by the Office of Commercial Space Transportation, which those launching Amateur Rockets (Class 1, 2, and 3) are spared.

The mountain of compliance actions and paperwork for procuring a launch license is alone enough to make orbit prohibitively expensive and difficult for an amateur group, quite apart from the engineering side.

That said, I agree with those who say that engineering for orbit is prohibitively expensive and difficult for amateurs at this time. Whether it will remain so forever is an interesting question.

* Conversely, I believe - though could be mistaken - there have been a few suborbital commercial projects in recent years that launched under the Amateur Rocket rules.

 

[Steve Shannon]

That passage describes the rocket, not the people launching it.

As does the title of this thread.

 

[bad_idea]

As does the title of this thread.

The FAA has a very specific definition of the words "Amateur Rocket" written out in great detail, but that doesn't preclude those words meaning something else to someone else. I think it's pretty clear the OP is referring to amateurs designing and launching an orbital rocket and doubt he was aware of the FAA definition when he started this thread.

 

[Steve Shannon]

The FAA has a very specific definition of the words "Amateur Rocket" written out in great detail, but that doesn't preclude those words meaning something else to someone else.

That’s exactly what a legal definition does.

 

[bad_idea]

That’s exactly what a legal definition does.

For the purposes of complying with the FAA regulations on Amateur Rockets (Title 14, Chapter 1, Subchapter F, Part 101) or rockets which are not Amateur Rockets (Title 14, Chapter 3), yes, the CFR's definition of Amateur Rocket (from Title 14, Chapter I, Subchapter A, Part 1, Section 1.1) very much applies

Whether or not a rocket is built by amateurs or professionals is not addressed by the Title 14, which does not define what an amateur is, only what is considered to be an Amateur Rocket. If a group of super rich and talented amateur rocketeers wanted to spend a huge amount of money on development and a similarly huge amount of money on regulatory compliance, I don't see anything in Title 14 standing in their way.

(Of course I very much doubt such a group exists.)

Again, I doubt the OP was aware of the distinction between a rocket built by amateurs and an Amateur Rocket as defined in the CFR.

 

[Steve Shannon]

For the purposes of complying with the FAA regulations on Amateur Rockets (Title 14, Chapter 1, Subchapter F, Part 101) or rockets which are not Amateur Rockets (Title 14, Chapter 3), yes, the CFR's definition of Amateur Rocket (from Title 14, Chapter I, Subchapter A, Part 1, Section 1.1) very much applies

Whether or not a rocket is built by amateurs or professionals is not addressed by the Title 14, which does not define what an amateur is, only what is considered to be an Amateur Rocket. If a group of super rich and talented amateur rocketeers wanted to spend a huge amount of money on development and a similarly huge amount of money on regulatory compliance, I don't see anything in Title 14 standing in their way.

(Of course I very much doubt such a group exists.)

Again, I doubt the OP was aware of the distinction between a rocket built by amateurs and an Amateur Rocket as defined in the CFR.

I agree completely.

 

[OzHybrid]

For the purposes of complying with the FAA regulations on Amateur Rockets (Title 14, Chapter 1, Subchapter F, Part 101) or rockets which are not Amateur Rockets (Title 14, Chapter 3), yes, the CFR's definition of Amateur Rocket (from Title 14, Chapter I, Subchapter A, Part 1, Section 1.1) very much applies

Whether or not a rocket is built by amateurs or professionals is not addressed by the Title 14, which does not define what an amateur is, only what is considered to be an Amateur Rocket. If a group of super rich and talented amateur rocketeers wanted to spend a huge amount of money on development and a similarly huge amount of money on regulatory compliance, I don't see anything in Title 14 standing in their way.

(Of course I very much doubt such a group exists.)

Again, I doubt the OP was aware of the distinction between a rocket built by amateurs and an Amateur Rocket as defined in the CFR.

You could partially get rid of some of those rules if you launched in international waters. Would depend on what rules applied to your nationality status and if you were prepared to surrender that nationality. Theoretically, someone who was stateless could do whatever they wanted if they were in international waters. Now keeping out of jail afterwards would be an interesting legal tangle.

 

[bad_idea]

You could partially get rid of some of those rules if you launched in international waters. Would depend on what rules applied to your nationality status and if you were prepared to surrender that nationality. Theoretically, someone who was stateless could do whatever they wanted if they were in international waters. Now keeping out of jail afterwards would be an interesting legal tangle.

Yes, Americans would have to renounce their citizenship not to be subject to the FAA, ITAR-related controls, and other regs. Maybe same for other nationalities? Doubt too many would be willing to do that, even aside from the other problems. Even if a small group had the know-how and money for an orbital shot, can you imaging slogging through an environmental impact study as an amateur, with no one paying you to deal with all that paperwork?

As an aside, I wonder how much paperwork falls on Copenhagen Suborbitals, given they're aiming to fly a human sooner or later.

 

[kavy8]

Unfortunately OpenRocket and RasAero do not have the capability for doing orbital trajectory sims. The best you can do with these programs is see if you can get a rocket that can achieve both the tangential, i.e., horizontal velocity for orbit and the needed altitude above 100 km. This though will be a rocket traveling straight-up so isn't really showing an actual trajectory to orbit. Attached is an attempt at such a rocket.

It is derived from the Cesaroni rocket that powers Up Aerospace's Spaceloft XL suborbital rocket. It consists of 4 stages with the first stage being the Cesaroni rocket. For the subsequent stages we will use a smaller motor by a factor of 1/4th at each stage. So the 2nd stage will be 1/4th that of the Cesaroni, the 3rd will be smaller by an additional factor of 1/4th, and the fourth stage smaller again by an additional factor of 1/4th.

Here's the specifications on the Cesaroni motor:

View attachment 549717

Here's the thrust data for the Cesaroni motor in RASP format from its .Eng file:

;
; Cesaroni Booster motor for UP Aerospace.
; @File: CTI_UPA-264-C.eng, @Pts-I: 42, @Pts-O: 31, @Sm: 0, @CO: 5%
; @TI: 438207.0, @TIa: 437890.0, @TIe: -0.05%, @ThMax: 52454.9, @ThAvg: 37051.4, @Tb: 11.827
; Exported using ThrustCurveTool, www.ThrustGear.com
S37029 265 3018 P 186.8801 242.672 NEW
0.037 540.773
0.061 1406.008
0.073 13086.69
0.086 48561.4
0.147 52454.9
0.257 50616.3
0.355 49859.2
0.698 48453.2
0.918 46073.8
1.175 44667.8
1.591 43586.3
2.338 42829.2
4.199 42288.4
4.701 41855.8
8.006 35907.3
9.658 32230.0
10.234 26606.0
10.368 23577.7
10.637 21414.6
11.176 21414.6
11.262 21847.2
11.335 21090.1
11.445 19575.96
11.543 17737.33
11.629 14600.85
11.69 11464.37
11.764 6813.73
11.825 4001.72
11.911 2163.09
12.021 648.927
12.376 0.0
;

The format of .ENG files is described here:
==============================================================

1. The common name of the motor; just the impulse class and average thrust.
2. The casing diameter in millimeters (mm).
3. The casing length, also in millimeters.
4. The list of available delays, separated by dashes. If the motor has an ejection charge but no delay use "0" and if it has no ejection charge at all use "P" (plugged).
5. The weight of all consumables in the motor. For solid motors this is simply the propellant itself, but for hybrids it is the fuel grain(s) plus the oxidizer (such as N2O). This weight is expressed in kilograms (Kg).
6. The weight of the motor loaded and ready for flight, also in kilograms.
7. The motor manufacturer abbreviated to a few letters. NAR maintains a list of manufacturer abbreviations on page 2 of the combined master list.

==============================================================

The lines preceded by a ; symbol are regarded as comments and are not interpreted by the sim programs.

For the smaller upper stages, I successively made the dry mass, propellant mass, length, and thrust smaller by a factor of 1/4th. I kept the same diameter for each stage. I didn't change the comment lines, other than saying it's one-quarter size, since I didn't know what they meant anyway. Here's the thrust data for my created 2nd stage in RASP format:

;
; Cesaroni Booster motor for UP Aerospace - quarter size.
; @File: derived from CTI_UPA-264-C.eng, @Pts-I: 42, @Pts-O: 31, @Sm: 0, @CO: 5%
; @TI: 438207.0, @TIa: 437890.0, @TIe: -0.05%, @ThMax: 52454.9, @ThAvg: 37051.4, @Tb: 11.827
; Exported using ThrustCurveTool, www.ThrustGear.com
Q9000X 265 755 P 46 61 NEW
0.037 135
0.061 350
0.073 3270
0.086 15411
0.147 13110
0.257 12654
0.355 12465
0.698 12110
0.918 11518
1.175 11166
1.591 10900
2.338 10707
4.199 10572
4.701 10463
8.006 8976
9.658 8057
10.234 6651
10.368 5894
10.637 5353
11.176 5353
11.262 5461
11.335 5272
11.445 4894
11.543 4434
11.629 3650
11.69 2866
11.764 1703
11.825 1000
11.911 540
12.021 162
12.376 0.0
;

Note the thrust values are 1/4th those of the full-size Cesaroni motor. For center burning solid motors, the thrust is made proportionally larger or smaller according to the length of the motor since that determines the burning surface area.

The 3rd and 4th stages are made successively, proportionally smaller as described.

For the orbital velocity for low Earth Orbit, that is ~7,800 m/s. But for low latitude launch sites such as Cape Canaveral you get ~400 m/s for free from the Earth's rotation. So I took the required velocity needed to be attained as 7,400 m/s. I simulated no airframes by given the body tubes in the OpenRocket sim a mass of 0 kg.

The payload mass is taken as 500 grams. For this ~330 kg gross mass rocket, this is a payload to gross mass fraction of 1 to ~660.

Issues and Problems.

1.)Notable I used a rounded ogive nose cone rather than conical or von Karman shape. The reason is a quirk in OpenRocket is that it sometimes for hypersonic flights will give a higher altitude for a short, squat nozzle than a long, pointed one. Aside from that, I also didn't assign a mass for the nose cone since I really didn't know what the size and shape it would wind up being. And anyway based on orbital rockets it should be only a fraction of the payload mass anyway. For example for the Falcon 9, it's payload fairing is at about 2 tons for an expendable payload of ~23 tons. So based on that, a 500 gm payload might need only a 50 gm nose cone.

2.)Not really an issue or problem but OpenRocket counts stages downwards from top to bottom, in contrast to the usual practice in the industry. Also, it starts up always with a single stage present as default which it calls the "Sustainer", even if you don't give that "stage" a motor. So in this case OpenRocket calls this rocket a 5 stager with the top stage, which it calls the 1st stage, only consisting of the nose cone and payload. I could probably change that by editing the names but didn't bother to.

3.)I am worried about the stability of the upper, powered stages. The rocket overall has the center of gravity CG ahead of the center of pressure CP, but for each stage above the booster, the CG is behind the CP. I'm thinking for the top most stages that won't matter since they fire at near vacuum. But it should matter for the stage above the booster stage.

4.)I'm interested in find out what the vacuum Isp is for the upper stages. We might be able to get improved performance using longer nozzles.

Attached is the .ORK file using OpenRocket version 15.03.

Robert Clark

View attachment 549721

If you want a rocket simulator that can handle orbital trajectories, look up MAPLEAF.

MAPLEAF is a rocket simulator develop by a former masters student at the University of Calgary. It is more accurate than OpenRocket, especially in to transonic regime. It also has capability to do optimization of a rocket, basically every little detail you can imagine. It is purely text based though so there is a large learning curve.

 

[jsdemar]

You could partially get rid of some of those rules if you launched in international waters. Would depend on what rules applied to your nationality status and if you were prepared to surrender that nationality. Theoretically, someone who was stateless could do whatever they wanted if they were in international waters. Now keeping out of jail afterwards would be an interesting legal tangle.

Your after-flight legal issues are solved by launching yourself.

 

[bad_idea]

If you want a rocket simulator that can handle orbital trajectories, look up MAPLEAF.

MAPLEAF is a rocket simulator develop by a former masters student at the University of Calgary. It is more accurate than OpenRocket, especially in to transonic regime. It also has capability to do optimization of a rocket, basically every little detail you can imagine. It is purely text based though so there is a large learning curve.

I'd not heard of MAPLEAF before, so thank you for mentioning it.

It does look very powerful. Also addresses a few things discussed often on this forum, such as base drag. Aside from the example simulations, do you know of any tutorials on using it?

 

[OzHybrid]

Your after-flight legal issues are solved by launching yourself.

Oh come on John.... I've eliminated a significant amount of pre-flight paperwork. It's now just a single letter saying "I surrender my nationality of the (insert country here). Please find my passport attached."
It will take me at least a couple more beers to come up with a solution for part 2.