Rockets are energetic devices. They are dangerous. No one working on them should ever forget that. Nor should we shy from the task at hand. Very often in human history progress has been paid for in blood. So it has been and so it always will be.
Our heartfelt condolences go out to the entire scaled family.
Thursday, July 26, 2007
Monday, July 23, 2007
Its all about the systems...
Its all about the systems integration.
I'm trying to diagnose the Helicopter systems to work on flight software. I have a GPS on the roof of my house and one mounted on the back of the helicopter, when working on the system I unplug the one on the helicopter and plug in the one on the roof We get ZERO gps reception inside. The one on the roof works really well.
So I take the helicopter out to fly it and after waiting a long time get no GPS lock at all. So I bring it back to the house and replace the GPS receiver with another one. (assuming the old GPS receiver got broken in the last heli cras h.) ,butI'm getting smarter I don't drive all the way to the flying field to test the new receiver. I go out in the back yard still no GPS.
So now I take a 6 foot cable and the "broken" gps and plug it into the helicopter it works from 6 feet away! So I then set the broken GPS on top of the gps on the helicopter and it still works! Then I remove the 6 foot cable and it does not work.
So then I plug in the 6 foot cable between the electronics and the GPS currently mouted on the helicopter. It works.....
So I now have 2 GPS receivers that have decided that they need 6 feet of cable to operate. 1 foot is not enough.
First working hypothesis: the 900Mhz telemetry radio is putting EMI on the wiring. The long cable is enough to filter it out, the short cable is not.
Experimental test don't transmit until you get GPS lock.
Still no GPS, add 6foot cable to verify the don't transmit till you get lock code works, the code works.
Second working hypothsis:
Some other component of the system (likely the CPU) is putting enough noise on the wire to kill the GPS, Next step put noise filter on all the cables and try again.
Well let you know......
I'm trying to diagnose the Helicopter systems to work on flight software. I have a GPS on the roof of my house and one mounted on the back of the helicopter, when working on the system I unplug the one on the helicopter and plug in the one on the roof We get ZERO gps reception inside. The one on the roof works really well.
So I take the helicopter out to fly it and after waiting a long time get no GPS lock at all. So I bring it back to the house and replace the GPS receiver with another one. (assuming the old GPS receiver got broken in the last heli cras h.) ,butI'm getting smarter I don't drive all the way to the flying field to test the new receiver. I go out in the back yard still no GPS.
So now I take a 6 foot cable and the "broken" gps and plug it into the helicopter it works from 6 feet away! So I then set the broken GPS on top of the gps on the helicopter and it still works! Then I remove the 6 foot cable and it does not work.
So then I plug in the 6 foot cable between the electronics and the GPS currently mouted on the helicopter. It works.....
So I now have 2 GPS receivers that have decided that they need 6 feet of cable to operate. 1 foot is not enough.
First working hypothesis: the 900Mhz telemetry radio is putting EMI on the wiring. The long cable is enough to filter it out, the short cable is not.
Experimental test don't transmit until you get GPS lock.
Still no GPS, add 6foot cable to verify the don't transmit till you get lock code works, the code works.
Second working hypothsis:
Some other component of the system (likely the CPU) is putting enough noise on the wire to kill the GPS, Next step put noise filter on all the cables and try again.
Well let you know......
Sunday, July 22, 2007
Software Hardware Hardware Hardware Paperwork
Software
Our current plans for developing the stability and control aspect of this are as follows:
1)Make the system fly on a Trex 600 RC helicopter.
2)Move all but the lowest level rate command servo loops from the helicopter to the rocket.
Toward that end we have been using a nice RC heli sim from source forge to simulate the helicopter systems in software. We have modified the sim to only update the data at the same rate as our IMU and GPS. The windows version of the simulator does not have any kind of control or autopilot, just a comment in the code that says put your control laws here.... Using that I've tuned the insane number of PID loops and adjusted it so it will fly a whole XPC LLC flight from start to finish. (You can run my compiled version of the code here) Again this is an exe that is compiled for my use etc etc .
Hardware Hardware Hardware
I took the video camera and wandered around the house and shop and
took video of: (Video is here (Fixed) )
Not awesome video and if you have not been following the blog it probably won't make sense, but my guess is that people like to see hardware from time to time.
Paperwork
No show stoppers in paperwork land. This last week I had to provide XPC a Mishap response plan. I think such plans should be really simple so that you can actually do them in time of crisis. The document is here.
Our current plans for developing the stability and control aspect of this are as follows:
1)Make the system fly on a Trex 600 RC helicopter.
2)Move all but the lowest level rate command servo loops from the helicopter to the rocket.
Toward that end we have been using a nice RC heli sim from source forge to simulate the helicopter systems in software. We have modified the sim to only update the data at the same rate as our IMU and GPS. The windows version of the simulator does not have any kind of control or autopilot, just a comment in the code that says put your control laws here.... Using that I've tuned the insane number of PID loops and adjusted it so it will fly a whole XPC LLC flight from start to finish. (You can run my compiled version of the code here) Again this is an exe that is compiled for my use etc etc .
Hardware Hardware Hardware
I took the video camera and wandered around the house and shop and
took video of: (Video is here (Fixed) )
- The helicopter with GPS, IMU and computer mounted on it.
- The test stand we have been running.
- The first vehicle airframe.
Not awesome video and if you have not been following the blog it probably won't make sense, but my guess is that people like to see hardware from time to time.
Paperwork
No show stoppers in paperwork land. This last week I had to provide XPC a Mishap response plan. I think such plans should be really simple so that you can actually do them in time of crisis. The document is here.
Sunday, July 15, 2007
Weekend Testing results...
This weekends motor tesoting started out with a lot of little issues.Not the least of which was sleep deprivation. We finally got them straightened out in the early afternoon and had two successful tests. The second test was operationally perfect. For some reason we did not get chamber pressure, but the light was perfect and the motor ran really well until we ran out of helium pressurizing gas at about 95 seconds of run time. (The previous minor problems used a lot of helium). the two key events were:
1)The motor started correctly. This was the result of using a lox lead and pre-flowing the igniter for a few seconds.
2)We did a number of throttle step tests with the new fast butterfly valves. From the gathered data we were only really throttling the fuel side, but the response time and the fact that the motor ran down to 75 PSI input pressure was really good news.
I was manually operating the valves in an open loop manner and the response from giving the step up/down command to seeing the mach diamonds change was instantaneous to my perception. Lastly we had a teperature probe in the fuel feed and we are ok for heat load. At full throttle my guess is we are getting some boiling, but not extreme boiling. The video camera shutdown about 15 sseconds into both tests. I'm beginning to wonder if the there is some sort of IR oscillation in the motor that is commanding the camera off. The first 15 seconds with the first throttle step at the the end of the video is here I'll put tape over the IR remote port next time. The gathered data is below:
1)The motor started correctly. This was the result of using a lox lead and pre-flowing the igniter for a few seconds.
2)We did a number of throttle step tests with the new fast butterfly valves. From the gathered data we were only really throttling the fuel side, but the response time and the fact that the motor ran down to 75 PSI input pressure was really good news.
I was manually operating the valves in an open loop manner and the response from giving the step up/down command to seeing the mach diamonds change was instantaneous to my perception. Lastly we had a teperature probe in the fuel feed and we are ok for heat load. At full throttle my guess is we are getting some boiling, but not extreme boiling. The video camera shutdown about 15 sseconds into both tests. I'm beginning to wonder if the there is some sort of IR oscillation in the motor that is commanding the camera off. The first 15 seconds with the first throttle step at the the end of the video is here I'll put tape over the IR remote port next time. The gathered data is below:
Wednesday, July 11, 2007
This weeks plans.
We are planning to do a test fire again this Saturday. We have made a number of changes. We have added very very fast butterfly valves just after the main (slow) ball valves. We hope this will have a bit more linear throttle action and be somewhat faster. Toward that end we have set up a flow test with an exact engine string, pressure transducer, ball valve, butterfly valve , pressure transducer,turbine flow meter , long tube and pintile orifice. We have started mapping how linear the valve is and it's flow response. This will all be on the test stand before Friday.
In addition I found some very small isolated thermocouples and we will instrument the fuel temperature rise for this event. So this weeks fireeing should generate some good data. I always planned to have the thermocouple, but the non-isolated version had some ground loop problems that totally swamped the signal I was trying to measure.
On the stability and control front I upgraded my helicopter from a Trex 450 to a Trex 600, it no longer wallows with the IMU, GPS and computer attached. We will report more on this effort next week.
In addition I found some very small isolated thermocouples and we will instrument the fuel temperature rise for this event. So this weeks fireeing should generate some good data. I always planned to have the thermocouple, but the non-isolated version had some ground loop problems that totally swamped the signal I was trying to measure.
On the stability and control front I upgraded my helicopter from a Trex 450 to a Trex 600, it no longer wallows with the IMU, GPS and computer attached. We will report more on this effort next week.
Thursday, July 05, 2007
A Quick update...
Due to some scheduling issues we will not be testing this comming weekend, but we will be testing the weekend of the 14th.
Since the airlander flight testing did not go so well I thought I'd sneak up on the problem. I took my IMU, CPU, Telemetry radio and GPS and weighed it. I then took that much lead and put it on my Trex 450 RC helicopter. It's a small helicopter as RC helicopters go and I wanted to see if it could carry that much weight. So with 290 grams of lead it flew just fine, hovered for close to 5 minutes.
Step 2 Actually mount all that stuff to the helicopter and see if all works.
So I mounted the GPS, IMU, Telemetry Radio to the Helicopter. I then took the outputs from the RC receiver to the CPU board and then ran the helicopter servos from the CPU. The CPU is in the loop, but not yet doing anything but passing the commands directly from the RC receiver. I added an additional input from the RC receiver that I call mode that will allow me to switch from manual contol to automated control as time goes on. The GPS, RC receiver and telemetry radio all seem to coexist with no detectable interference.
I also did a fair bit of work on my telemetry display framework. My windows coding is a bit rusty so that has been an interesting challenge. So I flew it in my driveway, everything worked perfectly but my thumbs. I've been flying the copter in my driveway for awhile, but my wife added a new shrub........In any case I need to get new blades at the hobby store as I cliped the edge of the shrub and this pulled the helicopter into the shrub. None of the electronics or expensive bits seems to be damaged, just the typical helicopter crash parts, blades, flybar etc...
I'll get the replacement parts on Friday and go to a large open field and start doing some serious testing this week end.
I recorded the telemetry during this whole flight.
You can take a look at it I've uploaded the telemetry data file and the executable to view it.
The executable is the same one that shows telemetry in real time so on startup you need to select the "replay log" button. Then load flight2.dat. The log file has a bit of dull data as I go from starting the recording to connecting the RC power battery and moving the helicopter into position. Liftoff is around frame 8000. You probably want to click the 10X button until data starts changing. The 5 combo boxes on top left control what data is displayed.
The screen shot on the left is centered at the moment of shrub acquisition.
The derived Roll, Pitch and Yaw seem really reasonable, the rates and accelerations seem really noisy. Enjoy following along.
As always its probably not a good idea to download and run an executable from someone you don't know without virus scanning it etc... This exe was done for me on my computers so if there is a missing DLL, it crashes etc... no guarantee....
Since the airlander flight testing did not go so well I thought I'd sneak up on the problem. I took my IMU, CPU, Telemetry radio and GPS and weighed it. I then took that much lead and put it on my Trex 450 RC helicopter. It's a small helicopter as RC helicopters go and I wanted to see if it could carry that much weight. So with 290 grams of lead it flew just fine, hovered for close to 5 minutes.
Step 2 Actually mount all that stuff to the helicopter and see if all works.
So I mounted the GPS, IMU, Telemetry Radio to the Helicopter. I then took the outputs from the RC receiver to the CPU board and then ran the helicopter servos from the CPU. The CPU is in the loop, but not yet doing anything but passing the commands directly from the RC receiver. I added an additional input from the RC receiver that I call mode that will allow me to switch from manual contol to automated control as time goes on. The GPS, RC receiver and telemetry radio all seem to coexist with no detectable interference.
I also did a fair bit of work on my telemetry display framework. My windows coding is a bit rusty so that has been an interesting challenge. So I flew it in my driveway, everything worked perfectly but my thumbs. I've been flying the copter in my driveway for awhile, but my wife added a new shrub........In any case I need to get new blades at the hobby store as I cliped the edge of the shrub and this pulled the helicopter into the shrub. None of the electronics or expensive bits seems to be damaged, just the typical helicopter crash parts, blades, flybar etc...
I'll get the replacement parts on Friday and go to a large open field and start doing some serious testing this week end.
I recorded the telemetry during this whole flight.
You can take a look at it I've uploaded the telemetry data file and the executable to view it.
The executable is the same one that shows telemetry in real time so on startup you need to select the "replay log" button. Then load flight2.dat. The log file has a bit of dull data as I go from starting the recording to connecting the RC power battery and moving the helicopter into position. Liftoff is around frame 8000. You probably want to click the 10X button until data starts changing. The 5 combo boxes on top left control what data is displayed.
The screen shot on the left is centered at the moment of shrub acquisition.
The derived Roll, Pitch and Yaw seem really reasonable, the rates and accelerations seem really noisy. Enjoy following along.
As always its probably not a good idea to download and run an executable from someone you don't know without virus scanning it etc... This exe was done for me on my computers so if there is a missing DLL, it crashes etc... no guarantee....
Tuesday, June 26, 2007
Out of Town this week.
I went testing last weekend and have some more video. The testing raised more questions than it answered. I'll be back in town Friday and try to post some of the video and more commentary. I'm away at the freescale technology forum in Orlando. The cool non-rocket news is that the new Netburner product I designed, the Product Kit won the best in show award!
One question for the rocket geeks... I'm still having troubles getting the engine reliably lit. Is there any harm to a really long (A second or more) LOX lead?
One question for the rocket geeks... I'm still having troubles getting the engine reliably lit. Is there any harm to a really long (A second or more) LOX lead?
Thursday, June 21, 2007
FAA paperwork milestone.
I just got off the phone with the FAA/AST and they have determined that my application is complete enough to begin the evaluation. (This used to be called sufficiently complete) This is the official milestone that starts the 120 day clock. Since the Application they deemed complete enough was received by the FAA on May 29th They are now legislatively bound to approve or disapprove the application by September 26th. They can still ask for a lot of information and request changes in the vehicle or safety systems, but at least the clock is started.
Here is the offical PDF (with addresses and phone numbers removed)
Here is the offical PDF (with addresses and phone numbers removed)
Sunday, June 10, 2007
Wednesday, June 06, 2007
More chamber failure testing...
We went out to the test site last Sunday to test the normal soldered
chamber. It failed by buldging in, but no where near as bad as the earlier failures. It bulged in exactly inline with the igniter outlet. So maybe the torch igniter is softening the chamber wall. We are goign to try a number of fixes for this this again this weekend. Three expeditions to Mojave in three weeks is a bit hard on the sleep schedule.
chamber. It failed by buldging in, but no where near as bad as the earlier failures. It bulged in exactly inline with the igniter outlet. So maybe the torch igniter is softening the chamber wall. We are goign to try a number of fixes for this this again this weekend. Three expeditions to Mojave in three weeks is a bit hard on the sleep schedule.
Thursday, May 31, 2007
Chamber failures explained.
Tonight I made a chamber liner by silver soldering it at high temperature.
In my pressure test fixture it failed between 380 and 400 PSI.
So this explains my motor failures, but does not really give me a huge amount of comfort. It means I can never get the liner hot enough to anneal it and I am Dependant on the annealed condition of commercial water pipe for my strength.
We are going to test fire again the weekend.
In my pressure test fixture it failed between 380 and 400 PSI.
So this explains my motor failures, but does not really give me a huge amount of comfort. It means I can never get the liner hot enough to anneal it and I am Dependant on the annealed condition of commercial water pipe for my strength.
We are going to test fire again the weekend.
Wednesday, May 30, 2007
Simulating Chamber failure at home.
Any time I can run an experiment at home that replicates things I see at the test site it's a huge win. Tonight I fabricated a plugged injector plate and soldered up a chamber inner liner and throat. I used the plugged injector plate to Hydro test the chamber to failure. The chamber liner failed at 1750 PSI. It failed in exactly the same way as the chambers that failed in the field did. This liner and throat were soldered with normal relatively low temp solder.
Thursday I will solder up a throat with high temp silver solder and test that to failure.
As part of doing this test I also abused my o-ring seals, no lubricant and hammered them together. I even got o-ring slivers sliced off the injector end o-ring. Still the o-rings held and did not leak at 1750 PSI.The Snap ring retainers and the fuel feed plumbing also held the pressure. All in all a good test.
For one last reality check Plain old un alloyed copper has a work hardened to fully annealed yield strength ratio of ~5. So 1750/5 = 350PSI we were running the fuel feed at around 375.
At some level it all makes sense.
Thursday I will solder up a throat with high temp silver solder and test that to failure.
As part of doing this test I also abused my o-ring seals, no lubricant and hammered them together. I even got o-ring slivers sliced off the injector end o-ring. Still the o-rings held and did not leak at 1750 PSI.The Snap ring retainers and the fuel feed plumbing also held the pressure. All in all a good test.
For one last reality check Plain old un alloyed copper has a work hardened to fully annealed yield strength ratio of ~5. So 1750/5 = 350PSI we were running the fuel feed at around 375.
At some level it all makes sense.
Monday, May 28, 2007
Chamber Failures
This weekend we had two chambers fail identically. We set out to verify we had solved our ignition problems. So for our first test we ran a few seconds , purged a few seconds and ran again. Both ignitions were perfect. On the second start we saw a big green copper flash. We thought this chamber failure was due to too short of purge. But in reviewing the video I see we got a green flash on shutdown. We ran a second motor and it failed on startup.
Thoughts on the failures:
The first chambers we built we used high temp silicon to seal to the carbon throat and had the spiral wires soldered on with normal solder. The chamber to aluminum jacket tolerance was so tight we had to assemble the motors with a sledge hammer.
The motor we ran for 106 seconds had the copper throat soldered into the chamber wall with normal solder and spiral wires soldered on with normal solder. This motor was tight, but only needed light taps, not the full sledge treatment.
When we disassembled that motor we discovered that some of the spiral wires were loose, we did no know if that was an issues with getting hot of breaking the wires loose on assembly / disassembly.
As a result we decided that we should silver solder the parts together. So the last two motors we built with silver solder. This requires that we get the copper liner much hotter and probably removes the temper. As we have been using copper water pipe the temper is a side effect of the forming process and is not guaranteed to be in any particular state of hardness.
My current set of hypothesis is as follows:
- We are softening the chamber walls when we silver solder the parts together.
- The Hotrod igniter is making a soft spot on the chamber side leading to local buckling.
- We got a different batch of water pipe and is is less tempered.
- Switch back to normal solder for the throat and spiral wires.
- Rerun our flow rate tests we ran on the first chamber to verify we have not drifted off of nominal.
- Do a hydrostatic collapse test on the pipe we have to see if the batches are different.
- Build up 4 chambers for testing, hopefully, next weekend.
- One of these chambers will use thicker pipe wall.
My verification tests are as follows:
- Run a test where we run the igniter and then hit the chamber with full fuel pressure, but no lox if this collapses then we have the igniter too hot or oriented wrong.
- Rerun the tests we tried this weekend.
- If both of these fail retest with the thick wall chamber.
Sunday, May 27, 2007
Murphy Wins!
We went testing this weekend....
The game was not even close, Murphy won.
Video Summary here
1)Saturday Afternoon Very little lox, almost none.
Masten Space was nice enough to sell us some of theirs.
Thank you thank you thank you!
2)Saturday late ran the test chamber twice
Melted the test chamber in a new way. Video and pictures Monday.
3)Late Saturday set up telescope.
One axis is broken and drive motor makes grinding noises.
Used it in manual mode looked at moon and Jupiter, very cool viewing.
4)Sunday Morning test stability and control air lander...
No stability no control we now have pieces...video later
5)Sunday noon time...Tested 2nd chamber failed immediately with the center copper chamber wall buckling and collapsing inward. Same failure as #2 above.
6)Sunday just after noon help SDSU students with telemetry for their rocket.
SDSU has spectacular hard start and fireball. (video Monday)
7)Early Saturday Successfully flew my RC helicopter.
Saturday Afternoon flew it again, tail rotor belt failed.
Failed in low hover, no other damage.
8)Sunday about 3:30 got flat tire.
Spare was flat. The road to the test site is rock and dirt, very hard on tires.
(Had a 12 V compressor with me, dodged Murphy a bit)
Murphy 8 unreasonable rocketeers ZERO.
No one was physically injured, when I got home the house had not been leveled by a stray meteor, its all part of the process.
The game was not even close, Murphy won.
Video Summary here
1)Saturday Afternoon Very little lox, almost none.
Masten Space was nice enough to sell us some of theirs.
Thank you thank you thank you!
2)Saturday late ran the test chamber twice
Melted the test chamber in a new way. Video and pictures Monday.
3)Late Saturday set up telescope.
One axis is broken and drive motor makes grinding noises.
Used it in manual mode looked at moon and Jupiter, very cool viewing.
4)Sunday Morning test stability and control air lander...
No stability no control we now have pieces...video later
5)Sunday noon time...Tested 2nd chamber failed immediately with the center copper chamber wall buckling and collapsing inward. Same failure as #2 above.
6)Sunday just after noon help SDSU students with telemetry for their rocket.
SDSU has spectacular hard start and fireball. (video Monday)
7)Early Saturday Successfully flew my RC helicopter.
Saturday Afternoon flew it again, tail rotor belt failed.
Failed in low hover, no other damage.
8)Sunday about 3:30 got flat tire.
Spare was flat. The road to the test site is rock and dirt, very hard on tires.
(Had a 12 V compressor with me, dodged Murphy a bit)
Murphy 8 unreasonable rocketeers ZERO.
No one was physically injured, when I got home the house had not been leveled by a stray meteor, its all part of the process.
Friday, May 25, 2007
I've received the first Tee Shirts
I've just received the first Unreasonable Rocket Tee's and they look good.
So feel free to order some at the Store.
So feel free to order some at the Store.
Learning Curve/Frustration...
I brazed my last injector myself, but it got really oxidized.
I was worried about the black oxide flakes plugging up the injector.
So I thought I would step up to the plate and have the next one furnace brazed.
So I did about 30 hours of machining making all the parts and took it to a company that specializes in furnace brazing. As I did it all myself I had the peice part drawings, but did not have an assembly drawing. The parts only fit together one way.
So I carefully showed them how it all goes together with the warning that it was very important that the gap between the pintile and the injector face not be brazed....
Unfortunately the person doing the work was not the person I presented the parts to. The person I presented the parts to came from the shop end of the building so I figured he would be doing the work.
I got it back today and the gap between the pintile and injector plate is brazed shut. $200.00 of telerium copper and more importantly 30 hours of work are scrap. Argggh!
Key learning point.... If the shop is used to detailed assembly drawings provide them one. Even if it is self explanatory to you it may not be so to them.
I was worried about the black oxide flakes plugging up the injector.
So I thought I would step up to the plate and have the next one furnace brazed.
So I did about 30 hours of machining making all the parts and took it to a company that specializes in furnace brazing. As I did it all myself I had the peice part drawings, but did not have an assembly drawing. The parts only fit together one way.
So I carefully showed them how it all goes together with the warning that it was very important that the gap between the pintile and the injector face not be brazed....
Unfortunately the person doing the work was not the person I presented the parts to. The person I presented the parts to came from the shop end of the building so I figured he would be doing the work.
I got it back today and the gap between the pintile and injector plate is brazed shut. $200.00 of telerium copper and more importantly 30 hours of work are scrap. Argggh!
Key learning point.... If the shop is used to detailed assembly drawings provide them one. Even if it is self explanatory to you it may not be so to them.
FAA Permit Application
I've just finished printing the two copies of my experimental permit application. I'm on my way out the door to send them.
As I've stated previously I would make anything I formally submit available.
Here is the Application and the Cover Letters.
I'm a tiny bit queasy making all of this public, but one of my main goals is to try to demystify the process of doing rocketry as much as possible. The regulatory aspects are a key part of that process.
As I've stated previously I would make anything I formally submit available.
Here is the Application and the Cover Letters.
I'm a tiny bit queasy making all of this public, but one of my main goals is to try to demystify the process of doing rocketry as much as possible. The regulatory aspects are a key part of that process.
Wednesday, May 23, 2007
AST News.
I got a chance to chat with my AST representative today and I'm pleased with the discussion. He indicated that I should probably formally submit my next revision and not just send them a draft for review. While not a formal endorsement, it at least implies that I'm close to "complete enough". I hope to finish up and Mail the Fed-X the formal application on Monday or Tuesday.
In a past life I was responsible for negotiating the technical engineering aspects of a significant subcontract. whenever we found ambiguity in the contract it was good news because we could exploit this to get more money from the prime. As a result I have a fine tuned "ambigious nit sensor". I have to fight this impulse to pick these nits when working with the FAA.
A simple example:
One of the comments I received on my draft application was :
AST understands that there are no hazardous materials asociated with the vehicle.
However for the purposes of documentation completeness, the application still needs to state positively that there are no hazardous materials used in the suborbital rocket.
Seems like a simple statement and they are really looking for a statement that I'm not using hydrazine or some other really nasty substance. This seems really simple,but my "ambigious nit sensor" goes off and I start wondering ....
Is Lead solder Hazardous?
Is the Lead in Brass Hazardous?
Is the gallium arsenide in the GASFET RF amplifiers hazardous?
So I write the following:
In a past life I was responsible for negotiating the technical engineering aspects of a significant subcontract. whenever we found ambiguity in the contract it was good news because we could exploit this to get more money from the prime. As a result I have a fine tuned "ambigious nit sensor". I have to fight this impulse to pick these nits when working with the FAA.
A simple example:
One of the comments I received on my draft application was :
AST understands that there are no hazardous materials asociated with the vehicle.
However for the purposes of documentation completeness, the application still needs to state positively that there are no hazardous materials used in the suborbital rocket.
Seems like a simple statement and they are really looking for a statement that I'm not using hydrazine or some other really nasty substance. This seems really simple,but my "ambigious nit sensor" goes off and I start wondering ....
Is Lead solder Hazardous?
Is the Lead in Brass Hazardous?
Is the gallium arsenide in the GASFET RF amplifiers hazardous?
So I write the following:
Unreasonable rocket will not be using any environmentally hazardous substance, we are only using benign non-toxic propellants . The non- consumable portions of the vehicle will be constructed with aluminum,copper, stainless steel and normal composite structures. The only components of vehicle that might contain nominally hazardous materials are the trace elements in the electronic components and lead containing solders that are part of these assemblies. The commercial components will all be RHOS compliant lead free, but the non commercial components assembled for this effort will use lead solder for reliability purposes.
What I finally put in the application is:
Unreasonable rocket is not using any hazardous consumables.
What I finally put in the application is:
Unreasonable rocket is not using any hazardous consumables.
Tuesday, May 22, 2007
Fabricating our first vehicle....
Our test stand used flight weight tanks and valves.
Our first vehicle is going to look a lot like four of these test stands.
Toward that end my son and I have been fabricating and buying parts, we hydroformed and machined 17 tank ends (1 spare ),
We had Thunderbird Water jet cut some valve parts and brackets.
We ordered and received a batch of tonegawa servos from Tokyo hobbies.
Tube services sold us some aluminum tubing to make tanks.
We ordered all the tank weld on AN fittings from Iindustrial liquidators They are a dealer for Earls Fittings.
Lots of Valves, snap rings and parts from McMaster Carr.
I have enough Tellirium Copper to build 20 or so Motors purchased from Cambrdige Lee.
3 Vehicles of solinoids from Predyne.
1.25 Vehicles of ignition modules from CH-Ignitions.
2 Vehicles worth of Composite helium tanks on Order from SCI.
O-rings from Real Seal.
On Friday I pick up a furnace brazed Injector assembly from Certified Metal Craft.
Flowers for my understanding wife from ProFlowers.com....
(Delivered some time Wednesday Morning. Shes' usually home in the mornings, so I've asked her if she can be home Wednesday Morning to receive a very important package for my project, she just doesn't know its flowers for her...yet....)
I'm sure I've left off and forgotten a million vendors.
Our first vehicle is going to look a lot like four of these test stands.
Toward that end my son and I have been fabricating and buying parts, we hydroformed and machined 17 tank ends (1 spare ),
We had Thunderbird Water jet cut some valve parts and brackets.
We ordered and received a batch of tonegawa servos from Tokyo hobbies.
Tube services sold us some aluminum tubing to make tanks.
We ordered all the tank weld on AN fittings from Iindustrial liquidators They are a dealer for Earls Fittings.
Lots of Valves, snap rings and parts from McMaster Carr.
I have enough Tellirium Copper to build 20 or so Motors purchased from Cambrdige Lee.
3 Vehicles of solinoids from Predyne.
1.25 Vehicles of ignition modules from CH-Ignitions.
2 Vehicles worth of Composite helium tanks on Order from SCI.
O-rings from Real Seal.
On Friday I pick up a furnace brazed Injector assembly from Certified Metal Craft.
Flowers for my understanding wife from ProFlowers.com....
(Delivered some time Wednesday Morning. Shes' usually home in the mornings, so I've asked her if she can be home Wednesday Morning to receive a very important package for my project, she just doesn't know its flowers for her...yet....)
I'm sure I've left off and forgotten a million vendors.
Our New Logo....
What would a new logo be without a Tee shirt Shop...
Buyer Beware I have not yet seen this printed on a Tee shirt.
The colors may not work... I've ordered a few I will update
the blog with a good/bad review later this week when they arrive.
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