Parts Came in...

The sheet of paper the parts are laying on is 8.5x11"
My Welder Sent me this Picture . He still needs to weld the bottom manifold on,
When I ordered this version I did not order the bottom manifold because I had one. alas I was showing the previous version to people and either I left it at FAR, or someone walked off with it.
I've ordered another bottom manifold ring it will be two weeks or so.

Some Data

I've now flown the simple instrumented HPR 5 times with data recording.
I've learned some things

Flight 1 at FAR Spark fun IMU, GPS and 6DOF Analog devices ADIS16360
GPS did not work at all, Spark fun was noisy, ADIS16360 worked reasonable well

Flight 2 At FAR, shorted battery cable, only goy Spark Fun IMU data.

Flight 3 at Plaster City (Yesterday) OpenPilot 10Hz GPS and ADIS16400 Analog deivces IMU.
GPS lost lock moments abter ignition (10 G or So) ADIS data all looks good.
On board recorder did not work, only have down link telemetry.


Flight 4 at Plaster City (Yesterday) OpenPilot GPS and ADIS16400 Analog deivces IMU.
GPS kept lock till parachute deployment (where the GPS is now pointing at ground).
Take off was only about 6-7G, while the GPS says it kept lock, the altitude data was wrong and did not follow the flight path, onboard data recording worked correctly. (A few minor drop outs, I think the data recording connector is intermittent)
Flight 5 At plaster City Same setup 10-12G launch, GPS lost lock, ADIS16400 data looks good.
Telemetry log only, on-board recorder did not work.


Things I've learned:

• The $125 Spark Fun 9DOF IMU does not like rocket vibration, and the accelerometer saturates on the rocket.
• The $500 ADIS16400 is really pretty good, the data is clean and seems to make sense.
• The low cost 10Hz GPS's are not happy with high acceleration. (To be expected)
• The Max stream 900Mhz Xbee seems to be reliable even with grossly sub optimal antennas.
  

My goal is to develop a low cost system, buying a 5K GPS and 10K IMU are not part of the program. I'm really happy with the analog devices IMU, now to solve the GPS. I have one more
gps to try the new Novatel OemStar, I suspect that it may do better, but it is not available in a form that does not have the COCOM limits. I really do want to develop a vehicle in the next 12 months that will exceed 1K knots and 60K ft at the same time. There is an open GPS project based on the old Novatel SuperStar, alas the super star hardware is not available anymore and the base band chip set used on that receiver is not available. I can buy a Novatel receiver that is unlocked but it would be about 2K. As I've said several times this year, I currently have more rocket time than rocket $, I can continue to do interesting things with my leftover LLC hardware, but it does not match the far end goal. The far end goal is a 100Km 5Kg payload rocket that is reusable and can be reproduced for less than 10K.

In the past few years there have been a number of interesting papers, and even some 100% open projects on building software GPS receivers with just a simple front end. There are also a number of GPS front end chips and module assemblies that will directly feed such a receiver.
In looking at these projects its clear to me that a high dynamic GPS receiver with real time 10Hz updates is still beyond state of the art for realtime software only receivers. I want to do some experiments in this area, so I'm bread boarding a MAX2769 GPS front end chip a small FPGA and a high data rate SD card to record about 60 seconds of GPS front end data. So some time in the next month or so I hope to fly a payload that records GPS front end data and can be post processed with the open source software GPS receivers. If this works I might think about developing a 100% open Tightly integrated GPS/IMU using these peices, with the high rate code and carrier loops in an FPGA. Having the IMU data available at the code and carrier phase tracking level can really help the GPS keep lock. The short version is I'm crazy enough to contemplate building my own GPS receiver as I can't find one that meets both my cost and performance targets.

For anyone that cares the raw data file for flight #2 at plaster city is here: http://www.rasdoc.com/data/

The GPS data is at 10Hz and unmodified, the ADIS16400 is shown in the $AIMU lines.
The data is raw from the ADIS16400,(look at that data sheet) the order is Ratex, Ratey, Ratez, Acel X, Acel Y, Acel Z, Magx, Magy, Magz, extra. (I recorded one too many fields)

This flight was a lower acceleration flight on a rocket with big fins so it made a fairly sharp turn into the wind and the flight path was more parabola than straight up. The parachute deployment was also fairly late and abrupt. Looking at the Magnetic data it looks like the rocket rolled about 5 revolutions during the boost phase.

Way to go Spacex!!!!!

From the video feed I saw that launch looked perfect.
Way to go spacex!!!!

Good luck to spacex.

I'm eagerly awaiting the spacex web-cast to watch the first F9 flight.
I sincerely hope they have a perfect flight.
It is a new rocket on a first flight so a perfect flight is unlikely.
If they have a problem it will most likely be something they could not test on the ground.
If I were to guess my biggest worries would be:

• First stage pogo oscillation, the Saturn V had significant issues with this.
• 2nd Stage ignition in vacuum, the first stage Merlin's have a fair bit of ground side support equipment, so the air start is a differnt beast. (The first hotfire scrub was do to an incorrect valve in GSE) A turbo pumped motor is a complex piece and getting the whole choior singing in tune on the first attempt in vacuum is tricky.

BP Oil spill and Space Robots

If you have been a long time reader of this blog you probably have a geeky desire to see all the technical details. I've been watching the BP spill response with morbid fascination.
BP looks like it is being very open with the technical aspects of its response.
just take a look at all the videos on this page, the scale and scope of the operation are mind numbing. If that link does not work as a permalink, just look for the June 1 Videos on the LMRP, or go back and watch all of Kent Wells presentations.

I've been watching the the technical videos, diagrams and briefings for at least the last two weeks. I think this whole thing could be used as a pretty detailed response to those space scientists that say don't send humans, send Robots. With the BP spill we have lots of very sophisticated ROV's ,they have reasonable access to the surface for repair, adjustment and tool change out, a round trip operating delay of ~10 micro seconds and yet the whole process looks painfully hard. Trying to do any serious resource extraction or heavy construction remotely without direct onsite human intervention is currently significantly beyond state of the art. We need Humans on site.

We need humans in space. Go F9-Dragon!

Trying the 3D print thing again....

Three days in the desert.

The Friends of amateur rocketry is the site where we do most of our testing and flying.
It is both a registered non-profit and a largely volunteer organization. In the last year of our LLC I felt we had become more of a user than contributor to the organization. This week FAR had a three day work party and I spent three days on site. All in all we did a bunch of trenching and in the end buried over a mile of Ethernet and power cable. It was three days of very hard physical work with as much time spent using a shovel as any other implement.

A large part of our culture probably doesn't understand why we as a group chose to spend our personal vacation time waist deep in a trench operating a shovel in the hot sun. The Majority of the people on site (self included) could afford to spend vacation time sitting on a tropical beach with a frozen drink, and choose otherwise.

On Saturday we had an active flight waiver so I took a break and did some experimenting. I'm evaluating sensors for high G use in rockets. I modified the Nose cone of the Liberty 2 I built a month or so ago.

You can see the stock nose cone on the bottom and the modified one on top. The electronics bay slides into the aluminum sleeve and screws in around the base with 10 counter sunk #4 flat head screws. The GPS antenna is on top and sticks up just above the metal/plastic transition. I am using this to evaluate IMU, GPS and telemetry components. It has an analog devices ADIS16350 6 DOF imu and a Spark fun 9DOF IMU (I know its really 9 measurements not 9 dof) A low cost 10hz GPS and a 100Mw Xbee-900 telemetry radio with non-optimum antenna. (The antenna is the white wire sticking out of the base) and 2Gb of micro SD data logger. The goal was to launch it and see how the different sensors compared. Alas the GPS worked at home and never got lock in the field so I got one flight with dual IMU data and on the second flight I pinched a wire reassembling and only got data from one IMU.
I'll review and commend on the data collected later. The flights were around 4000 ft with 8 or so G off the pad and the system seemed to have no telemetry glitches. On the ground I used a simple rubber duck antenna. At this point the IMU data is just one hour of raw numbers, but I'll locate the flight in the data stream and reduce it to something useful in the next week or so.

The CTI pro54 solid HPR motors are really easy to use, the flights themselves were pretty uneventful.

When I flew the vehicle at plaster city I bought a tracker/beeper to help find it. I did not purchase a receiver as the club had one. I put the tracker on with a fresh battery when I flew at FAR thinking that if I could not find the rocket I could go find a tracking receiver and come back in the next week to locate it. On the first flight it did not land with the rocket, the deployment was about 4 seconds late and had some speed so I guess I did not tape it on well enough.
So if someone is a real glutton for punishment there might be a tracker at 220.470 (ch 247) beeping away somewhere in the desert south of FAR.

Lastly on the 25th of this month the local San Diego AIAA chapter is having an awards dinner and Unreasonable Rocket's LLC effort is getting an award,that's kind of cool.

Catching up....

A bunch of Random thoughts... Business is picking up and if we can manage the many parts shortages I should be able to fill in the LLC $ hole I dug in 2009 and even do some modest development.

Toward that end I've been working on several things.
The four motors shown in the back of the rocket two blog posts ago are meant to be 3D printed with built in cooling passages. I had a plastic version I was showing at Space Access, the Metal version I ordered arrived today and it looks really good until you try to pass fluid through the cooling passages they are all plugged with sintered metal. Its a really pretty $400 paperweight.
I may have to build in a conventional way or change to a more expensive 3D printing process.
I used a supplier that uses the Prometal R1 and would really like to have the work done on a
EOSINT 270 M, but that process is about 5 or 6x as expensive.

Last weekend I went out to the San Diego Tripoli club launch and Joined Tripoli and successfully flew my Level 1 and Level 2 Qualification flights using the poorly painted Liberty 2 I discussed earlier. I'm in the process of building some test hardware to evaluate several lower cost IMU and GPS solutions that I will fly on the Liberty next FAR weekend (the 15th)

I'm working at doing some development work to lower the overall cost of things. One of the areas I'm working on is a lower cost IMU based on MEMs sensors. The Mems Sensors are getting much better and lower cost. The area I'm sort of stuck on is doing the drift bias correction stuff. The guys at www.diydrones.com have been working on IMU drift correction for aircraft and have generated some really good stuff. I just started a discussion topic over there that I hope will help me make some progress in extending some of this work to highly accelerated rockets. (http://diydrones.ning.com/forum/topics/rocket-imu-thoughts)

Calculating...

I've written a very simple simulator to try and do some vehicle optimizations.
Using a very simple drag model... I used the data from page 16 of
http://www.jmrconline.org/Drag_Coefficient_Prediction.pdf built a table of mach number and Cd and interpolated. (This is actual data from a 5" rocket, were building a 6" rocket so it seems reasonable)


One of the interesting results is this graph:

It shows peak altitude achieved (y axis in meters) piloted against the equivalent peak drag. The peak drag units here are equivalent velocity at sea level in m/sec. The peak is at 50500m and 303m/sec (165Kft and 677mph)

Another interesting result (from a slightly different run) I'm not using any real fancy integrator and the results vs time steps don't change much:

Time Step	Alt
1	47458
.1	49532
.01	49576
.001	49593

So this means for very crude integration steps you get reasonable results, thus allowing one to use the model for optimization seeking. Right now there are a number of limitations, the model assumes that the ISP does not change as the motor is throttled for peak drag limiting etc... so as I add more detail to the model it will be interesting to see what happens.

Space Access 10

I had a great time at space access. It was strange to be showing a space access regular the plastic model of the 75lb motor I'm having 3D printed in stainless and the CTO of Lockheed interrupts and asks for my business card. The motors is a 50 to 75 pound regen peroxide hydrocarbon biprop. I've ordered one from the 3D printer and I'll show pictures when I get it. This drawing shows 4 of these tucked into a 6" airframe:

For those of you that follow the blog that was actually the only 100% new picture in my entire presentation. I also talked about restarting my composite tank work that I started in 2006 at the very begining of the blog. (Go back and reread the first few months)

The Technical plan going forward is in several steps. Working on a smaller scale I can do 100% of this plan within my current budget.
1)Build a 4 engine gimbaled monoprop that uses irrigation tubing and HPR style recovery. I expect this to take two months to get ready for first flight attempt, this puts it in the middle of summer so first flight might be delayed until september as FAR in summer is miserable.

1a)In parallel test the bi prop motor I'm having printed.

1b)In parallel develop composite polyethylene lined tanks.

1c)Build some small canards for the 6" airframe and see if we can make it glide with tanks empty.

In no particular order do the following:

Trade out the mono prop motors for the bi-prop. (I'll Probably crash the mono-prop so its probably a series of mono-prop then bi-prop.)

Substitute the composite tanks for Irrigation tubing tanks.(or alternatively put one of Steves Flometrics pistonless pumps in instead of the composite airframe.)

Fly the whole assembly to 100K ft

Fly the vehicle to 100K ft twice in one day.

Seems like a simple list its probably two years work.
The first unpleasant step is to clean up my Garage so I can actually work on anything.

I hate painting...

I have done a bunch of stuff at FAR, but I've never done the traditional HPR rocket thing.
Some of the next steps (glide back, aerodynamic canard controls) will be done a bit easier with that sort of propulsion. So to be able to order/fly traditional HPR stuff I though I ought to get my Tripoli certification so I can just order HPR motors. Toward that end I built a Giant Leap Liberty 4 kit to do the L1 and L2 qual flights. The Local Tripoli club flew Sat and Sun this week, so I was trying to get it ready for Sunday. On Friday it was done, it just needed paint.

Did I remember to say I hate paint? I put a nice coat of high build auto primer on sanded it all off, repeat three times, its looking pretty nice in its gray primer. Then two coats of white base followed by florescent orange about 10pm last night. Then I went to bed, alas this morning it looks like on the those crinkle paint jobs the white was not dry enough and the orange crinkled.

I took my painting embarrassment out to plaster city to do the qual flights only to discover the motor vendor was only on site Saturday. Arghhhh! Oh and did I remember to say I hate paint.

Blue is dead...

We had a perfect tether flight on Saturday, followed by a bad free flight.
The vehicle started well, but as airspeed built up it started to spin.
It got to about 1Kft then started down. It went unstable probably due to the high rate of spin.
and started to leave the area of the pad and was heading toward the spectator area so I aborted. Both the software driven and RC only vent abort worked.
The vehicle is totaled.

The micro sd flash chip from the vehicle physically looks ok, but gets very warm when power is applied so I've gotten no data from the vehicle.

I had a camera pointed at the bottom of the motor with a good view of the vanes and if I can recover data from the video camera SD card it should provide some information.
The camera was destroyed on impact, the SD card is fine but the camera did not close the video file before impact. So it shows zero length.

Any advice on how to fix this?
My approach:
I've got some utilities for manipulating bare SD sectors that I use for my data logging cards.
Using this I wrote a utility to copy all the sectors off the Cameras SD card into a big file.
So the original card is safe and I won't mess with that.
I then wrote a short utility to copy the exact same sectors contents back onto a equal sized SD card. I'll then run chkdsk on this duplicate SD card.

One rub is that while the SD cards are the same brand and size they report slightly different numbers of physical sectors, will this mess up the FAT table accounting? The card I'm copying to has more sectors than the one off the camera.

The cards is formatted as FAT16 so I can start tracing clusters by hand and reassembling file chains, but its been along time since I did FAT table stuff by hand with a hex editor.
Any recommendations on good tools to do this?


If that does not work,
any other ideas on recovering the video data from the SD card?

Getting ready part N..

I've made my cat pack. I've built new tethers, the only thing left on my list is re zero the one vane I had to take apart and do final electronics checkout. In the next day or so I'll modify the software to match what I'm flying in simulation.

I'll probably leave for FAR Friday night and do a tethered flight very early Saturday. I've done a lot of simulations and a flight to the 1200 ft limit of G airspace. (1000 ft to give me some margin) and back to the pad is easily within the most pessimistic performance parameters. So if the tether flight goes without problems I'll make that attempt on Saturday.

Higher than that and I'll need FAA authorization to enter controlled airspace. (Which they are unlikely to grant me until I actually stop being lazy and formally ask for it. )

When I get that I'll try the flight to 11K ft and back to beat DCX. With out some aerodynamic drag on the way down it has ~3% margin. As a result I've ordered a parachute from Fruity Chutes (blue of course) and I will setup to deploy the drogue at apogee and basically fall back to 1200 ft or so before powering up to land. The purpose of the chute is to keep the vehicle upright and limit the speed to 60mph or so. This will either require a very calm day or compensation for winds aloft. I need to mdoel this. I can just use forecast winds, or I have to study the FAA rules to learn what I need to do to release a small balloon to measure the winds right before launch.
(A small Xbee transmitter and GPS cost less than $100 and is very light so I can actually fly a small instrumented balloon.)

Rough calculation says 11K ft to 1K ft at 60mph takes 113 seconds. So a 10mph wind would cause 1600 ft of displacement. I'll need to be very close on the wind calcs to land back on the pad. I might be better off to fly from the lake bed near FAR.

Working on Blue and....

Last week I fixed the landing gear on the blue ball in preparation for taking it to spaceup last week for show and tell. (You can see a picture of it there on its new gear here: http://www.flickr.com/photos/dizee/4395476515/)

Last night I worked on building up a new cat pack. I started with the cat pack from silver and added some new disks. The top third of the cat pack was stripped and dead, I'm not sure what is going on. If I'm overheating the cat pack I'd expect the bottom third to be bad, not the top third. This leads me to believe I have some kind of contaminate in the h2o2. The new pack is ready to install.

My prep list looks like:

• Remove the bottom half of the motor.
• Grease lube and inspect bearings on the vanes.
• Install cat pack in motor.
• Replace seals in all the sanitary fittings. (This is preventive)
• Reassemble the motor.
• Replace the GPS antenna cable. (It has a kink at one of the ends.)
• Inspect the wiring.
• Build new Tethers.
• Do a full electronics checkout.
• Charge all the batteries . (computer, actuators, abort rx, telmetry box, laptop,2x rc transmitters, 3x cameras )
• Do a tethered flight (on the 20th)
• Do a free flight to about 1K ft. (maybe on the 20th)
• Do a higher free flight???
  

I expect to finish all but the last four this weekend.

I have almost no traditional HPR experience with things like recovery high speed airframes etc... to remidy that I've been contemplating building a really simple H2O2 monoprop out of 4" or 6" aluminum tubing. Something that could go supersonic and reach to 20k ft or so. I'd use conventional dual stage recovery just like the big HPR guys do. This is something I can do with today's budget. Making the same basic vehicle bi-prop would make it capable of 100K ft.

It would probably be three increasing complex projects:

• Unguided simple blow down mono prop to learn recovery.
• Fin guided pressurized mono prop.
• bi prop.

One of the really cool things I saw at spaceup was Ventions LLC small 100lb thermally
decomposed biprop h202 and RP-5 motors. Dr London had some cool video of it fireing on his phone. The motors were interesitng for both the construction and the thermal decomposition.
The were constructed out of stacked photo etched plates diffusion bonded together.

Getting a reliable thermal decomposed h2o2 motor to work would also be a really cool project.

Watching STS-130

I'm in Florida to watch the STS-130 Launch. I have NASA Guest tickets and the Launch viewing area is next to the Saturn V display at the Cape. The Temps for last nights scrub were a tad below 50F but the wind was blowing and damp. I did not really pack appropriately for these temps, it was really cold. I left the hotel at Midnight and got back to the room at 7:15 am. My internal clock is saying WTF?

Once again I'm stunned by the scale of the Saturn V, the size of the launch vehicle necessary to put 2 men on the moon in one shot is just staggering. I post and tweet my observations of the launch when it happens. The couple sitting behind us on the NASA bus has come out for 9 shuttle launches and has seen 9 scrubs and zero launches. It looks like they will try again Tonight but Tuesday Mornings Forecast is for worse weather so they probably won't even make the attempt.

Non-rocket but fun...

EDN published a short "Tales from the Cube" of mine.
This happened along time ago ~1990

Notional Next Rocket...

Its still going to be six months or more before I can really start working on this, but its my next notional rocket. It uses the motor valves and actuators from the Silver vehicle in a more aerodynamic shape. The Green tanks are Wellmate WM12 tanks with the air bladders removed, and the blue tank is the WM-6 that was the fuel tank on the silver. With a 16" diameter and 380 liters of light weight 500 PSI tankage it should go to 100K ft +. Its basically 20 ft tall.
The tanks would be joined together with carbon fiber barrels bonded to the tanks.

Bucket List Item....

I've always wanted to watch a shuttle launch.
I saw the very first shuttle land at Edwards, but I've never seen an orbital launch of any kind.

After a little contact fishing I just received a VIP invite to watch STS-130. Thank you Will and Andrew!
This is a night launch so it should be spectacular.

Fate of the Blue Ball....

The Blue ball has minimal development value for where I want to go with Urocket.
I was going to donate it to the Xprize to hang in their lobby. I talked to my accountant today and learned that I can't have an increase in basis for a self created asset, that's CPA for I won't get any kind of deduction if I donate it. Its basically intact, it would be 100% ready to fly with less than 8 hours of work so next time I'm out at FAR I will bring it home and fix it. Then I will fly it.

Without doing any paperwork I can fly it to 1199 ft AGL and back. To go higher than that I'll need an FAA waiver. So in the next few days I'll do a detailed model of what it can do and write a waiver request. I'll probably fly it in 60 to 90 days to max altitude (more than 10K less than 30Kft) and back to the pad. If anyone wants to fly an experiment on it when I fly it let me know.

• less than 5Kg,
• self powered ,
• 100% open public results
  

I'll probably let people on the blog vote for their favorite if I get more than one request.

Tiger, Jaycee Dugard ,Me ,darwin, and motivation.

(Stick with this it will really end up almost on topic)
Tiger
The current fascination people have with the Tiger Woods is interesting because the image he projects is perfect, he is a gifted athlete, smart, well spoken, respected, rich, married to a super model, his life is perfect in every way. Yet we learn that at some level he is not satisfied with what he has.

Jaycee
Jaycee Dugard is captured as a little girl raped and held captive for 18 years, yet we read that she had adjusted to her life and even felt some attachment to the monster that did this to her.

Un-happiness in the perfect life and happiness in the horrible life, whats going on?

Me
I think its human nature to adjust your expectations to your situation. Last year my business had the best year ever, I had the time and budget to pursue the LLC dream and work on a really interesting project, I was truly fortunate to have that. It was a great year. In the Month after the contest I've not yet come to grips with the fact that the economy is in the pits and I really can't afford to work on the rockets for awhile. I've got to go work really hard to maintain the business in this climate rather than seeing it grow. (We're down 36% year to date yet we have not laid anyone off) My personal setpoint had adjusted to the thrill and success and its really depressing to try and adjust it back. The vast majority of humanity would be ecstatic to trade places with me, yet I'm depressed about it. 5 years ago I'd be ecstatic, I think we really only react to the changes, not the absolute level of things in our life.

Darwin
When I stop and ponder this I come it an interesting question. What is the natural state of humans? From an evolutionary standpoint I can see that sit in the corner depressed is not effective and would be selected out of the gene pool. However I can also see that a slight unease or paranoia could have benefits. If one group of humans is satisfied and happy and settles in for the winter, they would be at a disadvantage to another group the was just a little bit uneasy and focused that energy at being more productive and gathering a few more nuts and animal skins for the winter. So what is the natural state of the most productive humans?

Motivation
What drives productive motivation? Is motivation bordering on obsession good or bad for production? Should I just rest and relax for awhile, or shoudl I try and get fired up to work on the things I can actually do, like clean the workshop, develop a simulator, do a peper design for a nanosat vehicle? What purpose does recharge and satisfaction setpoint "reset" have in the process? My wife has studyied a lot of Buddhist philosophy, IE live in the now and be happy with what you have. Any really productive Buddhist scientists and engineers? Is society better served by the hedonist pursuing things in the free market where he is driven to create value so he can have pleasure? I've always though Maslow's hierarchy of needs was a better gage that pure hedonism. The happiest times in my life have been associated with creating something , or bringing an idea to realization. I've posed a lot of hard questions all much less clear than the rocket equation, yet more important when trying to accomplish things in the world.