Saturday, June 27, 2009

Propellant Progress..

It looks like we have secured another source of 50% peroxide.

The process of turning 50% food grade into 85–90% rocket grade is as follows:

1)Filter the peroxide through ion exchange resin to remove stabilizers.

2)Sparge from 50 to 70%

3)Sparge from 70 to 85%

Step 1 needs to be conducted with the bulk temperature below 70F or the resin tends to catch fire. The low temp at FAR is presently >70F with a high > 100. This leaves the bulk peroxide temperature too hot.  So we took a dewar of Lquid nitrogen out to the desert and cooled and then filtered about 1500lbs of peroxide. We cooled the ulk peroxide by bubblin Ln2 throu from the bottom. We started at 11PM and finished about 6:30 am just as ths sun was comming up. Everything worked exactly as desined and according to the TDS meter we removed the bulk of the stabilizers.  We got back home at about 11:30 am this morning. Its just after 6pm and I just woke up. This all nighter thing worked so much better 25 years ago in college.

We have about 30 minutes more work and we are ready to try step 2. We will proably do this next weekend. I can’t do the final step until the generator I ordered arrives. The 50 to 70% step can be done with filtered “desert” dry air, the 70 to 90 step needs the air to be dryer than that and our big oiless compressor and -100F due-point airdryer system needs more power than we presently have on site.

Saturday, June 20, 2009

Wind blown and dried out

Just got back from the desert. I spent two days on site at FAR, I went out Thursday night, I was there to help unload some deliveries of steel and concrete block Friday Morning.  The deliveries are for new viewing bunkers as the existing viewing bunker has been over full and crowded for a couple of recent launches.

I also got 3000 lbs of 50% peroxide delivered. I think I’ve resolved my propellant supply.

I spent most of the day Friday working on our refining equipment. Saturday was a general FAR work party.  I’d hoped to run the first de-ionization steps on the new propellant, alas it was really hot and the temperatures were just too high to do this safely.  I’d also hoped to fly the blue ball under tether but it was too windy. I did fly the helicopter in 25+ MPH gusty winds and it did just fine.

I spent two full days working hard and accomplished one of my three primary goals for the trip. There are always lots of secondary goals to accomplish. Often simple things like: we now have 5 large  bottles of compressed nitrogen on site and I had no way to tie them all down properly. I’d been laying the bottles on their sides. Now the bottles are standing up and properly restrained  to the container wall.


Monday, June 15, 2009

Things that work are important.

This project is a big project and its important to have some success along the way.  Its easy to get mired in a bunch of problems such that you experience no successes that you can celebrate.

So in a project this large its important to schedule small successes to keep the motivation up while you slog through the details of 10K things.

I went out and flew the helicopter again tonight. For the first time I turned on the integral term in the gps position hold. It made a huge difference. A helicopter flies with a slight tilt, the tilt is such that with purely proportional position gains it has to build up some error to stop moving. Then it also moves around as the wind changes and the proportional error grows to the point to counter the wind.  I’d been doing: Start where you are, climb vertically, hover for awhile and land.  I also like to be behind the helicopter when playing safety pilot as its easier to stay oriented and try a save if needed.  Well it just so happens that in proportional mode every time you do one of these cycles the helicopter backs up and to the left about 2m. Do it 5 times and you have  moved off the edge of the field and over the embankment. With the integral gains turned on I flew it 6 times and the final flight landed within 8 inches of the original take off point.

Its cool when everything works. I also fired up the helicopter flight data review system and it just reminds me how much detail work has gone into this project:  (The position hold accuracy plot is uninteresting as the errors are so small the lines look straight, so here I show the auto takeoff.)

Click on the picture for a bigger view  and you can figure out where I test ;-)


Sunday, June 14, 2009

Some updates

When I started this project it was really fun. Its now been almost three years and its gotten a bit more serious and not as fun.  I’ve got the perpetual internal battle about do I lighten up a bit and have more fun, or do I drive to completion with the thought that I may eventually be able to monetize what we have done. I don’t have an answer, but the struggle is still there.  One runs a risk turning something you enjoy doing into a business. Will you still enjoy it when its a have to?

Long time followers know that we started our software development with an RC Helicopter. Then we ported the software over to the blue ball and did some hovering. While a hovering rocket is cool the LLC task requires more than hovering. We need to navigate and sequence through the 3D way points with time delays etc… We also need to be be able to soft abort  allow some manual steering to try and hit the exact target. Its much easier to develop this stuff on the helicopter that does not require a 4 hour trip to test. So Today I spent the day putting the helicopter back together and checking it out. This entailed putting a new processor board on the helicopter and installing  a new GPS as I’d stolen the originals for the silver ball. I just returned from flying it about 20 times. Its currently set up to takeoff, hover for 15 seconds at 2m then land.  Here is a picture I took tonight of it sitting in the back of the truck after the flights.



We also are now using a new tool that was first tested with last weeks blue ball flight. The FAR desert is really hard on things like laptops. So when we setup the vehicle and then cycle valves, read voltages, check out the GPS and telemetry links we had been brining a laptop out to the vehicle. The Laptops are hard to read in the Sun and the sand gets every where. So I built a little box that had a daylight readable 4x20 reflective LCD two twist and push knobs and allows us to do all the checkout. Its about 1/3 the size of a normal laptop  and has enough battery in it to run for 48 hours. Its in a solid aluminum case and is pretty rugged. It also worked tonight with the helicopter, we did all the heli flights without setting up the main telemetry station and the computer.

Here is a picture: (Its about 8” long)



I also upgraded the laptop when the spare laptop died.  Ebay is your friend, I picked up a semi rugged Dell for 25% of what a new rugged dell would cost:


All the damage on the Silver ball from the eventful truck ride has been repaired and it should be back together for more static firing next weekend hers a picture of the motor and the ball.


This coming weekend we are going to have a busy weekend, we hope to:

  • Tether hover the blue ball.

  • Static test the silver ball.

  • Fly the full LLC profile from the pads with the Helicopter.

  • Do the first steps of the peroxide processing with the 1 55 gal drum of 50% food grade we got months ago.

This will probably take two full days. I’ll keep you all posted.

Saturday, June 06, 2009

Business ethics and cuts by a thousand lawyers.

A long time ago a normal mortal  could buy rocket grade peroxide. Then someone crashed their rocket pack and sued the  peroxide supplier.They won and the supplier lost more on that suit than they had erver made on the small rocket grade perxode sales. So they did the smart thing and stopped selling rocket grade peroxide to anyone that did not have a government contract.

Three or four months ago I was very worried about peroxide availibility as peroxide propulsion was not running and xlspace systems had stopped producing. So I set about to refine my own. Stabilized 50% hydrogen peroxide is a widely used industrial chemical, and seemed to be generally availible.  I consulted with an expert that had been in the usiness of refining rocket grade perixude and decided to follow his reccomended process.

I got a sample 55 gal drum of 50% food grade from the local chemical supplier and built the plant to do the process. If you can get 70% semiconductor grade you cut out two steps from the process.  There are only two chemical suppliers doing bulk proixde distribution in the U.S. One got burned as described above and will not sell to anyone that is doing “rocketry”. the other suppleir does not produce rocket grade peroxide, they do produce 70% semi. so we started the process of having them review our facility and procedures so they would sell us 70%, rather than the commonly availible 50%. After a number of weeks and many exchanges we got the following response:

First thank you for your time and patience as XXXXX reviewed your request to purchase hydrogen peroxide.  As outlined in your information, your process would concentrate the material to 85-90% for use in rocketry.  You forecast an ongoing use of ~ 10K lbs per year of 70% product.

Our review involved the technical aspects of your work, product stewardship, regulatory affairs, and a legal & liability review.Everyone was impressed with your facility and apparent knowledge of hydrogen peroxide handling.

We have made the decision not to supply Unreasonable Rocket directly or through distribution.  Our decision was really made based on our perceived risk of exposure for a very small volume of business.   We will also communicate this to XXXXXX(the distributor we were buying 50% food grade from.)

We wish you well in your future endeavors and look forward to reading about your successes.

So if I had hidden what I do, or been dishonest about where the peroxide was going I could have continued to buy the 50% food grade. Now niether peroxide supplier will knowling sell even the 50% food grade if it is going to Unreasonable Rocket.  I know of others using peroxide for rockets that have set up shell companies “bozos chemical safety systems” or the like, buy peroxide under an assumed use and then refine for their rocket belts, drag cars or whatever. Others have “friend companies” buy it for them etc.. My personal business ethics don’t feel comfortable with that. As a result of being honest and upfront about what I’m doing the  door is closed.

No discussion of what insurance do you carry, what sort of liability release will you sign etc… Just no. People should be allowed to take risks. My familiy knows that if something happend to me it was my choice. They also know how strongly I feel that lawsuit lottery is destroying the fabric of what made the USA  great. Americans were once risk takers.  

What we are doing is far enough outside the normal industrial processes that any one doing business with us is not following their carefully coregraphed ISO9000 script. As a result the system is not perfect. That is why when I get a valve that supposed to have compatible materials in it I TEST IT. If I asked for viton and they sent buna-n then they screwed up, in the normal  events that sort of screw up would cause a leak. With 90% peroxide it could cause an explosion.  This is my responsiility, a larger  organization would have a detailed incomming inspection for anything that critical, I don’t so its my responsibility.  Its why we test things at FAR were we have a bunker to hide in. Its whey we presurize and fly the vehicle remotely, its why we make people at FAR seek shelter in the viewing bunker when we are trying something untested.  What we do is risky, but we try not to take stupid risks.  When I started going to FAR I looked around  and saw a bunch of 40+ year old guys that normally drive a desk out in the hot desert sun doing hard physical lablor. One of my very first donations to the place was an AED automatic defibulator and a breathing  oxygen bottle. At the time it was the largest check I had yet written for my new rocketry hobby. 

If I screw up amd blow my self up, it was my choice to take the risk, its not the fault of whatever other things happened in the chain of cauasality, I knowlingly put myself in that position.

Damm the lawyers.

BTW we flew the blue ball tethered in high winds today and got mixed results, no damage, but control problems in the winds. more later.