The first tests were basic combustion tests, would streams of liquid nitrous oxide and liquid propane actually burn? The answer, just barely. A series of failed combustion chamber ignition tests with a small engine cast doubt on the propellant system, but intensive work on the mixture ratio resulted in successful firings of the small engineering development engine on December 24th 1993. Further firings of this 40 # thrust engine have and will continue for materials research purposes. With a proven propellant system, it was safe to invest further time and money in developing a 3000# thrust static test engine. The 3000# thrust rocket engine is a good first step, it is large enough to determine if the propellants will be stable in much larger engines. This engine was successfully fired on the third attempt on October 7, 1995.
The propellant system proved to be very forgiving. Any other choice of propellants would have destroyed the test stand during the two failed attempts to fire the static test engine. So much was learned during this test series that the vehicle was then completely redesigned, that made the static test engine with it's heavy 'battleship' tanks useless for further testing. It was decided to fly off the hardware and accomplish the first flight at the same time. A site was located in the canyons of West Texas, and a short but successful flight was achieved March 16th 1996. No one can say that the rocket hasn't flown .
This proven conservative design is being upgraded to an 8,000#s thrust rocket with an improved design. While not a high performance system like liquid oxygen and liquid hydrogen, the nitrous oxide engine system has commercial potential as a booster system. A major design criteria has been the avoidance of any factor that would limit the eventual size of this engine system. Indeed in the late sixties several aerospace companies determined that simple pressure feed engine systems have no real limits on their ultimate size. Consisting solely of tanks, valves, and ablative chambers, larger engines are in fact easier to build. With that in mind, a larger 100,000# thrust engine is also being constructed, with the configuration of a multistage vehicle as it's application. Even larger engines are possible.
8-96 Currently I am working on the valve systems for the 8k and 100k engines, and forming the combustion chamber. The flow testing of the injector elements has been completed, and a new safer pressurization scheme for the fuel system has been developed. 9-96 Recently a test item was constructed to actually test the sealing capability of the home built valves. I thought that it would be a good idea to test the valve concept before going to all the work and expense of installing the actual valves in the engine. Well, the valve worked perfectly. That will make me sleep better, one less thing to worry about. 10-96 I went down to Uvalde and found a piece of new 12 inch pipe for the tank. Once the tank is completed, I can begin hydro testing the valve section. The pipe is 0.188 wall thickness, which will set the mass ratio at about 0.45. That's closer to what I want. This new tank will be stressed at 27,000 #, up from the 12,800# of the first tank, but still below the 50,000# level that would be optimum. The safety margin is at about 2.2. 12-96 The end caps for the new tank were not too expensive, but they were very heavy. The standard 12 inch weld cap has a 0.375 wall thickness, and weighs 30 pounds. I am etching them down to the proper thickness and weight with a little bleach and a big battery charger. The battery charger speeds up the process, but basicly it's called rust. The bottom cap is now down to the required thickness, and we have started on the top cap which will be lighter. 1-97 New Years eve produced an initial combustion velocity test. I used the demonstration motor to fill a ballon (a small ballon) with a mixture of fuel and oxidizer, then supplied a spark. THUMP! Not a detonation, but a very rapid combustion. A more scientific determination of combustion velocity will occur soon. 6-97 The tank welding is now complete, and it has been penumaticaly tested. Penumatic testing is very dangerous because air is the best spring you can buy, and the tank becomes a bit of a bomb. The tank was tested to 60 psi, and the one leak was repaired. Extreme safety precautions were excerised during the test. This test is preliminary to the hydrostatic test, at which time the tank will be tested to 150% of its operating pressure, about 800 psi total. Hydrostatic testing is a little safer because water is much less compressable than air.7-97. The tank and flange passed the hydrotest with flying colors, which certainly makes me happy. Confidence in the flange design will allow construction to proceed.
A valve function test was also performed. This test will have to be repeated however, as the pump was not able to pump the system up to full pressure with the "Armstrong" method.(the "Armstrong" wore out) The valves were opened at only 100 PSI, although they did function well a full pressure test is needed to verify the structure of the operating system. An electric pressure pump will be rented next time.
A better number was obtained for the combustion velocity of nitrous oxide and propane. A long plastic bag filled with nitrous oxide and propane was ignited at one end. A camera recorded the conflagration for viewing on a frame stop VCR. 187 ft/sec was the latest result. This is an important number to determine how much propellant can be pushed into a given size of combustion chamber. This test result at least gives an idea of what that quantity could be.
8-97 NEMESIS 1 PASSES HYDROSTATIC AND VALVE FUNCTION TESTS WITH FLYING COLORS! Well actually, flying water. The Nemesis 1 has now completed the two most critical structural tests in the construction phase, the hydrostatic test which proved that the tankage will hold the pressure of the propellants, and the valve function test which proved that once you get the propellants into the tank, you can release them into the combustion chamber. The control systems and combustion chamber can now be added to the vehicle.
9-97 After a long period of dormancy the 40# thrust engineering test motor was fired again. The subject of the test was a new graphite throat material. The conditions in this small motor are intended to be especially harsh. The injector flame is impinges directly on the combustion chamber walls, and friction in the small diameter throat causes extreme throat erosion. No previous material has withstood the high temperatures and pressures in this engine. A recently received sample from Poco Graphite Company has now survived this test. While the search for better materials will continue, the final piece of the puzzle is in hand. I can proceed with confidence in the construction of the Nemesis launch vehicles. The stars are ours!
12-97 A donation of 500# of graphite blocks, enough for three 8K# nozzles and one 100K# nozzle, was gladly received anonymously. These blocks are now being turned on a home made 30 inch vertical lathe.
An interim location for the static test stand has been choosen, and the bunker and stand foundation are in place. The flame deflector is under construction.
The unique valve, injector, and pressurization technologies are now officially "patent pending". Application has been made to the U. S. Patent Office which will provide limited protection for the technological developments. Licensing agreements are available.
1-98 The test stand is being assembled and tested. Several leaks in the fuel tank have been troublesome, but they are being corrected. Everything is coming along fine except for the fact that I have not been able to find a vendor for the nitrous oxide. It would seem that it is easier for Sadamm Hussian to get chemical supplies then for an American citizen to get chemical supplies.
4-98 An attempt was made to static test the Nemesis 1a on April the 19th . There was a problem encountered in pressurizing the system and the test was stopped. The propellants were loaded onto the vehicle the next day to gain experience with the loading process and to determine the behavior of the tankage with propellants on board. It was unfortunate that the test was not completed, but much was learned. As the nature of the failure (a 25 cent valve stem) exposed a saftey issue, a modification to the fuel system will be required which will cause a short delay in the resumption of testing. Safety must always be the number one priorty. Keep checking this space for further announcements.
10-98 After constructing the 8K motor great difficulty was found in finding a site to test and launch the motor. Since the current test site is much too urban to safely test the 8K liquid engine, I have thrown together a quick hybrid engine. If you can't do one thing you do another. The hybrid is safe enough to test at the current site. I chose 1000# of thrust as the initial target, and I was fortunate to find a supply of thin wall 6 inch pipe for the tank and combustion chamber. I adapted the design to a 1850# thrust hybrid motor with an innovative high thrust fuel core design. It proved to correct many of the problems associated with hybrid engines, more importantly, it was safe enough to test in the field behind the house. After completing the construction and hydro testing, the first test ruptured the valve section gasket which had to be modified. The second test achieved a good start, but ruptured the combustion chamber gasket which had to be modified. With improved gaskets and proven procedures I flubed the start sequence on the third test. Bummer. Then I found out that I lost my supplier for the refractory cement we have been using for the nozzles, and after three starts the nozzle needs to be replaced. Big bummer. currently waiting for a shippment of refractory from another supplier.1-98 This time the fourth test was the charm. The engine, which now develops 1750# of thrust, roared to life. Hybrids are smokey, and slow to start, and not very efficient, but this will get the rocket flying. A new vertical launch rail has also been constructed (30 feet) and is portable enough to carry to remote sites. I am now searching for a launch site on the coast, anybody got a boat?
10-99 It took eight months to find a launch site, and then it was back at the same West Texas ranch as the first launch. I had hoped for a better site. But, the launch was a success. Calculations show that the rocket went to 10,000 feet and landed 1.3 miles from the launch site. It is now a substantially compacted rocket, get it Subcompact. ;-) The launch and recovery were very ardous in rough desert tarrain. Construction can now begin on an aluminum version of the hybrid, with a much smaller & very portable launch system.