The UCLA Project Prometheus had reserved the RRS MTA for Saturday, July 17, 2021, for another round of static fire testing of a nitrous oxide hybrid motor on our vertical test stand. Dave Crisalli was the pyrotechnic operator in charge for that day and recorded the successful static fire. The footage will be posted on the society Instagram page soon.
This summer semester test would demonstrate UCLA’s student designed and built custom hybrid motor. Average thrust was around 300 lbf with a maximum value of 349 lbf. Total impulse recorded was 2044 lbf-sec (in the M-motor range). UCLA shared a few pictures from the event.
This was another great example of a university team success thanks to careful design, lab testing, training, planning and smart, in-the-field engineering. The RRS is glad to offer our facility and technical advice. The RRS looks forward to working with UCLA again soon.
For teams seeking to schedule the use the RRS MTA, please contact the RRS president, Osvaldo Tarditti. Always include a full project description such that the society can accurately evaluate your request.
The Reaction Research Society held a launch event at the Mojave Test Area mainly to support the UCLA Prometheus team for a static fire test of their high powered hybrid motor. UCLA chose one of the largest nitrous oxide hybrid motor designs, the M1575, made by Contrails Rocketry. Dave Crisalli was the pyrotechnic operator in charge for this event. I was his apprentice for the hybrid static fire.
There were three main activities at this event. The first was the UCLA Rocket Project making their preparations to launch their ethanol and LOX vehicle from the Friends of Amateur Rocketry (FAR) site from the 60-foot rail. FAR is just to the south of the RRS MTA where the UCLA Rocket Project had twice in one day static fired their 750 lbf liquid propellant rocket engine just four weeks earlier on 05-01-2021.
Weather conditions were ideal with winds being nearly still for most of the morning. This makes little difference for the hybrid motor static fire testing at the RRS MTA which was the second project by UCLA. Wind would factor heavily in the flight of the UCLA’s liquid rocket.
The third planned activity for UCLA was a series of model rocket flights from several high school teams mentored by UCLA graduate and undergraduate students. Still winds made for easier recovery of the first rockets launched that day.
UCLA at the end of each Spring Quarter conducts a launch event where student groups build small rockets with egg payloads using single and dual-stage vehicles with model rocket class motors (G and under). UCLA graduate students and Professor Mitchell Spearrin were leading this event.
It is good experience for beginners and experts alike to build and fly model rockets., The RRS has it’s own such internal program called the Yoerg Challenge which is to motivate all members to build and fly a model rocket kit at least once from the RRS MTA. The RRS is known as an experimental society and not limited to the model rocket code, but we are also fully supportive of all forms of propulsion as long as it is safely conducted and compliant to the regulations set by the state of California.
As the UCLA hybrid rocket team was making their system checks, they discovered a problem in their nitrous filling system and valve commands. During this diagnostic period, some of the RRS members went to the nearby FAR site to see how the UCLA liquid rocket preparations were progressing.
Some of the RRS members remained at the FAR site to witness the launch. After two years of design, planning, build and world pandemic, the UCLA team liquid rocket launch was an amazing success. Due to the relatively low winds that day under clear skies, recovery was made just under a mile away. Preliminary data from telemetry confirmed a new university team altitude record of 22,000 feet. It was an amazing sight to witness from the observation bunker at the RRS MTA.
The UCLA Prometheus team had corrected their initial electrical problem and began the series of procedural checks to familiarize the new members of the hybrid rocket team. Some minor adjustments of the motor mount alignment was necessary before getting into test.
The hybrid motor firing proceeded without further problems and resulted in a spectacular test meeting expected performance. Continuous thrust levels over 600 lbf were recorded but data analysis is still ongoing.
The team had a second hybrid motor grain ready for another firing so they proceeded with disassembly and inspection of the parts. The floating injector seals were still in good condition but the graphite nozzle having survived many prior hot fire tests did not survive that day’s test. Although the throat was in good condition, the inlet taper had cracked requiring a replacement the team did not have.
UCLA Prometheus was pleased with the results from the single firing and will proceed with integrating the motor into their flight vehicle for a launch from FAR on June 19, 2021. The RRS will hold an event at the Mojave Test Area on this same Saturday for member projects and will observe the flight from our northern vantage point.
In the last hours of the day, after most of the UCLA liquid and hybrid teams had cleared the area, packaged and carried away their trash, packed their equipment and departed the RRS MTA and FAR sites. The UCLA avionics team remained at the MTA to conduct another series of tests on the GPS tracking system. The society was glad to support this diligence which will help assure success in one of the most important aspects of rocketry which is data acquisition from telemetry. If there is no data, it didn’t happen.
For any group interested in using the RRS MTA for their propulsion related projects, download one of our Standard Record Forms from our RRS.ORG website and submit this request to the RRS president. The society has had a long relationship with UCLA and USC, but we are also supportive to any amateur, professional or academic groups wanting to learn from test.
The RRS held a launch event at the Mojave Test Area on November 7, 2020. It was a largely overcast day with brief periods of sun. The daytime temperatures reached only 50 Fahrenheit but the winds were no more than 20 miles per hour which meets the criteria for safe launch. Osvaldo Tarditti, our society president, was the pyrotechnic operator in charge for this event.
RECOVERY OF ANOTHER ALPHA FROM JULY
John Krell was able to find the standard length micrograin alpha rocket laumched at the July 2020 event. The rocket was found further north than expected but the downrange distance was about right. This was the rocket with the ceramic coated nozzle which was to have its performance compared to the standard alpha with a plain steel nozzle which is known to erode from the high temperature exhaust.
Unfortunately, the data was absent on the memory chip. It appears there was a malfunction and flight data wasn’t recorded. John is looking into the problem.
The nozzle was removed and inspected from the recovered alpha. Preliminary results show that the nozzle stayed intact. Careful removal of the largely zinc metallic residue firmly adhered to the entrance and nozzle throat must be done to determine how well the ceramic coating survived the 2300 Fahrenheit flame temperature for the quick four-tenths of a second burn time, John Krell is trying a traditional remedy of heated white vinegar (acetic acid) which has been modestly successful in this application.
A FEW ROCKETS IN NOVEMBER
Keith Yoerg and a few others launched five model rockets from the MTA event that day. We’re getting a lot more participants at our launch events which is a trend the society will encourage as we are expanding our organization by supporting a range of projects.
The first was “Star Orbiter” which was prepared and launched by Wilbur Owens, and successfully recovered about 3/4 of a mile from the launch site.
The second launch of the “29mm Rocket” was prepared and launched by Ivan DeDios, and unfortunately was not found after a lengthy search.
The third launch of the day was “Charlie Horse” and featured the largest motor flown that day. The rocket was prepared and launched by Keith Yoerg and resulted in his first flight above Mach 1.0. In addition, it was the first flight of a GPS carabiner used to track the rocket which performed extremely well & was easy to use. Cheaper options of similar technology are being researched for future flights.
The fourth launch was the “Bell X-2” which was prepared and launched by Keith Yoerg, and was a textbook flight with a simple recovery.
The fifth and final launch of the day was “Low and Slow” which was prepared and launched by Alexander Jones. Unfortunately, the parachute failed to deploy at apogee and the rocket came back ballistically & was destroyed along with one of the carabiner GPS units.
The RRS encourages all forms of reaction-based propulsion including commercial solid motor rocket flights. We have our traditional love for the micrograin rockets, but our society is open to all ideas as long as they contact the society and our pyro-op in charge well in advance of our launch events.
BILL INMAN’S SOLAR COLLECTOR
Bill Inman came out to the MTA to test his next prototype of a solar collector. Bill’s latest project is exploring the idea of a solar-based heating system for a steam rocket. This second device had a wider collection area and a longer pipe length. He didn’t have good sun conditions that day and his larger collector structure was a little unstable in the wind, but he was able to get ideas for improvement.
There was a very short period of sun that day and in that time a measurable temperature gain was seen with the new collector.
Testing the same device in the days following the MTA event at another location showed this second design to be a substantial improvement with the larger parabolic mirror area which allowed the water pipe to reach fluid temperatures exceeding 300 Fahrenheit and internal pressures of 90 psig. This is closer to Bill’s goal of reaching above 400 Fahrenheit for his next generation steam rocket from his successful Scalded Cat design almost 20 years ago.
STATIC FIRE OF THE USC RPL ALUMNI SOLID MOTOR
A group of USC RPL alumni static fired an 8-inch solid motor at the MTA. The team worked very hard from the night before and all through the day in getting the motor ready for static fire. The RRS MTA is an excellent location for these operations and conducting safe motor testing.
Unfortunately with some experiments, the results can be disappointing. The hot-fire in the very last hours of daylight ended with a rupture near the bulkhead after roughly one second of the burn.
The details of the event will likely be discussed at the monthly meeting teleconference on November 13th. We’ll be also discussing our next launch event to be held next month in December.
We will likely attempt the nitrous oxide hybrid motor with the modified igniter. The colder temperatures should allow the propellant manifold to operate properly without any modifications.
The removal and replacement of the bent panel on the vertical thrust stand was deferred because of USC’s static firing of their solid motor. This maintenance activity will remain a high priority since the replacement plates are ready and at the MTA already.
Thanks to the many members that contributed to this report. We will be planning our next launch event for the month of December at the monthly meeting scheduled for Friday, November 13th.