Tag Archives: Prometheus

MTA Firing Event, 2024-03-02

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by Joel Cool-Panama, Secretary, RRS.ORG

The UCLA Prometheus team arrived to the MTA late Friday night under cold winds and light rain. Taking shelter from the elements, many set up their tents inside the Dosa Bldg.

The UCLA team brought their latest custom hybrid motor for a horizontal static fire. Dave Nordling served as pyrotechnic operator with Rushd Julfiker and Dimtiri Timohovich apprenticing. After passing low pressure leak check, they corrected issues in high pressure leak check.  Some minor control issues set back first hot fire to just past sunset. First igniter was a dud. Pyro-op in charge permitted a second attempt with a new igniter. Improper sequencing pushed out the second igniter before the booster charge could light the motor grain under the rush of the oxidizer stream which resulted in the dumping of the nitrous oxide flow over the grain with no ignition.   After some consideration to adjust the timing and reset a new electric match, given the late hour and a concern about hard starting the motor with a recently oxidizer soaked grain, the pyro-op in charge opted to call off the event.  Our unpaid volunteer pyro-ops sometimes will stay late, but sunset is generally considered the cutoff point. UCLA put a great deal of effort and ingenuity but with no success by the end of the event as sometimes happens despite best efforts. UCLA was very courteous throughout the whole event and the RRS looks forward to the Prometheus team’s return to the MTA.


Dimitri and his colleague, George Warner, began the trenching and electrical work this weekend needed to connect our new diesel generator at the MTA which will soon serve our larger electrical and lighting needs around our facility.  The work continued through Sunday, 3/3/2024. The crew cabin (Bldg 15) and the office (Bldg 14) were the first fully-owned RRS owned to be connected to electrical power as they have air conditioning. This will be a welcome resource in the late summer months.


Rushd Julfiker is working on his 38mm Contrails hybrid kit motor for an initial static fire.  Rushd refilled the society’s nitrous bottle. Dave Nordling and Dimitri Timohovich brought and shared their resources and experience. A hybrid motor firing hasn’t been done in a few years and its good to bring this work back as society. Unfortunately given the late hour and missing the nylon tubing needed, Rushd will return at a later date.

Osvaldo Tarditti worked on the shower systems in the restroom facility. We hope to have this convenience working in the coming months. The toilets, urinals and sinks continue to run well even during high usage periods.  The convenience of this facility at our remote location has been a much lauded benefit.

Dave Nordling added metal folding handles to the backsides of the wooden privacy panels in the windows of Bldg’s 14 and 15 for easier removal and replacement.  These heavy panels help insulate the interior from the beating sun. Also, the RRS ate its first meal inside Bldg 15.  The large interior space also can offer our visitors shelter from the elements once we add the beds and more chairs inside.


Dimitri brought the methanol run tanks and empty gas bottles used only for public exhibitions to the MTA. Dave Nordling brought the steel support frames to the MTA along with several components for the fluid feed systems for the 1936 GALCIT engine replica. The first engine parts will be brought to the MTA this coming Thursday when American Artist visits the site for the first time. We look forward to his visit and beginning the first steps in the project.



RRS members involved with the LACMA / American Artist project including RRS President, Frank Miuccio,will be at the MTA on Thursday, March 7, 2024. This will be the first time that American will see the site. Establishing the filming location for the static fire of the 1936 GALCIT replica rocket engine will be the first priority. American’s cinematographer (Chester) and a documentary film crew from PBS will also be present that day.

Next monthly meeting of the RRS will be March 8, 2024, at the Compton/Woodley Airport.

MTA launch event, 2021-05-29

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by Dave Nordling, Reaction Research Society

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 Prometheus team prepares for static fire at the RRS MTA on 5-29-2021
Dave Crisalli gives the MTA safety briefing for the event in the loading area where the model rockets were assembled for flight.
UCLA graduate students conducted the model rocket launches from just west of the large test stand at the MTA

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.

UCLA’s liquid rocket set on the 60-foot rail launcher at FAR. The team preparing the vehicle for erecting, loading then flight.
RRS members from left to right, Bill Inman, Waldo Stakes, John Wells and Manuel Marquez, inspect the UCLA liquid rocket on the 60-foot launcher deployed at the FAR site.
A few last minute fixes and the rocket was made ready.
The liquid rocket sits on the rail before raising it for launch.
UCLA’s rocket is in position getting ready to clear the area for propellant loading and pressurization operations.

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.

UCLA’s liquid rocket had a perfect launch on 5-29-2021 setting a new altitude record of 22,000 feet by a university team. Photo by Xavier Marshall, RRS.

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 UCLA Prometheus team makes some adjustments to better align the hybrid motor in the vertical skid mounted to classic I-beam at the RRS MTA.
The nitrous oxide K-bottle sits inverted in the sloped stand to allow the liquid to flow from the port. Some nitrous oxide bottles come with an internal siphon line to avoid having to invert the container. The bottle is also being chilled with ice to keep the oxidizer sufficiently dense and improve performance in hot-fire.
The top bulkhead of the hybrid motor is attached to the load cell for thrust measurement. A pressure transmitter is tapped into the nitrous oxide volume to further gauge performance.
The high-powered hybrid motor by Contrails uses four 1/4-inch fill lines and a single smaller vent line from the same floating injector at the mid-point inside
Dave Crisalli (right) inspects the hybrid motor on the test rails before the firing
UCLA Prometheus team tracks their written procedures as they progress to hot-fire in the old blockhouse.

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 hybrid motor at startup.
The UCLA hybrid motor at full thrust. Chamber pressure was over 1000 psia.

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.

The top half of the floating injector with its internal siphon tube protruding up to near the top bulkhead.
The floating injector being removed from the lower half containing the spent fuel propellant grain.
The floating injector was removed after hot-fire and the dual O-ring seals were inspected. Seals were ok for re-use.
The nozzle assembly did not pass inspection after the first and only hot-fire on 05-29-2021.
The graphite nozzle fractured at the inlet taper from the first and only firing that day.

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.

UCLA avionics team conducted a few tests on the GPS tracking module that will fly on their vehicle in June 2021.

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.

president@rrs.org