Tag Archives: hydraulic cylinder

MTA Launch Event, 2023-11-24

Posted on by

by Dave Nordling, President, RRS.ORG

The RRS met at the Mojave Test Area for a work event on the 60-foot launch rail project. While we were there, we had a launch or two thanks to Bill Inman and Keith Yoerg. The pyrotechnic operator in charge for that day was Keith Yoerg.

Bill brought one of his older rocket bodies. Unfortunately he had a mishandling error on the pad which broke one of his fins requiring repair. His mission was to test the avionics package that he will use in flight on the Solar Cat. Keith launched some smaller Estes model rockets to show one of our youngest potential members the basics of rocketry.

The work event benefited from having Osvaldo Tarditti, Joe Dominguez and Dimitri Timohovich moving the donated ham radio tower to the 40-foot flatbed next to Bldg. 11 for inspection. The goal was to fully extend the tower and examine its condition to see what modifications are necessary to use it in our 60-foot launch rail design.

Our thanks goes to member, Waldo Stakes, for finding and donating this old galvanized steel ham radio tower which can be reinforced, modified and slightly lengthened to create the stiff backbone for the launch rail guide. The tower was designed to be extensible, but the society will fully extend and fuse it at its full length. Several areas of repair were identified but with a little persistence and forcible persuasion, the structure was extended in preparation for the next event when our welder will start the initial work at the next work event in 2 weeks.

Our director of research, Rushd Julfiker, was selected as the project manager for this major infrastructure item that should allow university teams to launch from the RRS Mojave Test Area. With the basic requirements set at the first meeting, the sketches produced will be converted to CAD drawing files with Rushd’s assistance. Initial material procurement will begin as the backbone frame has been found to be acceptable for use in the design.

The loads are being carefully calculated along with sizing the dual-acting hydraulic ram system for raising and lowering. Waldo Stakes also found a pair of 3-inch cylinders and an electric hydraulic pump in surplus and donated them to the society. Their specifications are being assessed if they can be used which would save some costs.

In the days following the event, we put in wooden privacy panels in the windows of Bldg’s 14 and 15 both for security and improved insulation. The society will soon be discussing how to minimally furnish the interiors for functional needs only including some storage of our consumables. No pyrotechnics will be stored in these containers. Both Bldg 14 and 15 have air conditioners and insulation but still require connections to power. In the short term, each can be powered by our portable gasoline generator. In the near term, once fully funded the society will power both assets from a larger diesel generator we recently acquired.

Dimitri spoke about finding another 40-foot container which could be used for an on-site workshop at the RRS MTA (potentially new Bldg. 16). The council will have to consider this addition at the next meeting.

Lastly, Dimitri installed a solar powered light just above one of the restroom doors which will help our overnight guests find their way to sanitary relief on a moonless night.

Our launch pad pour was delayed to December 9th due to concrete availability. We’re making it thicker than most anticipating the greater loads of the launch rail structure. Our next work event at the MTA will coincide with the pad pour where we will continue the 60-foot launch rail work starting with the launch rail backbone. Materials will be procured in advance of the next meeting.

Also, our last monthly meeting of the year will be the day before, December 8th, 7:30pm, where election results for next year’s executive council will be announced. Also, it was declared that the December meeting will be our much anticipated pizza party funded by the accumulated funds from the RRS Amazon Smile account, now discontinued. Please arrive early at the front office of the Compton/Woodley Airport.

MTA launch event, 2021-05-29

Posted on by

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