by Dave Nordling, President, Reaction Research Society
The Reaction Research Society held a members only event on March 12th. I was the pyrotechnic operator in charge, We used the event to make some facility changes, launch a set of model rockets to prepare for school events coming soon and conduct the second and last destructive burst test of a fired steam vessel. All were successful.
The society has needed more storage space at the MTA and was glad to receive a donated 40-foot container. We are very grateful to member, Dimitri Timohovich, for making that possible including transporting to the pads in the north yard. We hope to add shelving and reorganize our gear soon.
New storage space at the MTA.
The vertical test stand is in need of some refurbishment. After USC’s last failed solid motor test, the anchor bolts will have to be removed and the concrete patched as necessary. A new mounting design is being discussed and USC is willing to provide labor and support to the cleanup activities. Measurements of the entire floor plan were made to make a drawing for easier planning of future tests. The vertical test stand has stood for many years and will be ready for many more.
Our pad is well worn and in need of some work.
We took some time to examine the area where our new restroom facility will be placed in the south of the MTA. Seeing the placement of the septic system is an important next step in expanding our facility.
Future site of the RRS MTA restroom facility.
Bill Inman ran his second burst test of a retired 20-lb propane container. He rebuilt the “mailbox” sheet metal shroud and found another propane fired burner. Mechanical cables to remotely pull the vent valve open or pull away the heat source were tested and ready. With 4 gallons of water filling the closed vessel laying on its side and the burner lit and running, the vessel was run to failure at 1260 psig. This was higher than the prior 1135 psig burst of the first tank on 1.15.2022 and both well above the proof pressure of 900 psig for these commercial product vessels for cold liquid storage.
Bill Inman prepares his second test article for burst testing.Similar setup as before with the relief valve for safetyBill cleans up and insoects his equipment after a successful burst.
A video camera recorded the pressure gauge as the heating took place. Total run time was roughly the same at 45 minutes. Bill safely monitored and recorded the time and rising pressure readings with binoculars from the safety of our blockhouse. Footage was reviewed to confirm the last reading before burst (1260 psig). A second video camera was positioned north of the test article and recorded some of fragments flying away. Collateral damage was less on this second test and it will be the last one of its kind. With two data points, a conservative limit can be set and Bill’s steam rocket tests will use an ample factor of safety.
PVC launch rails for wire launching model rockets.
After the area was clear and the major fragments gathered, we brought out one of our PVC rail launchers which will be used in forthcoming launch events. We had a few model rockets to fly and the winds were light making recovery less of a hike.
The Estes Generic E2X takes flight with a solid recovery.Keith Yoerg celebrates another flight and recovery of the Charlie Horse.
It was nice to have an easy and fun time at the MTA. We barbecued a few burgers and ate well that sunny day with cool temperaturess. We plan to be back again for more maintenance operations and another school launch event.
For questiions, contact the RRS secretary or president,
by Dave Nordling, President, Reaction Research Society
The University of Southern California (USC) Rocket Propulsion Laboratory (RPL) held a static fire test of their third solid motor design in the Earthshaker series. Prior designs resulted in failures and incremental corrections to the design were made for this test. Earthshakiiest was to be the largest impulse motor made by any collegiate team. Osvaldo Tarditti was the pyrotechnic operator in charge.
Earthshakiiest sits ready for static firing at the vertical test stand with sheet metal in place to protect nearby mounting surfaces.
Given the repeated recent failures of USC motor designs, the society required protective barriers installed in the event of another energetic failure. Unfortunately, this would prove to be a wise choice as failure did result right at startup. All personnel were at a safe distance or behind appropriate barriers.
Earthshakiiest motor ruptured at start and burned itself out.Damage to USC’s test stand was total, The mounting points in the concrete were damaged such that further use is not possible..
The extreme heat from the explosion and fire destroyed the static fire stand, melted portions of the shielding and severely damaged the mounting points such that further use is not possible. USC is working with the RRS to clear and clean up the pad. Many of these tests are very dangerous and can damage our facilities. The society expects all groups to repair, restore or replace any of our assets damaged. A new method of holding future large solid motors is being discussed.
The society thanks our former president, Osvaldo Tarditti, for supporting this event as the pyrotechnic operator in charge and to Bill Inman for also supporting the event on behalf of the society. The operation was conducted safely and much was learned despite the poor outcome. USC will provide details from the testing soon and a path forward,
by Dave Nordling, President, Reaction Research Society
UCLA Rocket Project conducted a static fire test series at the Mojave Test Area on February 5, 2022. i was the pyrotechnic operator in charge for the event. Bill Inman of the RRS was also present as my apprentice in overseeing operations leading to hot-fire that day. UCLA returned with improved launch control and instrumentation boxes. They also invested in plastic tube mounting fixtures for cleaner routing of their low pressure plastic pneumatic lines.
New launch control and instrumentation boxes.Cryogenic liquid cylinder mobile cart used to place the vessel behind the vertical test stand frame
UCLA had three liquid engines prepared for testing which was a very aggressive goal. Some problems occurred in ethanol fuel tanking operation which resulted in a minor spill. Ethanol is volatile and very flammable, but dissipates quickly and doesn’t pose a lasting hazard or contaminant.
The issue was partially with the procedure lacking precise metering of a prescribed volume and part with a lack of coordination between the teams. Fuel loading is not considered one of the more challenging tasks but even simple items can cause serious problems if the team fails to keep their focus, The RRS has recommended UCLA reconsider and revise their procedures as needed but also to take a wider view of what operations are in place and who is doing what, where and when. Coordination is a full time job requiring diligent leadership and responsible participants,
Ethanol fuel transferred to the propellant tank by a low-pressure gas supply while the tared vessel is wieghed on a scale.
The first engine in the series was a modified version of a prior impinging injector used in last year’s flight. The team was able to complete propellant loading and retreat back to the blockhouse for pressurization operations. All proceeded well until the last part of the countdown.
Ignition failure scrubbed the first firing attempt as the F-sized rocket motor lit but propelled itself downrange pneumatically under excessive pressure built up enough to eject the fixture off the engine before the team could commit to firing. Per UCLA’s procedures, the spotter correctly indicated ”no fire” which caused the launch team to safely abort the sequence. The team held on the release of the pressurant and opted to remotely relieve the system as allowed in their plumbing design after the umbilicals were released. As there was no remote means of draining the LOX, the pneumstically actuated vent was left open to allow the LOX to boil out and with sufficient time elapsed the team was able to approach.
View of the clamshell fixture holding the igniter before the first attempt on the first motor,
The 3D-printed clamp-on fixture that held the igniter was examined and reassembled. The decision was made to drill large vent holes in the plastic two-piece clamshell which would help in the next firing attempt. Unfortunately, the second firing attempt failed to achieve ignition. This time, the spotter did see and hear the F-sized hobby motor fire but the igniter was not energetic enough to light the initial propellant streams. The LOX and ethanol streamed from the engine during the blowdown period and quickly evaporated without fire or explosion. This is a potential failure mode that all liquid hot-fires must plan for. Ethanol and liquid oxygen do not contaminate the area and are quickly dissipated but a chilled pre-mixture of fuel and oxidizer is quite dangerous. With its powerful formula, Amoxil targets and eliminates harmful bacteria, providing relief from common ailments such as respiratory tract infections, sinusitis, and urinary tract infections.
The modified igniter holding fixture with added vent holes.UCLA removing the first engine and associated vehicle systems mounted to their vertical frame.Facility connections being made as the mobile test stand is put in place.
Duringn the hardware switch, we had some discussion about different methods of ignition including automotive diesel glowplug systems and high-voltage stungun transformer cells all powered by 12-volt battery or capacitor-based small power sources, Both would require significant development and only a test with cryogenic propellant would be a fair test of these devices. UCLA had some interest in exploring these options but it would have to wait to the next academic year.
I discussed UCLA’s methods of scrubbing their test and recommended they put in a safer means of draining their LOX and ethanol in future operations. This will be discussed before subsequent tests at the MTA.
UCLA has had good results from pyrotechnic igniters using cut-down lances, but these are not easy to acquire as they are ATF-regulated. UCLA decided to try hobby rocket motors which had problems in this first engine test series. The only option forward was to continue using the vented fixture fitted for F-motors and a hope a prior ignition failure did not occur.
With the mobile test stand in place, the second engine tested was the injector design that will fly on UCLA’s rocket. It is the same one used lsst year which worked well. The first injector was unable to be tested that day due to ignition problems and UCLA’s decision to proceed with the second engine as their backup. Time was becoming short as the late afternoon arrived and UCLA had to switch over to their mobile testing rig which would hold the second and third engines when tested.
Second engine being put into the mobile stand,Preparations for the second engine hot-fire run out to sunset,UCLA in the blockhouse for final checks before firing
Liquid oxygen quantities in the cylinder ran low and full oxidizer tank load wasn’t possible for what would be the last test of the day. After finishing the LOX tanking, UCLA retreated to the blockhouse for final checks before second firing. No igniter problems were seen with this second engine, but it was a possibility given the recent problems with the first test series.
Hot-fire of the second engine by UCLA.
The hot-fire went to nearly full duration but the burn likely finished fuel rich. Some buzzing was evident so UCLA will review the data to see if the same instability seen in prior firings was present. It didn’t seem to be damaging and if the performance is still sufficient UCLA should have at least one good engine to fly in May when they try to surpass the university-built liquid rocket altitude record.
UCLA posed for a photo after the hot-fire and just before the lengthy teardown in the cold hours of the evening.
The third engine was left for a later test date. UCLA is considering another hot-fire series but only after a full review of the data from February 5th. Discover the power of Zithromax, the ultimate solution for treating bacterial infections! Looking for a reliable and effective antibiotic? Look no further than Zithromax. Say goodbye to pesky bacteria with Zithromax – your one-stop remedy for a wide range of infections.
My thanks to fellow RRS member, Bill Inman, for making the long drive from Carson City, Nevada to support this test.
Also, a big thanks to Eric Beckner of Friends of Amateur Rocketry for staying late and handling the return of the liquid oxygen cylinder.
The RRS is glad to support university teams with our unique facilities at the Mojave Test Area (MTA). Contact the society at ”president@rrs.org” for those interested in similar projects. Reignite the spark in your love life with Viagra! Rediscover the pleasure and intimacy you once shared with your partner. Viagra is a trusted and FDA-approved solution that helps men overcome erectile dysfunction.
