MTA launch event, 2020-11-07

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By Dave Nordling, Reaction Research Society

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.

Recovered standard alpha from the July 2020 launch
The standard length alpha was recovered with its nozzle and the ceramic lined throat. No erosion seems to be present.

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.

The golden color of the coating can be seen at the inlet. The condition of the coating around the throat is what must be determined.

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.

  1. 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. 
  2. The second launch of the “29mm Rocket” was prepared and launched by Ivan DeDios, and unfortunately was not found after a lengthy search. 
  3. 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.
  4. 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.
  5. 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 aptly named “29mm rocket” by Keith Yoerg, powered by a 29mm H115 Darkmatter motor, seen at take-off from the RRS MTA on 11-07-2020
The 29mm Rocket taking off.
Keith Yoerg’s “Charlie Horse” takes flight again frim the RRS MTA on 11-07-2020 powered by a 38mm J520 Skidmark motor.
A great still capture on the Bell X-2 at launch.
Camera view of the Low and Slow rocket at take-off
The recovered remains of the “Low and Slow” rocket by Alexander Jones.

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.

The five commercial solid motors laid out on display.

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.

Dimitri Timohovich aids Bill Inman in deploying his second generation prototype solar heater. It was a less than ideal day for solar insolation at the RRS MTA. Even the Mojave Desert can be cold on winter days.
A wider collector area in the new design. It was a less than sunny day.

There was a very short period of sun that day and in that time a measurable temperature gain was seen with the new collector.

A wider view of Bill’s solar 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.

Vapor curve data for water, psia in the left column, degrees Fahrenheit on the right.
The vspor curve of water showing the whole range from triple-point to critical point.

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 8-inch motor in preparation for testing.
Preparation at the pad as the afternoon is fading at the MTA
Photo of the static firing, less than ideal performance

IN CLOSING

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.

October 2020 virtual meeting

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by the Reaction Research Society

The RRS held it’s monthly meeting by teleconference on October 9th at our usual starting time of 7:30pm. We had a few members calling in from out-of-state. We had a few new topics to cover.

Some of the attendees to the October 2020 monthly meeting

SUMMARY OF RECENT MTA EVENT

We held a work event at the Mojave Test Area on October 3rd which was very successful despite higher temperatures for that autumn Saturday. We cleared a lot of tumbleweeds, mended the barbed wire fence at our front gate, painted the metal window gratings on the front of the Dosa Building and even cleared off the decks of the large vertical test stand. We had a lot of great help and we hope to continue making these site improvements to make our facility more attractive and useful.

The large vertical test stand at the RRS MTA after some clearing.

We agreed to meet at the MTA again on November 7th which will coincide with a static fire test of USC’s Rocket Propulsion Lab latest multi-grain solid motor design. We will also attempt to remove and replace a bent panel on the vertical thrust stand. The nitrous oxide hybrid rocket by Dave Nordling, Larry Hoffing and Osvaldo Tarditti is also ready for launching. If there are other member projects that are ready we will add those to the event and notify the pyro-op in charge.

LIQUID ROCKET PROJECTS

Liquid rocket projects have become more popular recently and some have started within the RRS.

Loyola-Marymount University (LMU) in Marina del Rey started a capstone project for their upper classmen in their undergraduate aerospace engineering program to design and build a large liquid rocket. The LMU Lion project was inspired by the FAR-MARS competition. Dave Nordling has been supporting the early design work on behalf of the RRS starting early this calendar year prior to the pandemic restrictions ending in-person meetings. LMU has restarted the project with the new academic year with a series of specialized coursework and short presentations on topics from experts around the industry. Dave was glad to present the history and capabilities of the RRS. The presentation was well received and LMU has looked at using our vertical test stand when they get their first liquid rockets systems ready for test.

Loyola Marymount Aerospace Research Society

The Compton Comet project at Tomorrow’s Aeronautical Museum has been restarted with RRS members, Waldo Stakes, Kent Schwitkis and Dave Nordling. The Compton Comet is a liquid rocket to be built, tested and flown at the RRS. It is a larger vehicle design which has several parts built and will use a surplus XLR11 single-chamber fueled by LOX and a 75% ethanol-water blend, It is a very ambitious project for the Compton College STEM students but it will provide an excellent means of learning practical skills.

Engine section built from a surplus tailcone and ethanol-LOX engine sits on the workbench

UCLA is continuing Project Ares for this next academic year. Last year’s liquid rocket vehicle design was in its final preparations for a Spring 2020 launch at FAR until the pandemic closed campuses around the country including the UCLA Lab. UCLA invited a few RRS members to attend their preliminary design review by teleconference. They are proceeding with several design improvements from last year’s vehicle design and when their laboratory access is restored under carefully regulated conditions, they hope to have another static fire at the RRS and flight from FAR next spring.

Thr Rocket Project at UCLA

Richard Garcia had started a design for a small liquid fueled rocket that would be easier to build and serve as the basis for a common or standard design for society members wanting to test and fly a liquid rocket at reasonable cost. Propellants are ethanol and liquid oxygen. The design has features proven from past successful liquid motor testing at the RRS MTA. The first prototype of the small 125 lbf motor is in build now. After successful demonstrations of the motor in hot-fire, the vehicle will be built.

Illustration of the RRS standard liquid rocket concept

There is a rocket hangar space opening up at the Compton/Woodley Airport which RRS members will soon have access. It has been a goal to have a work space within the city centrally located for most of our members. Operations at the rocket hangar will be limited to construction activities and small-scale pressure tests and cold flow operations, but it will offer our members a greater convenience for those with limited working space in their homes. Contact Wilbur Owens and Xavier Marshall for details. Social distancing and mask protocols would apply.

MTA FIREFIGHTING MEASURES

Fires are one of the greatest risks that come with amateur rocketry. At the behest of several members we have been discussing way of better preparing to fight fires from our site. The roughly one dozen pressurized water containers we have in our storage container are filled and made ready at every event. These have been useful for containing any fires starting at the pads. The RRS is looking at storing large quantities of water at the MTA. We’re also looking at trailer mounted water tanks that could be pulled by a small all-terrain vehicle (ATV) with a motorized pump spray system. These are commonly found in agricultural locations and would be an excellent addition to help limit the propagation of downrange fires until county resources can arrive.

An example of a 200-300 gallon water tank with a motorized pump system

MTA FACILITY UPGRADES

New restroom facility designs have been discussed over this summer. Concepts have been discussed with contractors and firm cost proposals are being prepared. Issues like cost and permits are important concerns. The society last year approved this facility upgrade project as the top priority.

One of several concepts for a new restroom facility at the RRS MTA under discussion

ANNUAL ELECTIONS FOR EXECUTIVE COUNCIL

Next meeting teleconference will be held on November 13th. After appointing an election chairman, we will be holding nominations for executive council positions at the meeting. Administrative members of society are encouraged to participate as we select our next year’s leadership. Active membership is also required so be certain to pay your dues if you haven’t all year.

If there are any questions or comments, please contact me RRS secretary. You can also follow the RRS on Facebook and on Instagram.

MTA work event, 2020-10-03

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by Dave Nordling, Reaction Research Society

The long awaited work event at the Reaction Resesrch Society’s private testing site, the Mojave Test Area (MTA) took place as planned on Saturday, October 3rd. We had a good turn-out to take on a few of the much needed repairs, cleaning and maintenance activities around the site. These work events not only improve the site but also enhance it’s appearance for our visiting guests. The RRS takes pride in our one-of-a-kind site and working on our site makes us all more closely connected as public activities are so few during these unprecedented times. All activities were able to maintain social distancing and everyone had their mask.

The primary purpose of this event was maintence activities but secondarily we were ready to conduct launches if members had projects ready. I was the pyro-op in charge for that day if there was to be any launches. Wolfram had cancelled his first flight attempt of the Gas Guzzler two-stage rocket due to concerns with excessive heat. Also, my next attempt to fly my nitrous-oxide hybrid rocket was postponed as we needed more people to work the planned maintenance events throughout that day. Bill Inman had contacted me with his proposed solar heater experiment. After a cursory review of his experiment, the society allowed him to proceed. Bill makes a very long journey to the MTA from Carson City, Nevada, and we are glad he has chosen the MTA to conduct his initial experiments for his next generation steam rocket.

Osvaldo led the repair and refurbishment efforts that day. Despite the higher peak temperatures that day, a lot of work was done which has helpful in restoring the site.

The arched sign welcomes our membership and guests to the RRS MTA. Still looking great after years in the desert.

REPAIR OF THE 8-INCH ADJUSTABLE BOX RAIL LAUNCHER

The 8-inch adjustable box-rail launcher was damaged in a failed solid motor launch last year at the MTA. The resulting explosion destroyed the four adjustable rail guides and distorted a few of the box frame members. Given the heavy and large size of this box rail launcher, it was only practical to conduct repairs at the site and bring in new steel materials to be cut, grinded and fitted for welding such that all parts fit correctly.

Getting ready to build new rails in the 8-inch adjustable rail launcher

The replacement rail guides used thick square stock instead of the previously used round stock. This was done for both having a flatter surface for clamping and holding the rails in place but it also made moving the rails easier to do than with the closer fitting round rails. The square slider pieces were also more easily welded to the square rails with much grinding.

Osvaldo and Dmitri did excellent work. With the right tools, material and skill, the job was done by mid-afternoon. The four rails are back in place, but some of the box rail members remain bent or distorted. Although not entirely perfect, the rail launcher should now be useful again for future tests,

John Krell (left) and Dmitri Timohovich (right) inspect the repairs on the 8-inch box rail launcher at the RRS MTA on 10/3/2020

TUMBLEWEED AND BRUSH REMOVAL

A lot of the team was working on clearing the immediate area of tumbleweeds near the many structures and sites around the MTA. Alastair Martin and Keith Yoerg worked many hours with a metal rake and shovel and made a marked difference around several overgrown spots. Tumbleweeds are a persistent nuisance throughout the western United States and Mexico as they thrive in the dry hot climate. Removing them is fairly easy, but disposing of them is far more challenging. Fire hazards are one of the topmost concerns in amateur rocketry. Our desert launch site is always under this threat. By periodic clearing and disposal, the threat of fire propagation can be minimized.

Clearing the east side of the container fenced area.
The large vertical test stand after some clearing efforts both on the ground and on the upper decks.
Second view of the large vertical test stand at the RRS MTA at the end of our 10/3/2020 work event.
Waldo drags an old iron launch platform to clear the vegetation from around the MTA site

Keith and Alastair did a lot of hard work in manually clearing the edges and the upper decks of the vertical test stand. Waldo Stakes was also kind enough to drag the area to clear wider spaces more quickly, The result is a clearer work area better able to conduct rocketry activities at the MTA.

CORROSION PREVENTION AND PAINTING

Frank Miuccio and Chris Lujan worked on the metal lattice covers on the two front windows of the Dosa Building. They sanded and brushed on rust remover to clear the surfaces for a protective paint coating, It was a lot of fine detailed work but the resulting look of the metal grates without rust looks so much better.

Frank carefully sands, treats and paints the metal lattice covering on the front windows of the George Dosa building at the 10/3/2020 MTA work event.
Chris Lujan steps back from his work on the other front window of the George Dosa building.

Little touch-ups can be very time-consuming but it is worth taking the time to do the job well. There are many areas around the MTA that could benefit from some corrosion removal and surface protection. Although the desert is dry, the caustic, salty, dry lake environment can erode steel surfaces over the years.

SOLAR CONCENTRATOR EXPERIMENT

RRS corresponding member, Bill Inman came out to the RRS MTA work event to conduct a test of his first prototype solar concentrator for heating his next generation steam rocket. The experiment was a simple apparatus design to focus sunlight on a length of 2-inch black-painted iron pipe holding roughly 2,7 liters of water.

The wooden box had two angled mirrors to focus most of the incident sunlight near the pipe. To avoid natural convection losses, his concentrator had a clear glass panel enclosure. In essence it is a trough heater. The goal was simply to understand the practical operation of this first device and make improvements to see if a solar-based heating scheme for a steam rocket is feasible. Bill’s device had approximate pressure relief should the concentrator over-perform.

Bill Inman’s first prototype solar trough collector for heating a steam rocket tested on 10/3/2020

Results were a little lower than expected, but a measurable gain in water temperature was measured after operating throughout that afternoon, Air temperatures reached a peak of 104 degrees Fahrenheit (F) and the peak water temperature was 180F, far short of boiling temperature (212F) at amibent pressure. Effective steam rocket temperatures are often around 350F to 400F. There is more work to be done.

A FEW SMALL ROCKETS LAUNCHED

Keith Yoerg prepares the Big Bertha for launch on his wire rail launcher.

Keith Yoerg had brought a few small rocket kits for launching at the MTA during a break in the maintenance work. A classic Big Bertha and Baby Bertha each with B6-4 motors. The winds were very light and good for launching these small rockets. Both were ably recovered.

IDEAS FOR FUTURE WORK AT THE MTA

Near the end of the day, we discussed new improvement tasks at the MTA. A few of these were listed below:

  • Further removal and disposal of tumbleweeds, there are a lot along the eastern fence and in the flame bucket of the large vertical thrust stand. Burning them under controlled conditions is one possibility but winds must be very low
  • More ideas for the new restroom facility were discussed that could take advantage of pre-existing materials or assets at the MTA
  • Removal and replacement of the bent steel panel on the vertical thrust stand. New steel panels were made with the matching hole pattern.
  • Rust removal, corrosion prevention and painting of the large vertical test stand structure is a lengthy project but would greatly improve the look of the whole site.
  • Removal and replacement of the old blockhouse roof and shoring up the existing walls is being considered as a lower cost upgrade to this important and often used asset at the MTA.
Taking some measurements around the bent panel on the vertical test stand at the RRS MTA

It was a great team effort that day and everyone worked very hard. Nearly all of the planned objectives were accomplished. It has been suggested that another work event at the MTA be planned for next month. We also hope to work in a few launches if we can.

These ideas and other topics will be discussed at the next meeting of the RRS on Friday, October 9th. We’ll hold this meeting by teleconference again due to COVID-19 restrictions. Those wishing to attend should contact the RRS secretary.

secretary@rrs.org