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.
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.
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,
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.
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.
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.
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 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.
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.