MTA Firing Event, 2022-07-31

by Dave Nordling, President, Reaction Research Society


The University of Michigan came to the Mojave Test Area for another static fire campaign starting Monday, July 25th and ending July 31st. Pyrotechnic operators, Jim Gross, Osvaldo Tarditti and myself supported this protracted campaign in the July heat. The weather was challenging during that week with few heat-related problems other than slow progress which is understandable given the conditions. New RRS member, Rushd Julfiker, and long time member, Jim Gross, assisted me in the cold flow and hot-fire testing. MASA’s academic adviser, Professor Mirko Gamba was also present at the MTA for the days of cold flow and hot-fire testing.

University of Michigan held a Test Readiness Review on Sunday, 7/17/2022, with RRS members present. Many good questions were raised but few corrections were needed. MASA proceeded with packing and departed campus for the MTA on Friday, 7/22/2022.

University of Michigan first day at the Mojave Test Area

The team arrived at the MTA on Monday night (7/25/2022) and began to unpack their gear and assemble the mobile test trailer. Leak checking went more smoothly due to design improvements. Problems with the igniter channel would prove to be a recurring concern.

Initial setup of the mobile trailer at first arrival.
Attaching frequently used tools by retractable tethers means never hunting for the right wrench again. Genius.
Hewlett-Packard film crew prepares to have interviews with the students.
Control trailer operations leading up to test.
A clean injector ready to be installed.
Fuel transfer operations before next test.
230-liter cryogenic liquid cylinders from Linde.

On Friday (7/29/22), gas bottles and cryogenic liquids were recieved from the supplier. Delays in receiving these consumables allowed sufficient time to verify systems were ready. MASA achieved significant progress towards hotfire after completing four valve timing coldflows and one abort test. Analysis of the data from our tests in preparation for hotfire tomorrow.

The RP-D2 engine sits on its thrust stand.
University of Michigan’s mobile test trailer beside the vertical test stand

Saturday (7/30/22) was the first attempt at hot-fire which was unsuccessful due to an igniter failure. The cause was traced back to an intermittent problem with the switch in the junction box. The prior igniter test demonstrated the igniter would fire in the cold flow conditions the day before. Comparing data sets, the team found that a simple verification of continuity in the voltage data stream during the countdown would safely identify a failed igniter firing circuit and allow a safe abort if it were to repeat.

RRS members Jim Gross and Rushd Julfiker examine the setup before the next test attempt.

In the last hour of the last day (Sunday, 7/31/22) of the campaign, MASA completed a successful 1 second hot-fire of the 2,000 lbf RP-D2 engine. The chamber and injector remained intact and the system safed itself properly.

Screenshot from the 1-second firing of RP-D2 as seen from the Garboden bunker

After examining the data, pressures were significantly off from the expected profile, but the engine passed the visual inspection After further consideration, the team opted not to proceed with a longer 4-second burn due to the uncertainty about our data values and pressure drops seen from hot-fire. MASA would conduct a more thorough examination of the data and hardware back at the university.

The MASA team began cleaning up the test site on Sunday night and continued throughout the night to prepare for the 1800 mile jouney home. University of Michigan was extremely happy with the result of their campaign and were grateful to our pyro-op’s and membership that supported every day with the MASA team.

The RRS was glad to provide our testing site, resources, experience, labor and insight to this successful testing campaign.

For inquiries about using the RRS Mojave Test Area, contact the RRS president.

president@rrs.org


MTA Launch Event, 2022-06-04

By Dave Nordling, President, Reaction Research Society


The RRS held a launch event on Saturday, June 4, 2022, at our Mojave Test Area (MTA). I was the pyro-op in charge. Winds were brisk and steady, but still under the 25 MPH limit. We had two operations that day.

The first was the UCLA Senior Capstone project led by Professor Brett Lopez. This quarterly class has seniors build and balance their own rockets from scratch. They load F-sized motors and fly them at the end of the quarter to prove their team’s skills in flight.

The UCLA students gather their materials in the propellant loading area.

Secondly, RRS member Wolfram Blume returned to the MTA with the latest rebuild of the Gas Guzzler. He had concerns about flying in the strong winds that day so he limited his work to testing the staging system with both halves on the 1515 rail. Bill Inman and new member, Dale, offered their assistamce in positioning the rocket on the rail.

Dale, Wolfram and Bill Inman

Bill Inman and Dale assisted Wolfram in trying out the new staging system in the Gas Guzzler. The old system (e.g., last December) was a hassle and required assembling the upper stage (main body tube, cowling, nose cone) on the rail with a screw driver and a step ladder. The mating of the booster thrust rods into the upper stage was very difficult. So after December, he redesigned and rebuilt the thrust rods and the staging system. The result was a successful design. The new system is fairly easy to stage on the rail, does not require any assembly (with the ever-present danger of losing small screws) and does not require a ladder. Wolfram feels good about this system for future launches.

The Gas Guzzler during its fit check on 6/4/2022

Wolfram doesn’t think he’ll make it back to the MTA until the summer heat is over. His goals for the summer both involve the fuel system:

  • The flameholder is the ramjet needs to ignite every time.
  • The ramjet slows down very quickly after stage separation (25m/sec/sec = 60mph/sec), so the ramjet must ignite within less than 2 seconds after stage separation; less than 1 second would be better.

Using the 270-volt, 3-phase electricity at Wolfram’s laboratory, he can run a 20hp air blower which can mimic the air flow at stage separation with a K-motor in the booster (175 m/sec). The blower can be run higher to mimic stage-separation flight speeds of about 250 m/sec which is just below the separation speed of an L-motor in the booster (280-300 m/sec).

Wolfram’s workshop is good for the tuning and testing the flameholder. but running the main burner would require returning to the MTA. The main fuel flow could be tuned using water. After the summer’s heat is over, he will return to the MTA and finish testing the parachute system. The first powered flight of the ramjet with a short – 5 second burn is under discussion.

This short event was also a good time to clean up the site a bit. The society has big plans for the summer including some much anticipated facility upgrades.

The next monthly meeting will be June 10th (2nd Friday of each month) by teleconference. Contact the RRS secretary for details.


April 2022 virtual meeting

by Keith Yoerg (RRS Secretary)


The latest meeting of the Reaction Research Society was held Friday, April 8th 2022 and had twenty-two attendees, including several student presenters from the UCSD Colossus project.

Screenshot of discussion during the monthly meeting

PRESENTATION FROM UCSD COLOSSUS TEAM

The meeting began with a presentation from the University of California San Diego (UCSD) Students for the Exploration & Development of Space (SEDS) team, led by the Colossus Project Manager Shannon Lin. Colossus is a trailer-mounted thrust stand developed by UCSD students with funding from a NASA grant, intended to accommodate a wide range of liquid bi-propellant rocket engines (up to 3,000 lbf).

Title slide from the UCSD presentation

The UCSD team hopes to market use time on Colossus to student, amateur, and professional groups that are building liquid rockets and would like to collect data without designing and building their own thrust stand. Colossus can collect concurrent data from 13 pressure transducers, 8 thermocouples, and 5 load cells at 1,000 Hz sample rate. They also expect to add a 20,000 fps high-speed camera as well as a mass-spectrometry camera to their data collection options.

The presentation prompted many questions from RRS members, and there was a lengthy description of the prior failure, refurbishment, and upgrades made to their mobile and modular test stand. The team expects to conduct coldflow testing in the coming months, and hope to use the MTA to test fire a CalTech rocket and a UCSD project sometime in the coming summer.

REVIEW OF RECENT MTA EVENTS

Following the UCSD presentation, membership discussed the recent events at the MTA since the March meeting. On March 12, Dimitri delivered and placed the new 40-foot storage container, Bill Inman performed his second and final burst test of a fired vessel for steam rocketry, and members conducted low and high-power launches. A firing report from Dave Nordling can be found here.

On April 2nd, LAPD CSP sponsored an event with STRIVE featuring Baby Bertha launches, a high-power launch, and one zinc-sulphur alpha. Maintenance of the MTA site was also performed that day by USC RPL and RRS president, Dave Nordling. A firing report from Dave can be found here.

The RRS executive council for 2022: from left to right, Larry Hoffing (treasurer), Frank Miuccio (vice president), Dave Nordling (president), Keith Yoerg (secretary)

UPCOMING MTA EVENTS

April 14th-15th the UCLA Rocket Project plans to use the Dosa Building at the MTA in preparation for a launch from our neighbor FAR on 4/16/2022. We are requiring that the group complete some site maintenance by way of brush clearance to help reduce the risk of fire at the MTA in exchange for use of the Dosa Building.

On April 23rd, USC RPL intends to static fire their Earthshaker 4 solid rocket, as well as launch a 6-inch rocket called Jawbone from the MTA. The group has been working with Jim Gross, who will be the pyro-op in charge that day. USC has also been conducting repairs on the concrete pad below the vertical test stand, including anchor bolt removal, concrete patching, and installing a new, larger female anchor bolt pattern via a template for accurate placement of future projects from any team.

The University of Michigan (MASA) is planning to conduct testing at the MTA from May 6th – 13th. Mutliple pyro-ops from the RRS will be required to support the campaign that the students hope to complete. The TRR is 4/21/2022, pyro-ops who are available should reach out to the RRS President to request the meeting details at: president@rrs.org Cryogenic deliveries to the MTA through Linde in Lancaster have been resolved, which was an important step considering the difficulties from the last time MASA tested at the MTA.

Frank and Larry have been teaching another rocketry class, this time with the YMCA. This class also uses Big Bertha launches and will likely include an alpha launch as well. This launch is planned for May 21st.

In early June, UCLA Senior Capstone project will use the MTA to launch rockets they have been building.

OTHER ITEMS

  • New and improved website coming soon!
  • Two new members of the society joined the Compton Comet team, Drake Perason and Alexis Monitel
  • Reminder for all pyro-op’s to renew their licenses with CALFIRE using new online system, deadline 6/30/22
  • Quarterly Amazon Smile disbursement

SAFETY AND RISK MITIGATION

Richard Dierking requested info on eye-wash station or similar on-site safety shower. Richard is researching and will present to the executive council in a few weeks.

Example of a portable eyewash station from an RRS member on the meeting

Richard Garcia did research on flame stacks, and whether the RRS should require their use when methane is used at the MTA. He is working on building reference to know what safe distances should be based on existing plume models. As the RRS Director of Research, Richard may draft a paper to add this information to the RRS member library. Other members or student groups with papers they would like considered for addition to the library can contact Richard at:

research@rrs.org

NEXT MONTHLY MEETING

The next RRS monthly meeting will be held virtually on Friday, May 13th at 7:30 pm pacific time. Current members will receive an invite via e-mail the week of the meeting. Non-members (or members who have not received recent invites) can request an invitation by sending an email to:

secretary@rrs.org

Please check your spam folders and add secretary@rrs.org to your email whitelist to make sure you are receiving the meeting invitation.