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UCIRP Liquids Team Q4 Report for 2024

Written by Kai Meyers

UCI Rocket Project (UCIRP) Liquids Team

Overview of the UCI Rocket Project Liquids Team:

The UCI Rocket Project (UCIRP) Liquids team is a group of undergraduate students building a bi–propellant liquid rocket with our sights set on breaking the collegiate methalox altitude world record of 13,205 feet above ground level (AGL).

In Q2 of 2023, the Project launched our first bi–propellant liquid rocket Preliminary Test Rocket (PTR) 9,100 feet into the air but failed to recover the rocket. Through the learnings of this experience, the team has clearly defined objectives for how we will accomplish our goal of breaking the collegiate methalox altitude world record. 

 

These include:

  1. Decreasing the weight and size (decreases drag)
  2. Decreasing horizontal velocity (fly straighter)
  3. Increasing thrust (by optimizing engine efficiency

 

 Q4 Management Overview:

After 10 Cold Flows this Quarter, we conducted the first Vertical Test Fire (VTF) on December 7, 2024 to gather data on MOCH4’s latest updates. Unfortunately, we experienced an unexpected phenomenon during VTF that caused our engine to hard start and ultimately explode.

Although we do not know the source of the issue, we are looking at the data and working hard over break to plan out our next steps, including another test fire likely at the end of Q1 2025.

We would like to thank the Dean of Engineering Magnus Egerstedt, our advisor Professor Shi, and EH&S for assisting us with the Cold Flows throughout the Quarter leading up to our test fire. We are extremely excited about furthering our pursuit to break the collegiate methalox altitude world record May of 2025.

Vertical Fire Test: A test conducted to comprehensively verify the rocket’s propulsion system (the engine and internal plumbing) in a vertical launch configuration. The Vertical Test Fire helps the Project confirm whether we are meeting the critical requirements for the Q2 2025 launch.

Cold Flow: A test conducted on the rocket’s propellant feed system to verify that all propulsion components function nominally in a fully integrated system, simulating test fire / launch conditions as close as possible without using actual reactive propellant. Cold flows allow us to verify system pressure and temperature profiles, test operations, and check for leaks or other potential issues.

Propulsion

The Propulsion subteam is responsible for developing the dual cryogenic propulsion system, which combusts liquid oxygen (LOX) and liquid natural gas (LNG) to generate thrust, enabling our rocket to overcome Earth’s gravitational pull. Their primary objective for Q4 of 2024 was to attempt several Cold Flows and one Vertical Test Fire of their system.

During Q3 (Summer Break), the Propulsion team developed a success criteria system for their Q4 Cold Flow testing campaign. This standardized framework not only held the Propulsion team accountable but established technological development benchmarks for the Avionics team. The criteria included five critical factors:

  1. COPV Pressure Target Achievement
  2. MVAS Operation Success
  3. LN2 Fill Success
  4. Data Capture Success
  5. Pressure Maintenance Success

COPV (Composite Overwrapped Pressure Vessel) is a specialized tank designed to store pressurized gases.

LN2 (Liquid Nitrogen) is used as a cryogenic fluid to simulate actual rocket propellants during testing.

Working with a 10-week timeline, the team has three distinct development phases. The Initial Configuration phase (Tests 1-3) focused on fundamental system integrity, addressing issues with quick disconnects, resolving leaks, and implementing manual control systems. The Mid-Program Changes (Tests 4-6) enhanced measurement capabilities and system reliability through pressure transducer configurations and check valve implementations. The Final Configuration phase (Tests 7-10) optimized the entire system’s performance through improved valve systems and feed system orientation.

Each Cold Flow led to valuable insights that influenced system improvements. Key successes included the implementation of manual vent valves for enhanced reliability and the addition of check valves to resolve DLPR (Dome Loaded Pressure Regulator) loading issues. The team also successfully addressed critical challenges in tank pressurization, MVAS (Main Valve Actuation System) operation consistency, and COPV pressure maintenance.

At the end of the Quarter, these insights and improvements were tested at the VTF where we fell short of the targeted COPV pressure (3700+ psi) and performance goals (900 lbf thrust, 10-second burn time). However, VTF demonstrated proper MVAS operation, propellant filling, and data capture capabilities. It also showcased the effectiveness of the new Ground Support Equipment (GSE), Engine Control Unit (ECU) designs, and the improved fluid system with a single DLPR configuration.

The Propulsion team has a lot to look forward to in Q1 and Q2 of 2025. The procedures established from the weekly Cold Flows resulted in a 61% time reduction in VTF procedures (ie. 9 hours for PTR to 3.5 hours for the new system). Furthermore, the Cold Flows from the last third (Tests 7 – 10) had the highest success rates, leading to consistent and predictable test outcomes. With this minor setback, the Propulsion team will prepare for another Vertical Test Fire in Q1.

Avionics

The Avionics (AV) team is tasked with the development and implementation of the Engine Control Unit (ECU: manages engine functions for optimal performance and safety) and the Avionics Flight Sensors (AFS: controls flight operations, navigation, and data management).

Over this past quarter, the Avionics team worked on perfecting the Graphical User Interface (GUI), completing the Engine Control Unit (ECU), and preparing the Load Cell for Vertical Test Fire (VTF).

The GUI is the interface our full-stack engineers produced and had 2 main uses this quarter:

  1. The Command Box: Sends commands to the rocket such as opening valves for Cold Flow
  2. Displaying Data: The quick refresh rate of 100 Hz shows live data of pressure in tanks for Cold Flow

The Avionics team has utilized every Cold Flow to better understand how to produce the perfect GUI. For instance, at the beginning of the year, a schematic of the top-down overview of the Feed System of the Rocket was provided. With the Avionics team having the critical role of opening and closing certain valves and components, they have refined the User Interface (UI) and User Experience (UX) to utilize this schematic, making it easier for anyone to understand what opening or closing a certain component on the rocket can do.

While MOCH4 will require a GSE (Ground System Electronics) and an ECU (the brain of the rocket), we were able to bypass the need for an ECU when testing our Cold Flows by using the second GSE as an ‘ECU’. This is primarily because the ECU is essentially the GSE with enhanced features. These additional features include an antenna that enables radio frequency communication. A key distinction between the ECU and GSE is their power sources – while the GSE relies on wall power, the ECU incorporates a battery system with sophisticated power management logic to monitor charging status and power source switching. With MOCH4 projected for launch in the middle of Q2 2025, the Avionics team has successfully completed the ECU schematic.

Lastly, as a team utilizing liquid propellants – specifically a blend of LNG (Liquid Natural Gas) and LOX (Liquid Oxygen) – we are particularly interested in comparing our performance data against traditional solid-fuel rockets. Our load cell, an electro-mechanical sensor designed to measure force and weight, will play a crucial role in this analysis. Initial calculations suggest our methalox propulsion system could provide up to 15% greater specific impulse compared to conventional solid rockets, potentially offering significantly improved efficiency and control. The load cell data from our upcoming static fire tests will be instrumental in validating these projections and fine-tuning our engine performance parameters.

This quarter has demonstrated significant progress in our avionics systems development, from GUI refinement to ECU completion. As we move toward our Q2 2025 launch target, the Avionics team remains committed to ensuring safe, reliable, and efficient rocket operations through continued testing and system optimization.

Operations

The Operations (Ops) subteam is responsible for supporting pivotal initiatives within the development of MOCH4, driving foundational developments for future rocket projects, and fostering enhanced integration within the team. For Q4, the subteam focused on streamlining communication and documentation, enhancing resource allocation, and managing and seeking new stakeholders.

The Operations team has evolved to include new roles: 

  • Brand Marketing Manager
  • Industrial Engineer
  • System Engineer

These new roles have been influential with practicing effective communication and documentation for the weekly Cold Flows and Vertical Test Fire. The Industrial Engineer and System Engineer work closely with the other subteams to make the testing procedures and rehearsal processes efficient. For instance, they have created a timeline for the Cold Flow and Vertical Test Fire. Furthermore before Cold Flows or VTFs, the Brand Marketing Manager has a specific plan for what angles can help the Project analyze each test to make them better. In addition, the Brand Marketing Manager has compiled and edited footage of various leadership positions talking about what is happening in the Cold Flows to build a greater appreciation and understanding of what the Project is doing.

The Application Engineers have been tirelessly working to establish manufacturing partnerships for the Q2 2025 schedule. There is a new sense of urgency for finding manufacturers to help build specific parts (ie the top section of the airframe) and reliable suppliers who can provide parts for MOCH4’s specific requirements (ie a nose cone with the allocated weight). While several promising manufacturers have demonstrated the necessary technical capabilities, the Project faces the challenge of balancing manufacturing precision with budget constraints.

With the Project’s current funding streams primarily coming from the Quarterly Student Fees, we are grateful for the generous contribution from Dean Magnus Egerstedt that supported the VTF campaign. To bridge the funding gap for specialized manufacturing, the team initiated a strategic fundraising initiative targeting UCI’s alumni network and Orange County’s high net worth individuals. With a target of $20,000 by May 1, 2025, this funding will be crucial for achieving the project’s record-breaking mission objectives while maintaining the high engineering standards established throughout the development process.

Looking ahead to Q1 2025, the Operations team will focus on maximizing the value of its newly established roles – Brand Marketing Manager, Industrial Engineer, and System Engineer – who have already demonstrated success in improving test documentation and communication. The team will continue supporting critical manufacturing partnerships needed for the Q2 2025 timeline, with particular emphasis on securing specialized component manufacturers while carefully balancing precision requirements and budget constraints.

Launch Vehicle

The Launch Vehicle (LV) subteam is responsible for designing and building the rocket’s aerostructure (body) and recovery system. For Q4, the LV team focused on completing their GANTT Chart through finalizing designs, testing manufactured components at FAR, and preparing Bills of Materials (BOMs) while negotiating with Suppliers to support Q1 2025 development initiatives.

The LV team prioritized finalizing designs for their fins and camera mount in anticipation for a busy Q1 2025 where they will focus on manufacturing and assembling. They decided on a swept-back configuration which produces less drag during ascent and creates more laminar flow conditions (laminar flow is when air moves smoothly, therefore making the rocket more aerodynamically efficient and stable during flight). Optimizing the fins design is essential because the fins maintain the center of mass and center of pressure on the rocket.

Thought experiment: Think of the rocket as a dart where the heavy tip (center of mass) stays in front and the feathers (center of pressure) stay in back to make the dart fly straight. The rocket needs its weight concentrated toward the front and its aerodynamic forces toward the back for stable flight to hit the bulls eye.

Furthermore, the LV team designed a dual-camera mount system for the Insta 360 camera to record the engine and recovery and also to gain a wide perspective on flight analysis. The new design features an aluminum interior bracket and carbon fiber exterior mount; the inner bracket holds the camera firmly in place while the outer mount is a case that wraps around the camera and inner bracket, preventing the camera from being pushed or shaken loose during flight and maintains the aerodynamic efficiency of the rocket. 

As a little precursor to Q1 2025, a couple members of LV manufactured the top and bottom of the ejection chamber that underwent the Ejection Test Plan (Trinity) at FAR (location of VTF). Previously, the ejection chamber was 3D printed with PETG (Polyethylene Terephthalate Glycol) filament, but the LV members machined an aluminum ejection chamber to increase the strength of the system. Trinity’s purpose was to resemble the nose cone ejection test using black powder conducted on SR-1 (Q1) and SR-2 Q2. Unfortunately, the result of Project Trinity was not ideal, as the first test used slightly too much black powder, resulting in parts of the system that became unusable for future tests.

The LV team also prioritized finalizing the design for their top airframe section. The section needs to be transparent for radio frequencies while maintaining structural integrity – eliminating traditional materials like metals and carbon fiber and choosing fiberglass for the skin. Fiberglass is great because it can handle complex flight forces and house critical recovery components. However, finding a manufacturer capable of producing the custom fiberglass tubing proved challenging due to the uncommon thin thickness requirements and the need for precise hole placements and cuts within tight tolerances. The manufacturing process requires special attention to prevent material delamination, where layers of the fiberglass could separate and compromise the structural integrity of the section. The team spent considerable time coordinating with potential manufacturers to ensure their specific requirements could be met without sacrificing the critical radio transparency or structural properties of the design. 

Looking ahead to Q1 2025, the LV team will focus on manufacturing and assembly of these finalized designs, incorporating lessons learned from the Trinity test to improve the ejection system, and working closely with selected manufacturers to begin production of the custom fiberglass sections.

Conclusion

During Q4 2024, UCI Rocket Project achieved significant milestones but faced a major setback. The team successfully completed 10 Cold Flows, demonstrating improved efficiency with a 61% reduction in testing procedures. However, their first Vertical Test Fire on December 7th resulted in an engine hard start and explosion. Despite this challenge, the team maintained strong partnerships with faculty and administration, including Dean Magnus Egerstedt and Professor Shi, while establishing new operational roles and refining their avionics systems. The team plans to analyze the failure data and conduct another test fire in Q1 2025, maintaining their goal of breaking the collegiate methalox altitude world record in May 2025.