MUTT
supporting Evidence for TRL 4 Classification
This document provides supporting evidence for the MUTT technology’s current TRL 4 status, with documentation of analytical models, laboratory testing, and hardware development status.
1. Theoretical Development and System Modeling
| Document | Evidence Link | Description |
| 1.1 | Helium Evolution Analysis | Calculations of available helium in 135-liter MMH/NTO tanks at 450 psi, showing solubility dynamics and expected evolution rates during pressure changes |
| 1.2 | Gumerov Model Implementation | Numerical implementation of the Gumerov acoustic bubble migration model, adapted for helium-MMH/NTO systems |
| 1.3 | Transfer Time Projections | Simulated complete tank filling operation showing multiple pressure-driven transfer cycles with ullage evolution and venting |
| 1.4 | Acoustic Field Pressure Analysis | Computational results showing acoustic field pressures below cavitation threshold while maintaining sufficient force for bubble migration |
| 1.5 | ConOps for Reference Design Tank | Detailed ConOps for 135 l Reference Design Tank |
2. Laboratory Testing and Experimental Results
| Document | Evidence Link | Description |
| 2.1 | High-speed camera data showing acoustic nucleation of oxygen bubbles in FC-72 liquid under varying acoustic frequencies (160 - 70 kHz); PIV analysis of bubble nucleation and volume computation. | |
| 2.2 | Data showing total O₂ volume distribution and migration rates for FC-72 experiment | |
| 2.3 | Test results showing optimal frequency ranges for different bubble size regimes |
3. Flight Hardware Development Status
| Document | Evidence Link | Description |
| 3.1 | Flight Hardware Design | Flight Hardware Elements and Flight Heritage |
| 3.2 | Environmental Test History | Vibe/Shock and EMI: results from environmental testing of flight hardware (from previous flight of related payload). |