The MHTB Primary Is a TVS Performance Study, Not a Self-Pressurization Characterization — Auditing the 161-Page Primary Report Beneath a Liquid Hydrogen Validation Citation

Technical Note 003 in the ElarionX CPMS series. Computational papers validate tank self-pressurization models against data from the MHTB self-pressurization experiments. This note audits the primary document beneath that citation - NASA/TM-2003-212926, Spray Bar Zero-Gravity Vent System for On-Orbit Liquid Hydrogen Storage, 161 pages, eight authors across four organizations - and reports what a modeler finds there. The finding that reframes the rest: the primary public document beneath the MHTB self-pressurization citations is not a self-pressurization characterization report. It is a performance report for a pressure-control device - a thermodynamic vent system with a spray bar. Self-pressurization appears as the lockup phase between the device's interventions, bounded to a 7 kPa band and terminated by active intervention. The 2015 modelling paper prints no test identifiers at all; the association from its 50 and 90 percent fill cases to the test segments (P263968E/F, P263981D, P263981T) rests on fill level and campaign description, and the note states that inference as an inference, resolved against the TM's own figure captions. What a modeler must know: bulk liquid state is monitored by a single silicon diode standing for 18 cubic metres; the measured ortho/para composition of the fluid remains undeclared in all three LH2 records examined in this series; and a machine-verified census of the TM's eight numbered tables shows none is a time-history series - every pressure and temperature history, including the 1996/1998 self-pressurization tests, is plotted, not tabulated, with no statement of a reachable archive. The test team's own candor is documented: an energy discrepancy analyzed with instrumentation ruled out, and a 60,350-second model alignment shift disclosed with the unshifted comparison plotted alongside. Criterion six receives a partial assessment, under the dated-search discipline of the series: the declared context is absent from the 2015 paper examined and from the 2025 Marshall presentation audited for this version (NTRS 20250004637 - zero statements of measurement uncertainty, zero context carried); two 2016 journal validations (Cryogenics 74, DOIs verified) are located but paywalled and not yet obtained, and the criterion closes only after they are audited. Scope and limitations. Exploratory (A0) work by one auditor with AI assistance and no independent human review; the audit of the TM is section-targeted, and the subtitle says auditing, not reading, for exactly that reason. Defects found after writing, including by externally commissioned review, are recorded in the errata table of Technical Note 000 (Errata 14-18). Full audit records are published as a separate dataset; the series index is Technical Note 000.