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NASA STMD Propulsion Technology Landscape

Created: 2026-04-05 (session 6) | Updated: 2026-04-06 (session 57)

Overview

Propulsion (TX01) is the most cross-program technology area in TechPort — 1,849 projects across 37 programs, with SBIR/STTR accounting for 68.1%. This page maps the propulsion landscape from chemical to nuclear, tracing how technologies move from NIAC concept → SBIR component → TDM flight demonstration.

Key programs by propulsion focus: - SBIR/STTR (1,260 TX01 projects): Component-level development across all propulsion types; industry-led; TRL 2-8 - TDM (21 TX01 projects): System-level flight demonstrations — GPIM, NTP Technology Maturation - NIAC (62 TX01 projects): Concept-level advanced propulsion — PPR, NearStar, EmberCore - CIF centers (MSFC/GRC/SSC, combined ~85 TX01 projects): Center-internal R&D and test infrastructure, especially NTP - STRG (135 TX01 projects): Academic R&D in electric propulsion, fuel chemistry, advanced concepts

Active portfolio snapshot (April 2026) — 59 projects

Theme Count Notes
Electric propulsion (Hall, electrospray, EP systems) ~16 SEP TDM + STRG research + SST/SAT/FO demos
Cryogenic propulsion / fluid management ~10 FO parabolic flight tests + TDM LOXSAT 1
RDRE (rotating detonation rocket engines) 7 TDM + FO + SBIR + STRG; dominant emerging theme
Aviation propulsion (TX01.3.x) ~9 AAVP, TACP, ARMD — not space propulsion
Advanced/exotic (directed energy, fusion, nuclear-academic) ~8 STRG only, all TRL 2-3
Nuclear propulsion TDM/GCD 0 Both NTP and NEP TDM terminated Dec 2025
SBIR TX01 active 7 Near-empty; multiple misclassifications; only 1 legitimate EP SBIR

Structural insight: SBIR TX01 is near-empty (7 active vs. ~170 SBIR TX01 in any prior year), reflecting commercial maturity of EP and chemical propulsion. New propulsion investment has shifted to FO (flight demonstrations) and STRG (academic research) rather than industry SBIR. RDRE has displaced nuclear propulsion as the "hot" emerging technology.

1. Green Propellant / Non-Toxic Monopropellant

Technology summary

Replacement for hydrazine (toxic, carcinogenic, ITAR-controlled). Two leading propellants developed independently: - AF-M315E (ASCENT): Air Force Research Laboratory formula; higher energy density than hydrazine; high combustion temperature requires new chamber materials - LMP-103S: Swedish ECAPS/Bradford company formula; already at TRL 9 (flying commercially on commercial satellites as of 2017)

Key projects and pathways

Supply chain structure (multi-SBIR → TDM → AFRL):

Project Program Org TRL Period Technology
102945 SBIR/STTR Plasma Processes LLC (Huntsville) 5→9 2017–2019 1N/5N/22N combustion chambers for AF-M315E
18043 / 72032 SBIR + GRC partnership Busek + GRC 4→6 2014–2017 5N green thruster flight qualification
93603 SBIR/STTR Sienna Technologies 2→4 2017 Catalytic multi-cold-start thrusters
90577 SBIR/STTR (unnamed) 1→4 2016 Additive manufactured catalyst beds
33585 SBIR/STTR Ultramet 3→4 2015 Green monopropellant secondary payload
11585 TDM Ball Aerospace (prime) + AFRL 5→7 (target 8) 2012–2020 GPIM flight demonstration

GPIM (11585) — the system-level outcome: - TDM program; Ball Aerospace prime; collaboration with AFRL and Air Force partners - Flew STP-2 mission, June 2019 — validated AF-M315E in orbit - Infused_To: Air Force Research Laboratory (921) — AFRL adopted ASCENT (the renamed AF-M315E) as their operational propellant. This is a real, confirmed infusion. - TRL reached: 7 (target was 8 — did not reach full qualification in flight, but orbital demonstration was successful) - Advanced From: AFRL prior work (2 Advanced_From records) + multiple SBIR components - 9 library items including NASA mission page and AFRL testing confirmation

Closed_Out masking at supply chain level: All SBIR component suppliers (102945, Busek, Sienna, Ultramet, etc.) show Closed_Out, not Infused_To, despite their components flying in GPIM. This is the clearest example of the Closed_Out masking pattern: the mission infusion credit accrues to the TDM project (11585), not to the SBIR supply chain. Confidence: confirmed (n=5+ Closed_Out SBIR projects, 1 TDM Infused_To).

Continuation: - Green propellant ecosystem is mature — ECAPS LMP-103S already commercial; Aerojet's ASCENT thruster post-GPIM - Multiple SBIR companies continue scaling (dual-mode, CubeSat sizes, high-thrust variants) - 116406: "Green Hydrazine Blend" (Aerojet, GRC, 2021-2025) — next-generation blend beyond AF-M315E - 113181: Dual-mode green for interplanetary SmallSats — TRL 3→6, 2021-2023

Cross-references

2. Electric Propulsion

Technology landscape overview

Electric propulsion (TX01.2.x) is the largest EP investment in STMD — 464 projects matching TX01.2 + keyword filter. Three main sub-types: - Hall effect thrusters (electrostatic, TX01.2.2): High thrust-to-power, well-understood, primary NASA SEP baseline - Ion thrusters (electrostatic): Very high ISP, lower thrust, heritage on Dawn and Deep Space 1 - RF thrusters (electromagnetic): Novel category, no moving parts, propellant-flexible; emerging commercial segment

GRC (Glenn Research Center) is the electric propulsion center — most EP development work runs through or is tested at GRC.

Key projects

HiVHAc — High Voltage Hall Accelerator (94160) - GRC CIF, TRL 4→5, 2016–2017 (wear and structural tests phase) - 4.5 kW-class Hall propulsion system: thruster + PPU + xenon feed system (XFS) - Dual-mode capability: high thrust-to-power ratio AND high specific impulse modes - COMPASS mission studies identified 4.5 kW-class as the enabling size for multiple science and exploration missions - Outcome: Transitioned_To Industry (no named partner) — technology handed off for commercialization - Context: GRC has been developing HiVHAc since ~2012; this 2016-17 project is the wear test phase of a longer program

Busek 15 kW Hall Thruster for SEP (16574, 18291, 102707) - Three sequential SBIR projects 2013–2018, TRL 5→6 - "Hall Effect Thruster for High Power Solar Electric Propulsion Technology Demonstration" - Supports Asteroid Redirect Mission (ARM, since cancelled) → later Gateway Power and Propulsion Element (PPE) - Magnetic shielding design — predicts very long lifetime (the key limiting factor for SEP missions) - 102707: duplicate Phase II record, TRL 0→0 (data quality issue)

Phase Four RF Thruster (106833) - SST (Small Spacecraft Technology) program, GRC, TRL 6→8, 2020–2024 - Phase Four Inc commercial thruster validated by NASA GRC lifetime trend testing - Radio frequency plasma acceleration — propellant-flexible (any noble gas), no electrodes to erode - TX01.2.4 Electrothermal — likely a mismatch; RF thrusters are electromagnetic, not electrothermal - TRL 8 is flight-ready — highest-TRL EP project in this survey. Commercial product validated by NASA.

Iodine Hall Thruster (17556) - GRC, TRL 4→6, 2014–2018 - Enabling technology for SmallSat EP: iodine is solid at room temperature (no pressurized tank needed), enabling compact nanosatellite propulsion - "Game changing system level performance" — eliminates propellant tank mass budget issue

X3 Nested Hall Thruster / High Power EP (116381) - GCD program, TRL 4→5, 2018–2019 - XR-100 project: X3 Nested Hall Thruster (developed by U. Michigan) + modular PPU + mass flow controller - NextSTEP program (NASA → contractor partnership) - Testing achieved highest power of any Hall thruster system at the time - Target: cislunar cargo missions requiring 100+ kW EP

EmberCore radioisotope EP (158529) - NIAC Phase II, USNC-Tech (Seattle), 2023–2025, Completed - EmberCore: proprietary novel radioisotope (not Pu-238) with higher specific power than standard RPS - Architecture: EmberCore power → electric propulsion → 50-100 km/s ΔV - Target missions: outside zodiacal glow, parallax microlensing, Kuiper Belt Object intercepts — interstellar precursor capability - Advanced from EmberCore Flashlight (158589) — a NIAC project using EmberCore as passive X-ray source for lunar surface characterization - TX01.4.4 Solar Thermal — confirmed mismatch (this is radioisotope EP, not solar thermal) - USNC-Tech crossover: Same company contributing NTP fuel development to MSFC's NTP Maturation program (158561) — USNC spans both thermal and electric nuclear propulsion

Magnetoplasmadynamic (MPD) thrusters — emerging high-power type: - MPD thrusters operate at higher power densities than Hall/ion — potential for high-thrust EP for human Mars - 158679 (U Michigan, STRG, 2024-2028, TRL 2→?): "Development of an Electrodeless Magnetoplasmadynamic Thruster" — removes electrode erosion lifetime limits - NEP TDM publication list includes Polk et al. (IEPC 2024): "Development of High-Power Lithium Magnetoplasmadynamic Thrusters to Support Human Mars Exploration" — indicates MPD was within the NEP research scope - Prior: 5580 (GRC SBIR, 2005) — lithium propellant purification for MPD; technology has decades of GRC history - Lithium propellant is the enabling factor for high-Isp MPD (vs argon/xenon) — same challenge USNC-Tech has with nuclear fuels

SEP TDM (13075) — current status: The SEP TDM (GRC, 2014–2029, 5,187 views) is NASA's flagship EP program. It has evolved over its 15-year life. Current description focuses on the Plasma Diagnostics Package (PDP) — a flight instrument delivered as Government Furnished Equipment (GFE) to the Power and Propulsion Element (PPE, Gateway). The Hall thruster itself (HERMeS, Advanced Electric Propulsion System/AEPS, developed by Aerojet Rocketdyne under a NextSTEP contract) is no longer the project's core focus. TRL shows 4 (current) against target 8 — this likely reflects PDP flight readiness, not thruster TRL (the thruster is separately at higher TRL in contractor hands).

MicroLink ELO solar cells (112889) — SEP supply chain: TRL 9, Completed Sep 2021, Closed_Out (no Infused_To). Description names NASA SEP missions as the intended application; Airbus is a customer. Production target: 1 MW/year from 6-inch GaAs ELO process. No TechPort downstream mission use visible — another Closed_Out masking instance for a flight-ready component.

STRG academic EP research: Active investigations into Hall thruster oscillation modes and facility effects (118354, 118463, 156361, 158626) — substantial cluster of diagnostic research supporting long-lifetime Hall thruster development. Multiple electrospray thruster fundamental studies (158560, 156320, 118444, 156356) at MIT/Cornell for SmallSat EP. Colloid thruster life test (157593) at JPL for exoplanet mission pointing precision (SAT program, 8000h test, TRL 4→5).

ExoTerra Courier (106825) — SST Hall CubeSat: 12U CubeSat with Hall thruster + deployable solar array, TRL 5→8, SST program, 2020–2027. Targets Moon and Cislunar — the EP demo mission in the commercial small spacecraft tier.

Cross-references

  • See topics/cif-lineage.md — GRC CIF specialization in power/propulsion/sensors
  • HiVHAc → Transitioned_To Industry case study
  • EmberCore → see Nuclear/Advanced Propulsion section below
  • NEP TDM → see Nuclear Electric Propulsion section below

3. Nuclear Electric Propulsion (NEP)

Overview

NEP couples a nuclear fission reactor with electric thrusters — higher ISP than NTP (~3000-10000s vs ~900s) but lower thrust. Best suited for: outer planet science missions, high-value robotic deep space missions, and human Mars with longer transit times. Requires nuclear power conversion system (Brayton turbine) at much lower temperatures than NTP.

NEP TDM (158369) — "Nuclear Electric Propulsion Technology Maturation"

  • TDM program; GRC (Glenn Research Center); 2022-10-01 to 2025-12-31
  • TRL: 3→3 (target: 5) — Closed_Out December 2025
  • Partners: Idaho National Laboratory, Oak Ridge National Laboratory, JPL, Analytical Mechanics Associates, MSFC Engineering Directorate
  • Primary TX: TX01.2.2 Electrostatic Propulsion (ML predicted: TX01.4.3 NTP — interesting inversion)
  • PI: Jason B. Turpin (jason.b.turpin@nasa.gov); Program Director: John W. Dankanich

Research scope (from description and publication list): - 5 major subsystem tracks: nuclear reactor, power conversion (Brayton), thermal management, PMAD, electric thrusters - Reactor focus: higher-temperature reactor enabling higher thermal efficiency for power conversion - Power conversion: lightweight closed-cycle Brayton engine - Electric thrusters: high-power Hall, ion, and MPD thruster development - Application studies: cislunar, human Mars, outer planet science missions

Publication list (document 387845, Oct 2023-Oct 2024) — 7 items (vs NTP's ~75): 1. "Accelerating Space Science with Nuclear Technology: The Tempe Workshop" (Dec 2023) 2. "Roles of NEP and NTP in Cislunar Space" (NETS 2024) 3. "Monte Carlo Shield Mass Modeling for a Reference NEP Reactor" (NETS 2024) 4. "NEP Mission Trajectory and Mass for Jupiter Rendezvous" (NETS 2024) 5. "NEP for Outer Planet Science Missions" (IEPC 2024) 6. "Development of High-Power Lithium MPD Thrusters to Support Human Mars Exploration" (IEPC 2024) 7. "Review of NEP for Interplanetary Missions" (IAC 2024)

Pattern: Much less output than NTP (~7 publications vs ~75 in same period). NEP was a younger, smaller program with less existing infrastructure to build on. Outer planet science (Jupiter rendezvous) and human Mars are the primary mission contexts.

Critical finding — dual termination: Both NTP (158561) and NEP (158369) TDM programs closed simultaneously in December 2025, both at TRL 3 vs. target 5. This was not a staggered technical sunset but a portfolio-wide termination of nuclear propulsion advanced development. See surprises/nuclear-propulsion-dual-termination.md.

Active nuclear propulsion survivors (post-Dec 2025)

The full landscape as of April 2026:

Project Program Lead Org TRL Period Type Notes
158683 STRG MIT (Shirvan PI) 2→3 2024-2028 NTP liquid core modeling Houts (MSFC) as PM — institutional continuity
158586 STRG UCSB (Oropeza PI) 2→3 2024-2028 NTP refractory metal AM W/W-alloy powder via ultrasonic atomization
118498 STRG UC Berkeley (Van Carey PI) 2→3 2022-2026 NEP thermionic power conversion Computational modeling
183676 STRG Colorado School of Mines (Beik PI, Barth GRC PM) 2→3 2025-2028 NEP PMAD generator MW-scale high-voltage multiphase dual-rotor generator for reactor→thruster power conversion; TX01.4.5 ✓ (human correct)
183686 STRG UT Austin (Underwood PI, Adams MSFC PM) 2→3 2025-2028 Fusion Z-pinch EM propulsion Low α fusion + EM accel; no external magnets; TX01.4.6 ✓ (human correct); full details in Section 5
158371 ECI LaRC (Stark PI) 2→3 2024-2026 NEP radiator panels MARVL — modular assembled radiators
158619 NIAC Howe Industries — 2024-2026 Pulsed fission plasma PPR — see Section 5; uses HALEU/HEU
158735 SBIR Ultramet 3→5 2024-2026 NEP radiator coatings High-emissivity CVD dendritic rhenium, Phase II
158679 STRG U Michigan 2→? 2024-2028 Electrodeless MPD thruster EP side; relevant to NEP high-power thrusters

Institutional continuity signal: Michael Houts (MSFC) appears as PM on [158683] — he was the central MSFC figure throughout the NTP TDM. Robert Adams (MSFC) is PM on [183686] Z-Pinch — he was the PuFF NIAC PI cited in the PPR poster. The MSFC nuclear propulsion community persists through STRG grants even as TDM funding ended.

HALEU dependency: [158619] PPR requires HALEU + HEU — same fuel as the terminated NTP TDM. The fuel supply chain bottleneck that may have constrained NTP also applies to PPR.

2025 STRG advanced propulsion cohort — complete 4-project picture (session 58): The May 2025 solicitation produced 4 TX01 advanced propulsion projects, all sharing identical metadata (start 2025-05-01, end 2028-05-31, Deans/Nguyen PDs, last-updated 2026-01-23):

Project Lead Org TX Track
183683 U. Minnesota (Ilic, Gregg ARC PM) TX01.4.6 Directed energy — metasurface/photonic lightsail
183676 CSM (Beik PI, Barth GRC PM) TX01.4.5 Nuclear electric — NEP PMAD generator
183686 UT Austin (Underwood PI, Adams MSFC PM) TX01.4.6 Nuclear fusion — Z-pinch EM propulsion
183697 Purdue (Oguri JPL PI) TX01.4.6 Directed energy — origami diffractive sail

Two distinct tracks: nuclear (power conversion + fusion physics, responding to TDM termination) and directed energy (lightsail propulsion, responding to interstellar mission interest). All TX01.4.x, all TRL 2→3. Human TX is correct on all four, confirming Deans/Nguyen have stronger taxonomy discipline than the NIAC classifiers who assigned PuFF/PPR as TX01.4.4 (Solar Thermal).

[183683] Metasurface Lightsail (U. Minnesota): Ognjen Ilic's group engineering nanostructured photonic lightsails — using metamaterial design to control light-sail interactions from nano to macro scales. Goal: lightweight, stable, high-thrust lightsails for directed energy propulsion within and beyond the solar system. Christine Gregg (ARC) is the NASA PM. Connected to origami diffractive sail [183697] (Purdue, parallel branch) — see topics/diffractive-solar-sailing.md.

No active TDM, GCD, or CIF projects in nuclear propulsion as of April 2026. ECI is the only non-academic, non-NIAC active program, and only for a radiator component.

Cross-references

  • See organizations/usnc-tech.md — company with both NTP reactor and radioisotope EP portfolio
  • See surprises file for dual-termination analysis
  • See NTP section below for supply chain details

4. Nuclear Thermal Propulsion (NTP)

Background and significance

NTP offers ~2× higher specific impulse than chemical propulsion (ISP ~900s vs ~450s), enabling ~120–160 day Mars transit vs ~6–9 months chemical. NASA has studied NTP since NERVA/ROVER (1955–1973). Modern NTP programs begin ~2011.

The fundamental challenge: Enriched uranium fuel that stays intact in ~2700°C flowing hydrogen for hours. No flight test since 1972.

Program history in TechPort

Project Program Period TRL Outcome
10730 "NCPS/NTP" MCO (MSFC) 2011–2015 4→4 Closed_Out (partner: Other, i.e. DOE)
158561 "NTP Technology Maturation" TDM (MSFC) 2020–2025 3→3 (target: 5) Closed_Out Dec 2025

Critical finding: NTP Technology Maturation (158561) did not reach TRL 5. The program ran 2020–2025, produced ~75 peer-reviewed publications in 2023–2024 alone (document 389926), but closed at TRL 3 against a target of 5. This is the second consecutive NTP program to end below its TRL target (10730 also held at TRL 4). The program was active until the end — publications through October 2024 — suggesting external termination rather than technical failure.

Research themes from the NTP publication list (document 389926, Oct 2023–Oct 2024)

Fuel chemistry (most active area, ~40 of 75 papers): - Uranium nitride cermet fuels (UN in Mo/W matrix, W-coated kernels) - (U,Zr)C solid solution carbide fuels (ZrC coating by CVD) - TRISO-based ZrC fuel elements (USNC prismatic and CFEET minifuel) - Zirconium hydride moderators for low-enriched uranium (LEU) designs - Hot hydrogen exposure testing: mass loss, coating integrity, thermophysical properties

Novel reactor concepts (emerging, ~20 papers): - Centrifugal Nuclear Thermal Propulsion (CNTP): Liquid/gaseous fuel in rotating cylinder — eliminates the hydrogen-fuel cracking problem by keeping fuel liquid. Multiple papers on bubble dynamics, 3D simulation, thermochemistry. New concept, no NERVA heritage. - Liquid core nuclear thermal rockets: Similar goal — operate above fuel melting point for higher ISP - These concepts appear alongside solid-core NERVA-heritage work, suggesting the program was exploring both near-term (solid core) and far-term (liquid/centrifugal) simultaneously

Applications studied: - Mars crewed missions (120-160 day transit, PADME engine design) - Cislunar transportation — NTP for Artemis - Deep space science missions, Kuiper Belt - "Extrasolar science mission profile" (multi-launch NTP architecture) — implies ISP >1000s needed

Ground test infrastructure: - High-pressure real-time exhaust processing system - Hazards analysis frameworks for NTP ground testing - Auxiliary pressurized run tanks and propellant management

SBIR supply chain

NTP has a substantial SBIR supply chain (20+ projects identified): - Fuel fabrication: Ultramet (W-Re coatings, 9176), NTR fuel testing at MIT reactor (102952), UN fuel development (112848, 103014, TRL 3→5) - Test hardware: hydrogen wave heater components (18292, 33629, 102759), ground test hardware (18245, 33479, TRL 4→6) - Turbomachinery: superconducting boost pumps (18412, 34098, TRL 3→6), long-life bearings (34103) - Instrumentation: radiation-tolerant neutron flux sensors (33591), extreme temperature instrumentation - Center (SSC CIF): effluent treatment (13746), oxygen containment (14690), CFD facility design (14685)

Pattern: SSC CIF specializes in NTP ground test infrastructure (consistent with SSC center-specialization finding from cif-lineage.md). MSFC CIF develops the fuel elements. SBIR provides components and sub-systems.

Cross-references

5. Advanced and Fusion Propulsion

PPR lineage: PuFF Phase I → PuFF Phase II → PPR

The PPR has a two-predecessor NIAC chain, all PI'd or PM'd by Robert B. Adams (MSFC):

Project ID Period TRL Mechanism PI
PuFF Phase I 13725 2013–2014 2→2 MIF: FRC + Z-pinch + D-T fusion + UF gas fission trigger Robert Adams (MSFC)
PuFF Phase II 95694 2018–2020 2→3 MIF: Z-pinch compression of fission-fusion target, lithium liner, magnetic nozzle Robert Adams (MSFC)
PPR 158619 2024–2026 Active Pure fission pulse: HALEU/HEU barrel-bullet criticality, electromagnetic coil gun Howe Industries (Clements + T. & S. Howe)

Mechanism divergence: PuFF ≠ PPR. PuFF Phase I used a Field-Reversed Configuration (FRC) plasma injected into a Z-pinch chamber with Lithium Sheath liner, Deuterium-Tritium (D-T) plasma core, and Uranium Fluoride (UF) gas as fission trigger — classic magneto-inertial fusion (see concept diagram assets/puff-phase1-concept-diagram.jpg). Howe Industries' PPR abandoned the fusion component entirely and replaced it with a pure fission-criticality mechanism using solid HALEU/HEU fuel in a barrel-bullet configuration. The evolution direction was: MIF (technically harder; requires fusion ignition) → fission criticality (technically simpler; proven physics). This is a substantial architectural departure.

PuFF Phase II [95694] has no TechPort outcome records — no Closed_Out, no Transitioned_To. This is the "third mechanism" data quality issue: a project that completed (2020) with no terminal outcome, yet PPR explicitly cites it in its poster. The intellectual lineage is real; the TechPort traceability is broken.

TX classification chaos across the lineage: - [13725] PuFF Phase I: human = TX01.4.4 Solar Thermal; ML = TX01.4.4 Solar Thermal → both wrong, mismatch=False - [95694] PuFF Phase II: human = TX01.1.8 Warm Gas; ML = TX01.4.4 Solar Thermal → both wrong, mismatch=True (different wrong answers) - [158619] PPR: human = TX01.4.4 Solar Thermal; ML = TX01.4.4 Solar Thermal → both wrong, mismatch=False

The same wrong TX bin (TX01.4.4) persists across a 10-year lineage. The mismatch detector oscillates True/False but never catches the underlying error.

PPR — Pulsed Plasma Rocket (158619)

NIAC Phase II, Howe Industries LLC, active 2024-2026. PIs: Brianna Clements, Troy Howe, Steven Howe.

Architecture (from poster, document 317211): - Barrel/bullet configuration: Barrel = subcritical HALEU assembly with small HEU ring (fast reactor). Bullet = HALEU/ice encased in iron shell (moderated reactor). - Operation: Bullet accelerated to high velocity by electromagnetic coil gun → enters barrel → control drums + fissionable material drive criticality (keff=1) → transient fission → plasma → redirected by liquid-cooled magnetic nozzle - Power system: Brayton cycle generator for housekeeping power - Criticality control: 12 control drums in the barrel - Builds on PuFF (Pulsed Fission-Fusion) NIAC Phases I/II (PI: Robert Adams, MSFC) and Orion thermonuclear propulsion heritage; mechanism diverged from fusion to pure fission (see PuFF lineage above)

Performance claims: - 100,000 N thrust AND Isp 5,000 s average — the only active concept combining both - 200 metric tons to Mars and back in 120-160 days (including 20-day surface stay) - Crew radiation dose: 116-155 mSv (well within NASA career limit of 600 mSv) via polyethylene shielding

HALEU dependency: Uses same HALEU/HEU fuel as the terminated NTP TDM. HALEU supply chain bottleneck applies to PPR as well.

  • TX01.4.4 "Solar Thermal" — coordinated mismatch; mismatch=False but both human+ML wrong. See field-completeness.md — Issue 11.
  • Policy context cited in poster: Space Policy Directive-6 (2020), 2021 Executive Order on small modular reactors

NearStar Fusion (92621)

NIAC Phase I completed, MSFC, 2017–2018.

Official title: Gradient Field Imploding Liner (GFIL) Fusion Propulsion System

Mechanism (from project diagram, file 366141 — saved as assets/gfil-nearstar-concept-diagram.jpg): 4-stage passive implosion sequence: 1. Fusion fuel target capsule enters a static high-gradient magnetic field at axial velocity V_z 2. The converging field lines compress the liner radially (dBz/dt = Vz · ∂Bz/∂z — the target's own velocity creates the time-varying B field) 3. Radial stagnation → target burn at fusion conditions 4. Plasma expands outward through a magnetic nozzle for directed thrust

Key distinction from PuFF: GFIL uses passive kinematics — no active Z-pinch pulsed power system. External power requirement is only the hypervelocity launcher. Mechanically simpler; avoids megavolt pulsed power at the chamber.

NIAC project details: - PI: Michael R. Lapointe (MSFC); PM: Gary Fleming, John Nelson - TRL 2→3, NIAC Phase I only (no Phase II follow-on in TechPort) - Destinations: Mars - TX01.4.4 "Solar Thermal" — confirmed mismatch; this is magneto-inertial fusion propulsion - Partners: OH (likely AFRL at Wright-Patterson, listed in states)

Commercial spin-out: NearStar Fusion Inc. - Outcome: Infused_To → NearStar Fusion Inc (org ID 10126) — one of the clearest NIAC → commercial spin-out in TechPort - Company disclosed publicly: July 13, 2021 (3 years post-NIAC closeout) — press release filed in TechPort as file 366142 - Location: Chantilly, Virginia (NOT Huntsville — Lapointe remained at MSFC; company is separate) - President & Chief Scientist: Doug Witherspoon (not Lapointe) - Commercial branding: HGFF — Hypervelocity Gradient Field Fusion - Mechanism adapted for commercial power: hypervelocity launcher drives pulsed fuel capsules → molten salt heat capture → turbine → electricity - Dual-use intent: energy first (scalable from tens of MW to GW, drop-in for power plants worldwide), then spacecraft propulsion - Target: "limitless clean always-on energy" — commercial fusion power narrative, not aerospace-first - No subsequent TechPort projects (no SBIR, GCD, or FO entries under NearStar Fusion as of April 2026)

Z-Pinch STRG — Academic PuFF Continuation (183686)

STRG, University of Texas at Austin (Underwood PI), active 2025-05-01 to 2028-05-31, TRL 2→3. 591 views.

Project title: "Stabilized Z-Pinch Fusion Driven Electromagnetic Propulsion"

PI: Thomas C. Underwood (UT Austin) — first TechPort appearance; no prior projects
PM: Robert B. Adams (MSFC, robert.b.adams@nasa.gov) — the PuFF Phase I/II PI, now in PM role
Program Manager: Hung D. Nguyen; Program Director: Matthew C. Deans (STMD STRG)

Concept:
The system combines two distinct physics mechanisms: 1. Z-pinch compression → drives "low α" fusion reactions (sub-break-even; does not require ignition) 2. Electromagnetic acceleration → separate mechanism accelerates the fusion-heated plasma for thrust

Key claims: - Compact — does not require large external magnets (unlike PuFF Phase I's FRC coils). Z-pinch self-confinement replaces external B-field infrastructure. - Scalable — "low α" (below fusion break-even) operation makes laboratory validation feasible without reactor-scale conditions - Lab-testable — designed from the start to be demonstrable in existing plasma labs

Pre-query expectation vs. finding:
- Expected: Adams as PI, academic Z-pinch continuation → Partial: Adams is PM not PI; Underwood (UT Austin faculty, new to TechPort) is PI. The Adams → UT Austin channel keeps MSFC institutional continuity alive while injecting new academic talent. - Expected: TRL 2-3, no documents → Confirmed. Last updated 2026-01-23, no library items in live record.

TX classification — FIRST CORRECT HUMAN CLASSIFICATION in this lineage:
- Human assigned: TX01.4.6 Advanced Energetic Propulsion Approaches ✓ — correct - ML predicted: TX01.4.4 Solar Thermal Propulsion ✗ — the familiar wrong bin - Contrast: PuFF I/II and PPR were all TX01.4.4 from humans too. For the first time in the 12-year Adams fusion propulsion lineage, the human classifier got it right. The ML model remains stuck on TX01.4.4 as a catch-all.

Mechanism comparison — PuFF vs. Z-Pinch STRG:

Feature PuFF Phase I [13725] (Adams PI) Z-Pinch STRG [183686] (Underwood PI)
Confinement External FRC + large B-field coils Self-pinching Z-pinch (no external magnets)
Fusion requirement D-T + UF fission trigger — ignition-class "Low α" — sub-break-even fusion
Acceleration Lorentz force from Z-pinch current Separate EM acceleration mechanism
Lab testable? Requires very large infrastructure Designed for existing plasma labs
TRL path 2→2 (Phase I stalled) 2→3 target (2025-2028)

The conceptual shift: from "achieve fusion ignition to generate thrust" (PuFF) to "use sub-ignition fusion to create high-velocity plasma, then accelerate electromagnetically" (Z-Pinch STRG). This is analogous to how PPR simplified the physics (fusion → fission), but in a different direction: instead of dropping fusion, this approach retains it while making the fusion requirement less demanding.

Lineage narrative — Adams arc: - 2013-2014: PuFF Phase I [13725] — MSFC PI, NIAC, MIF concept - 2018-2020: PuFF Phase II [95694] — MSFC PI, NIAC, Z-pinch + fission-fusion target - 2024-2026: PPR [158619] — cited as predecessor by Howe Industries; Adams as intellectual lineage not project lead - 2025-2028: Z-Pinch STRG [183686] — MSFC PM, UT Austin PI (Underwood), new academic channel

Adams has kept nuclear/fusion propulsion alive for 12+ years: 2 NIAC as PI, cited in 1 NIAC from Howe, now STRG PM channeling funding to UT Austin academic partner. The TDM termination (Dec 2025) removed the system-level program; STRG preserves the physics research layer.

Destinations: Moon and Cislunar, Mars, Others Inside the Solar System — same ambitious scope as PuFF.

EmberCore (158529) — radioisotope EP bridge concept

NIAC Phase II, USNC-Tech, 2023–2025. See Electric Propulsion section for details.

  • Bridges nuclear power + EP: novel radioisotope → high ΔV without reactor
  • Complementary to TRC (158671) which also bridges radioisotope heat → propulsion power
  • The radioisotope → EP pathway is being explored in parallel via: TRC (passive solid-state), EmberCore (active commercial radioisotope)

Taxonomy note: TX01.4.4 is overloaded

TX01.4.4 "Solar Thermal Propulsion" is being used as a catch-all for all advanced non-NTP propulsion: - PPR (pulsed nuclear plasma) → TX01.4.4 ❌ - NearStar Fusion (magneto-inertial fusion) → TX01.4.4 ❌ - EmberCore (radioisotope EP) → TX01.4.4 ❌ - TRC (thermoradiative cell power for EP) → TX03.1.2 (ML: closer to heat source) ⚠️

One counterexample (session 57): Z-Pinch STRG 183686 was assigned TX01.4.6 Advanced Energetic Propulsion Approaches by the human classifier — correct. ML still predicted TX01.4.4 Solar Thermal. First instance in the 12-year Adams fusion propulsion lineage (PuFF I → PuFF II → PPR → Z-Pinch STRG) where the human got the TX right. Suggests the STRG program manager (Matthew Deans) may be more taxonomy-aware than the NIAC classifiers who assigned PuFF/PPR.

This bin is effectively useless for distinguishing propulsion concepts. Any cross-program analysis of "advanced propulsion" must start with keyword search, not taxonomy.

6. Rotating Detonation Rocket Engines (RDRE)

Added session 19. Expanded session 39 with full development chain.

RDRE is the most active emerging propulsion technology in NASA's current portfolio — 7 active projects across TDM, FO, SBIR, and STRG, with a dedicated 4-year TDM program started October 2024. The full development arc from first STRG grants to TDM spans 14 years (2011–2025).

What is RDRE?

Rotating detonation replaces conventional deflagration (subsonic combustion) with a continuous detonation wave rotating in an annular combustor. Pressure gain from detonation gives 5–10% higher specific impulse and allows shorter combustors (40–80% shorter than conventional). Key application case from GCD description: "a recent vehicle level study showed the ability to close the design of a Mars Ascent Vehicle with an RDRE, when the design would not close with a conventional rocket engine" — making weight savings mission-critical, not just nice-to-have.

Current technical challenges: injector coupling with propellant manifolds, optimized combustor contours, nozzles for unsteady flow, heat flux management, and combustion kinetics that capture both detonative and deflagrative behavior.

Full development chain (2011–2028)

Phase 1 — STRG academic foundations (2011–present): First STRG grants for detonation concepts in 2011 (Purdue [4321], [93901]; U Alabama [118407]). ~10 university STRG projects at TRL 2→3, covering injector physics, spray dynamics, aerospike nozzles, wave mode structure, and geometry optimization. These are the feeder research base.

Phase 2 — GCD flagship consortium (2020–2024): [116281] GRC GCD: 2020-03 to 2024-09, TRL 3→3 (target was 3), 7,345 views (highest RDRE view count). - PM: Hugh D. Perkins (GRC); Program Director: Mary Werkheiser - Partners: GRC, AFRL (Notre Dame), Purdue, Spectral Energies, UAH, UCLA, UIUC — identical consortium to current TDM - Destinations: Earth, Moon, Mars, Others — broad application scope - Target was TRL 3, not higher — GCD's goal was to establish and validate the concept, not advance to engineering - Taxonomy: both human AND ML assign TX01.4.4 Solar Thermal — a stable wrong classification (not caught as mismatch)

Phase 2b — ECI capability gap bridge (2022–2024, concurrent with GCD): [154860] MSFC ECI: 2022-10 to 2024-09, TRL 4→6 target achieved, 882 views. - Lead: Thomas W. Teasley (MSFC PI) - Partner: Venus Aerospace (Houston, TX) — emerging commercial RDRE company - Goal: "Develop the capability within the US to design and operate a high performance rotating detonation rocket engine for hypersonic, Lunar/Martian lander, and interplanetary propulsion applications" - Misclassified TX12.4.1 (Manufacturing Processes); ML correctly predicts TX01.3.4 ✓ - Achieved TRL 6 — the highest sub-system TRL reached in NASA RDRE work

Phase 3 — TDM integrated system (2024–2028, current): [158559] GRC TDM: 2024-10 to 2028-09, TRL 3→5 target. - PM: John C. Fikes (GRC); Program Director: John Dankanich - Same consortium as GCD: GRC, AFRL, Purdue, Spectral Energies, UAH, UCLA, UIUC + U Illinois - TRL paradox: ECI reached TRL 6 for sub-components (2024), but TDM starts at TRL 3 (2024). The difference is scope: ECI developed specific manufacturing/hot-fire capabilities; TDM targets the integrated system at TRL 3→5. Sub-system TRL ≠ integrated system TRL.

Active RDRE projects (April 2026)

Project Program Org Period TRL Technology focus
158559 TDM GRC 2024–2028 3→5 Integrated RDRE system — NASA's flagship development
182901 SBIR/STTR Spectral Energies LLC 2023–2027 4→6 Multiphase injector dynamics, gaseous/liquid propellants
184154 FO Juno Propulsion Inc. 2025–2027 4→7 RDRE with green propellants for satellite propulsion
158616 STRG Stanford University 2024–2026 2→3 Spray-detonation dynamics fundamentals
118443 STRG UT San Antonio 2022–2027 2→3 Thermal management via generative design
118450 STRG UIUC 2022–2027 2→3 Wave/mode structure computational investigation
156358 STRG Purdue 2023–2028 2→3 Device geometry optimization (misclassified TX01.4.3 NTP)

Total: 7 active projects. TDM 158559 is the system integration effort; FO 184154 is the commercial application demo; SBIR 182901 is the supply chain component; STRG grants are the research foundation.

Completed predecessor projects

Project Program Org Period TRL Notes
116281 GCD GRC (Perkins PM) 2020–2024 3→3 NASA flagship, 7,345 views; built consortium
154860 ECI MSFC + Venus Aerospace 2022–2024 4→6 Capability gaps; highest RDRE TRL achieved
146980 MSFC CIF MSFC 2023–2024 2→4 RP/Ox staged combustion operability
146489 MSFC CIF MSFC 2021–2022 1→3 AM RDRE hardware exploration
157894 MSFC IRAD UAH 2024 2→4 Calorimetry: chamber heat flux measurement
93901 STRG Purdue 2017–2019 2→3 Aerospike nozzle for RDRE
4321 STRG Purdue 2011–2015 2→3 First valveless detonation concepts

Commercial ecosystem

  • Spectral Energies (Dayton OH): 7-year continuous SBIR funding 2019–2026, TRL 2→6 across multiple phases. Diagnostics partner on both GCD and TDM main projects. The most important industrial supplier in the RDRE ecosystem.
  • Venus Aerospace (Houston TX): ECI partner [154860] + independent SBIR lead [158172] (rotating detonation nozzle, TRL 3→4). Emerging commercial RDRE company.
  • Juno Propulsion: FO [184154], green propellants for satellite propulsion, TRL 4→7. Aggressive claim — FO means flight validation.
  • Astrobotic: Two SBIR injector design projects [125748], [154561], TRL 3→6. Unexpected player (known for lunar landers, not propulsion).
  • Quadrus, CFD Research, CPEC Technologies, Plus Designs: Each with one SBIR Phase I project, TRL 1-6 range.

TDM detail

  • GRC, John C. Fikes PM; Program Director John Dankanich (same as SEP TDM)
  • 6,643 views — highest view count of any active TX01 project; no library items attached (confirmed in live API, not just cache)
  • Destination: "Foundational Knowledge" — building enabling technology, not mission-tied
  • Misclassified TX01.4.4 Solar Thermal; ML predicts TX01.3.4 Airbreathing Pressure Gain Combustion ✓

Juno Propulsion RDRE (184154) detail

  • New company; FO program (flight demonstrations); 2025–2027, TRL 4→7
  • Green propellants + RDRE: combining two clean propulsion trends
  • FO program means Juno is targeting actual flight validation — TRL 7 = flight demonstrated

Strategic significance

Nuclear propulsion TDM (both NTP and NEP) terminated Dec 2025, leaving a gap in NASA's "beyond-chemical" propulsion portfolio. RDRE is the nearest-term viable alternative — it can improve efficiency by 5-10% without nuclear complexity. The TDM program starting Oct 2024 (one year before nuclear termination) may reflect a portfolio rebalancing decision. Confidence: suggestive (no document evidence of explicit linkage).

Taxonomy notes

RDRE projects are scattered across TX01 sub-areas — taxonomic inconsistency across the portfolio: - TX01.3.4 Airbreathing Pressure Gain Combustion — the most accurate (ML preference) - TX01.4.4 Solar Thermal — catch-all for "other"; used by TDM [158559] (human+ML agree = stable wrong) - TX01.4.4 Solar Thermal — GCD [116281]: same error, both human AND ML agree (trained-in error, not corrected) - TX01.1.9 Rocket-Based Pressure Gain Combustion — correctly used by Juno FO [184154] ✓ - TX01.4.3 Nuclear Thermal Propulsion — incorrect (156358 RDRE geometry error) - TX12.4.1 Manufacturing Processes — used by ECI [154860] (human); ML correctly predicts TX01.3.4

7. Cryogenic Propulsion and Propellant Depots

Added session 19.

Cryogenic fluid management (CFM) is receiving substantial NASA investment for lunar and Mars operations — the Artemis architecture requires propellant transfer/storage in orbit and on the surface. Multiple FO flight tests + one dedicated TDM program.

Active cryogenic projects

Project Program Org Period TRL Technology
116757 LOXSAT 1 TDM Eta Space 2021–2027 4→7 LOX fluid management demo on Rocket Lab Photon
106718 Green Prop Zero-G FO Purdue 2022–2027 4→5 Green propellant positioning in microgravity (FO parabolic)
155235 Cryogenic spray HT FO Purdue 2023–2027 4→5 LH2 chilldown spray heat transfer models
106638 Two-phase HTC FO Purdue 2021–2026 4→6 Flow boiling rates for in-space cryogen transfer
158460 Thermomagnetic propellant FO Georgia Tech Research 2024–2027 4→6 Magnetic propellant positioning devices
184147 MUTT FO Carthage College 2025–2027 4→6 Acoustic ullage bubble control
158498 LH2 critical HF STRG Washington State 2024–2026 2→3 LH2 critical heat flux optical imaging

Purdue dominates FO cryogenic work — 3 of 7 projects, all basic fluids/thermal research relevant to in-space propellant depots.

LOXSAT 1 (116757) detail

  • Eta Space (Merritt Island FL), commercial company
  • First orbital LOX fluid management demonstration — 10 CFM technologies on a 9-month mission
  • Rocket Lab Photon as spacecraft bus
  • TRL 4→7 target — flight demonstration is the goal
  • Active through April 2027; 3,247 views
  • Outcomes: Advanced To × 2 (partner: Other) — already feeding into follow-on programs
  • This is the critical enabler for orbital propellant depots for Gateway and Artemis

Cross-references

  • LOXSAT feeds directly into the depot architecture needed for fission-surface-power.md lunar power delivery
  • Green Propellant Zero-G (106718) connects to the GPIM ASCENT story in Section 1 above

8. SOFC for Mars — New GCD Initiative (2025)

Added session 19.

Two GCD projects started Aug–Oct 2025 at GRC develop solid oxide fuel cells (SOFCs) for Mars missions. Both are misclassified as TX01.1.4 (Solids) — ML correctly predicts TX03.1.4 (Dynamic Energy Conversion).

Projects

Project Program Period TRL Purpose
184655 SOFC Test Capability GCD 2025-10-01 – 2026-12-31 0→0 Facility: convert GRC CH4/air test stand → CH4/O2 capability
184672 Solid Oxide Fuel Cell Task GCD 2025-08-01 – 2026-12-31 2→5 SOFC power system for cis-Mars transit, landers, surface power

Both: GRC PI Jennifer L. Rock; Program Director Niki Werkheiser (STMD GCD Program Director).

Why SOFCs for Mars now?

Mars mission architecture has converged on CH4/LOX propellant (Starship and competing concepts all use methane for ISRU compatibility). SOFCs convert CH4 + O2 → electrical power, enabling the propellant tanks themselves to serve as the energy store. This eliminates carrying separate power storage for transit and surface operations.

Key rationale from 184672: "Mars missions have emphasized the mass and energy savings resulting with maintaining cryogenic methane (CH4) propellant compared to cryogenic hydrogen (H2) propellant."

Misclassification note

TX01.1.4 "Solids" is solid propellant (i.e., rocket motors). SOFC is an electrochemical power device. The ML classifier correctly predicts TX03.1.4 (Dynamic Energy Conversion) for both projects. These should be in TX03, not TX01.

Context

These are the newest active GCD projects in the propulsion space. They started 9 months after the NTP/NEP terminations. Whether this represents a deliberate portfolio shift (away from nuclear, toward chemical ISRU power) or an independent initiative is not determinable from TechPort data alone.

Summary: Technology Maturity Map

Technology TRL Range Flight Heritage Key STMD Programs
Green monopropellant (AF-M315E) 5→8 via TDM ✓ GPIM (2019, STP-2) SBIR supply chain → TDM (GPIM) → AFRL
Green monopropellant (LMP-103S) 9 commercial ✓ Commercial satellites ECAPS/Bradford (commercial, not TechPort primary)
Hall thruster (4.5 kW, HiVHAc) 4→5 — GRC CIF → Industry transition
Hall thruster (15 kW, SEP-scale) 5→6 — SBIR (Busek)
Hall thruster (100+ kW, X3) 4→5 — GCD NextSTEP
RF thruster (Phase Four) 6→8 — SST (commercial validated)
Iodine Hall (SmallSat) 4→6 — GRC CIF
SEP TDM (13075) — PDP for PPE 4 (PDP) ongoing TDM (GRC, 2014-2029, 5187 views)
LOX cryogenic fluid management 4→7 Flight demo active TDM (LOXSAT 1, Eta Space, 2021-2027)
RDRE (rotating detonation) 3→5 TDM target — TDM (GRC 158559, 2024-2028); FO + SBIR + STRG
SOFC for Mars (CH4/O2) 2→5 (target) — GCD (GRC, 2025-2026, NEW)
NEP (nuclear electric, fission + thrusters) 3→3 ✗ Program ended Dec 2025 TDM (GRC, Closed_Out Dec 2025)
NTP (solid core NERVA-heritage) 3–4 ✗ Program ended Dec 2025 MCO → TDM (both Closed_Out)
NTP (CNTP/liquid core) 1–2 — STRG academic only (2024-2028)
MPD thruster (electrodeless) 2 — STRG (U Michigan, 2024-2028)
PPR (pulsed nuclear plasma) 2–3 — NIAC Phase II (active)
NearStar Fusion 3 — NIAC → commercial spin-out
EmberCore (radioisotope EP) ? — NIAC Phase II (Completed 2025)
ELO multi-junction solar cells (MicroLink) 9 Closed_Out; Airbus customer SBIR (112889, 2019-2021); feeds SEP via TechPort gap

Open Threads

  1. Dual nuclear termination context: Both NTP and NEP TDM Closed_Out Dec 2025 at TRL 3. Budget cut? Administration change? Policy decision? TechPort data cannot answer — requires external context. The timing (late 2025 = new administration) is suggestive. Filed as surprise.
  2. HiVHAc downstream: Transitioned_To Industry — which company? Anonymized transition record limits lineage tracing. Query: find SBIR projects citing HiVHAc or GRC Hall thruster license 2017-2022.
  3. EP for Gateway PPE: Power and Propulsion Element uses AEPS (Aerojet Rocketdyne). What TechPort projects feed into AEPS? The 118354 STRG project (Hall thruster facility effects for Gateway PPE) is one entry point.
  4. ~~NearStar Fusion company: Does NearStar Fusion Inc have any follow-on TechPort projects? Check by org ID 10126.~~ RESOLVED (session 39): find_projects(lead_organization="NearStar") → 0 results. NearStar Fusion Inc (Chantilly VA, org ID 10126) has no TechPort projects as lead organization. They remain in the TechPort org database but have no direct STMD funding footprint visible here.
  5. ~~MPD thruster maturity: 158679 is active 2024-2028. Is this the Polk et al. (IEPC 2024) work from the NEP publication list?~~ RESOLVED (session 9): 158679 is a U Michigan STRG grant (PI: Benjamin Jorns), exploring an electrodeless MPD concept at TRL 2→3 (2024-2028). PM is James Polk (JPL), who also authored the NEP publication. However, 158679 is a basic research STRG project exploring a novel electrodeless concept, NOT a continuation of the terminated NEP TDM (which worked with conventional GRC Hall thrusters at TRL 3). The shared PM (Polk) reflects JPL's institutional interest in high-power EP, not a programmatic link. These are separate lineages. Destinations: Mars, Others Inside the Solar System — consistent with long-duration human missions.
  6. EmberCore follow-on: USNC-Tech has now completed EmberCore Phase II NIAC. Any continuation in TechPort as SBIR, STTR, or GCD? Check for new projects post-2025.
  7. ~~RDRE TDM 158559 documents: 6,579 views but no library items in the batch cache.~~ RESOLVED (session 39): Confirmed via live API — no library items attached to [158559] at all. The 6,643 view count is organic discovery traffic to the project description page, not document downloads. No documents expected imminently.
  8. LOXSAT 1 (116757) flight status: TDM active through April 2027. Two "Advanced To" outcomes already recorded. Has the Rocket Lab Photon satellite launched? TechPort data doesn't include mission status. External check needed.
  9. SOFC Mars (184655/184672) — short timeline: Both projects end Dec 2026. TRL 2→5 in 16 months is aggressive. Monitor for completion outcomes and whether they produce a follow-on GCD system project.
  10. SEP TDM (13075) — 15-year program, TRL 4: Why is current TRL 4 after 12 years of work? Likely PDP tracking, not thruster TRL. Read one of the 43 library items to confirm PDP vs. thruster scope.
  11. TX01 active SBIR misclassification rate: 5 of 7 active SBIR TX01 projects appear misclassified (PAL → TX04, Project Tethys → TX07, RDRE → TX01.4.3 instead of TX01.3.4, etc.). This is a 71% mismatch rate — far higher than the ~4% found in the broad SBIR survey. Investigate: is this systematic in propulsion or a small-sample artifact?

Verification

Claim Source n Confidence
1849 TX01 projects, 37 programs portfolio_aggregate(group_by="program", filter={"primaryTx":"TX01"}) 1849 confirmed
GPIM Infused_To AFRL get_project(11585), technologyOutcomes array 1 confirmed
102945 Closed_Out (not Infused_To) get_project(102945), technologyOutcomes array 1 confirmed
NTP 158561 TRL 3→3 vs target 5 get_project(158561), trlCurrent=3 1 confirmed
NTP 75 publications in 2023-2024 get_document(389926), count from bibliography ~75 confirmed
NEP 158369 TRL 3→3 vs target 5 get_project(158369), live API 1 confirmed
NEP closed Dec 2025 (Closed_Out) get_project(158369), technologyOutcomes 1 confirmed
Both NTP+NEP closed Dec 2025 get_project(158561, 158369) 2 confirmed
0 active TX01.4 projects portfolio_aggregate(filter={"primaryTx":"TX01.4","status":"Active"}) 0 confirmed
USNC-Tech 13 TechPort projects find_projects(lead_org="Ultra Safe Nuclear") 13 confirmed
Active STRG NTP projects 158683, 158586 tagged TX01.4.3 get_project batch 2 confirmed
TX01.4.4 overloaded (3 mismatches) get_project(92621, 158619, 158529), txMismatch field 3 confirmed
Phase Four TRL 6→8 get_project(106833) 1 confirmed
59 active TX01 projects (all programs) find_projects(technology_area="TX01", status="Active", limit=100) 59 confirmed
7 active TX01 SBIR projects find_projects(program="SBIR/STTR", technology_area="TX01", status="Active") 7 confirmed
RDRE TDM 158559: TRL 3→5, 2024-2028, 6579 views get_project([158559]) 1 confirmed
SOFC Mars 184655/184672: GCD, GRC, 2025 start get_project([184655, 184672]) 2 confirmed
LOXSAT 1 (116757): TRL 4→7, TDM, Eta Space, 2021-2027 get_project([116757]) 1 confirmed
SEP TDM 13075: Active 2014-2029, PDP focus, 5187 views get_project([13075]) 1 confirmed
MicroLink ELO solar (112889): TRL 9, Closed_Out Sep 2021 get_project(112889), technologyOutcomes 1 confirmed
PAL 158389 txMismatch: TX01.1.3 → TX04.4.1 predicted get_project([158389]), txMismatch field 1 confirmed

Cross-references