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Fission Surface Power: Kilopower → FSP Lineage

Created: session 15, 2026-04-05 | Updated: session 18, 2026-04-05

Summary

NASA has a continuous, active investment in compact nuclear fission power for surface missions. The two key TechPort records are:

Project ID Program Status TRL Period
Kilopower Small Fission Technology 14405 GCD Completed 3→5 2014–2018
Fission Surface Power 105671 TDM Active 4→8 2019–2028

Direct TechPort lineage: Kilopower Advanced To → Fission Surface Power (Oct 2019).

Why this matters for ocean worlds: SLUSH (the primary SESAME cryobot, project 97168) explicitly states it "uses the Kilopower reactor for both thermal and electrical needs." FSP is the program maturing that reactor to TRL 8. SLUSH cannot fly without a flight-qualified 10 kWe fission source.

Kilopower Small Fission Technology (14405)

  • Program: GCD | Lead: Glenn Research Center | PI: Marc A. Gibson | PM: Dionne M. Hernandez-lugo
  • Period: 2014-07-01 to 2018-10-18
  • TRL: 3 → 5 (target 5, met)
  • Scope: Demonstrate fission power subsystem technology in a relevant environment for 1–10 kWe. The KRUSTY (Kilopower Reactor Using Stirling Technology) non-nuclear ground test was conducted in 2018 at Nevada National Security Site, using HEU-fueled core at full power.
  • Outcome: Closed Out Oct 2018; Advanced To → FSP (105671) Oct 2019

Multi-organizational team

Organization Role Type
Glenn Research Center Lead, systems integration NASA Center
Los Alamos National Laboratory Reactor design and fuel FFRDC/UARC
Y-12 National Security Complex (DoE) Highly enriched uranium fuel US Government
Advanced Cooling Technologies, Inc. Heat pipe radiators Industry
Sunpower, Inc. Free-piston Stirling power conversion Industry
Marshall Space Flight Center Structural/systems support NASA Center
Johnson Space Center Mission applications NASA Center
Ohio State University Academic support Academia

States involved

MS, NM, OH, TN, TX — reflecting the nuclear-supply-chain geography (LANL in NM, Y-12 in TN, GRC in OH, MSFC in AL/MS).

Fission Surface Power (105671)

  • Program: TDM | Lead: Glenn Research Center | PM: Lindsay K. Kaldon
  • Period: 2019-10-01 to 2028-09-30
  • TRL: 4 → target 8 (engineering flight unit)
  • Mission Directorates: STMD
  • Destinations: Moon and Cislunar, Mars

Scope

Design, build, and qualify an Engineering Flight Unit (EFU) for a minimum 10 kWe nuclear-powered generator, demonstrable on the lunar surface and extensible to Mars. Four 10-kW units could supply power for sustained human operations on Moon or Mars.

Contractor ecosystem

Organization Role (inferred from states + context)
GRC Lead, system integration
BWX Technologies (Lynchburg, VA) Reactor fuel / nuclear components
Aerojet Rocketdyne Power conversion or structural
Lockheed Martin System design / lander integration
Boeing System integration
Westinghouse Electric Reactor design
Maxar Technologies Spacecraft/deployment hardware
Creare, LLC Thermal management (same firm doing cryobot pump)
IX, LLC Mission systems
Department of Energy Nuclear fuel and regulatory

States: ID, MD, NM, OH, PA, TX, WA — reflecting DOE sites (Idaho, NM), GRC (OH), and major contractors.

Significance

FSP is the successor to Kilopower but at substantially higher maturity target — TRL 8 means a flight-qualified engineering unit. This is the most mature fission surface power program in TechPort. View count: 5,521 — reflects high community interest.

The SLUSH Dependency Chain

SLUSH COLDTech (97168)
  └─ explicitly requires 10 kW Kilopower-class fission
      └─ Kilopower (14405, GCD, TRL 5, Completed 2018)
          └─ Advanced To →
              Fission Surface Power (105671, TDM, Active 2019-2028, TRL 4→8)
                  └─ Target: lunar surface flight demonstration by ~2028

Gap analysis: FSP's TRL 8 target is for lunar surface. SLUSH needs this for Europa. The delta between lunar FSP and Europan deployment involves: 1. Radiation hardening (Jupiter radiation belt — orders of magnitude harsher than Moon) 2. Deep space thermal environment (Europa ~−160°C surface, 5.2 AU from Sun) 3. Mass and volume constraints for planetary mission delivery 4. 13-year operational life (vs. 10-year FSP design target)

These are not addressed in TechPort FSP scope. The lunar demonstration is a prerequisite, not a sufficient condition.

Alternative: LCF Tunnelbot (158419)

A conceptually distinct alternative: use lattice confinement fusion (LCF) fast fission to power an ice-melting robot directly.

  • Program: NIAC Phase I | Lead: Glenn Research Center
  • PI: Theresa L. Benyo; Deputy PI: Lawrence P. Forsley
  • Period: 2023-05-01 to 2024-01-31
  • TRL: 1 → 2 (study only)
  • Target: Enceladus (20–40 km ice shell)

Key differentiator vs. SLUSH/Kilopower: Passive heat transfer via thermoacoustic engine — no pumps required. Uses depleted uranium (DU) + beryllium (Be) for non-enriched fusion-fast-fission. ~30 cm diameter reactor cross-section. Waste heat directly melts ice.

Status: NIAC Phase I completed 2024. No Phase II visible in TechPort. TRL 2 — purely conceptual. The claim of "previous experiments demonstrated fusion-fast-fission of DU" provides some experimental basis but the technology is far from engineering relevance.

SBIR Supply Chain — Layer-by-Layer Analysis

Added session 16, 2026-04-05. Evidence basis: batch project retrieval + two document reads.

The FSP SBIR supply chain is dominated by thermal management. The reactor core, fuel fabrication, and primary power conversion are invisible in SBIR — handled by prime contractors and DOE national labs.

Layer 1: Reactor Core Thermal Interface (heat pipe–to–core bonding)

The Peregrine Falcon Corporation has the most technically specific FSP SBIR work — bonding heat pipes to uranium core material.

Project Title TRL Period
90572 Liquid Interface Diffusion Bonding of FPS Heat Pipes to Core (Phase I) 2→3 2017
113150 Consolidation of Heat Pipes within a U-8Mo Core (Phase II) 4→6 2020–2023

Document evidence (fileId 378371): Phase II deliverable was a ~16.5 cm diameter depleted uranium (DU) core mockup with 6+ heat pipes bonded using LID (Liquid Interface Diffusion) process. Shear strength target: >8,000 psi. Process equipment and procedure delivered to NASA.

Dual-use finding: The Phase II document explicitly lists NASA applications (FSP 10 kWe lunar, FSP ≥10 kWe Mars, deep space probes, NTP) AND non-NASA applications: Project Pele (DoD/Army portable microreactor) and Project DRACO (DARPA nuclear thermal propulsion). NASA SBIR funding directly fed DoD nuclear reactor programs through a shared supplier.

Layer 2: Heat Transport (core → power converter)

Company Project(s) Technology TRL
Advanced Cooling Technologies 9593, 16158, 102780 High-temp heat pipes for fission systems 2→4, 4→6
ThermAvant Technologies 158725 High-temp oscillating heat pipe transport, NEP-scale 4→4, Active 2024–2026

ThermAvant (158725) document evidence (fileId 317075): Physical 3-meter long OHP prototype demonstrated at 1100K, >2 MW/m² axial heat flux, k_eff >100,000 W/m-K. Requirements: 4-10 MW transport at 1200-1400K over 3-10 meters with <150K temperature drop. This is NEP-scale, not FSP-scale — FSP is 10 kWe, NEP would be ~MW. Yet this SBIR remains Active through July 2026, two months after the NEP TDM was terminated Dec 2025. The program is likely continuing on its contracted timeline; whether it finds a FSP application post-NEP is unknown.

Layer 3: Waste Heat Rejection (power converter → radiator → space)

ACT is the dominant supplier with the highest TRL radiator in the fission SBIR ecosystem.

Company Project(s) Technology TRL
Advanced Cooling Technologies 16141, 17803 VCHP radiator, low-cost single-facesheet 4→7 (Phase II)
Advanced Cooling Technologies 17879, 34095 Ti/water heat pipe radiators 3→5
Creare, LLC 8131 Two-phase cooling loop for FSP waste heat 2→4
Roccor, LLC 94554 Deployable composite radiator (Ti/water HP) 2→4
ThermAvant Technologies 113074, 102494 High-temp heat rejection, Phase I/II 3→4, 4→5
ThermAvant Technologies 158346 High-temp oscillating HP radiator (NEP-scale) 3→4

ACT TRL 7 radiator — confirmed hardware delivery (fileId 357927): Phase II (17803) built 12-cluster modular VCHP radiator (titanium/water heat pipes, direct bond, single facesheet, operates ~450K). Deliverable to NASA GRC for incorporation into the Fission Power System Technology Demonstration Unit (TDU). This is the highest TRL component in the FSP SBIR supply chain — and explicitly an FSP hardware deliverable, not just a prototype.

Layer 4: Power Conditioning and Control

Company Project(s) Technology TRL
QorTek, Inc. 94730, 112882 Radiation-shielded AC-DC converters for FSP 3→4, 4→5
QorTek, Inc. 158160 Radhard FSP controller (WBG, dust/EM mitigation) 2→4 (Phase I only, 2024–2025)
CFD Research Corporation 103055, 112845 SiC power electronics for fission reactors 3→4, 4→5
Sigma Technologies 113195 Energy buffer capacitors for Stirling ACU 5→7
Analysis & Measurement Services 8945, 9908 Autonomous I&C health monitoring 3→5, 4→6

QorTek's 2024-2025 Phase I (158160) explicitly names FSP and mentions "lunar rover mounted FSP generator" — the most recent SBIR explicitly in the FSP scope. TRL only reached 2 (vs. target 4) in the short 6-month Phase I.

Layer 5: Reactor Instrumentation and Sensing

Company Project(s) Technology TRL
Luna Innovations 8518, 8991 Neutron/gamma flux sensors for reactor control 3→5

Layer 6: Surface Power Distribution (FSP → lunar load)

Previously uncharted layer — the cables and transmission infrastructure that deliver FSP power from the generator unit to habitats, equipment, and other power nodes across the lunar surface.

Company Project Technology TRL Period
Astrobotic Technology 158548 Low-mass high-voltage cables + connectors for lunar power distribution 4→6 2024-2026 (Active)

Document evidence (fileId 317005): Briefing chart explicitly states "Multiple VSAT and fission surface power nodes could be interconnected with long distance cabling solutions." Specification: 3-phase, 3kV, 1kHz, supports 10kW — derived from GRC's "lunar microgrid definition and interface team (MIPS)". Target environment: -153°C (lunar night). Deliverable: tested prototype cable assembly (Prototype A + Prototype B) qualified to TVAC, EMI, Accelerated Life.

Commercial angle: Astrobotic's non-NASA application is LunaGrid — a commercial "Power as a Service" offering for CLPS landers and rovers. This is the first SBIR in the FSP supply chain that directly targets a commercial lunar power market (~$300M annual market per Astrobotic's estimate). If FSP flies and demonstrates on the lunar surface, Astrobotic LunaGrid becomes the distribution infrastructure customer.

This is the only active SBIR explicitly named to FSP surface distribution. No comparable cable/connector project was identified from earlier SBIR cohorts (pre-2024).

What Is NOT in SBIR (prime/DOE territory)

Domain Who Does It Why Invisible
Reactor core design Westinghouse, LANL, INL Prime contractor on FSP
Fuel fabrication (HEU→LEU conversion) BWX Technologies, Y-12 (DoE) Nuclear weapons complex
Primary power conversion (Stirling) Aerojet Rocketdyne / Sunpower Prime subcontract
Reactor shielding design National labs Classified/DoE domain
Thermal power transport (sodium/potassium loops) National labs Critical nuclear systems

Stirling gap: Sunpower provided the free-piston Stirling for Kilopower. For FSP, Aerojet Rocketdyne is listed as a prime contractor and likely holds the power conversion work. No Stirling SBIR projects are explicitly linked to FSP — the prime contractors absorb this subsystem.

Supply Chain Summary

FSP (105671) Prime Contract Layer:
  BWX Technologies — reactor fuel
  Westinghouse — reactor design  
  Aerojet Rocketdyne — power conversion (Stirling?)
  Lockheed Martin — system design
  Boeing / Maxar — deployment hardware
  DOE — regulatory + fuel
  Creare LLC — thermal management (dual-use: also on cryobot water pump)

SBIR SBIR Ecosystem (supplemental subsystems):
  ACT ──── TRL 7 radiator (hardware delivered to TDU) ────────→ FSP ✓
  Peregrine Falcon ─ TRL 6 HP/core bonding (also → Pele, DRACO) → FSP ✓
  QorTek ─── TRL 5 power converter / TRL 2 FSP controller ──→ FSP
  CFD Research ── TRL 5 SiC electronics ─────────────────────→ FSP
  Luna Innovations ─ TRL 5 neutron/gamma sensors ───────────→ FSP
  ThermAvant ─ TRL 4 OHP (Active, NEP-scale, post-NEP TDM) → FSP?
  Astrobotic ── TRL 4→6 lunar cables (Active, FSP named) ──→ FSP surface distribution ✓

ACT supplier status: CONFIRMED via document evidence. Peregrine Falcon: CONFIRMED dual-use. All others: inferred from project descriptions mentioning FSP.

Key People

  • Marc A. Gibson (GRC): Kilopower PI — the lead engineer behind KRUSTY
  • Lindsay K. Kaldon (GRC): FSP PM — current program manager
  • John W. Dankanich (GRC): FSP Program Director
  • Theresa L. Benyo (GRC): LCF Tunnelbot PI — alternative concept

Open Threads

  1. FSP timeline risk: FSP targets TRL 8 by 2028. No evidence of schedule slip or program threat in TechPort — but given nuclear regulatory + DOE coordination complexity, delays are plausible. TRL field still shows 4 after 6+ years Active — either no CDR-level advancement yet or field not updated.
  2. Lunar demo → Europa path: The gap between FSP lunar and Europa application is real but unstudied in TechPort. Worth noting as a dependency chain break.
  3. NTP termination context: NTP TDM (158561) confirmed Closed Out 2025-12-01 at TRL 3 vs. target 5. FSP is also TDM — if nuclear budget pressures continue, FSP could face similar risk. No evidence of this yet.
  4. ThermAvant NEP OHP orphan status: Active SBIR (158725) doing 3-meter 1100K OHP runs through July 2026, two months after the NEP TDM (its primary application) was terminated. Worth checking at session completion whether this transitions to FSP or terminates without follow-on.
  5. FSP TechPort document gap: The Active program with highest community interest (5,521 views) has NO readable technical documents in TechPort — only a news link. This is a structural visibility gap, not a data quality issue. Technical progress lives in prime contractor reports, not in TechPort.
  6. Peregrine Falcon Pele/DRACO cross-use: LID bonding technology is feeding DoD nuclear programs. Worth monitoring if follow-on contracts appear in TechPort under different program labels.

Cross-references

Confidence: confirmed — all claims traceable to TechPort project records (14405, 105671, 158419, Kilopower Advanced_To outcome). Contractor list from otherOrganizations field in live API call.