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Positioning, Navigation, and Timing (PNT)

Cross-cutting topic page for SST projects in precision timing, navigation instruments, and PNT systems for smallsats — particularly beyond GPS coverage (cislunar, deep space).

Updated: session 22, 2026-04-14

CHOMPTT — The Only TRL 9 in SST

93925 — CubeSat Handling of Multisystem Precision Time Transfer

Field Value
Lead University of Florida
PI John W. Conklin
TRL 4 → 9
Period 2015-02 → 2020-08
Partners NASA ARC (bus, EDSN/Nodes derived), AFRL, University of Central Florida (ground laser)
Launch Dec 16, 2018, Rocket Lab Electron (ELaNa XIX), 491×511 km, 85°

What it is: 3U CubeSat with 1U OPTI (Optical Precision Timing Instrument) payload — chip-scale atomic clocks (CSACs), picosecond event timers, avalanche photodetectors, retroreflectors. First CubeSat dedicated to precision optical time transfer.

Results: CSAC performance measured 75 ps Allan deviation at 1s — 3× better than the 200 ps spec. Over one orbit (~6,000 s), timing accuracy <20 ns. Both CSACs operated nominally. 8,098 beacon packets + 6,038 OPTI payload packets collected. Full laser time-transfer ops were delayed by laser safety approvals and weather, but the optical payload performed. Confidence: confirmed (published in Advances in Space Research 2023, eoportal, NTRS 20190027323).

Why TRL 9: The technology was demonstrated in actual operational environment — real LEO orbit, actual laser from ground station, actual CSAC timing. This is the standard for TRL 9.

Why it matters: Precision time transfer is foundational for cislunar navigation (beyond GPS coverage), distributed aperture arrays, and formation flying. Directly relevant to future lunar constellations.

Downstream: TechPort outcome = Closed Out Aug 2020. No Transitioned_To or Infused_To linkage. No identified commercial spinout. The TRL 9 appears to reflect mission success rather than an infusion event. The technology contribution (proving CSACs work on CubeSats for precision timing) feeds the broader PNT research community rather than a single product line. Confidence: confirmed (TechPort outcomes).

Cislunar/Deep Space PNT Instruments

These newer SST projects (2023-2025) push PNT beyond Earth orbit:

155360 — Deep Space PNT Instrument (X-ray Pulsar Navigation)

Field Value
Lead University of Minnesota
PI Demoz Gebre-Egziabher
TRL 3 → 6 (target)
Period 2023-10 → 2025-09
Destinations Moon, Mars, Others Inside Solar System

Sensor for CubeSat PNT using signals from celestial X-ray sources (pulsars, asynchronous X-ray sources). Records photon arrival times to estimate distance. A single pulsar measurement gives rough distance; refined with additional sources and trajectory knowledge. This is the smallsat version of SEXTANT/NICER X-ray navigation demonstrated on ISS. Co-I: Marcus Murbach (ARC). Confidence: pending (no flight; TRL advancement unknown).

155361 — Ultrastable Microphotonic Clocks

Field Value
Lead Caltech
PI Kerry Vahala
TRL 3 → 5 (target)
Period 2023-10 → 2025-09
Destinations Moon and Cislunar
Co-I Andrey Matsko (JPL)

Chip-scale photonic oscillator using optical frequency combs (OFCs). The oscillator integrates onto a chip, supporting mass production and rapid spacecraft development. Kerry Vahala is a leading photonics researcher (h-index ~125). This is the next-generation timing technology after CSACs — potentially orders of magnitude more stable. TechPort status: Completed. Confidence: pending (no flight demo yet).

External lineage (confirmed — commercial spinoff exists): Vahala cofounded hQphotonics (with Dr. Jiang Li, formerly of his Caltech group; Li is President). The company focuses on ultra-low phase noise photonic microwave oscillators using electro-optical frequency division (eOFD). hQphotonics has been awarded multiple DARPA contracts — GRYPHON program (prime) and two DARPA Phase II programs — for chip-scale photonic oscillators. Published chip-scale photonic microwave oscillator achieving record-low phase noise for chip-scale (Science Advances 2024). The connection between the NASA SST cislunar clock work and the hQphotonics DARPA-funded military PNT line is direct: same PI, same silicon nitride resonator + OFC technology, same Andrey Matsko (JPL) as collaborator. NASA SST pushed TRL for space; DARPA/hQphotonics pushed TRL for defense. Confidence: confirmed (hQphotonics website; Semiconductor Review profile; PMC article on chip-scale photonic microwave oscillators).

155359 — Autonomous Optical Navigation Instrument

Field Value
Lead Georgia Tech
PI John Christian
TRL 3 → 6 (target)
Period 2023-10 → 2025-09
Destinations Mars, Others Inside Solar System

Horizon-based OPNAV in 1U form factor. PI was involved with Orion Artemis 1 OPNAV — direct heritage transfer from human spaceflight to smallsat. Confidence: suggestive (Artemis heritage confirmed in description).

106826 — Surface Feature-Based Navigation (Active)

UT Austin (Brandon Jones) | TRL 3→? | Active through 2027-08. ML-based crater navigation and timing (CNT) for lunar orbit, targeting 100m/100ms accuracy. SCOPE-1 LEO CubeSat demo pending ~end 2026 (NASA launch agreement secured). Jones moved CU Boulder→UT Austin — career move IS the tech transfer. STRG→SST pipeline confirmed (TechPort Advanced_To from [91512]). See UT Austin. Confidence: confirmed (TechPort outcomes, UT Austin faculty page).

106828 — High-precision Continuous-time PNT Module for LunaNet

Field Value
Lead UCLA
PI Chee Wei Wong
Co-I Andrey Matsko (JPL)
TRL 3 → 7 (target)
Period 2020-07 → 2025-09

High-precision laser inertial navigation unit as the key complement of a continuous-time PNT chip module for GPS-denied environments — specifically the LunaNet architecture. Uses chip-scale optomechanical inertial sensors using optical readout near thermodynamic limits. Published results: 8.2 µg/Hz½ velocity random walk at 100 Hz, 50.9 µg bias instability (Laser & Photonics Reviews 2020, 2023). TechPort status: Completed.

External lineage (confirmed — SST→FO pipeline): Wong's optomechanical accelerometer was selected for Flight Opportunities [145005] flight test follow-on — one of 4 SST projects to transition via the SST→FO pipeline (alongside Purdue FEMTA, Montana State RadSat, SDSU 5G phased array). Andrey Matsko (JPL) co-investigates on both the Vahala cislunar clock (Caltech, [155361]) and the Wong LunaNet PNT module — he is the connector in the emergent LunaNet PNT stack. See UCLA. Outcome: transitioned. Confidence: confirmed (TechPort projects, Wong PI on both SST and FO).

The LunaNet PNT Stack — Emergent Architecture (Session 20 surprise)

Four SST projects from the same 2020 funding cycle build complementary layers of NASA's LunaNet cislunar architecture. This was not top-down coordinated — it emerged from independent selections that happen to tile the PNT problem space:

Layer Project PI Org Status
Positioning [106826] Crater Nav & Timing Brandon Jones UT Austin Active (SCOPE-1 pending)
Sensing [106828] Optomechanical Accel Chee Wei Wong UCLA Transitioned → FO [145005]
Timing [155361] Microphotonic Clocks Kerry Vahala Caltech Completed (hQphotonics spinout)
Comms [106823] 5G Ka-Band Phased Array Satish Sharma SDSU Transitioned → FO FIGARO-FT

Andrey Matsko (JPL) co-investigates on both the sensing (UCLA) and timing (Caltech) layers — he is the human bridge between two of the four projects. Two of four transitioned to Flight Opportunities. This looks like an emergent technology stack, possibly with JPL informal coordination.

See: LunaNet PNT Stack surprise, Archetype #15: Emergent Architecture Stack.

Precision Timing Heritage

91596 — Miniaturized Phonon Trap Timing Units

U Michigan (Mina Rais-Zadeh) | TRL 3→6 | 2015-10 → 2018-06. Chip-scale all-silicon integrated clock based on phonon trap resonators. Claims 10× better frequency stability than quartz and 100× lower acceleration sensitivity — key for smallsat clocks that must survive launch vibration. Published in NTRS as fact sheet (20160013215, grant NNX15AW42A). Also presented at SmallSat 2016 (USU Digital Commons).

External lineage (confirmed): Rais-Zadeh left U Michigan for NASA JPL (~2019), where she is now Group Supervisor, Advanced Optical and Electromechanical Microsystems Group (MEMS and micro-instrument development). She received JPL's NASA Early Career Faculty Award (2012) for the original clock work, then moved the research in-house to JPL. This is the commercialization-adjacent outcome: the technology IP transferred into a NASA center rather than a startup. No identified commercial spinout. TechPort outcomes: "Advanced From" two predecessors, then Closed Out June 2018. Confidence: confirmed (JPL Science and Technology profile; NASA ECF award record).

94049 — Precision GNSS Relative Navigation

Stanford (Simone D'Amico, SLAB) | TRL 3→6 | 2016-08 → 2018-12. Centimeter-level relative navigation using multi-constellation GNSS. See Autonomy/GNC.

External lineage (confirmed): D'Amico's SST project produced the DiGiTaL (Distributed Multi-GNSS Timing and Localization) system. Hardware-in-the-loop testing at Stanford and GSFC achieved <1 cm (1D RMS) relative positioning and nanosecond-level time synchronization on full CubeSat avionics (ION GNSS+ 2018, Navigation Journal 2019). The technology pipeline continued into three subsequent missions: - Starling (July 2023, NASA SST): four 6U CubeSats; D'Amico's SLAB delivered the StarFOX (Starling Formation-Flying Optical Experiment) payload — angles-only optical navigation using star trackers, successfully demonstrated multi-spacecraft orbit estimation in flight (Nov 2023–May 2024). NTRS 20240007230. - SWARM-EX (NSF-funded, Q1 2026 target): three-CubeSat formation for ionosphere science. - VISORS (two 6U CubeSats, distributed solar telescope, 40 m focal length): formation-flying for high-resolution solar corona imaging. - DWARF (KACST/Stanford binary formation): planned launch ~2022; less clear status.

The arc from SST [94049] → DiGiTaL hardware → Starling StarFOX flight demo is the cleanest university-project-to-flight lineage in the SST PNT cluster. Confidence: confirmed (NTRS 20210015447, 20210015478, 20240007230; SLAB project pages).

93925 CHOMPTT (above)

106832 — Lunar Communications and Navigation System

CU Boulder | TRL 3→? | 2020-07 → 2024-06. See Smallsat Communications.

Maturation Pattern

The PNT cluster shows a clear progression in SST's investment thesis:

2015-2018 (Phase 1): Prove timing and nav hardware works on CubeSats - CHOMPTT: CSACs in orbit ✓ (TRL 9) - Phonon Trap: Alternative timing oscillators (TRL 6) - Stanford GNSS: Centimeter-level relative nav (TRL 6)

2020-2024 (Phase 2): Push beyond GPS coverage — and the LunaNet PNT stack emerges - CAPS/CAPSTONE: Cislunar autonomous nav ✓ (TRL 8, flew) - UCLA LunaNet PNT: Optomechanical inertial sensing → transitioned to FO - Surface Feature Nav (UT Austin): ML-based crater navigation → Active, SCOPE-1 demo pending - SDSU 5G phased array: Ka-band lunar comms → transitioned to FO (FIGARO-FT HAB flight Sep 2024)

2023-2025 (Phase 3): Deep space and next-gen timing - X-ray Pulsar Nav: Mars/deep-space PNT using celestial sources - Microphotonic Clocks: Chip-scale OFC oscillators (potentially revolutionary stability) - Autonomous OPNAV: 1U deep-space horizon navigation

The trajectory: Earth-orbit timing → cislunar navigation → deep-space PNT. Each generation addresses the next gap: "we proved it works in LEO, now what about at the Moon? now what about at Mars?"

Key finding (session 20): The 2020 cycle produced an emergent LunaNet architecture stack — four independent SST projects that tile the positioning/sensing/timing/comms layers. Two of four transitioned to FO flight tests. Matsko (JPL) bridges the sensing and timing layers. This is Archetype #15.

Cross-references