Lunar PNT systems in Europe and USA
Masaya Murata, Kyohei Akiyama
Japan Aerospace Exploration Agency
December 15th, 2022

Outline

1. Upcoming lunar programs
2. LuGRE (NASA) and Lunar Pathfinder (ESA)
3. Moonlight (ESA)
4. LunaNet and LCRNS (NASA)
5. Conclusions

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Upcoming lunar programs3 / 34

Upcoming lunar programs
I November 16th, 2022: US Artemis 1 (launched)I 2024: NASA Lunar GNSS Receiver Experiment (LuGRE)- First-ever GNSS acquisition at moon, navigation, and orbit
determination experiments in cis-lunar and moon environment

I 2024: US Artemis 2
I 2025: NASA’s Lunar Communications Relay and Navigation
systems (LCRNS) Inc-Alpha- One satellite to provide communication and PNT for moon,
especially at the lunar South Pole region

I 2025: US Artemis 3 and Lunar Gateway
I 2026: ESA Lunar Pathfinder- Cis-lunar communication and first-ever GNSS acquisition
experiments in elliptical lunar frozen orbit (ELFO), navigationand orbit determination
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Upcoming lunar programs (cont’d)
I 2027: ESA’s Moonlight Initial Operating Capability (IOC)- 1 large COMM/NAV satellite in ELFO

I 2027: NASA’s LCRNS Inc-Bravo- Composed of two or three satellites

I 2028: NASA’s LunaNet and LCRNS Initial OperatingCapability (IOC)- The total of four satellites

I 2028?: JAXA’s lunar navigation satellite system (LNSS)
demonstration mission- First-ever lunar PNT experiment at the South Pole region inconjunction with ESA and NASAI 2030: ESA’s Moonlight Full Operating Capability (FOC)- Plus 3 NAV-only satellites in ELFOs (4 satellites in total)

I 2031?∼: China’s lunar PNT satellite constellation system- For building International Lunar Research Station (ILRS)
5 / 34LuGRE (NASA) and Lunar Pathfinder (ESA)

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NASA LuGRE mission in 2024
I GNSS reception in moon transfer orbit and at moon surface© 2022 Qascom
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NASA LuGRE mission in 2024 (cont’d)
I Receiving GNSS (GPS+Galileo) signals at the Moon
- Demonstrating navigation and time estimation using GNSS
- Utilizing the collected data to support development of moon
GNSS receivers- Landing on the Mare Crisium

I Joint NASA and Italian space agency (ASI) mission- The GNSS receiver is manufactured by the Qascom in Italy© 2022 NASA8 / 34

GNSS main and side lobes signal acquisition
I Because GNSS satellites are all pointed towards the earthcenter, the signals coming from the far side of the earth are
only available at the moon

© 2022 Qascom

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Lander and GNSS receiver
I Delivered by the NASA’s (Commercial Lunar PayloadServices) CLPS
- Lander (blue ghost) by the Firefly in Austin, Texas

I The GNSS receiver by the Qascom is just 1.3 Kg- Pseudo range and carrier phase are both collected and theGRoup And Phase Ionospheric Correction (GRAPHIC)
navigation will be performed© 2022 NASA and Qascom

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ESA’s lunar pathfinder mission in 2026
I Deploying one data-relay COMM satellite in the ELFO whose
orbital period is about 10.8 hr and the low-rate cislunar
communication experiment will be performed
I Moon GNSS receiver will be also onboard and the orbit
determination accuracy will be evaluated (first-ever GNSS
data acquisition in the lunar orbit)© 2022 ESA

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ESA’s lunar pathfinder mission in 2026
I The GNSS receiver manufactured by the SpacePNT inSwitzerland
I Same GPS and Galileo signals as the LuGRE mission arecollected. SpacePNT’s GNSS receiver is again just 1.3 Kg© 2022 ESA

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Lunar pathfinder satellite
I The satellite size is 330 Kg and expecting the 8-year
operational time
I X-band Earth link, S-band Moon link, laser retro reflector© 2022 SSTL

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Laser retro reflector (LRR)
I Developed by NASA. The LRR is less than 4 Kg
I First-ever three ranging techniques in the ELFO: GNSS, laser,and X-band ranging© 2022 ESA

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Laser retro reflector (LRR) (cont’d)
I The LRR delivered to SSTL manufacturing the satellite
I The second gentleman from the right is Dr. Javier
Ventura-Traveset (ESA) who has been very kind to us andencouraging the collaboration between ESA and JAXA

© 2022 ESA

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Lunar-capable laser ranging stations
I ESA will add Tenerife-based laser ranging station to support
the lunar pathfinder mission
I NASA’s Apache Point laser ranging station provides the mostprecise capability, approaching 1 mm normal point precision© 2022 ESA

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ESA and NASA relationship
I NASA will deliver lunar pathfinder to lunar orbit and ESA will
provide NASA with access to lunar telecommunications© 2022 SSTL
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Moonlight (ESA)

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Overview of ESA Moonlight
I Providing communication, positioning, navigation, and timing(CPNT) service at the lunar South Pole region and above
I Mainly focusing on the service for lunar lander
I Timeline:- 1 large COMM/NAV satellite in 2027 (Moonlight IOC)- Plus 3 NAV-only satellites in 2030 (Moonlight FOC)

© 2022 ESA

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Moonlight constellation
I 2 or 3 ELFOs whose semi-major axes are ∼ 10, 000 km (about24 hr orbital periods)
I Providing GNSS-like one-way ranging∗ to South Pole region© 2022 ESA∗

will be compliant with the LunaNet requirements to ensure interoperability

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Key performance requirements for PNTI Temporal coverage is consecutive 15 hrs per 24 hrs at South
Pole region
I Note that the PVT accuracy below is when using the othersensors as well such as digital elevation map (DEM) and IMU© 2022 ESA
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Rover navigation
I Combined surface navigation with DEM and IMU© 2022 ESA
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Rover navigation (cont’d)
I DEM+Moonlight = 15 meter accuracy
I DEM+IMU+Moonlight = 5 meter accuracy© 2022 ESA
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Lunar landing
I Moonlight-assisted landing at South Pole region© 2022 ESA
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Lunar landing scenario
I Low lunar orbit whose altitude is 100 km to 15 km (coasting)
I Then braking to 2-3 km from where the vertical landing starts© 2022 ESA

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Landing performance
I Landing accuracy required below 100 meters
I Note that these results are those using IMU and altimeter too- Altimeter only activated for the final vertical descent- SE stands for single epoch EKF, while ME stands for
multi-epoch sequential batch filter© 2022 ESA

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LunaNet and LCRNS (NASA)27 / 34

LunaNetI LunaNet is framework of standards for interoperable networks
I The latest LunaNet interoperability specification (LNIS)
published in Sept. 2022 by NASA and ESA© 2022 NASA28 / 34

LunaNet (cont’d)
I Communication, position, navigation, timing (CPNT) service
I Also providing search and rescue (SAR) and alert messages© 2022 NASA29 / 34LCRNSI NASA’s lunar PNT was presented at the ICG-16 on Oct.
2022. Unlike the Moonlight, few information had been
available from NASA until then© 2022 NASA30 / 34

Most likely targeting the Artemis V in 2028
I The IOC split into 3 increments: Alpha, Bravo, and Charlie© 2022 NASA

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Validation timeline
I On-orbit service testing and verification in 2025 and 2027,
respectively
I IOC is scheduled in 2028 (Artemis V is also in the same year)© 2022 NASA32 / 34

Conclusions

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Conclusions
I NASA’s LuGRE and ESA’s lunar pathfinder are in 2024 and2026, respectively, and the first-ever GNSS acquisition inmoon transfer orbit, lunar orbit, and at the moon surface will
be accomplished
I NASA LCRNS and ESA Moonlight will enter their IOC andFOC in 2028 and 2030, respectively, and the first-ever lunar
communication and navigation satellite systems will beestablished
I We, JAXA and Japan, need to accelerate our effort on
establishing our own lunar systems such as our LNSS andpressurized rover- The first collaboration discussion with ESA was just completed
last week in Netherlands. The second discussion is expected
next summer at Tokyo- Discussion with NASA will be initiated on Jan. 2023 in USA
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