Neutron Measurements at the Lunar Surface (NMLS)

Blue Ghost Mission 3 · manifested · NASA payload

A small neutron counter (about 4 kg) with two lithium-6 glass-fiber scintillator sensors, one shielded with cadmium and one with tin. It counts thermal and epithermal neutrons made when cosmic rays hit the regolith. The counts give ground truth for orbital neutron maps, constraints on surface composition (iron, titanium, thorium), the hydrogen cycle through the lunar day, and the surface neutron environment.

PI: Heidi Haviland (NASA Marshall), PI on NASA's CP-21 page; Peter Bertone was PI in 2020-2023 and Haviland the project scientist
Built by: NASA Marshall Space Flight Center (in-house), with the University of Alabama in Huntsville and USRA on the science team (NASA center)

Technology	science instrument (neutron spectrometer)
Moon Base need	DN-012 L, DN-010 L, DN-007 L (Partly NASA's link. NASA's CP-21 page says NMLS could teach us about future human habitability, and the CLPS manager ties its neutron measurements to a long-term presence on the Moon. The ties by ID are the study's reading: the surface neutron environment (DN-012 L, which asks for neutron measurements on the surface to validate crew-dose models; NMLS counts thermal and epithermal neutrons, not the fast-neutron spectrum that drives dose), composition (DN-010 L) and hydrogen (DN-007 L). All three gaps are written for the South Pole; Gruithuisen is a northern near-side site, so the fit is partial.)
Route onto CLPS	NPLP; NASA-Provided Lunar Payloads, SMD's 2019 request to NASA centers, funded by the Lunar Discovery and Exploration Program. The 21 February 2019 NPLP list names 'Advanced Neutron Measurements at the Lunar Surface'; whether that is NMLS is not stated, but the team's posters tie NMLS and the advanced spectrometer to the same work. NASA assigned NMLS to Astrobotic's Peregrine Mission One (TO2-AB) in January 2020. It was taken off in 2023 (the team says because of Peregrine's under-performing engines) and waited for a ride. NASA assigned it to Firefly's CP-21 on 18 December 2024.; 2019
Timeline	first funding 2019 (NPLP); the parent ANS/FNS from about 2013; first flight test No flight of NMLS itself; parent FNS on the ISS from 2016; selected 2019 (NPLP); assigned to Peregrine 2020-01-22; removed 2023; task order CP-21 to Firefly 2024-12-18; launch Not yet launched. Landing targeted for 2028.; landing not in public sources
On the Moon	not yet flown
FO	none

Flights before the Moon

• ISS or MISSE: International Space Station, inside: Marshall's Fast Neutron Spectrometer (FNS, first called the Advanced Neutron Spectrometer, ANS-ISS), 2016-2018 technology demonstration; operations until 2023. The parent instrument: the same composite lithium-6 scintillator technique, measuring the crew's neutron exposure. NMLS is a smaller re-design of it. The team reported no degradation after three years in orbit, and the flight unit was in good condition on return. Not NMLS hardware.

"NMS-Lunar is a re-design of the MSFC Fast Neutron Spectrometer (FNS) currently operating on the ISS."
— NTRS 20200002131, Overview

"From 2016 to 2018, it conducted a technology demonstration on the International Space Station (ISS) as an intravehicular neutron environment monitor, with sustained operations until 2023."
— TechPort project 182429, description; lastUpdated 2026-03-30

"No performance degradation has been seen in 3 years of continuous operation."
— NTRS 20205007245, Summary

"ISS will provide the space flight environment to test ANS-ISS and mature the technique and design ANS-ISS"
— NTRS 20150022206, presentation, 2015

Heritage hardware

• flown design (parent instrument): The Fast Neutron Spectrometer on the ISS; its composite scintillator (lithium-6 glass in plastic) was first tested with accelerator beams around 2013-2014. NMLS keeps the scintillator technique in a smaller, simpler unit.

"NMS is a derivation of MSFC’s larger and more complex FNS that is currently operating on the ISS and is also in development for Gateway."
— NTRS 20200002131

"show preliminary results from laboratory tests and exposures at particle accelerators"
— NTRS 20140012857, abstract, 2014

Funding before the lunar flight

• NASA SMD, Lunar Discovery and Exploration Program, through NPLP; built in-house at Marshall, so no contract appears in USAspending (a search for NMLS found none). The team's 2020 poster gives a budget of USD 2 million for NMLS. A budget figure from the team, not an obligation record. (NASA SMD LDEP / NPLP; from 2019): amount not in public sources

"Budget: $2M for NMLS, and $4.6M for ANS-LSM."
— NTRS 20205007245, LEAG 2020 poster

"Neutron Measurements at the Lunar Surface (NMLS) is a funded effort to measure thermal and epithermal neutron count rates on Astrobotic Mission 1 (ABM1)."
— NTRS 20205007245

How it got onto CLPS

"Lunar Discovery and Exploration Program (LDEP), NASA Provided Lunar Payloads (NPLP) Solicitation."
— NTRS 20200002131, (poster, LPSC 2020), Funding

"The Neutron Spectrometer System and Advanced Neutron Measurements at the Lunar Surface are neutron spectrometers that will measure hydrogen abundance."
— NASA Selects Experiments for Possible Lunar Flights in 2019 - NASA, release of 21 Feb 2019

"Neutron Measurements at the Lunar Surface (NMLS) - Marshall Space Flight Center (MSFC)"
— TO2-AB Science Payloads - NASA Science, payloads 'being reallocated to future lunar delivery missions', update of 6 Apr 2023

"Due to Astrobotic’s under performing engines, NMLS and other NASA payloads were removed."
— NTRS 20230008654, page 28

"is a neutron spectrometer that will characterize the surface neutron radiation environment, monitor hydrogen, and provide constraints on elemental composition"
— More NASA Science, Tech will Fly to Moon Aboard Future Firefly Flight - NASA, release of 18 Dec 2024

On the Moon

Planned for 2028 at the Gruithuisen Domes. In 2020 the team expected it to reach TRL 9 after a 2021 Peregrine flight; it has not flown.

"TRL: Will be TRL 9 after 2021 flight."
— NTRS 20205007245, instrument table

FO's role

Grade: none. No FO project, flight or report names NMLS, the Fast Neutron Spectrometer or the Marshall neutron team; the study searched the 430 FO TechPort records, FO's reports and FO's pages. FO flew other neutron detectors under other teams (Ames' INTREPID, TechPort 106627; the ARMAS thermal neutron monitor, TechPort 106715): topic only, not a link. The parent instrument's flight test was on the ISS, not with FO. The study's earlier traceback grade (none found) stands.

"the Neutron Measurements at the Lunar Surface (NMLS)"
— earlier finding of this study (not a public source)

Who built it

"PI: Heidi Haviland, Marshall Space Flight Center"
— CLPS CP-21 Science - NASA Science

"PI Peter Bertone/ST12, Project Scientist Heidi Haviland/ST13, Lead System Engineer Jeff Apple/ES11"
— NTRS 20230008654, page 28 (Haviland, UCLA talk, 6 Jun 2023)

"It’s based on an instrument that currently operates on the space station and is being developed at Marshall Space Flight Center in Huntsville, Alabama."
— First Commercial Moon Delivery Assignments to Advance Artemis - NASA, 22 Jan 2020

Moon Base need

"NMLS measurements could also help identify other elements present, provide insight into processes that shape the Moon, and even teach us about future human habitability on the lunar surface."
— CLPS CP-21 Science - NASA Science

"test solar cells, and characterize the neutron radiation environment, supplying invaluable information as NASA works to establish a long-term presence on the Moon"
— More NASA Science, Tech will Fly to Moon Aboard Future Firefly Flight - NASA, Chris Culbert, CLPS manager

"interactions of energetic particles with the lunar regolith. Neutron spectrum measurements"
— Moon to Mars knowledge base: DN-012 L: In situ lunar surface radiation environment measurements and space weather monitoring, Description

Open questions

• Is NMLS the 'Advanced Neutron Measurements at the Lunar Surface' of NASA's February 2019 NPLP list? The names differ; NASA does not say.
• NASA's actual spending on NMLS (in-house at Marshall): not in public sources. The USD 2 million is the team's 2020 budget figure.
• Was the NMLS unit built for Peregrine (the engineering and flight units of 2020-2023) kept as is for Blue Ghost Mission 3, or changed? Not in the sources read.