Graphic depiction of the EmberCore Flashlight.
Credit: Christopher Morrison.
An innovative flashlight to allow scientists to see the dark areas of the Moon to better understand their composition has been selected to participate in NASA’s Innovative Advanced Concepts (NIAC) program.
The EmberCore Flashlight: Long Distance Lunar Characterization with Intense Passive X- and Gamma-ray Source Phase 1 project is a 9-month concept feasibility study that will evaluate source parameters and possible mission architectures. If successful, the proposal team may progress to Phase 2 and eventual maturation of the concept. NIAC aims to move ideas from “science fiction to reality.” As such, funded projects are deemed high risk with potential long-term benefits.
“This technology will enable characterization of the structure and composition of the lunar surface in unprecedented detail,” said Planetary Science Institute Senior Scientist Thomas Prettyman, who is the science Principal Investigator and Co-investigator for the EmberCore Flashlight project. “The capabilities for standoff analyses of elemental composition and operation in darkness are potentially game changing.
“My job is to determine how to use Flashlight for in situ analysis and remote sensing of lunar surface composition. I bring expertise in lunar science, radiation transport modeling, and sensor design required to support this work,” he said.
The EmberCore radioisotope source is being developed by Ultra Safe Nuclear Corporation (USNC) to enable lunar night survival by keeping lunar rovers and landers warm through the cold lunar night. By slightly modifying EmberCore an X-ray/gamma-ray flashlight can be produced which would have an intensity orders of magnitude greater than what has been previously deployed in space. This intensity would enable long range interrogation of the lunar surface using X-ray Fluorescence Spectroscopy (XRF). The signal that is returned to the sensor provides an elemental fingerprint that will provide valuable information about the lunar surface and what lies beneath it. Backscattered gamma rays could be used to infer the presence of substances such as water.
“The EmberCore Flashlight excites atoms in the lunar surface, which fluoresce producing X-rays that identify the elements in the target. The abundance of detected elements can be determined from the intensity of the fluorescence X-rays,” Prettyman said. “The backscatter of uncollimated gamma-rays from the lunar surface in the vicinity of the rover provides additional information about the density and composition of the regolith.”
A rover equipped with an EmberCore Flashlight could use its X- and gamma-rays to map the composition of broad areas of the lunar surface from a distance. With a beam strength several orders of magnitude greater than any X-ray source previously deployed in space combined with the mobility of a rover, it would be possible to map the composition of the lunar surface in far greater fidelity than ever before.
“We have several ideas for how the source and detectors would be deployed. For example, the source might accompany a rover into a permanently shadowed crater, illuminating the floor of the crater and providing power to the rover. A second rover or lander might sit outside the crater, measuring the emission of fluorescence X-rays from the interior,” Prettyman said. “In this project, we’ll explore different configurations for the source and detectors as well as their deployment. The source can illuminate selected regions of the surface from a distance. As such, it can be used for elemental analysis of selected targets using X-ray Fluorescence Spectroscopy (XRF).”
The NIAC Phase 1 study will focus on the application of the EmberCore Flashlight at two distinct locations on the Moon: craters in permanent shadow near the lunar poles, and lava tubes, such as those found in Mare Tranquillitatis. The proposed technology could be used to search for significant amounts of water and other volatile materials that are crucial for making the Moon habitable for humans long-term. The source may simplify studies of the lunar subsurface via remote interrogation of exposed materials in the walls of lava tube collapse pits.
“We selected two cases to study: a permanently shadowed region (PSR) near the lunar south pole, and a lava tube collapse pit. Understanding the nature and origin of volatiles cold-trapped in PSRs should be a primary goal of any future lunar polar mission. Such volatiles may be a target for in situ resource utilization. Hydrogen-bearing volatiles may have been delivered by the solar wind, water-rich asteroids, or sourced from the interior. Understanding the origin of volatiles requires measurement of surface composition. In the second case, the EmberCore Flashlight will enable geochemical characterization of the layers from the edge, rather than having to descend into the pit.”
This flashlight technology could be used on any airless body and could be just as impactful for operations on asteroids, small moons, and Mercury, he said.
Prettyman’s work on the project was funded through a subcontract from USNC by NASA, grant #80NSSC23K0595.
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