Lunar Radiometer (LRAD)¶
IM-2 · landed · commercial payload
A small thermal-infrared radiometer with six thermopile sensors, mounted on Intuitive Machines' hopper. It was to measure surface brightness temperatures, roughness and thermal inertia, including inside a permanently shadowed crater, at decimeter-to-meter scale, as ground truth for orbital maps.
PI: not in public sources saved here (the instrument papers are led by Maximilian Hamm, with Matthias Grott and Jörg Knollenberg, DLR)
Built by: German Aerospace Center (DLR), Berlin, with Freie Universität Berlin; Intuitive Machines and Arizona State University as hopper partners (partner agency)
| Technology | science instrument (thermal infrared radiometer) |
| Moon Base need | DN-003 L, DN-007 L (The study's reading. DN-003 L asks for thermal maps of South Pole sites finer than LRO Diviner's 240 m pixels; LRAD's team says its decimeter-to-meter data would complement Diviner and constrain where water ice is stable (DN-007 L). No NASA source ties LRAD to a gap.) |
| Route onto CLPS | commercial; Not a NASA selection. Intuitive Machines added DLR's radiometer to its Tipping Point hopper as a guest payload in 2021-2022 (the hopper's FY2022 review lists it as a new payload). NASA's CLPS office mentions LRAD; NASA's IM-2 timeline does not count it. |
| Timeline | first funding not in public sources (German grant 50OW2103); first flight test not in public sources; selected by early 2022 (described on the hopper in the March 2022 LPSC abstract); launch 2025-02-26; landing 2025-03-06 |
| On the Moon | not in public sources |
| FO | none |
Flights before the Moon¶
- Earth orbit or deep space: DLR MASCOT lander on JAXA Hayabusa2 (asteroid Ryugu), 2014-12 launch; landed on Ryugu 2018-10-03. The MARA thermopile radiometer, a predecessor from the same DLR department; the LRAD team names its radiometer heritage as MASCOT/Hayabusa2 and MMX (MMX had not flown by March 2025).
"It is derived from the rich heritage of radiometers built at the Planetary Sensor Systems department. Previous radiometers were provided to MASCOT/Hayabusa2 and MMX (Martian Moons eXploration)."
— geo.fu-berlin.de: index.html, section 'Collaboration and Support'"The instrument design is based on the miniRAD radiometer of the Martian Moons Explorer’s (MMX) rover"
— hou.usra.edu: 1162.pdf, LRAD section
Heritage hardware¶
- design heritage: LRAD is based on DLR's miniRAD radiometer for the rover of JAXA's Martian Moons eXploration (MMX) mission; the team calls miniRAD its predecessor. Whether miniRAD had flown before IM-2 is not in these sources. The team cites its earlier thermopile radiometer papers for the method; the study did not read them.
"The instrument design is based on the miniRAD"
— elib.dlr.de: 1393.pdf"miniRAD instrument is the predecessor of the LRAD"
— elib.dlr.de: 1393.pdf
- ground calibration: Radiometric calibration in a small vacuum chamber against a black body, reported in 2024.
"CALIBRATION OF THE LUNAR RADIOMETER FOR INTUITIVE MACHINES’ S.P. HOPPER."
— hou.usra.edu: 1876.pdf, LPSC 2024 abstract 1876
Funding before the lunar flight¶
- German Federal Ministry for Economic Affairs and Climate Action, through DLR, grant 50OW2103. Amount not in public sources here; no US award. (German national space program (BMWK); not in public sources): amount not in public sources
"German Federal Ministry for Economic Affairs and"
— hou.usra.edu: 1876.pdf, acknowledgements"Bundestag. Grant: 50OW2103"
— hou.usra.edu: 1876.pdf
How it got onto CLPS¶
"Addition of new German Aerospace Center (DLR) payload (Lunar Radiometer)"
— NTRS 20220013035, accomplishments (Sept 2022)"The hopper will take images and Lunar RADiometer (LRAD) thermal IR measurements"
— ntrs.nasa.gov: CLPS2025LPSCv1.pdf, CLPS office, LPSC 2025
On the Moon¶
LRAD rode on the hopper, which never left the lander because Athena lay on its side, so the planned measurements from hopper flights did not happen. Whether LRAD was powered or returned any data during the hopper's checkouts is not in public sources.
"Due to the off-nominal landing orientation, the Hopper surface operations were constrained and it did not deploy from the lander."
— TechPort project 116372, description
FO's role¶
Grade: none. No FO project, flight or report names LRAD, DLR's radiometers or this team. A foreign instrument would not normally be FO's to fly.
"The CLPS office also mentions radiometer measurements by IM-2's hopper"
— earlier finding of this study (not a public source)
Who built it¶
"Germany's DLR provided the Lunar Radiometer instrument, which will measure surface temperatures and map temperature variations."
— Falcon 9 launches second lunar mission of 2025 with IM-2 lander - NASASpaceFlight.com"LRAD – A RADIOMETER FOR THE LUNAR SOUTH POLE HOPPER µNOVA. M. Hamm1,2, M. Grott1, J."
— elib.dlr.de: 1393.pdf, LPSC 2022 abstract 1393
Moon Base need¶
"radiometer, whose polar maps are 240 m/pixel."
— Moon to Mars knowledge base: DN-003 L: High-resolution, time-resolved thermal mapping of lunar south pole exploration regions and sites"measurements at decimeter to meter scale resolution to"
— elib.dlr.de: 1393.pdf, continues: 'will complement LRO Diviner observations'
Open questions¶
- LRAD's principal investigator and the amount of German grant 50OW2103: not in the sources saved here (DLR's pages refused automated fetches).
- Did LRAD power on or return data during the hopper's checkouts on IM-2? Not in public sources.
- Does LRAD share flight hardware or heritage with DLR's earlier radiometers (the 2022 abstract cites papers by Spohn and Grott for the method)? Not read here.