Laser Retroreflector Array (LRA), on the FLIP rover¶
Griffin Mission One · manifested · NASA payload
The same passive Goddard array (eight quartz corner-cube prisms in a dome-shaped aluminum frame), mounted on Astrolab's FLIP rover instead of a lander deck. An orbital laser altimeter can range to it to track where the rover is; after the rover's mission it stays as a fixed marker. Astrolab calls it the first LRA on a lunar rover.
PI: Xiaoli Sun (NASA Goddard)
Built by: NASA Goddard Space Flight Center (NASA center)
| Technology | passive navigation marker (laser retroreflector) on a rover |
| Moon Base need | #0101, #1101 (The study's reading. No NASA gap names the LRA. On a rover the fit to #0101 is closer than on a lander: the gap asks for systems that track mobile surface assets and give their absolute location, and Astrolab says the array is for tracking the rover's position from orbit. How precise that can be is open: LOLA locates small arrays to tens of meters today. After the rover stops, it is one more fixed marker for the network NASA describes (#1101, #0101).) |
| Route onto CLPS | other NASA; No payload call found. The LRA line was developed under NASA's CLPS program. Astrolab announced the rover array among four NASA payloads on FLIP on 18 May 2026; NASA's August 2026 update says five NASA payloads ride on FLIP, and NASA's Moon Base page lists two LRAs for Griffin-1. How and when NASA chose to put an LRA on FLIP, and whether this is a CLPS task-order item or an arrangement with Astrolab, is not in public sources.; 2026-05-18 |
| Timeline | first funding not in public sources (the design was space-qualified at Goddard in 2018); first flight test 2019-02-21 (the design, on Beresheet); never on a rover before; selected 2026-05-18 (announced by Astrolab); NASA's decision date not in public sources; launch target late 2026 (NASA, Aug 2026); landing not in public sources |
| On the Moon | not yet flown |
| FO | none |
Flights before the Moon¶
- earlier lunar mission: SpaceIL's Beresheet lander (the same Goddard LRA design, metal-coated version), 2019-02-21. The first flight of the design: the first NASA instrument on a non-governmental mission to the Moon. How Beresheet ended is not in these sources.
"LRALL was integrated with the SpaceIL Beresheet spacecraft prior to its February 21, 2019 launch and became the first NASA instrument to fly on a non-governmental mission to the Moon."
— NTRS 20205001993
- earlier lunar mission: ISRO's Chandrayaan-2 Vikram lander (an uncoated version), 2019. A space-qualified uncoated version, integrated in April 2019. The landing attempt is not described in these sources.
"one of which was integrated in April, 2019 with the Indian Space Research Organization (ISRO) Vikram lander, a part of the Chandrayaan-2 mission"
— NTRS 20205001993
- earlier lunar mission: ISRO's Chandrayaan-3 Vikram lander (NASA LRA), 2023-08-23. The design on the surface. LRO's laser altimeter (LOLA) first ranged to it on 12 December 2023; by December 2025 about a third of daytime attempts succeeded.
"Vikram lander, with a NASA retroreflector on it, touched down on the Moon on Aug. 23, 2023."
— Laser Instrument on NASA’s LRO Successfully ‘Pings’ Indian Moon Lander - NASA Science"At 3 p.m. EST on Dec. 12, 2023, NASA’s LRO"
— Laser Instrument on NASA’s LRO Successfully ‘Pings’ Indian Moon Lander - NASA Science"32% daytime and 9% nighttime for CH3"
— hou.usra.edu: 1707.pdf
- earlier lunar mission: JAXA's SLIM lander (a NASA retroreflector), 2024-01. A NASA LRA on a lander resting in an off-nominal attitude. LOLA has ranged to it, but rarely.
"including one on JAXA’s (Japan Aerospace Exploration Agency) SLIM lander, due to land on the Moon on Jan. 19, 2024"
— Laser Instrument on NASA’s LRO Successfully ‘Pings’ Indian Moon Lander - NASA Science"The number of opportunities and success rate to SLIM were low given the off-nominal lander attitude."
— hou.usra.edu: 1707.pdf
- Earth orbit or deep space: Astrobotic's Peregrine Mission One (a NASA LRA on the lander deck), 2024-01-08. Nothing: the LRA is passive and works only on the surface, and Peregrine did not land. Same lander company as Griffin.
"As NASA’s LRA (Laser Retroreflector Array) instrument is a passive experiment, and operations could only take place"
— NASA Science, Astrobotic Peregrine Mission One Concludes - NASA
- earlier lunar mission: Intuitive Machines' IM-1 (Odysseus), a NASA LRA, 2024-02-22. The design on a CLPS lander. Odysseus tipped over and its LRA sits on a solar panel almost facing the horizon; LOLA had no returns from it as of December 2025.
"It landed on February 22, 2024."
— Commercial Lunar Payload Services (CLPS) Deliveries - NASA Science"So far, no returns have been received from IM-1"
— hou.usra.edu: 1707.pdf
- earlier lunar mission: Intuitive Machines' IM-2 (Athena), a NASA LRA, 2025-03-06. The design at Mons Mouton, Griffin's target area. The lander came to rest on its side; no ranging to this LRA is reported in these sources.
"IM-2 touched down at approximately 11:30 a.m. March 6"
— NASA Receives Some Data Before Intuitive Machines Ends Lunar Mission - NASA"will remain affixed to the top deck of the lander"
— NASA Receives Some Data Before Intuitive Machines Ends Lunar Mission - NASA
Heritage hardware¶
- design heritage (CLPS LRA line, flight-proven): The same miniature design that has flown since 2019: eight 1.27 cm fused-silica corner cubes in a 5 cm aluminum dome, about 20 g, no power. Goddard space-qualified it in 2018 and optically tested 13 units. NASA calls the LRA flight-proven. Similar small LRAs flew on the ExoMars and InSight landers.
"These devices consist of a small aluminum hemisphere, 2 inches (5 centimeters) in diameter and 0.7 ounces (20 grams) in weight"
— How NASA Uses Simple Technology to Track Lunar Missions - NASA"The metal-coated version of LRALL underwent space qualification and optical testing at Goddard Space Flight Center in 2018"
— NTRS 20205001993"All 13 LRALL units tested met the design specification"
— NTRS 20210010915, LPSC 2021 poster"These three payloads are flight-proven"
— NASA Awards More Moon Base Science, Previews New Opportunities - NASA"Similar small LRAs were placed on the ExoMars and InSight landers"
— NTRS 20205001993
- design heritage (retroreflectors on rovers): Rover-mounted retroreflectors are not new: the Soviet Lunokhod 1 rover (1970) carried a French-supplied laser reflector, and Goddard's paper cites the Lunokhod LRAs. Astrolab's 'first LRA mounted on a lunar rover' can hold only for NASA's small CLPS-type arrays. Goddard's team wrote in 2020 that the design could go on rovers.
"The Apollo and Lunokhod LRAs on the lunar surface"
— NTRS 20205001993, Introduction"and a laser retro-reflector (supplied by France"
— Wikipedia article "Lunokhod 1", revision 1355703317 of 2026-05-23T11:54:30Z, Wikipedia, revision 1355703317"other types of spacecraft (e.g., rovers, rotorcraft, hoppers, boats, etc.)"
— NTRS 20205001993
Funding before the lunar flight¶
- NASA's CLPS program (with a NASA Postdoctoral Program fellowship for the optical tests). No amount public for the program, the LRA line or this unit. (NASA CLPS; not in public sources): amount not in public sources
"Funding National Aeronautics and Space Administration (NASA) Commercial Lunar Payload Services (CLPS)"
— NTRS 20205001993, Funding"developed under the Commercial Lunar Payload Services (CLPS) program"
— NTRS 20210010915, LPSC 2021 poster
How it got onto CLPS¶
"NASA Goddard Space Flight Center — Laser Retroreflector Array (LRA). First LRA mounted on a lunar rover"
— Astrolab Announces NASA Payloads for Upcoming Mission to the Moon – Astrolab, 18 May 2026"Five NASA payloads will be mounted on the Astrolab FLIP (FLEX Lunar Innovation Platform) rover"
— NASA Provides Updates on Moon Base Cargo Landers, Tech Demonstrations - NASAFacebook logoInstagra…, 4 Aug 2026"Additional NASA payloads include two Laser Retroreflector Arrays (LRA)"
— Moon Base Phases - NASA"developed under the Commercial Lunar Payload Services (CLPS) program"
— NTRS 20210010915, LPSC 2021 poster
On the Moon¶
Manifested on FLIP, which rides Griffin Mission One. Tracking a moving rover would be new for LOLA, which has ranged only to arrays on landers, with location uncertainty of tens of meters.
"LOLA ranging to CH3, SLIM, and CE6 is a demonstration of ranging to mini-LRAs on the lunar surface from a moving spacecraft"
— hou.usra.edu: 1707.pdf"After the rover completes its mission, the LRA will remain as a permanent location marker on the Moon for future exploration."
— Astrolab Announces NASA Payloads for Upcoming Mission to the Moon – Astrolab
FO's role¶
Grade: none. No entry in the earlier traceback for Griffin's LRAs (the study's earlier traceback lists Griffin Mission One with no NASA payloads), but the study's earlier traceback found no FO link for any of the five earlier CLPS LRAs, and none was found here: no FO project, flight or report names the LRA or its Goddard team. Mounting on a rover changes the array's attitude and motion, not its technology; no flight test of a rover-mounted array is reported.
"No FO record or report names SCALPSS, ROLSES, LN-1, the retroreflectors,"
— earlier finding of this study (not a public source)"Nothing in the FO sources (a passive reflector)."
— earlier finding of this study (not a public source)
Who built it¶
"PI: Dr. Xiaoli Sun, GSFC"
— TO20A Science Payloads - NASA Science"Laser Retroreflector Arrays (LRA), developed by NASA’s Goddard Space Flight Center"
— Moon Base Phases - NASA
Moon Base need¶
"absolute and relative PNT systems and technologies that accurately track crew and mobile"
— Moon to Mars knowledge base: ESDMD #0101: Positioning, Navigation, and Timing for Lunar Surface Extreme Environments, description"First LRA mounted on a lunar rover to retro-reflect laser beams for precision tracking of the rover's position by an orbital laser altimeter."
— Astrolab Announces NASA Payloads for Upcoming Mission to the Moon – Astrolab"Placement of a small LRA on the deck of a lander or rover enables tracking with an orbital laser altimeter with a precision on the order of centimeters."
— NTRS 20205001993, Introduction"The observed LRA location uncertainty is 10s of meters peak-to-peak"
— hou.usra.edu: 1707.pdf"this growing network will allow scientists to gauge the location of key landers and other points of interest more and more accurately"
— How NASA Uses Simple Technology to Track Lunar Missions - NASA
Open questions¶
- How precisely can LOLA (or a future orbiter) track the rover with this array, given tens-of-meter location uncertainty for fixed arrays today? Not in public sources.
- Is the rover array a standard CLPS unit or modified for rover vibration and tilt? Not in public sources.
- Is the FLIP array part of the CLPS task order or a separate arrangement between NASA and Astrolab? Not in public sources.
- The cost of the array and its accommodation on FLIP: not in public sources.