Laser Retroreflector Array (LRA)¶
Blue Ghost Mission 4 · manifested · NASA payload
A passive optical marker: eight small corner-cube prisms in a dome-shaped aluminum frame, about 5 cm across and 20 g. Laser altimeters on orbiters, or lidars on landers coming in later, can range to it from most directions, so it marks the lander's position for decades and helps place the other instruments in the lunar frame. It needs no power, data or heating.
PI: Xiaoli Sun (NASA Goddard), named PI on NASA's CS-6 page; deputy PI Daniel Cremons
Built by: NASA Goddard Space Flight Center (NASA center)
| Technology | passive navigation marker (laser retroreflector) |
| Moon Base need | #0101, #1101 (The study's reading. No NASA gap names the LRA, and the knowledge base calls it a navigation aid, not a data gap's subject. A permanent marker at the South Pole fits #0101 (positioning in extreme surface environments, cited by the Users Guide under long-duration operations) and #1101 (precision landing): NASA's LRA team says such arrays can help later spacecraft land in dark places near permanently shadowed regions. This site, near Haworth crater, is such a place. A 2029 landing sits on the phase boundary (web: Phase 1 'Now–2029', Phase 2 '2029–2032'; Ignition deck 2: Phase 1 'Now through 2028'); the study reads it as Phase 2.) |
| Route onto CLPS | other NASA; No payload call. The LRA was developed under NASA's CLPS program itself and goes on most CLPS landers. NASA named it among the payloads of Firefly's task order CS-6 (Blue Ghost Mission 4, $176.7 million, awarded 29 July 2025), and the CS-6 page lists it as one of four NASA science payloads. When this unit was assigned is not public. The CS-6 page's photo caption still says the array 'will be mounted on Astrobotic’s Peregrine lander deck', a caption carried over from Peregrine.; 2025-07-29 |
| 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); selected 2025-07-29 (named in the CS-6 award); launch no earlier than 2029 (Firefly); landing 2029 (NASA, target) |
| On the Moon | not yet flown |
| FO | none |
Flights before the Moon¶
- earlier lunar mission: SpaceIL's Beresheet lander (the same Goddard design, metal-coated), 2019-02-21 (launch). The first flight of the design, integrated in November 2018. 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"
— NTRS 20205001993
- earlier lunar mission: ISRO's Chandrayaan-3 Vikram lander (NASA LRA), 2023-08-23 (landing). The design on the surface, working: LRO's laser altimeter ranges to it, with a success rate of 32% by day and 9% by night by late 2025.
"ISRO's (Indian Space Research Organization) 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"32% daytime and 9% nighttime for CH3"
— hou.usra.edu: 1707.pdf
- earlier lunar mission: JAXA's SLIM lander (a NASA retroreflector), 2024-01-19 (landing). A NASA LRA on the surface; LRO ranged to it, though rarely, because SLIM rests in an off-nominal attitude.
"The number of opportunities and success rate to SLIM were low given"
— hou.usra.edu: 1707.pdf
- Earth orbit or deep space: Astrobotic's Peregrine Mission One (its NASA LRA), 2024-01-08 (launch); did not land. Nothing: the LRA is passive and works only on the surface, and Peregrine did not land.
"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 (Nova-C 'Odysseus'), 2024-02-22 (landing). The design on a commercial lander. Odysseus tipped over and its LRA sits on a solar panel; LRO had no returns from it by late 2025.
"So far, no returns have"
— hou.usra.edu: 1707.pdf, continues: 'been received from IM-1'
- earlier lunar mission: Intuitive Machines' IM-2 (Nova-C 'Athena') at Mons Mouton, 2025-03-06 (landing). The design near the South Pole. Athena landed on its side; the array stays fixed to its top deck. No ranging to it is reported in these sources.
"NASA’s Laser Retroreflector Array, a passive instrument meant to provide a reference point on the lunar surface"
— NASA Receives Some Data Before Intuitive Machines Ends Lunar Mission - NASA
Heritage hardware¶
- design heritage and batch build: Eight 1.27 cm corner cubes in a 5 cm aluminum dome, about 20 g, built for decades on the surface and radiation-tested to 19 Mrad; space-qualified at Goddard in 2018. Similar small arrays flew on the ExoMars and InSight Mars landers. Goddard had optically tested 13 units by 2021; which unit flies here is not stated. This would be the first Goddard LRA on a Firefly lander: Blue Ghost Mission 1 carried a different reflector, the University of Maryland's NGLR-1.
"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"including radiation testing to 19 Mrad (Si)"
— NTRS 20210010915, LPSC 2021 poster"All 13 LRALL units tested met the design specification"
— NTRS 20210010915, LPSC 2021 poster"Similar small LRAs were placed on the ExoMars and InSight landers"
— NTRS 20205001993"Lead Development Organization: University of Maryland"
— TO19D Science Payloads - NASA Science, NGLR on Blue Ghost Mission 1
Funding before the lunar flight¶
- NASA's CLPS program, which developed the LRA design (with a NASA Postdoctoral Program fellowship for the optical tests). No amount public for the program or for one unit, and no SBIR or USAspending award names a CLPS LRA unit (see open questions). (NASA CLPS; from about 2018): amount not in public sources
"Funding National Aeronautics and Space Administration (NASA) Commercial Lunar Payload Services (CLPS)"
— NTRS 20205001993, Funding
How it got onto CLPS¶
"Laser Retroreflector Arrays for Lunar Landers (LRALL) developed under the Commercial Lunar Payload Services (CLPS) program"
— NTRS 20210010915, LPSC 2021 poster, Introduction"Laser Retroreflector Array is an array of eight retroreflectors on an aluminum support structure that enables precision laser ranging"
— NASA Selects Firefly for New Artemis Science, Tech Delivery to Moon - NASA, 29 Jul 2025"It will be mounted on Astrobotic’s Peregrine lander deck"
— CS-6 Science - NASA Science, photo caption
On the Moon¶
Manifested on Blue Ghost Mission 4, for a 2029 landing about 40 km south of Mons Malapert on the rim of Haworth crater. LRAs are also manifested on IM-4, IM-5, Blue Moon Pathfinder Mission 1, Griffin Mission One and the four late-2028 landings, some of which may land first.
"approximately 40 km south of Mons Malapert on the rim of the Haworth Crater"
— Blue Ghost + Elytra: Lunar South Pole - Firefly Aerospace, Our Destination
FO's role¶
Grade: none. No FO project, flight or report mentions the LRA or its Goddard team. A passive marker had no need of a suborbital test; its proof came from earlier landers and LRO ranging. The study's earlier traceback grade for every earlier LRA (none found) applies.
"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"
— CS-6 Science - NASA Science"Lead development organization: NASA’s Goddard Space Flight Center in Greenbelt, Maryland."
— NASA Selects Firefly for New Artemis Science, Tech Delivery to Moon - NASA"deputy principal investigator for the"
— How NASA Uses Simple Technology to Track Lunar Missions - NASA, Daniel Cremons
Moon Base need¶
"LRAs can eventually be used to help spacecraft land in otherwise pitch-dark places close to permanently shadowed regions near the lunar South Pole"
— How NASA Uses Simple Technology to Track Lunar Missions - NASA"will serve as a permanent location marker on the Moon for decades to come"
— NASA Selects Firefly for New Artemis Science, Tech Delivery to Moon - NASA"Navigation aid, not a data gap's subject."
— Moon to Mars knowledge base: Architecture data gaps: all 25, June 2026 landings table, LRA row"Phase 1 "Now through 2028", Phase 2 "2029–2033""
— Moon to Mars knowledge base: Moon Base phases, Ignition deck 2
Open questions¶
- Which tested LRA unit flies on Blue Ghost Mission 4, and where on the lander it is mounted: not in public sources.
- The LRA program's cost and the cost per array: not in public sources. A June 2024 purchase, 'Precision optical laser retroreflector array' from Sellers Optical (80NSSC24PB542, $58,890, performed in Greenbelt), may be LRA hardware; the record does not say.