Navigation Doppler Lidar (NDL)¶
Peregrine Mission One · failed to land · lander system
A lidar landing sensor: an electronics chassis and an optical head with three small telescopes. It measures the lander's velocity and its range to the ground with high precision during descent. On Peregrine it was Astrobotic's primary navigation sensor for landing, built into the lander, not a NASA CLPS payload.
PI: Farzin Amzajerdian (NASA Langley)
Built by: NASA Langley Research Center (engineering test unit #4); integrated by Astrobotic as a lander component (NASA center)
| Technology | landing sensor (Doppler lidar) |
| Moon Base need | #1101 (The study's reading, as for the IM-1 unit: gap #1101 and the guide's landing challenge do not name NDL, but the challenge asks for landing systems that take accurate range and velocity measurements, which is what NDL does.) |
| Route onto CLPS | NPLP; NASA-Provided Lunar Payloads: on the 21 February 2019 list. In January 2020 NASA assigned NDL to both of the first two deliveries, Peregrine and IM-1. On Peregrine, Astrobotic used it as the primary landing sensor, and NASA's press kit says it was not a NASA CLPS payload; FO's pages call it a payload on both missions.; 2019-02-21 |
| Timeline | first funding 2005 (Langley proof of concept); first flight test 2008-08 (helicopter, NASA Dryden); selected 2019-02-21 (NPLP); assigned to Peregrine and IM-1 in January 2020; launch 2024-01-08; landing not in public sources |
| On the Moon | partly operated |
| FO | tested |
Flights before the Moon¶
- aircraft (not FO): Helicopters at NASA Dryden (2008) and Kennedy (2012), ALHAT project, 2008-08 and 2012-12. Early NDL prototypes: real-time altitude and velocity against GPS and inertial navigation.
"conducted a series of helicopter flight test campaigns in August 2008 at NASA Dryden (now Armstrong) Flight Research Center"
— NTRS 20250010290, page 9
- NASA test vehicle: Morpheus rocket-powered test lander, Kennedy, ALHAT project, 2014. Second-generation NDL on six flights, the last three in the closed-loop navigation. FO's NDL page dates the Morpheus flight 2012.
"The ALHAT project conducted six flight tests of the NDL sensor on the rocket powered Morpheus test vehicle at KSC in 2014"
— NTRS 20250010290, page 9
- FO: Masten (now Astrobotic) Xodiac rocket-powered lander, Mojave, in NASA's COBALT payload, 2017-04-06 and 2017-04-13. The third-generation NDL, open-loop, on a 500 m climb and 300 m divert: the effect of real landing-vehicle dynamics on NDL. Its lessons went into the engineering test unit design that Peregrine's unit shares.
Data: date: Apr 6 and Apr 13, 2017
— FO annual report, FY2017, flights of TechPort project 91351 (flight table, p. 48)"the Navigation Doppler Lidar Sensor Demonstration for Precision Landing on Solar System Bodies"
— nasa.gov: flightopportunities-2017-annualreport-508-highres.pdf, FY2017 report"The third-generation NDL model"
— Moon Mission for Flight-Tested Navigation Doppler Lidar
- FO: Blue Origin New Shepard, in NASA's SPLICE payload (FO technology T0269, TechPort 106705; also part of NASA's Tipping Point with Blue Origin), 2020-10-13 and 2021-08-26. A sister engineering test unit (ETU #2) in SPLICE's descent-and-landing package. The rocket's helium environment limited the NDL data, and the second flight's fixes did not work.
Data: date: Oct. 13, 2020
— FO annual report, FY2021, flights of TechPort project 106705 (p. 8)"The SPLICE project flew NDL sensors on the Blue Origin New Shepard suborbital rocket on two flights in 2020 and 2021"
— NTRS 20250010290, page 9"# 2: Suborbital flight test on Blue Origin New Shepard vehicle (2020,2021)"
— NTRS 20230008771, page 10
- aircraft (not FO): Aircraft flight tests (type not stated), NDL ETU #1, 2021-2023. A sister engineering test unit in aircraft tests and integrated tests with other avionics.
"# 1: Aircraft flight tests (2021 - 2023)"
— NTRS 20230008771, page 10
Heritage hardware¶
- design heritage (engineering test unit line): Peregrine's sensor was ETU #4 of four NDL engineering test units of one design; ETU #3 flew on IM-1 five weeks later. Psionic built a copy of the same unit for Griffin Mission One. Peregrine's optical head was designed for best precision and range, because Astrobotic used NDL as its primary sensor.
"Four NDL ETUs have been built and tested"
— NTRS 20240016238, slide 9"identical to the one flown on both the Astrobotic Peregrine and Intuitive Machines Odysseus CLPS missions"
— Moon Mission for Flight-Tested Navigation Doppler Lidar"Optical head was designed for optimum precision and range"
— NTRS 20240016238, slide 10
Funding before the lunar flight¶
- Langley seed money for a proof of concept (2005), then ALHAT and Morpheus (second-generation NDL), COBALT (third generation, 2013-2017) and SPLICE (engineering test units). The same line as the IM-1 unit; see the IM-1 record for the full list. (NASA Langley; STMD and HEOMD projects (ALHAT, COBALT, SPLICE); 2005-2023): amount not in public sources
"In 2005, he and his team received funding from Langley to put together a proof of concept."
— NASA’s Laser Navigation Tech Enables Commercial Lunar Exploration - NASA"from 2013 through 2017, NDL was part of the Cooperative Blending of Autonomous Landing Technologies (COBALT) project"
— Moon Mission for Flight-Tested Navigation Doppler Lidar"The NDL sensor development was supported by multiple NASA program offices including the Space Technology Mission Directorate"
— NTRS 20250010290, page 4, Acknowledgments
- NDL parts bought by NASA in 2019, the period of the engineering-test-unit builds: FPGAs from Avnet. Linked by the award description. Other 2019 orders name NDL too (ADCs 80NSSC19P1354, $45,897.12; switching converters 80NSSC19P1738, $31,937; NAND flash 80NSSC19P1111, $21,050). The sources do not say which of the four units used them. (NASA purchase order 80NSSC19P1892; 2019-08 to 2019-10): $180,000
"FPGAS FOR NAVIGATION DOPPLER LIDAR (NDL)"
— USAspending.gov, award 80NSSC19P1892, description; amount 180000.0"ADCS FOR NAVIGATION DOPPLER LIDAR (NDL)"
— USAspending.gov, award 80NSSC19P1354, description; amount 45897.12
How it got onto CLPS¶
"The Navigation Doppler Lidar for Precise Velocity and Range Sensing payload will make precise velocity and ranging measurements during the descent"
— NASA Selects Experiments for Possible Lunar Flights in 2019 - NASA"Two of the payloads will be integrated onto both the Astrobotic lander and the Intuitive Machines lander."
— First Commercial Moon Delivery Assignments to Advance Artemis - NASA, 22 Jan 2020"NDL is a flight-controlled guidance and navigation sensor but is not considered a NASA CLPS payload."
— NASA press kit, Commercial Lunar Payload Services Initiative: Astrobotic's Peregrine Mission One…"NASA selected the NDL technology as a payload on two lunar missions within the CLPS (Commercial Lunar Payload Services) initiative: the Astrobotic Peregrine Mission 1"
— Moon Mission for Flight-Tested Navigation Doppler Lidar, FO's NDL page
On the Moon¶
NDL powered on in space and operated nominally for 6.5 hours. Peregrine's propulsion failed about 7 hours after launch, so there was no descent, and NDL's job as the landing sensor was never tested. Its sister unit worked through descent on IM-1 in February 2024.
"NDL operated nominally for 6.5 hours"
— NTRS 20240016238, slide 11"Astrobotic: NDL was the primary navigation sensor Not a CLPS payload"
— NTRS 20240016238, slide 10"has also been successfully powered on"
— NASA Science, Data Collection Ongoing Aboard Peregrine Mission One - NASA
FO's role¶
Grade: tested. Graded tested, as for the IM-1 unit: FO flew the direct predecessor (2017) and a sister engineering test unit (2020-2021) before Peregrine. FO says the Xodiac flights gave 'a unique environment for examining the effect of landing vehicle dynamics on the NDL operation', and their lessons 'were critical in design, build, and testing of an NDL Engineering Test Unit'. The study's earlier traceback left Peregrine's NDL unresolved because NASA did not count it as a payload; as a lander system it is outside the earlier traceback's counts of NASA payloads, so those counts do not change. With the TRN sensor (graded tested after the second check), it is one of two FO-tested items on Peregrine.
FO flights: 4. The same FO flights as for the IM-1 unit (two Xodiac flight days in 2017, two shared New Shepard flights in 2020-2021); their cost per payload is in FO records. The New Shepard flights were also part of NASA's Tipping Point with Blue Origin.
"The rocket-powered Xodiac vehicle provided a unique environment for examining the effect of landing vehicle dynamics on the NDL operation."
— Moon Mission for Flight-Tested Navigation Doppler Lidar"This flight testing helped prepare the technology for two trips to the Moon in early 2024"
— Moon Mission for Flight-Tested Navigation Doppler Lidar"Tested on Flight Opportunities-facilitated"
— nasa.gov: dr-fop-pub-anr-20-03-fop-accomp-report-online.pdf, FY2020 report p. 5"SPLICE (Safe & Precise Landing Integrated Capabilities Evolution)"
— TechPort project 106705, title (FO program)
Who built it¶
"PI: Dr. Farzin Amzajerdian"
— NASA press kit, Commercial Lunar Payload Services Initiative: Astrobotic's Peregrine Mission One…"# 4 – Lunar Landing Demonstration onboard Astrobotic lander (2024)"
— NTRS 20240016238, slide 9 (AIAA SciTech 2025, Langley)"which Astrobotic incorporated as a Peregrine lander component"
— NASA Science, Data Collection Ongoing Aboard Peregrine Mission One - NASA
Moon Base need¶
"Develop precision landing systems capable of taking highly accurate range and velocity"
— Moon to Mars knowledge base: Moon Base technology and knowledge challenges, Headline challenge 1, technology challenge"technologies should enable safe and accurate landings in all visibility conditions"
— Moon to Mars knowledge base: ESDMD #1101: Lunar Precision Landing and Hazard Avoidance for Human Exploration, Description
Open questions¶
- Was NDL a NASA payload on Peregrine? NASA's press kit and Langley say no; FO's NDL page and FY2020 report say NASA selected it as a payload on both missions.
- The cost of ETU #4: not in public sources. USAspending shows only parts orders that name NDL, not tied to a unit.
- Did Astrobotic pay for or own the Peregrine NDL unit, or was it NASA-furnished? Not in public sources.
- What FO paid for the 2017 Xodiac and 2020-2021 New Shepard flights: FO records.