Lunar Environment heliospheric X-ray Imager (LEXI)

Blue Ghost Mission 1 · landed · NASA payload

A wide-field soft X-ray telescope with nine 'lobster-eye' micropore optics. From the Moon it looks back at Earth. It images the X-rays made where the solar wind meets Earth's magnetic field, to see how the magnetopause moves as the solar wind changes.

PI: Brian Walsh (Boston University)
Built by: Boston University (lead), with NASA Goddard and Johns Hopkins University; NASA Marshall managed the payload for CLPS (university)

Technology	science instrument (heliophysics: soft X-ray imager)
Moon Base need	none named (The study's reading: none. LEXI studies Earth's magnetosphere and space weather at Earth, not the lunar surface environment, so no Moon Base gap or data gap fits. Its tie to space weather is at most indirect to DN-012 L (surface radiation and space weather), which asks for measurements at the lunar surface; it is not listed.)
Route onto CLPS	LSITP; Lunar Surface Instrument and Technology Payloads: one of 12 payloads NASA selected on 1 July 2019 (release 19-053). NASA Marshall signed the development contract with Boston University on 19 Mar 2020. Assigned to Firefly's TO 19D (NASA's award of 4 Feb 2021, release 21-012). The PI proposed refurbishing STORM in answer to a call for CLPS projects that could be done 'quickly and with a limited budget'.; 2019-07-01
Timeline	first funding 2011-10-01 (Goddard IRAD for the STORM prototype); first flight test 2012 (STORM on the DXL sounding rocket); selected 2019-07-01 (LSITP); contract signed 2020-03-19; on TO 19D from 2021-02-04; launch 2025-01-15; landing 2025-03-02
On the Moon	operated as planned
FO	none

Flights before the Moon

• sounding rocket or balloon (not FO): NASA sounding rocket, DXL (Diffuse X-rays of the Local galaxy) mission, White Sands, New Mexico; STORM flew as the secondary instrument, 2012. STORM, the first lobster-eye X-ray imager flown in space: wide-field soft X-ray imaging of solar wind charge exchange. NASA says LEXI is this same instrument, kept in a display case at Goddard for a decade, then refurbished with some optics and parts replaced. The team's paper says LEXI's design has 'significant heritage' from STORM.

"In 2012, STORM launched into space on a sounding rocket, collected X-ray images, and then fell back to Earth."
— NASA’s LEXI Will Provide X-Ray Vision of Earth’s Magnetosphere - NASA Science, 'The CLPS delivery won’t be LEXI’s first trip to space' paragraph

"The design has significant heritage from the STORM instrument (Collier et al. 2014, 2015) which flew as a technology demonstration on the Diffuse X-rays of the Local galaxy (DXL) sounding rocket in 2012"
— NTRS 20250000391, page 6

"instrument that flew on a sounding rocket from White Sands, New Mexico, in 2012"
— NTRS 20220013537, CuPID instrument paper

Heritage hardware

• flown hardware, refurbished (STORM): The STORM instrument itself, after the 2012 flight: restored and refurbished, with some old optics and other components replaced.

"Some old optics and other components were replaced, but the instrument was overall in good shape and is now ready to fly again."
— NASA’s LEXI Will Provide X-Ray Vision of Earth’s Magnetosphere - NASA Science, Walsh quote paragraph

• design heritage (CuPID CubeSat, same PI): Walsh's Boston University CubeSat CuPID flew a single-optic soft X-ray imager in low Earth orbit from 27 Sep 2021; its detector electronics were themselves refurbished hardware from a later DXL rocket flight (DXL-2). A related instrument by the same team, not a version of LEXI.

"Additional design heritage stems from the CuPID cubesat mission which flew a single optic X-ray imager"
— NTRS 20250000391, page 6

"The CuPID was launched on September 27, 2021, from Vandenberg Space Force Base"
— NTRS 20220013537

"The CuPID soft x-ray telescope detector and signal chain elec- tronics are refurbished hardware that flew on a sub-orbital sounding rocket mission"
— NTRS 20220013537

Funding before the lunar flight

• Goddard internal R&D (IRAD) for the STORM prototype, 'The First Wide-field X-ray Imaging Telescope for Observations of Charge Exchange' (TechPort 10775). Amount not public. (GSFC IRAD; 2011-10-01 to 2012-09-01): amount not in public sources

"The STORM prototype is fully self-contained, including integrated pre-amps, HV power supplies, and C&DH."
— TechPort project 10775, description (GSFC IRAD)

• LSITP development contract from NASA Marshall to Boston University (80MSFC20C0019), which the team calls the LEXI funding. Linked by name. (SMD LSITP (Planetary Mission Program Office); 2020-03-19 to 2025-12-31): $3,318,911

"LUNAR ENVIRONMENT HELIOSPHERIC X-RAY IMAGER (LEXI)"
— USAspending.gov, award 80MSFC20C0019, description; obligated 3318911.0; subawards 350002.0

"The LEXI mission is funded by NASA grant 80MSFC20C0019 through the Planetary Mission Program Office."
— NTRS 20250000391, page 23, Funding

How it got onto CLPS

"LEXI will capture images of the interaction of Earth’s magnetosphere with the flow of charged particles from the Sun"
— NASA Selects 12 New Lunar Science, Technology Investigations - NASA, release 19-053, 1 Jul 2019

"When NASA put out a call for CLPS projects that could be done quickly and with a limited budget, Walsh thought of the instrument"
— NASA’s LEXI Will Provide X-Ray Vision of Earth’s Magnetosphere - NASA Science, paragraph after 'The CLPS delivery won’t be LEXI’s first trip to space'

"LUNAR ENVIRONMENT HELIOSPHERIC X-RAY IMAGER (LEXI)"
— USAspending.gov, award 80MSFC20C0019, description; signed 2020-03-19, NASA Marshall

"NASA has awarded Firefly Aerospace of Cedar Park, Texas, approximately $93.3 million to deliver a suite of 10 science investigations and technology demonstrations to the Moon in 2023."
— NASA Selects Firefly Aerospace for Artemis Commercial Moon Delivery in 2023 - NASA, release 21-012, 4 Feb 2021

On the Moon

LEXI ran checkouts in transit and then operated for more than 150 hours on the surface, through temperatures above and below those expected, recording X-ray images until sunset. Whether the images show the magnetopause moving, LEXI's science goal, is not yet in the public sources used here.

"captured a series of X-ray images to study the interaction of the solar wind and Earth’s magnetic field"
— NASA Science Continues After Firefly’s First Moon Mission Concludes - NASA

"In total, LEXI operated for more than 150 hours on the lunar surface, accumulating a trove of valuable data."
— The Moon Landing That Made Boston University History (BU Today, 2025); text extracted from the HT…, BU Today, 2025

"There were some challenges while LEXI was on the moon, including higher- and lower-than-anticipated temperatures."
— The Moon Landing That Made Boston University History (BU Today, 2025); text extracted from the HT…, BU Today, 2025

FO's role

Grade: none. No FO flight of LEXI, STORM or the Boston University or Goddard team was found. LEXI's earlier flight was a NASA sounding rocket outside FO. The study's earlier traceback grade (none found) stands.

"Using the Lunar Environment heliospheric X-Ray Imager (LEXI)"
— earlier finding of this study (not a public source)

Who built it

"Lead Development Organization: Boston University"
— TO19D Science Payloads - NASA Science

"Payload PI: Dr. Brian Walsh"
— TO19D Science Payloads - NASA Science

"Lead organizations: Boston University, NASA’s Goddard Space Flight Center, Johns Hopkins University"
— NASA press kit, Commercial Lunar Payload Services: Firefly's Blue Ghost Mission 1 (Jan 2025), press kit p. 8

Moon Base need

"LEXI will use X-ray imagery to study Earth’s magnetosphere"
— TO19D Science Payloads - NASA Science

Open questions

• LEXI's science results (did it image the magnetopause moving?): not yet in the public sources used here.
• The exact date of the 2012 DXL flight with STORM, and which NASA program paid for the rocket: not in the sources saved here.
• How much of the flown 2012 STORM hardware is in LEXI? NASA's article says it was refurbished; the team's paper speaks of design heritage.