LRO is a NASA orbiter that images the Moon's landing sites and measures its terrain.
nasa-lro The Lunar Reconnaissance Orbiter, or LRO, has mapped the Moon from orbit since 2009. NASA's Goddard Space Flight Center built it, and its seven instruments also look for places where ice may lie near the poles. The maps supported site selection for Artemis.
The main structure is aluminium. The instruments are mounted in a module made of graphite composite, a material that barely expands or shrinks as the temperature changes. Heat pipes carry heat from the electronics to radiators, and a hydrazine propulsion system holds 894 kg of fuel in two titanium tanks.
NASA orbiter that has mapped the Moon from lunar orbit since 2009, imaging landing sites, measuring topography and finding polar ice candidates. It carries seven instruments and supported site selection for Artemis.
The main structure is aluminium, built up from a heating and cooling panel, edge members, fittings and brackets. The instruments sit in a module known as the Wine Box, made from sheets of graphite and cyanate ester. Its optical bench is graphite composite, and flexible titanium mounts hold the instruments.
Two titanium tanks hold 894 kg of hydrazine. Four 80-newton insertion thrusters are for entering lunar orbit, and eight 20-newton thrusters control attitude and keep the orbit steady. A composite-wrapped helium tank supplies the pressure.
The solar array is one wing of three graphite composite panels, 10.7 square metres in all, rated at 1,850 W at the end of its life. The wing turns about two axes. An 80 amp-hour lithium-ion battery is built from Sony cells, each a steel can holding rolled electrodes.
Most of the electronics are coupled to an aluminium honeycomb panel with heat pipes built in. Header heat pipes link that panel to a radiator mounted separately on the spacecraft. The high-gain antenna has multilayer insulation and heaters, and two instruments have radiators of their own.
The main structure, and the 18-inch flywheels inside the four reaction wheels.
The two propellant tanks and the flexures that mount the instruments.
The propellant, 894 kg of it, carried in two tanks.
The instrument optical bench and the three panels of the solar array.
The instrument module, known as the Wine Box. It changes size very little with temperature.
The 80 amp-hour battery, built from Sony cells.
An Atlas V 401 launched LRO on 18 June 2009, sharing the ride with a companion spacecraft, LCROSS. The Atlas has a single RD-180 engine in its first stage and a single RL10A-4-2 in its Centaur upper stage. Goddard built the orbiter in-house, using star trackers from SELEX Galileo, gyros from Honeywell, a computer from BAE Systems and cells from Sony. Its power electronics follow the design of an earlier spacecraft, the Microwave Anisotropy Probe.
United Launch Alliance
launched 18 June 2009 with LCROSS as companion; one booster and a Centaur, no solid boosters
shared the launch; Centaur later impacted the Moon as part of LCROSS
LRO's power electronics architecture is modeled after MAP
two star trackers
Miniature Inertial Measurement Unit (3 ring-laser gyros)
ten coarse sun sensors
single board computer (off-the-shelf)
US18650HC lithium-ion cells for the battery
built the spacecraft in-house and runs the Mission Operations Center
ESA
Aluminium. Here: Primary structure (heating/cooling panel, edge members, fittings, brackets); Optical-bench heater aluminum tape and more. There: Telescope (structure and mirrors, 3 telescopes).
Titanium. Here: Propellant tanks (2); Instrument mounting flexures. There: Focal plane interconnecting structure; Instrument mounting feet / flexures and more.
lithium-ion. Here: Battery cells. There: Battery.
Multilayer insulation. Here: High Gain Antenna multi-layer insulation and heaters. There: Instrument thermal wrap.
ESA / Airbus
Aluminium. Here: Primary structure (heating/cooling panel, edge members, fittings, brackets); Optical-bench heater aluminum tape and more. There: Main structure tube; Equipment box (EQB) and more.
Titanium. Here: Propellant tanks (2); Instrument mounting flexures. There: OBA unit attachment fittings; Instrument support bipods (3).
lithium-ion. Here: Battery cells. There: Batteries and solar cells.
Multilayer insulation. Here: High Gain Antenna multi-layer insulation and heaters. There: Outer thermal blanket (both spacecraft).
North American Aviation
Aluminium. Here: Primary structure (heating/cooling panel, edge members, fittings, brackets); Optical-bench heater aluminum tape and more. There: Radial beams; Crushable ribs (x4) and more.
Titanium. Here: Propellant tanks (2); Instrument mounting flexures. There: Helium tanks (2); Fuel tanks (2) and more.
aluminum honeycomb with embedded heat pipes. Here: Iso-thermal panel with embedded heat pipes. There: Inner pressure shell (crew compartment); Sector and RCS exterior panels (1 in thick).
steel. Here: Battery cell can. There: Crew couch frames (x3); Couch shock-attenuating struts (x8).
NASA
Aluminium. Here: Primary structure (heating/cooling panel, edge members, fittings, brackets); Optical-bench heater aluminum tape and more. There: Sunshield layer coating (all 5 layers).
graphite composite. Here: Instrument optical bench; Solar array wing (three panels, 10.7 m2). There: Backplane structure.
Titanium. Here: Propellant tanks (2); Instrument mounting flexures. There: Backplane fittings and interfaces.
hydrazine. Here: Propellant. There: Monopropellant engine fuel.
NASA
Aluminium. Here: Primary structure (heating/cooling panel, edge members, fittings, brackets); Optical-bench heater aluminum tape and more. There: Pressure vessel (seven large pieces, friction-stir welded); Backbone assembly (floor structure) and more.
Titanium. Here: Propellant tanks (2); Instrument mounting flexures. There: Heat shield skeleton.
aluminum honeycomb with embedded heat pipes. Here: Iso-thermal panel with embedded heat pipes. There: CFRP sandwich panel core.
Multilayer insulation. Here: High Gain Antenna multi-layer insulation and heaters. There: Passive thermal control: multilayer insulation blankets (incl. high-temperature blankets at thrusters and nozzle) and heaters.
Grumman / NASA
Aluminium. Here: Primary structure (heating/cooling panel, edge members, fittings, brackets); Optical-bench heater aluminum tape and more. There: Cabin front-face, RCS cluster trusses, decks and bulkheads; Micrometeoroid shield and more.
Titanium. Here: Propellant tanks (2); Instrument mounting flexures. There: Some brackets and fasteners (lunar module); Descent-stage hot-area structure and more.
aluminum honeycomb with embedded heat pipes. Here: Iso-thermal panel with embedded heat pipes. There: Primary struts with crushable aluminum-honeycomb cartridge; Footpads (x4, aluminum honeycomb).
The published figures for the orbiter's total mass do not agree. The makers do not say which aluminium alloy forms the main structure, who built the tanks and thrusters, or what solar cells the array uses. The antenna dish, the insulation films and the optics inside the seven instruments are also not described.
What is written above is built from these numbers and quotes. Each row links to the page it was taken from. Get all of it as JSON, or ask our MCP server.
| What | Value |
|---|---|
| Launch | 18 June 2009 |
| Launch vehicle | Atlas V 401, with LCROSS as companion |
| Mass | Less than 949 kg dry, 1846 kg fully fueled |
| Solar array | 10.7 m2, 1850 W end-of-life |
| Battery | 80 A-hr lithium-ion |
| Propellant load | 894 kg hydrazine |
| Reaction wheel momentum storage | 130 Nms (assembly) |
| Attitude control accuracy | 60 arcsec control; 30 arcsec knowledge |
| Recorder capacity | two 100 Gbyte recorders |
| Downlink | Ka-band 25 to 100 Mbps; S-band return 125 bps to 256 kbps; S-band forward 4 kbps |
| Data volume | 461 Gb per day |
| Battery pack size | 700 x 300 x 180 mm maximum |
| Delta-V capability | over 1300 m/s |
| Thermal design stack | heat pipes carry heat to zenith-facing radiators |
| Observatory mass | less than 949 kg dry and 1846 kg fully fueled |
| Atlas V 401 first-stage thrust | RD-180 delivers 860,200 lb at sea level |
| Laser ranging | 532 nm pulses from Greenbelt, Maryland |
Each material named in the sources: where it is used here, which other products use it, and its key numbers when its material page exists.
Used in 3 partsPrimary structure (heating/cooling panel, edge members, fittings, brackets) · Optical-bench heater aluminum tape · Reaction wheels (x4)
Used in 2 partsInstrument optical bench · Solar array wing (three panels, 10.7 m2)
Used in 2 partsPropellant tanks (2) · Instrument mounting flexures
Used in 1 partIso-thermal panel with embedded heat pipes
Used in 1 partHeat-pipe working fluid
Used in 1 partInstrument module (‘Wine Box’ structure)
Used in 1 partPropellant
Used in 1 partBattery cells
Used in 1 partBlack-painted calorimeter (MSA94B)
Used in 1 partHigh Gain Antenna multi-layer insulation and heaters
Used in 1 partWhite-painted calorimeter (NS43C)
Used in 1 partBattery cell can
Used in 1 partBench inserts with BR127 primer
Structure, tanks, propellant and battery chemistry are named in NASA catalog text; radiator, array and optics materials are not. Components, suppliers and links were added from public sources. A material is left blank where no source states it.
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Primary structure (heating/cooling panel, edge members, fittings, brackets)“1. Primary Structure (aluminum)” | aluminum (alloy not stated)aluminium | — | NASA Goddard |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Propellant tanks (2)“titanium diaphragm propellant tanks” | titaniumtitanium | — | TDRSS-type tanks |
| Propellant“Fuel load is 894 kg of hydrazine” | hydrazinehydrazine | — | — |
| Insertion thrusters (x4, 80 N class)on-axis hydrazine thrusters near the centre of gravity for lunar orbit insertion“four of which are on-axis 80 Newton class insertion thrusters” | Not said | — | — |
| Attitude-control thrusters (x8, 20 N class)canted thrusters for attitude control, orbit maintenance and momentum dumping“Eight canted 20 Newton class attitude control thrusters provide attitude control, lunar orbit maintenance maneuvers, and momentum dumping.” | Not said | — | — |
| Helium pressurant tank (composite overwrapped)4200 psi tank, 17 in diameter by 29.6 in long, that pressurizes the propellant tanks“The Helium Pressure Regulated System is a 4200 psi COPV Helium pressurant tank” | Not said | — | — |
| Two-stage pressure regulatorsingle-fault-tolerant regulator set at 270 psi nominal“A two stage regulator (single fault tolerant) is set at 270 psi nominal.” | Not said | — | — |
| Pyro valves and high-pressure latch valveredundant pyro valves isolate high pressure on the ground and at launch; the latch valve isolates it in flight“Redundant pyro valves provide for high pressure isolation during ground and launch operations” | Not said | — | — |
| Isolation valves and flow-control orificesvalves with redundant coils isolate thruster banks; orifices prevent water-hammer surges“Isolation valves with redundant coils are used to isolate thruster banks in the event of a thruster failure.” | Not said | — | — |
| Propulsion Deployment Electronics (PDE)fires the thrusters and the initiators; four identical boards give redundant drive“the PDE commands the firing of the thrusters when desired” | Not said | — | — |
| NASA Standard Initiators (NSI)pyrotechnic initiators that open the propulsion pressurization tank“firing of the Propulsion NASA Standard Initiators (NSI) for opening of the propulsion pressurization tank” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Battery cells“An 80 A-hr Lithium-ion battery maintains” | lithium-ionlithium-ion-cell | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Avionics radiator surface“Optical Solar Reflector (OSR) covered heat pipe radiator” | Not said | — | — |
| Iso-thermal panel with embedded heat pipesaluminum honeycomb panel that couples most avionics to a radiator“Most avionics are thermally coupled into an embedded constant conductance heat pipe (CCHP) aluminum honeycomb panel.” | aluminum honeycomb with embedded heat pipesaluminium-honeycomb | — | — |
| Zenith CCHP radiator and header heat pipesdual-bore header heat pipes carry heat to the zenith-mounted radiator“Dual bore header heat pipes couple the isothermal panel to a CCHP radiator that is separately mounted on the zenith surface of the spacecraft.” | Not said | — | — |
| Heat-pipe working fluidfluid inside the heat pipes“stratified with ammonia liquid and vapor” | ammoniaammonia | — | — |
| Battery heat-pipe networkseparate CCHP network with heat pipes on the battery sidewalls“The Lithium Ion battery is maintained on a separate CCHP network with two heat pipes mounted on its sidewalls” | Not said | — | — |
| Reaction-wheel baseplate heat pipestwo baseplate heat pipes connect to two header pipes“two baseplate heat pipes are connected to two header pipes” | Not said | — | — |
| CRaTER and LEND individual radiatorsthermostatically controlled radiators for two instruments“The CRaTER and LEND instruments are provided with individual radiators that are thermostatically controlled.” | Not said | — | — |
| High Gain Antenna multi-layer insulation and heatersblankets and heaters keep the antenna within limits“The High Gain Antenna uses multi-layer insulation (MLI), thermal isolation, and heaters to maintain temperatures within allowable limits.” | multilayer insulation (film types not stated)multilayer-insulation-mli | — | — |
| White-painted calorimeter (NS43C)measures orbital variations of lunar infrared flux“LRO is flying a NS43C (white) painted calorimeter and a MSA94B (black) painted calorimeter” | NS43C white paintns43c-white-paint | — | — |
| Black-painted calorimeter (MSA94B)second calorimeter with a black coating“LRO is flying a NS43C (white) painted calorimeter and a MSA94B (black) painted calorimeter” | MSA94B black paintmsa94b-black-paint | — | — |
| Constant-conductance heat pipes embedded in the avionics iso-thermal panelheat pipes that couple most avionics to a radiator (the aluminum panel itself is in the entry bom)“Most avionics are thermally coupled into an embedded constant conductance heat pipe (CCHP) aluminum honeycomb panel.” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Instrument module (‘Wine Box’ structure)low-CTE graphite structure that carries the optical bench and star trackers; fewer fasteners and continuous bond lines“The entire structure has a low coefficient of thermal expansion (CTE) made of graphite material (M55/CyanateEster Q.I. sheets).” | graphite M55 / cyanate ester quasi-isotropic sheetsgraphite-m55-cyanate-ester | — | — |
| Instrument optical benchgraphite composite bench with honeycomb panels, inserts and spools for LAMP, LOLA and LROC“The instrument module includes a graphite composite optical bench with honeycomb panels, inserts, and spools.” | graphite composite (M55J, low CTE)graphite-composite | — | — |
| Instrument mounting flexurestitanium flexures that mount the instruments on the bench“Flexures for mounting the instruments are titanium.” | titaniumtitanium | — | — |
| Bench inserts with BR127 primertitanium inserts coated with an electrically conductive primer“Insert material is Titanium with BR127 electrical conductive primer.” | titanium inserts with BR127 conductive primerbr127-primer | — | — |
| Optical-bench heater aluminum tape2 to 3 layers of tape spread heat across the bench heaters (about 25 heater circuits)“2 to 3 layers of 3 mil aluminum tape was required to keep the bench relatively isothermal” | aluminum tape (3 mil, alloy not stated)aluminium | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Solar array wing (three panels, 10.7 m2)one articulated wing of three low-CTE graphite composite panels“Three low-CTE graphite composite solar array panels are contained within one articulated wing.” | graphite composite (low CTE)graphite-composite | — | — |
| Solar array gimbal actuators (2 axes)turn the wing 180 degrees in azimuth and 90 degrees in elevation to track the Sun“Once fully deployed, the wing rotates about two axes, with power going through Gimbal Actuators at each axis.” | Not said | — | — |
| Solar array deployment hardwareseparation nuts, restraining rods, panel springs, viscous dampers and cam latches release and unfold the panels“Separation nuts release rods that restrain the array in the stowed configuration.” | Not said | — | — |
| Power Subsystem Electronics (PSE)conditions solar power, charges the battery and distributes power“The basic design and operation of the LRO PSE architecture is modeled after the Microwave Anisotropy Probe (MAP)” | Not said | — | — |
| Battery cell cansteel can that forms the anode of each lithium-ion cell“The cell is a steel can (anode) containing a roll of interleaved electrodes soaked in electrolyte” | steel (grade not stated)steel-grade-unstated | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Reaction wheels (x4)fine pointing and momentum storage; the fourth wheel gives redundancy“Each RW uses an 18-inch aluminum flywheel, providing inertia for momentum exchange.” | aluminum (flywheel; alloy not stated)aluminium | — | Supplier: NASA Goddard GN&C Hardware Branch (in-house) |
| Star trackers (x2)fine attitude determination, 16 x 16 degree field of view“Fine pointing attitude determination is accomplished by two SELEX Galileo Star Trackers.” | Not said | — | Supplier: SELEX Galileo |
| Inertial reference unit (Honeywell MIMU)three ring-laser gyros, one per axis, give spacecraft body rates“Honeywell’s Miniature Inertial Measurement Unit (MIMU) serves as a single IRU.” | Not said | — | Supplier: Honeywell |
| Coarse sun sensors (x10)small sunlight-current sensors that give a Sun direction for the safe-hold mode“The most basic sensors used on LRO to determine spacecraft attitude are ten Adcole coarse sun sensors.” | Not said | — | Supplier: Adcole |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Flight computer (single board computer)RAD750-class processor at 133 MHz hosting the attitude control and flight software“The flight computer is a RAD-750 processor executing at 133 MHz.” | Not said | — | Supplier: BAE (British Aerospace Engineering) off-the-shelf board |
| Data Storage Boards (x4)mass storage of 384 Gbit at beginning of life, about 17.5 hours of science and housekeeping data“Four Data Storage Boards (DSBs) operate as a mass storage system for the spacecraft.” | Not said | — | — |
| Housekeeping / Input-Output (HK/IO) cardLAMP interface and timing synchronization for all instruments“provides an interface to the LAMP instrument as well as providing synchronization to all instruments” | Not said | — | — |
| Multi-function Analog Card (MAC)custom card that manages thermal environments in lunar orbit“The Multi-function Analog Card (MAC) has been custom designed to manage the wide range of thermal environments in the lunar orbit.” | Not said | — | — |
| Ultra-stable oscillators (primary and redundant)externally mounted timing references belonging to the C&DH subsystem“The primary and redundant USOs are components of the C&DH subsystem, but are externally mounted separate assemblies.” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Ka-band modulatormodulates the 25 to 100 Mbps science downlink“The Ka-band sub-system includes a Ka-Band modulator” | Not said | — | — |
| Ka-band traveling-wave tube amplifier (TWTA)TWT, electronic power conditioner and high-power isolator; at least 40 W output“a Traveling Wave Tube Amplifier (TWTA) consisting of a traveling wave tube (TWT), an Electronic Power Conditioner (EPC), and a High Power Isolator” | Not said | — | — |
| S-band transponder and RF switchSTDN-compatible transponder for commands, telemetry and tracking“The S-Band subsystem consists of one Spacecraft Tracking and Data Network (STDN) compatible transponder, an S-band RF Switch” | Not said | — | — |
| Omni-directional TT&C antennascontinuous receive capability on the S-band“the RF paths to and from the TT&C omni-directional antennas and the S-band feed on the High Gain Antenna (HGA)” | Not said | — | — |
| Diplexerslet the transponder receiver and transmitter share one antenna port“Diplexers allow the transponder's receiver and transmitter to connect to a common antenna port” | Not said | — | — |
| High Gain Antenna System: Ka-band antenna with S-band patchKa-band dish with an S-band patch, coax cable, Ka waveguide and rotary joints“RF components include Ka-band antenna with an S-band patch antenna, an S-band coax cable and a Ka band waveguide” | Not said | — | — |
| High Gain Antenna two-axis gimbaltwo-axis gimbal with slightly more than 180 degrees of rotation per axis and two rotating cable wraps“The articulation system is a two axis gimbal system capable of slightly greater than 180 degrees of rotation about each axis” | Not said | — | — |
| High Gain Antenna deployment and non-explosive actuatorstwo latches, three restraint areas and a non-explosive actuator that releases a spring-wound split spool“The High Gain Antenna System (HGAS) includes a deployment system with two latches requiring mechanical release, and three restraint areas.” | Not said | — | — |
| Laser ranging telescope on the high-gain antennareceives 532 nm laser pulses from Earth; fiber optic cable feeds the LOLA instrument“A small laser ranging telescope is mounted on the wave guide with fiber optic cable providing the connectivity to the LOLA instrument.” | Not said | — | — |
| Part | Material | Finish and standard | Made by |
|---|---|---|---|
| Cosmic Ray Telescope for the Effects of Radiation (CRaTER)measures the lunar radiation environment and its biological impact“CRaTER characterizes the lunar radiation environment and determine its potential biological impacts.” | Not said | — | — |
| Diviner Lunar Radiometer (DLRE)orbital thermal mapping of surface and subsurface temperatures“Diviner provides orbital thermal mapping measurements, giving detailed information about surface and subsurface temperatures” | Not said | — | — |
| Lyman Alpha Mapping Project (LAMP)far-ultraviolet mapping of the surface, searching for ice and frost; mounted on the optical bench“LAMP maps the entire lunar surface in the far ultraviolet spectrum.” | Not said | — | — |
| Lunar Exploration Neutron Detector (LEND)maps neutron flux to find hydrogen and possible water ice“LEND creates high-resolution hydrogen distribution maps and provides information about the lunar radiation environment.” | Not said | — | — |
| Lunar Orbiter Laser Altimeter (LOLA)laser altimeter that builds the global topography and measures slopes and roughness; on the optical bench“LOLA measures landing site slopes and lunar surface roughness, and generates a high-resolution 3D maps of the Moon.” | Not said | — | — |
| Lunar Reconnaissance Orbiter Camera (LROC)black-and-white narrow-angle imaging plus wide-angle imaging; on the optical bench“LROC retrieves high resolution black-and-white images of the lunar surface.” | Not said | — | — |
| Mini-RF Technology Demonstrationradar that searches for subsurface water ice and images permanently shadowed regions“The primary goal of Mini-RF is to search for subsurface water ice deposits.” | Not said | — | — |
Aluminum alloy, solar cell type, heat pipe working fluid, OSR and blanket materials, antenna and instrument optics materials are not stated on the NASA pages read. Structure composites, if any, were not confirmed. Mass figures differ between NAIF (1846 kg fueled) and a NASA paper (about 1850 kg). More detail: Not published on the pages read: who built the propellant tanks, helium tank and the 80 N and 20 N thrusters (the paper says a Goddard in-house propulsion system); the solar cell type and maker; the high-gain antenna dish material; the builders of the seven instruments (only principal investigators are named; the press kit lists PIs in the same order as the instrument list, which is how they are matched here); instrument optics and detector materials; the TWT and transponder makers; MLI film types. Mass in the NASA page (about 1000 kg) differs from the PDS catalog (1846 kg fuelled). The 4-by-20-lb and 8-by-5-lb thruster sizes in the thermal paper are the same thrusters as the 80 N and 20 N classes in the PDS text. Atlas V engines are linked as launch-vehicle engines, not spacecraft engines. More detail: Not published on the pages read: who built the propellant tanks, helium tank and the 80 N and 20 N thrusters (the paper says a Goddard in-house propulsion system); the solar cell type and maker; the high-gain antenna dish material; the builders of the seven instruments (only principal investigators are named; the press kit lists PIs in the same order as the instrument list, which is how they are matched here); instrument optics and detector materials; the TWT and transponder makers; MLI film types. Mass in the NASA page (about 1000 kg) differs from the PDS catalog (1846 kg fuelled). The 4-by-20-lb and 8-by-5-lb thruster sizes in the thermal paper are the same thrusters as the 80 N and 20 N classes in the PDS text. Atlas V engines are linked as launch-vehicle engines, not spacecraft engines.
Collected from public pages and documents, checked 4 Nov 2026.
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