Glossary

Summary. ADD Rev C's Appendix F, "Terminology" (pp. 291–304), has three parts. F.1 lists 112 acronyms with a "Usage/Context" column, F.2 defines 107 terms, and F.3 sets the rough quantities behind words like "limited" and "moderate" in the objective decomposition. This page gives all three in NASA's wording. It then sets F's definitions beside the other places the architecture defines the same words: the ADD's own key-terms tables, its Appendix C, the 2025 "Architecture Definition" white paper, the 2022 objectives glossary and the 2023–2024 executive overviews. Most match. The real differences are "trade space", which Appendix F defines unlike everywhere else, and a few smaller shifts ("function", "exploration asset", "legacy decision", "continuous presence"). Appendix F predates the Moon Base and has no Moon Base terms. It doesn't define "technology gap" or "Mars vicinity" either.

All page numbers are ADD Rev C unless marked otherwise. The text layer splits several glossary rows from their terms, so pp. 291–294, 298 and 300–302 and p. 304 were checked against the PDF. The "Wiki pages" column and every comparison on this page are the wiki's, not NASA's.

Contents

• Acronyms (F.1)
• Terms (F.2)
• Quantity descriptors (F.3)
• Same word, other definitions
• What Appendix F leaves out

Appendix F's one-line introduction: "This appendix captures acronyms and abbreviations, defines terms used throughout the document" (p. 291, as printed).

Acronyms (F.1)

F.1, "Acronyms and Abbreviations" (pp. 291–294), in the printed order. The third column is NASA's "Usage/Context", left blank where the ADD leaves it blank.

Acronym	Meaning	Usage/Context	Wiki pages
ACR	Architecture Concept Review		Architecture definition process
ADD	Architecture Definition Document		ADD Rev C
ALARA	As Low As Reasonably Achievable	Technology Gaps	#0308
APH	Advanced Plant Habitat	Technology Gaps	#0305
ARMADAS	Automated Reconfigurable Mission Adaptive Digital Assembly Systems	Technology Gaps	#0504
AS	Applied Science	Objective Category	Objectives
ASA	Australian Space Agency	Space Agency
ASI	Italian Space Agency (Agenzia Spaziale Italiana)	Space Agency
CAPSTONE	Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment	Mission	Missions and assets
CaRD	Carbothermal Reduction Demonstration	Technology Gaps	#0601
CLDP	Commercial Low Earth Orbit Development Program	Program	RT-8
CLPS	Commercial Lunar Payload Services	Element	CLPS
CNES	French Space Agency (Centre National D'Etudes Spatiales)	Space Agency
COTS	Commercial Off-The-Shelf
C&PNT	Communication and Positioning, Navigation, and Timing	Sub-Architecture	C&PNT Systems
CSA	Canadian Space Agency	Space Agency
DEM	Digital Elevation Map	Data Gaps	DN-002 L
DLR	German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt)	Space Agency
DSAC-1	Deep Space Atomic Clock	Technology Gaps	#0104
DSN	Deep Space Network	Sub-Element	SCaN Networks
DSNE	Design Specification for Natural Environments	Data Gaps	DN-008 L
ECLSS	Environmental Control and Life Support System
EDL	Entry, Descent, and Landing		#1103
EGS	Exploration Ground Systems	Element	EGS
EP	Electric Propulsion	Technology Gaps	#0503
ESA	European Space Agency	Space Agency
ESM	European Service Module	Sub-Element	Orion
ESPIRIT	European System Providing Refueling Infrastructure and Telecommunication	Gateway Component	Gateway. Spelled "ESPRIT" in the Gateway pages (p. 53).
EVA	Extravehicular Activity		xEVA
FE	Foundational Exploration	Segment	FE
GCR	Galactic Cosmic Radiation	Technology Gaps	#0307
GDOP	Geometric Dilution of Precision	Technology Gaps	#0101
GRAM	Global Reference Atmospheric Model		DN-003 M
GNSS	Global Navigation Satellite System
H2M	Humans to Mars	Segment	H2M
HALO	Habitation and Logistics Outpost		Gateway
HBS	Human and Biological Science	Objective Category	Objectives
HD	High Definition	Technology Gaps
HDL	Human-class Delivery Lander		HDL
HLR	Human Lunar Return	Segment	HLR
HLS	Human Landing System	Element	HLS
HS	Heliophysics Science	Objective Category	Objectives
I/O	Input/Output	Technology Gaps
I-Hab	International Habitation Module	Gateway Component	Gateway
IM&R	Inspection, Maintenance, and Repair	Technology Gaps	#0501
IPEx	ISRU Pilot Excavator	Technology Gaps	#0605
ISA	Israel Space Agency	Space Agency
ISRO	Indian Space Research Organization	Space Agency
ISRU	In-Situ Resource Utilization		ISRU Systems
IVA	Intra-Vehicular Activities
JAXA	Japan Aerospace Exploration Agency	Space Agency	Pressurized Rover
KASA	Korean AeroSpace Agency	Space Agency
KASI	Korea Astronomy and Space Science Institute	Space Agency
KPLO	Korea Pathfinder Lunar Orbiter	Mission	DN-001 L
LCRNS	Lunar Communication Relay and Navigation Systems	Sub-Element	SCaN Networks. "Lunar Communications Relay …" in the SCaN one-pager (p. 64).
LEAP	Lunar Exploration Accelerator Program		RT-1
LEO	Low Earth Orbit		RT-8
LI	Lunar Infrastructure	Objective Category	Objectives (the goals table prints "(LS)", p. 16)
LOLA	Lunar Orbiter Laser Altimeter	Data Gaps	DN-002 L
LPS	Lunar/Planetary Science	Objective Category	Objectives
LRO	Lunar Reconnaissance Orbiter	Mission
LROC	Lunar Reconnaissance Orbiter Camera	Data Gaps	DN-001 L
LTV	Lunar Terrain Vehicle	Element	LTV
LuPEX	Lunar Polar Exploration	Mission	RT-1
MBRSC	Mohammed Bin Rashid Space Centre	Space Agency	Gateway
MEGANE	Mars-moon Exploration with GAmma rays and NEutrons	Mission	RT-1
MI	Mars Infrastructure	Objective Category	Objectives
NAC	Narrow Angle Camera	Data Gaps	DN-001 L
NASA	National Aeronautics and Space Administration	Space Agency
NEP	Nuclear Electric Propulsion	Technology Gaps	#1104
NPR	NASA Procedural Requirements
NRHO	Near Rectilinear Halo Orbit		Gateway; LD-04-L
NSN	Near Space Network	Sub-Element	SCaN Networks
NTP	Nuclear Thermal Propulsion	Technology Gaps	#1104
NZSA	New Zealand Space Agency	Space Agency
OHRC	Chandrayaan-2 Orbiter High Resolution Camera	Data Gaps	DN-001 L
OP	Operations	Objective Category	Objectives
PL&HA	Precision Landing and Hazard Avoidance	Technology Gaps	#1101, #1102
PMAD	Power Management and Distribution	Technology Gaps	#0903
PNT	Positioning, Navigation, and Timing		C&PNT Systems. F.2 heads its entry "Position, Navigation, and Timing" (p. 299).
PPD	Pixel/Degree	Data Gaps	DN-003 L
PPE	Power Propulsion Element	Gateway Component	Gateway
PPS	Physics and Physical Sciences	Objective Category	Objectives (the goals table has "Physics and Physical Science")
PR	Pressurized Rover	Element	Pressurized Rover
PRISM	Payload and Research Investigations from the Surface of the Moon	Solicitation	RT-1
PSI	Plume Surface Interaction	Technology Gaps	#1101; DN-017 L
PSR	Permanently Shadowed Region		Environment; #0804
RT	Recurring Tenet	Objective Category	Recurring tenets
SCALPSS	Stereo Cameras for Lunar Plume-Surface Studies	Payload	DN-017 L; RT-6
SCaN	Space Communications and Navigation	NASA Program	SCaN Networks
SE	Science-Enabling	Objective Category	Objectives
SEP	Solar Electric Propulsion	Technology Gaps	#1104
SfS	Shape from Shading	Data Gaps	DN-018 L
SLE	Sustained Lunar Evolution	Segment	SLE
SLIM	Smart Lander for Investigating Moon	Mission	RT-1
SLS	Space Launch System	Element	SLS
SOA	State of the Art	Technology Gaps	Gaps index
SPE	Solar Particle Event	Technology Gaps	#0307
SSA	Saudi Space Agency	Space Agency
SWaP	Size, Weight, and Power
TLT	Tall Lunar Tower	Technology Gaps	#0504
TH	Transportation and Habitation	Objective Category	Objectives
TOCA	Total Organic Carbon Analyzer	Technology Gaps	#0304
TRL	Technology Readiness Level	Technology Gaps	Gaps index
TRN	Terrain Referenced Navigation	Data Gaps	DN-002 L
TTC	Telemetry, Tracking, and Command	Technology Gaps	#1003
UHF	Ultra High Frequency	Technology Gaps
VEGGIE	Vegetable Production System	Technology Gaps	#0305
VIPER	Volatiles Investigating Polar Exploration Rover	Technology Gaps	Missions and assets
WEH	Water Equivalent Hydrogen	Data Gaps	DN-006 L
xEVA	Exploration EVA Systems	Element	xEVA (heading: "Exploration EVA System")
3GPP	3rd Generation Partnership Project	Technology Gaps	#0103; LD-103

Notes on F.1:

• "Usage/Context" says where in the ADD a term comes up, not what kind of thing it is. VIPER, a rover, is tagged "Technology Gaps"; RT, the recurring tenets, "Objective Category"; NASA "Space Agency". HALO and HDL have no tag, while PPE and I-Hab are "Gateway Component" and the other elements "Element" (the wiki's reading of the column).
• Spellings that differ from the body. "ESPIRIT" here, "ESPRIT" in the Gateway pages (p. 53); "Lunar Communication Relay" here, "Lunar Communications Relay" on p. 64. The 2023 executive overview also prints "ESPIRIT" (open question 56).
• Expanded in the body but not listed: ESDMD, "Exploration Systems Development Mission Directorate" (p. 12); AxEMU, "Axiom Extravehicular Mobility Unit" (p. 48); CEV, "Crew Exploration Vehicle", and ESAS, "Exploration Systems Architecture Study" (both p. 191). The ADD never expands the LD and MD prefixes of its definition tasks, here or in Appendix C (Key definition tasks).
• The wiki's own ID formats (UC-, FN-, DN-, the four-digit gap numbers) aren't acronyms in F.1. How to read them is on Use cases and functions, the gaps index and the data gaps index.

Terms (F.2)

F.2, "Glossary of Terms" (pp. 295–303), in the printed order. Fourteen entries end "(Definition from Moon to Mars Strategy and Objectives)"; the table marks them "M2M S&O" instead of repeating it. Two others cite a source of their own (the Systems Engineering Handbook; NPR 7120.5). The order is mostly alphabetical. Out-of-place entries include "Explore" before "Exploration Asset" and "Function" before "Frozen Samples" (p. 297), "Large Cargo" before "Large Asset" (p. 298), "Scalability" after "Semi-Autonomous System" (p. 301), "Definition Task", "Definition Outcome" and "Trade Space" between "System" and "Transit", and "Traverse" before the two "To Be" entries (p. 302). Pp. 298 and 301–302 were checked against the PDF; p. 297 is from the text layer.

Term	NASA's definition	p.	Notes and wiki pages
Architecture	"The high-level unifying structure that defines a system. It provides a set of rules, guidelines, and constraints that defines a cohesive and coherent structure consisting of constituent parts, relationships and connections that establish how those parts fit and work together."	295	"(Definition from NASA's System Engineering Handbook)". Architecture framework; compared below
Architecture-driven Data Gap	"Data the agency needs to advance the Moon to Mars Architecture that is not met by any existing information."	295	Data gaps index (Section 3.3 has nearly the same words, p. 80). No entry for technology gaps.
Artemis Mission	"The crewed portion of an Artemis Mission Campaign, beginning at crew liftoff from Earth and ending at crew return to Earth."	295
Artemis Mission Campaign	"A collective grouping of uncrewed missions and their associated crewed mission."	295
Automation	"Automatically controlled operation of an apparatus, process, or system by mechanical or electronic devices that take the place of human labor (e.g., computer control of a docking operation or vehicle surface traverse). Human intervention can be available, as determined by hazard controls (e.g., breakout or transition to safe mode), but not required to complete an automated operation."	295	Autonomous Systems and Robotics
Autonomous System	"A combination of elements that function together to achieve goals while operating independently of external controls. An autonomous system may involve any combination of elements (e.g., humans and machines) and is not limited to uncrewed capability."	295	as above
Autonomy	"The ability of a system to achieve goals while operating independently of external controls. Autonomy does not preclude external reprioritization or generation of new goals. It only requires execution of existing goals without external control."	295	as above
Baseline	"An agreed-to set of requirements, designs, or documents that will have changes controlled through a formal approval and monitoring process."	295
Campaign	"A series of interrelated missions that together achieve Agency goals and objectives."	295	M2M S&O
Cargo	"Items that are transported from one location to another."	295	Redefined in Rev A.1 (pp. 3–4); see below
Carrier	"A transport structure or container used to secure and protect logistics items that require transport to the point of use."	295	Logistics Systems; LD-102
Characteristics	"Features or activities of exploration mission implementation that are necessary to satisfy the goals and objectives."	295	Objective decomposition; compared below
Cislunar Space	"The region of space from the Earth to the Moon. Specifically for the Moon to Mars Architecture, elements under the influence of lunar gravity, beyond Earth's geosynchronous orbit and inclusive of low lunar orbit but distinct from the lunar surface."	295
Co-Manifested Payload	"Cargo on a transportation element utilizing excess volume and mass (e.g., cargo located inside the payload attach fitting adapter ring)."	295
Concept of Operations	"Developed early in Pre-Phase A, describes the overall high-level concept of how the system will be used to meet stakeholder expectations, usually in a time-sequenced manner. It describes the system from an operational perspective and helps facilitate an understanding of the system goals. … It serves as the basis for subsequent definition documents and provides the foundation for the long-range operational planning activities (for nominal and contingency operations). It provides the criteria for the validation of the system. …"	295–296	Shortened here. The full entry also says it "stimulates the development of the requirements and architecture related to the user elements of the system" and "becomes part of the concept documentation".
Consumables	"Supplies (not including propellant) that are needed to support mission activities."	296	Same words as "Logistic Items"; redefined in Rev A.1 (pp. 3–4)
Continuous Presence	"Steady cadence of human/robotic missions in subject orbit/surface with the desired endpoint of 24/7/365 operations."	296	M2M S&O. The 2022 wording has "365/24/7" (below)
Control Mass	"Used to define the capability and baseline architecture of the system. It represents the controlled, not-to-exceed allocation of mass to an element."	296
Crew Countermeasure System(s)	"Systems that enable aerobic and resistance exercise for crew inside habitable assets."	296	#0401
Cryogenic Samples	"Samples that are typically below -153°C/120K."	296	#1201, whose targets leave the ranges TBR
Deep Space Environments	"Deep space is the vast region of space that extends to interplanetary space, to Mars and beyond. It is the region of space beyond Earth's Moon, including Lagrange 2, or L2, (274,000 miles from Earth). This environment has many defining factors, including harsh radiation (both solar particle events and galactic cosmic rays), space weather, and microgravity."	296	B.1's note on "deep space" (p. 109): Use cases and functions
Deep Space Transport	"Deep Space Transport is used to describe the assembled Mars transit vehicle stack, which will consist of a propulsion and power transportation system backbone and attached cargo. There are two Deep Space Transport variants: in the crew variant, the cargo will consist of a transit habitat that may or may not be a separate free-flyer that docks with transport; in the cargo variant, the cargo will consist of orbital assets to be delivered to Mars orbit, or surface assets mounted to Mars descent systems that will be delivered to the Mars surface."	296	#1104; Humans to Mars
Deep Sub-Surface Samples	"Samples collected from locations 10–100m below the lunar or Martian surface."	296
Demonstrate	"Deploy an initial capability to enable system maturation and future industry growth in alignment with architecture objectives."	296	M2M S&O; develop or demonstrate
Deploy	"To move into place or bring into effective action."	296
Develop	"Design, build, and deploy a system, ready to be operated by the user, to fully meet architectural objectives."	296	M2M S&O
Earth Vicinity	"The region of space around the Earth-Moon system, including cislunar space, low Earth orbit, and orbits around the Earth-Moon barycenter."	296
Effectivity	"The conditions or mission for which a requirement is initially applicable."	296
Element	"Any exploration system that enables a high-level functional allocation (e.g., crew transport, habitation, logistics delivery) that is primarily self-sufficient."	296	Elements
Excursion	"The activity of moving to and/or returning from a location on the lunar surface through extravehicular operations and/or surface mobility assets."	297	Mobility Systems
Explore	"Excursion-based expeditions focused on science and technology tasks."	297	M2M S&O
Exploration Asset	"All items that are in place and being used as part of the exploration architecture."	297	Elements; p. 21 adds "including payloads"
Exploration Strategy	"Establish the scenarios, conceptual missions, and systems needed to extend humanity's reach beyond low Earth orbit, return to the Moon, and proceed on toward Mars and beyond."	297
Function	"Actions that an architecture would perform that are necessary to complete the desired use case."	297	Use cases and functions; p. 17 lacks "that are necessary"
Frozen Samples	"Samples that are typically around the -85°C range."	297	#1201
Global	"Infrastructure and capabilities that support human and robotic operations and utilization across the subject planetary surface."	297	M2M S&O
Gravity	"'Gravity' refers to acceleration on Earth (~9.81 ms−2), and is expressed in the international system of units (SI) as g. A gravity level lower than 1 g is called 'partial gravity' or 'reduced gravity'."	297
Habitable Environment	"The environment that is necessary to sustain the life of the crew and to allow the crew to perform their functions in an efficient manner."	297	Habitation Systems
Human Landing System Initial Configuration	"Any crewed mission to the lunar surface executed with the initial HLS configurations as defined in the HLS Broad Agency Announcement Option A. (Effectivity for requirements unique to this configuration are noted as 'HLS Initial Configuration.')"	297	HLS
Human-Rating	"A human-rated system accommodates human needs, effectively utilizes human capabilities, controls hazard with sufficient certainty to be considered safe for human operations, and provides, to the maximum extent practical, the capability to safely recover the crew from hazardous situations. Human-rating consists of three fundamental tenets: Human-rating is the process of designing, evaluating, and assuring that the total system can safely conduct the required human missions. Human-rating includes the incorporation of design features and capabilities that accommodate human interaction with the system to enhance overall safety and mission success. Human-rating includes the incorporation of design features and capabilities to enable safe recovery of the crew from hazardous situations."	297	RT-3 Crew Return
Hybrid Propulsion System	"A vehicle consisting of two or more unique propulsion systems, each optimized for different types of maneuvers. For the purpose of this document, two hybrid systems are considered: solar electric propulsion/chem, which combines a solar electric propulsion system with a chemical stage, and Nuclear Electric Propulsion/chem, which combines a nuclear electric propulsion system with a chemical stage."	297	#1104
Increment	"The period of time between the end of one crew mission (i.e., crew splashdown) and the end of a second crew mission, including the uncrewed activities and operations that commence during this defined timeframe."	297
Incremental	"Building compounding operational capabilities within the constraints of schedule, cost, risk, and access."	298	M2M S&O
Integrated Element	"A portfolio that comprises multiple individual assets and provides a suite of integrated capabilities, offering flexible, evolvable concepts to achieve NASA's Moon to Mars Objectives."	298	The body uses the phrase once, for the SCaN Networks: "this integrated element" (p. 64; the wiki's search). See open question 32.
Interoperability	"The ability of two or more systems to physically interact; exchange data, information, or consumables; or share common equipment while successfully performing intended functions."	298	RT-7 Interoperability
Intravehicular Activity Facilities	"Facilities inside a habitable asset, sustained across crewed and uncrewed increments, that allow the hosting and operation of dedicated utilization payloads."	298
Key Architecture Definition Task	"An architecture definition task that influences the end-to-end architecture and warrants elevated scrutiny."	298	Key definition tasks; compared below
Large Cargo	"Items greater than 6t in mass that are transported from one location to another."	298	Rev A.1 "removed 'large cargo' from glossary" (pp. 3–4); below
Large Asset	"For lunar, an asset that is greater than 6t in mass."	298	#0808 Relocation of Large Assets
Legacy Decision	"A decision made before the implementation of the architecture decision roadmapping process."	298	Key definition tasks
Limited Capability Mission	"A mission to a polar landing site where the utilization capability of the mission is limited to the threshold capabilities of HLS and Orion, with no additional delivery or return mass available from goal capabilities or other elements. Additionally, certain missions may prioritize crew time and transportation mass to the delivery and outfitting of new elements in NRHO (e.g., Gateway elements) or the lunar surface (e.g., Pressurized Rover and initial surface habitat). For the purposes of analysis, a two-crew, 6.5-day sortie was assumed as a representative case. … Thus, this mission category represents a case in which only a threshold of utilization activities is expected to be performed."	298	Shortened here; the omitted lines say crew time for "ingress, setup, outfit, and checkout" of new elements and their logistics mass leave less for utilization. Compare LD-07-L's sortie of "around 6 days" (p. 191).
Live	"The ability to conduct activities beyond tasks on a schedule. Engage in hobbies, maintain contact with friends and family, and maintain healthy work-life balance."	298	M2M S&O
Logistics	"Capabilities associated with packaging, handling, storage, transportation, and tracking of logistics items and goods not initially delivered as part of an exploration element, including equipment, tools, consumables, maintenance items, spares, and subsystem components needed to support mission activities such as operations, outfitting, science, research, and utilization. Logistics also includes capabilities associated with reuse, recycling, and disposal of trash and waste."	298	Logistics Systems
Logistic Items	"Supplies (not including propellant) that are needed to support mission activities."	298	Same words as "Consumables"
Loss of Crew	"Death of or permanently debilitating injury to one or more crew members."	299	MD-04 (Key definition tasks)
Loss of Mission	"Loss of or inability to complete significant/primary mission objectives, which includes loss of crew. Each mission is defined with different assumptions and mission objectives. Therefore, specific mission loss-of-mission assessments are accomplished evaluating the attainment of specific mission objectives, using methods tailored to the specific mission risk drivers and each specific program but consistent with defined NASA Probabilistic Risk Assessment standards."	299	MD-08 (open)
Maintenance	"The function of keeping items or equipment in, or restoring them to, a specified operational condition. It includes servicing, test, inspection, adjustment/alignment, removal, replacement, access, assembly/disassembly, lubrication, operation, decontamination, installation, fault location, calibration, condition determination, repair, modification, overhaul, rebuilding, and reclamation. Preventative maintenance is performed before a failure occurs, whereas corrective maintenance occurs in response to a failure."	299	RT-5
Mechanical Assistance	"Device intended to allow the crew to transport more mass than they can hand carry while walking."	299	Mobility Systems
Mission	"A major activity required to accomplish an agency goal or to effectively pursue a scientific, technological, or engineering opportunity directly related to an Agency goal. Mission needs are independent of any particular system or technological solution."	299	M2M S&O
Mobility	"Powered surface travel that extends the exploration range beyond what is possible for astronauts to cover on foot. Spans robotic and crewed systems and can be accomplished on and above the surface."	299	M2M S&O; Mobility Systems
Near-Surface Samples	"Samples collected from locations 1–2m below the lunar or Martian surface."	299
Needs	"A statement that drives architecture capability, is necessary to satisfy the Moon to Mars objectives, and identifies a problem to be solved, but is not the solution."	299	Objective decomposition
Permanently Shadowed Regions	"Areas of the lunar surface that never receive direct sunlight (or have not seen direct sunlight in billions of years). These extremely cold regions, often found in craters near the lunar poles, can contain frozen volatiles of interest for lunar science and ISRU."	299	Environment
Planetary Protection	"Approaches used to avoid harmful contamination of solar system bodies during exploration activities, as well as avoiding possible harmful extraterrestrial contamination from material that may be returned from other solar system bodies, in compliance with Outer Space Treaty constraints."	299	Planetary protection, where the ACR25 paper defines forward and backward separately
Position, Navigation, and Timing	"Position, navigation, and timing (PNT) encompasses the ability to enable broad awareness of a user's location in space and time. Accomplishing PNT relies on both infrastructure and user capabilities. Infrastructure includes the critical foundations of lunar reference system components and lunar reference time, and the sources provided by a broad suite of network assets that rely on those foundations. … Together these foundational elements, radionavigation sources, and user-provided sensors enable a user, either in orbit or on the surface, to maintain awareness of their position, velocity, and time."	299–300	Shortened here. C&PNT Systems
Powered Mobility Asset	"Asset that allows the crew to travel further distances than they can walk (e.g., Lunar Terrain Vehicle or Pressurized Rover)."	300	LTV; Pressurized Rover
Priority Key Definition Task	"A key definition task with many flow-down impacts upon subsequent tasks and which therefore was presented and approved at the Architecture Concept Review to be made early in the architecture roadmapping process."	300	Key definition tasks
Reconfiguration	"If a system is required to provide a function, any time required by the crew associated with making that function available for use, including changing spaces and moving logistics to allow for use of the space for a different purpose (e.g., exercise, eating, sleeping, medical, training, working)."	300	RT-4 Crew Time
Reference Mission	"A defined set of elements with assumed functional allocations working together in a focused mission context that serves as a common point of comparison for strategic analysis and early program formulation activities (prior to Authority to Proceed) and will be updated when necessary to remain in alignment with the overall exploration goals and objectives."	300	Segments
Reference System	"A theoretical system of coordinates and standards sufficient to define the position and motion of objects in space and time. A reference system is composed of a specified origin, the directions of fundamental axes, and a set of conventional models, procedures, and constants used to realize the system."	300	C&PNT Systems (the 2024 reference-frames paper)
Refrigerated Samples	"Samples that typically need to be maintained in the +4°C to -20°C range."	300	#1201
Reposition/Relocate	"The act of moving cargo from one location to another on the lunar or Martian surface."	300
Robotic Systems	"Systems intended to interact with their environment and/or objects in the environment through powered motions and a controlled relationship between sensing and action. Robotic systems can perform physical tasks (e.g., manipulating or moving objects, mobility across terrain), and they may or may not exhibit some degree of autonomy. Habitation and transportation systems (as defined by those sub-architectures) and disembodied autonomous systems that lack the capacity for physical interaction are not robotic systems."	300	Autonomous Systems and Robotics
Routine	"Recurring subject operations performed as part of a regular procedure rather than for a unique reason."	300	M2M S&O
Routine Preventative Maintenance	"Planned maintenance done on a regular (daily, weekly, monthly) basis that is part of the design, such as filter changes, lubrication, cleaning, etc."	300
Samples/Commodities/Logistics Items	"Samples, commodities, and supplies (not including propellant) that are needed to support mission activities."	300
Secondary Payloads	"Additional cargo carried on a transportation element, currently on an adapter ring, after the primary and co-manifested payloads are accommodated, limited by the remaining transportation element resources (e.g., mass, volume, power)."	301
Semi-Autonomous System	"A system that operates independent of external control in the execution of a subset of its operational goals or task objectives while relying on operator control input (from crew and/or ground) for its complete end-to-end operations (i.e., a system that shares control with an external operator, exhibiting autonomy over some, but not all, of its operational goals/objectives)."	301	Autonomous Systems and Robotics
Scalability	"Initial systems designed such that minimal recurring DDT&E is needed to increase the scale of a design to meet end state requirements."	301	M2M S&O. DDT&E is not in F.1.
Segments	"A portion of the architecture, identified by one or more notional missions or integrated use cases, illustrating the interaction, relationships, and connections of the sub-architectures through progressively increasing operational complexity and objective satisfaction."	301	Segments; Architecture framework
Small Asset	"For lunar other, non-utilization assets less than 6t in mass. Excludes utilization payloads, utilization equipment, and samples/commodities/logistics items."	301	"For lunar other" as printed (PDF checked)
Small Cargo	"Any item less than 6t in mass that is transported from one location to another, including utilization payloads and equipment, small assets, or samples/commodities/logistics items."	301
Sol	"Martian day, approximately 24 hours and 39 minutes long. For the purpose of this document, operational timekeeping on the surface of Mars uses Martian sols to align with the Martian day/night cycle."	301
Sortie Missions	"A single crewed mission to a lunar surface location for a period of days supported solely by the lunar crewed lander. The main characteristics of the sortie mission are that crew habitation is provided by the crewed lander and the crew can perform all lunar surface activities using self-contained resources—although pre-deployment of resources is not necessarily precluded during a sortie mission."	301	HLS
Stakeholder	"An organization with an interest in a particular architecture definition task because it can either affect or be affected by the definition outcome. Different architecture definition tasks may have different stakeholders who are responsible for contributing supporting data and analyses. In some cases, stakeholders are authorities for prerequisite definition tasks that feed into a particular key definition task."	301	Key definition tasks
Stage	"Provide an area in which participants and logistics are brought together and readied for an activity."	301
Stow	"Provide physical space for the storage of items, usually samples that have been collected and placed in containers."	301
Sub-Architecture	"A group of tightly coupled elements, functions, and capabilities that perform together to accomplish architecture objectives."	301	Sub-architectures
Sub-Surface Samples	"Samples collected from locations 2–10m below the lunar or Martian surface."	301
System	"The combination of elements that function together to produce the capability required to meet a need. The elements include all hardware, software, equipment, facilities, personnel, processes, and procedures needed for this purpose."	302	"(Refer to NPR 7120.5.)"
Definition Task	"An examination of a question within the architecture, typically to shape or reduce the trade space."	302	Compared below
Definition Outcome	"The result of an architecture definition task, which could include a decision, down-select, ground rule, methodology, or other narrowing of the trade space."	302	as above
Trade Space	"An exploratory part of the systems engineering process that identifies and analyzes potential solutions for an architectural concept, function, or component. The trade space includes assessments of state-of-the-art and anticipated future capabilities applied as part of a range of solutions, and assessments of impacts that each solution could have across a system's development lifecycle or the architecture as a whole."	302	Defined differently in Appendix C and the white paper (below)
Transit	"The carrying of people, goods, or materials from one place to another in space."	302
Transport	"The act of moving crew or cargo from one location to another in space."	302
Traverse	"To travel across or over the surface."	302
To Be Determined (TBD)	"Used when the value to be placed in a requirement is not known and there is open work to determine what it should be."	302	Common in gap targets (gaps index)
To Be Resolved (TBR)	"Used when a value for a requirement is presented but it is to be resolved or refined as to whether it is the right number."	302	as above
Use Case	"Operations that would be executed to produce the desired needs and/or characteristics."	302	Use cases and functions
User Burden	"The demands imposed on exploration elements or assets seeking to access a service or capability (e.g., for missions or systems accessing C&PNT sub-architecture services)"	302	C&PNT Systems
Utilization	"Use of the platform, campaign, and/or mission to conduct science, research, test and evaluation, public outreach, education, and industrialization."	302	M2M S&O; Utilization Systems
Utilization Mass	"The mass of utilization payloads."	302
Utilization Payloads and Equipment	"Any item that is primarily in support of and attributed to utilization objectives. Utilization payloads include science/research payloads and technology demonstrations. Equipment includes other internal and external hardware, supporting tools, supplies, etc."	302	Elements
Validate	"Confirming that a system satisfies its intended use in the intended environment (i.e., did we build the right system?)."	302	M2M S&O
Verification (of a product)	"Proof of compliance with a requirement. Verification may be determined by testing, analysis, demonstration or inspection."	302
Volatiles	"Elements, molecules, and compounds that readily vaporize, converting to their gaseous form (e.g., water and carbon dioxide). To preserve the scientific integrity of these materials, sample return efforts require preservation of their native environmental conditions (e.g., cold conditioning)."	302	DN-013 L; #1201
Work Time	"Non-personal time. Time during which the crew is in a duty status (e.g., typically 8–8.5 hours, but could be 11.5 hours for an EVA day or other mission-specific extension)."	303	RT-4 Crew Time

Entries that overlap inside Appendix F

• Consumables, Logistic Items, Samples/Commodities/Logistics Items. The first two have the same words, "Supplies (not including propellant) that are needed to support mission activities" (pp. 296, 298); the third adds samples and commodities (p. 300). Rev A.1 (March 2024) "Updated definitions of 'cargo' and 'consumables'" (revision history, pp. 3–4).
• Large and small, at 6 t. Large Cargo and Large Asset are over 6 t; Small Cargo and Small Asset under (pp. 298, 301). F.3 uses the same line for "Large Exploration Assets" (p. 304). Rev A.1's entry says it "removed 'large cargo' from glossary" (pp. 3–4), but Rev C's glossary has a "Large Cargo" entry (p. 298). The ADD doesn't say when it came back (open question 21).
• Two sortie-type missions. "Sortie Missions" are supported "solely by the lunar crewed lander" (p. 301). A "Limited Capability Mission" assumes "a two-crew, 6.5-day sortie" (p. 298). LD-07-L puts early sorties at "around 6 days", to match "the NRHO orbit of around 6.5 days" (p. 191).
• Transit and Transport. "The carrying of people, goods, or materials" against "The act of moving crew or cargo", both "from one place to another in space" or "from one location to another in space" (p. 302). "Reposition/Relocate" is the surface counterpart for cargo (p. 300).
• Samples by depth and temperature. Near-surface 1–2 m, sub-surface 2–10 m, deep sub-surface 10–100 m (pp. 296, 299, 301). Refrigerated +4 °C to -20 °C, frozen around -85 °C, cryogenic below -153 °C/120 K (pp. 296, 297, 300). Gap #1201 still gives its storage temperatures as TBR; the F.2 values are not in its table (the wiki's comparison).

Quantity descriptors (F.3)

"The following descriptors define terms used in the objective decomposition; they capture approximate quantities for terms like small, medium, and large, etc." (p. 304). Five small tables, merged here (PDF checked):

Activity (table heading)	Term	Description
Transport of cargo to the lunar surface	Limited Amount	100s of kg
	Moderate Amount	1000s of kg
	Large Exploration Assets	Assets greater than 6t in mass
Transport of cargo from the lunar surface	Small Amount	10s of kg
	Large Amount	100s of kg
Unloading of cargo	Limited Amount	100s of kg
	Moderate Amount	1000s of kg
	Large Exploration Assets	Assets greater than 6t in mass
Repositioning of cargo	Limited Amount	100s of kg
	Moderate Amount	1000s of kg
	Exploration Assets	Assets greater than 6t in mass
Repositioning of samples and containers	Small Amount	10s of kg
	Large Amount	100s of kg

Notes (the wiki's reading):

• No "medium". The introduction names "small, medium, and large", but no table uses "medium"; "limited" and "moderate" take its place. The repositioning table says "Exploration Assets" where the others say "Large Exploration Assets", for the same 6 t line.
• Where the words appear. The lunar use-case and function titles carry them with the quantity in brackets, for example FN-T-201 L "Transport a limited amount of cargo (100s of kg) from Earth to south pole region sites on the lunar surface" and FN-T-202 L, "a moderate amount of cargo (1000s of kg)" (Lunar functions).
• Two element descriptions use "moderate". The Lunar Utility Rover "can also transport a moderate amount of cargo (thousands of kg)" (p. 61), which matches F.3. The Lunar Surface Cargo Lander delivers "moderate amounts of cargo to the lunar surface" with no figure (p. 59). F.3 says it defines terms "used in the objective decomposition", not in element descriptions, so the wiki doesn't size the lander from it (open question 58).

Same word, other definitions

The ADD defines some terms twice: in Sections 1–2 or Appendix C, and again in Appendix F. Some are also defined in the white papers, the objectives documents and the executive overviews. Where F differs from the body of the same document, neither is newer, so the wiki records both. The comparisons are the wiki's.

The building blocks: Appendix F against Sections 1 and 2

Term	Appendix F	ADD body	What differs
Architecture	"The high-level unifying structure that defines a system …" (p. 295)	"the high-level, unifying structure that defines a system …" (p. 11), from the Systems Engineering Handbook	Same definition, same source; punctuation and "defines"/"define" only
Characteristics; Needs	Two entries: "Features or activities of exploration mission implementation that are necessary to satisfy the goals and objectives" (p. 295); "A statement that drives architecture capability …" (p. 299)	One entry, "Characteristics and needs": "Features to satisfy the goals and objectives; statements that drive architecture capability …" (p. 17)	F splits the term and adds "activities" and "necessary" to the first half
Use Case	"Operations that would be executed to produce the desired needs and/or characteristics." (p. 302)	Same words (p. 17)	none
Function	"Actions that an architecture would perform that are necessary to complete the desired use case." (p. 297)	"Actions that an architecture would perform to complete the desired use case." (p. 17)	F adds "that are necessary"
Segments	"A portion of the architecture …" (p. 301)	"Portions of the architecture …" (pp. 18, 21)	singular against plural; otherwise the same
Sub-Architecture	as on p. 301	Same words (pp. 18, 21)	none
Element	as on p. 296	Same words (p. 21)	none
Exploration Asset	"All items that are in place and being used as part of the exploration architecture." (p. 297)	"Any item that is in place and being used as part of the exploration architecture, including payloads." (p. 21)	F drops "including payloads"
Utilization Payloads and Equipment	as on p. 302	Same words (p. 21)	none
Utilization	"Use of the platform, campaign, and/or mission …" (p. 302)	"the use of a platform, campaign, and/or mission …" (p. 21, footnote 8)	"the" against "a"

Against the executive overviews. The 2023 and 2024 overviews print a shorter seven-term box (Architecture, Characteristics & Needs, Use Case, Function, Element, Sub-architecture, Segment), compared with the ADD body on the 2024 overview's source page. Appendix F follows the ADD body, not the box, for Architecture, Use Case, Element, Sub-Architecture and Segments. For two terms it shares words with the box that p. 17 lacks: the box's "Features, activities, and capabilities necessary to satisfy goals and objectives" and F's "Features or activities … necessary to satisfy the goals and objectives"; the box's "An action necessary to satisfy a use case" (2024) and F's "Actions … that are necessary to complete the desired use case" (2023 overview, PDF p. 3; 2024 overview, PDF p. 20).

Definition-task terms: Appendix C, Appendix F and the white paper

Appendix C opens with its own "key roadmapping terms" table (p. 186). Appendix F defines most of the same terms again, and the ACR25 "Architecture Definition" white paper has a key-terms table too (WP p. 2; transcribed on Architecture definition process). All three are from December 2025.

Term	Appendix C table (p. 186)	Appendix F	White paper (p. 2) and ADD Section 3
(Architecture) definition task	"An examination of an open question or trade within the architecture."	"An examination of a question within the architecture, typically to shape or reduce the trade space." (p. 302)	WP: as F, plus "(e.g., trade studies in ser-vice to Moon to Mars Architecture definition)"
Definition outcome	"The result of a definition task, which could include a decision, down-select, ground rule, methodology, or other narrowing of the trade space."	"The result of an architecture definition task …", otherwise the same (p. 302)	WP: as F
Trade space	"The range of options for a particular area of the architecture."	"An exploratory part of the systems engineering process that identifies and analyzes potential solutions for an architectural concept, function, or component …" (p. 302)	WP: "A range of possible options for implementation for a particular area of the architecture." ADD p. 72: "the trade space — the range of options for exploration missions". NASA's Mars trade space web page: "the range of possibilities for a mission or campaign" (source page, "Introduction").
Key definition task	"A definition task that so profoundly influences the end-to-end architecture that it warrants elevated scrutiny."	"Key Architecture Definition Task": "An architecture definition task that influences the end-to-end architecture and warrants elevated scrutiny." (p. 298)	ADD p. 72: key tasks "significantly influence the end-to-end architecture and flow down to impact many other areas of the trade space"
Priority key definition task	"… which was therefore presented and approved at the Architecture Concept Review to be made early in the architecture process."	"… which therefore was presented and approved … early in the architecture roadmapping process." (p. 300)	WP p. 4: "the 'priority' key definition tasks, which should be made early in the architecting process"
Legacy decision	"A decision made before the implementation of the architecture roadmapping process."	"… before the implementation of the architecture decision roadmapping process." (p. 298)	ADD p. 74: "decisions NASA made prior to the initial publication of the Architecture Definition Document"
Roadmapping; Guiding Questions; Trade Studies	not defined	not defined	WP only
Stakeholder	not defined	defined (p. 301)	—

What the wiki reads from the table:

• "Trade space" is the one real difference. Appendix C, the white paper, Section 3 and NASA's Mars trade space web page make it a range of options or possibilities; Appendix F makes it "an exploratory part of the systems engineering process", closer to what the white paper calls "Trade Studies". The rest differ only in wording.
• "Decision roadmapping" survives in Appendix F. Rev C renamed "architecture decisions" to "architecture definition" (p. 4), and the 2024 executive overview's "decision roadmapping" became "architecture roadmapping" (Key definition tasks). F's "Legacy Decision" keeps the older phrase; Appendix C's table doesn't.
• "Legacy" by two yardsticks. The tables say before the roadmapping process; Section 3 says before the first ADD. The ADD doesn't say whether these are the same date.

These are recorded in open question 21.

The objectives glossary terms

The 2022 Moon to Mars Objectives defines 15 words used in the objectives, transcribed with their 2023 variants on Objectives. Appendix F carries 14 of them, each ending "(Definition from Moon to Mars Strategy and Objectives)". That title matches neither document's exactly (the 2022 Moon to Mars Objectives, the 2023 Strategy and Objectives Development).

• Architecture is the fifteenth, and F replaces it with the Systems Engineering Handbook definition (above). The objectives documents' "A set of functional capabilities, their translation into elements …" is not in Rev C's glossary (Architecture framework).
• F follows the 2022 wording, not the 2023 variants. It has Incremental without "to achieve a goal", Continuous Presence with "desired endpoint" rather than "desired future state", and Scalability with "DDT&E" not spelled out (2022, p. 12; 2023, PDF p. 33).
• One reordering: Continuous Presence ends "24/7/365 operations" in F (p. 296) and "365/24/7 operations" in 2022 (p. 12).
• The rest match the 2022 wording apart from capitals ("Agency goals" in Campaign; "an agency goal" once in Mission), commas (Mobility, Utilization) and "i.e.," added in Validate.

Other terms defined elsewhere

• Architecture-driven data gap. F: "Data the agency needs to advance the Moon to Mars Architecture that is not met by any existing information" (p. 295). Section 3.3: "data the agency needs to advance the Moon to Mars Architecture but that is not met by any existing information" (p. 80; data gaps index).
• Deep space. F: "the vast region of space that extends to interplanetary space, to Mars and beyond. It is the region of space beyond Earth's Moon, including Lagrange 2" (p. 296). B.1: "the vast region of space that extends to interplanetary space, including Mars and beyond" (p. 109; Use cases and functions). F also defines "Cislunar Space" and "Earth Vicinity" (pp. 295–296), but not B.1's "Mars vicinity".
• Planetary protection. F gives one definition covering both directions, "in compliance with Outer Space Treaty constraints" (p. 299). The ACR25 planetary protection paper defines "Forward Planetary Protection" and "Backward Planetary Protection" separately, as kinds of contamination (Planetary protection).

What Appendix F leaves out

• "Technology gap". F defines "Architecture-driven Data Gap" but has no entry for technology gaps. Section 3.2 defines them (p. 77; gaps index).
• "Data need" (p. 80) and "Mars vicinity" (p. 109). B.1 says "Appendix E captures additional terms and definitions" (p. 109); Appendix E is the data-gap catalog, and Appendix F doesn't define "Mars vicinity" either (open question 21).
• "Roadmapping", defined only in the white paper (WP p. 2).
• Moon Base terms. Appendix F is from December 2025; the Moon Base was announced in March 2026. The Moon Base phases and their terms are on the Moon Base hub.
• The LD and MD prefixes and DDT&E, used but never expanded (above).

Related pages

Objectives: words the objectives use · Architecture framework · Objective decomposition · Use cases and functions · Elements · Key definition tasks · Architecture definition process · ADD Rev C source page · 2024 executive overview

Sources

ADD Rev C, pp. 3–4, 11, 12, 16, 17, 18, 21, 48, 53, 59, 61, 64, 72, 74, 77, 80, 109, 186, 191, 291–304 · "Architecture Definition" white paper, pp. 2, 4 · Moon to Mars Objectives (2022), p. 12 · Strategy and Objectives Development (2023), PDF p. 33 · 2023 executive overview, PDF p. 3 · 2024 executive overview, PDF p. 20 · ACR25 planetary protection white paper, p. 1