Glossary & Acronym Reference

    A working reference for the terminology used across this site and throughout aerospace engineering and federal contracting. Definitions are descriptive. They explain what a term means, not what any organization has been awarded or certified to do.

    81 of 81 entries shown

    A

    ADCS— Attitude Determination and Control System
    The spacecraft subsystem that senses orientation and applies torques to hold or change pointing.
    Space Systems

    B

    BPA— Blanket Purchase Agreement
    A simplified arrangement that establishes prearranged terms for recurring purchases, reducing the administrative effort of repeated solicitations.
    Federal Acquisition

    C

    CPFF— Cost-Plus-Fixed-Fee
    A contract type in which the government reimburses allowable incurred costs and pays a fee negotiated at award. Common for research and development where scope carries uncertainty.
    Federal Acquisition
    CAGE Code— Commercial and Government Entity Code
    A unique identifier assigned to organizations doing business with the federal government, used across registration, contracting, and logistics systems.
    Federal Acquisition
    CDRL— Contract Data Requirements List
    The list of data deliverables a contract requires, including format, frequency, and recipient for each item.
    Federal Acquisition
    CPARS— Contractor Performance Assessment Reporting System
    The federal system of record for past-performance evaluations, which source-selection officials consult on later competitions.
    Federal Acquisition
    CUI— Controlled Unclassified Information
    Government-created or -owned information that requires safeguarding or dissemination control under law or policy, but is not classified.
    Compliance & Security
    CMMC— Cybersecurity Maturity Model Certification
    The Department of Defense framework that defines cybersecurity practice levels for contractors handling federal contract information and controlled unclassified information.
    Compliance & SecuritySecure Architecture →
    Cryogenic Propellant
    Propellant stored at very low temperature, such as liquid hydrogen or liquid oxygen. High performance is offset by boil-off and storage complexity on long missions.
    Propulsion & Energy
    Cislunar
    The volume of space between Earth and the Moon, including lunar orbits and libration points. A focus of current exploration and space-domain planning.
    Space SystemsMoon To Mars Alignment →
    CLPS— Commercial Lunar Payload Services
    A NASA acquisition approach for purchasing delivery of payloads to the lunar surface from commercial providers.
    Space Systems
    CFD— Computational Fluid Dynamics
    Numerical simulation of fluid and plasma flow, used where physical test is impractical, expensive, or limited to partial conditions.
    Research & Engineering
    CDR— Critical Design Review
    The milestone review confirming the detailed design is complete and appropriate to proceed into fabrication, integration, and test.
    Research & Engineering
    CCB— Configuration Control Board
    The governing body that reviews and dispositions proposed changes to a controlled baseline, preserving traceability of what changed and why.
    Research & EngineeringPrime Integration →
    Capture
    The disciplined pre-solicitation work of understanding a customer's requirement, shaping an approach, assembling a team, and positioning before a proposal is written.
    InstitutionalCapture & Proposal →

    D

    DFARS— Defense Federal Acquisition Regulation Supplement
    The Department of Defense supplement to the FAR. It adds defense-specific requirements, including clauses covering controlled unclassified information and supply-chain safeguards.
    Federal AcquisitionPrime Integration →
    DCAA— Defense Contract Audit Agency
    The agency that performs contract audits for the Department of Defense and, by agreement, other federal agencies, including examinations of accounting systems and incurred cost.
    Compliance & Security
    Delta-v
    The change in velocity a spacecraft must achieve to perform a maneuver. It is the fundamental currency of mission design and sizes the propulsion system and propellant load.
    Propulsion & EnergyAdvanced Propulsion →
    Digital Engineering
    The practice of using integrated digital models and data as the primary basis for design, analysis, decision-making, and lifecycle support.
    Research & EngineeringAdvanced Propulsion & Space Energy Systems →
    Digital Twin
    A continuously updated model of a specific physical asset, informed by its as-built configuration and operational data, used for prediction and diagnosis.
    Research & Engineering

    E

    EVMS— Earned Value Management System
    A disciplined method of integrating scope, schedule, and cost so that performance against plan can be measured objectively over the life of a program.
    Federal AcquisitionProgram Execution →
    EAR— Export Administration Regulations
    United States regulations governing the export of dual-use commodities, software, and technology that fall outside the munitions list.
    Compliance & Security
    ERM— Enterprise Risk Management
    A structured, organization-wide approach to identifying, assessing, mitigating, and monitoring risk across technical, financial, and operational categories.
    Compliance & SecurityEnterprise Risk Management →
    Electric Propulsion
    Propulsion that uses electrical power to accelerate propellant, achieving high specific impulse at low thrust. Suited to long-duration transfer and station-keeping.
    Propulsion & EnergyAdvanced Propulsion & Space Energy Systems →
    EDL— Entry, Descent, and Landing
    The mission phase in which a vehicle enters an atmosphere, decelerates, and lands. Historically one of the highest-risk segments of planetary missions.
    Space Systems
    ECLSS— Environmental Control and Life Support System
    The crewed-vehicle system managing atmosphere, water, waste, and thermal conditions to keep the habitable environment within limits.
    Space Systems

    F

    FAR— Federal Acquisition Regulation
    The primary regulation governing how United States executive agencies purchase goods and services. It sets uniform rules for solicitation, evaluation, award, and contract administration.
    Federal AcquisitionHow Nasa Contracting Works →Governance & Quality →
    FFP— Firm-Fixed-Price
    A contract type with a price set at award that does not adjust with the contractor's incurred cost. Performance risk sits with the contractor.
    Federal Acquisition
    FedRAMP— Federal Risk and Authorization Management Program
    The standardized federal program for assessing and authorizing cloud service offerings used by government agencies.
    Compliance & Security
    Fusion Energy
    Energy released when light atomic nuclei combine. Of interest to space systems for its potential power density, subject to unresolved confinement and materials challenges.
    Propulsion & Energy
    FEA— Finite Element Analysis
    Numerical analysis of structural, thermal, and dynamic response by dividing a body into discrete elements.
    Research & Engineering

    G

    GWAC— Government-Wide Acquisition Contract
    A pre-competed contract vehicle that multiple federal agencies may order from, most commonly for information technology requirements.
    Federal Acquisition
    GEO— Geostationary Orbit
    A circular equatorial orbit at approximately 35,786 kilometers where a satellite's period matches Earth's rotation, holding a fixed ground position.
    Space Systems
    GNC— Guidance, Navigation, and Control
    The discipline covering trajectory determination, state estimation, and the control authority needed to fly a vehicle along an intended path.
    Space SystemsSpacecraft Systems →

    H

    Hall Thruster
    An electric propulsion device that uses a radial magnetic field and axial electric field to ionize and accelerate propellant, widely used for orbit raising and station-keeping.
    Propulsion & Energy

    I

    IDIQ— Indefinite Delivery / Indefinite Quantity
    A contract vehicle that establishes terms and a ceiling value, then allows the government to order work through individual task or delivery orders over a defined ordering period.
    Federal AcquisitionPrograms →
    ITAR— International Traffic in Arms Regulations
    United States regulations controlling the export and transfer of defense articles, services, and related technical data, including disclosure to foreign persons.
    Compliance & SecurityContact →Export Control →
    IP— Intellectual Property
    Rights in inventions, technical data, software, and know-how. Federal contracts allocate these rights explicitly through data-rights and patent clauses.
    Compliance & Security
    In-Space Propulsion
    Propulsion used after launch for orbit transfer, rendezvous, station-keeping, and deep-space maneuvering, as distinct from launch propulsion.
    Propulsion & Energy
    ISRU— In-Situ Resource Utilization
    The use of materials found at a destination, such as lunar regolith or Martian atmosphere, to produce propellant, water, oxygen, or structure.
    Space SystemsMoon To Mars Alignment →
    IMI— Integrated Mission Intelligence™
    The secure stakeholder environment through which program, compliance, and engagement information is made available to authorized parties.
    InstitutionalIntegrated Mission Intelligence™ →

    L

    LEO— Low Earth Orbit
    Orbits roughly below 2,000 kilometers altitude, where most crewed spaceflight, Earth observation, and large constellations operate.
    Space Systems

    M

    MHD— Magnetohydrodynamics
    The study of electrically conducting fluids and plasmas interacting with magnetic fields. Relevant to plasma acceleration, power conversion, and flow control.
    Propulsion & EnergyResearch Pillars →
    MRL— Manufacturing Readiness Level
    A companion scale to TRL that describes how mature the production process is, independent of whether the technology itself works.
    Research & Engineering
    MBSE— Model-Based Systems Engineering
    An approach in which an authoritative digital model, rather than a set of documents, carries requirements, architecture, and interface definitions.
    Research & Engineering

    N

    NFS— NASA FAR Supplement
    NASA's agency supplement to the Federal Acquisition Regulation, adding NASA-specific procurement policy, clauses, and source-selection procedure.
    Federal AcquisitionHow Nasa Contracting Works →
    NAICS— North American Industry Classification System
    The classification system used to identify a business's industry. Solicitations assign a NAICS code, which sets the applicable small-business size standard.
    Federal AcquisitionAbout →
    NIST— National Institute of Standards and Technology
    The United States standards body whose publications, including SP 800-171 and the Cybersecurity Framework, are widely referenced in federal security requirements.
    Compliance & Security
    NDA— Non-Disclosure Agreement
    A binding agreement establishing how confidential information exchanged between parties may be used, stored, and disclosed.
    Compliance & SecurityNDA Request →
    NEP— Nuclear Electric Propulsion
    An architecture in which a nuclear reactor generates electrical power that drives electric thrusters, trading low thrust for sustained high efficiency.
    Propulsion & Energy
    NTP— Nuclear Thermal Propulsion
    An architecture in which a nuclear reactor heats propellant directly, producing higher specific impulse than chemical propulsion at comparable thrust levels.
    Propulsion & Energy
    NRHO— Near-Rectilinear Halo Orbit
    A stable cislunar orbit family that balances Earth and Moon gravity, used in lunar architecture for staging and communications continuity.
    Space SystemsMoon To Mars Alignment →

    O

    OTA— Other Transaction Authority
    A statutory authority allowing certain agencies to enter agreements outside standard FAR procedures, generally for prototypes and research.
    Federal Acquisition
    OCI— Organizational Conflict of Interest
    A situation in which a contractor's other work, relationships, or access could impair objectivity or create an unfair competitive advantage, requiring disclosure and mitigation.
    Compliance & Security

    P

    PWS— Performance Work Statement
    A statement of work written in terms of measurable outcomes rather than prescribed methods, leaving execution approach to the contractor.
    Federal Acquisition
    POAM— Plan of Action and Milestones
    A tracked plan documenting known security weaknesses, the remediation approach, responsible parties, and target completion dates.
    Compliance & Security
    Plasma
    An ionized gas containing free electrons and ions. Its response to electric and magnetic fields underpins most non-chemical propulsion concepts.
    Propulsion & Energy
    PDR— Preliminary Design Review
    The milestone review confirming that the preliminary design meets requirements with acceptable risk before detailed design proceeds.
    Research & Engineering
    Prime Contractor
    The organization holding the direct contract with the government and accountable for total performance, including work executed by subcontractors.
    InstitutionalPrime Integration →
    Past Performance
    The documented record of how an organization executed prior contracts. It is an evaluated factor in most competitive federal source selections.
    Institutional

    Q

    QPRL— Quantum Propulsion Research Lab
    The research division of Monarch Space Systems, focused on advanced and alternative propulsion research under the Beyond Rocketry™ program.
    InstitutionalQPRL →

    R

    RFI— Request for Information
    A pre-solicitation notice used by an agency to survey the market and refine requirements before issuing a formal solicitation. Responses are informational and are not offers.
    Federal AcquisitionHow Nasa Contracting Works →
    RFP— Request for Proposal
    A formal solicitation inviting offerors to submit technical, management, past-performance, and cost volumes for competitive evaluation and source selection.
    Federal AcquisitionCapture & Proposal →
    RFQ— Request for Quotation
    A solicitation seeking price quotations for well-defined goods or services, typically used for simplified acquisitions.
    Federal Acquisition
    RMF— Risk Management Framework
    The NIST process for categorizing systems, selecting and implementing controls, assessing them, authorizing operation, and monitoring continuously.
    Compliance & Security

    S

    SBIR— Small Business Innovation Research
    A federal program that funds small-business research and development in phases, from feasibility through prototype and commercialization.
    Federal AcquisitionPrograms →
    STTR— Small Business Technology Transfer
    A federal program similar to SBIR that requires formal collaboration between a small business and a research institution.
    Federal Acquisition
    SAM— System for Award Management
    The federal registration system where entities record representations and certifications required to receive contract awards.
    Federal Acquisition
    SOW— Statement of Work
    The contractual description of the tasks to be performed, the deliverables expected, and the standards against which performance is judged.
    Federal Acquisition
    SLSA— Supply-chain Levels for Software Artifacts
    A framework of graduated requirements for software build integrity and provenance, used to reduce supply-chain tampering risk.
    Compliance & Security
    Specific Impulse
    A measure of propulsion efficiency: the thrust produced per unit of propellant consumed per second, usually expressed in seconds. Higher values mean more velocity change per kilogram of propellant.
    Propulsion & EnergyAdvanced Propulsion →
    SDA— Space Domain Awareness
    The detection, tracking, characterization, and prediction of objects and activity in space, supporting collision avoidance and operational planning.
    Space Systems
    Space Weather
    Conditions driven by solar activity — radiation, energetic particles, and geomagnetic disturbance — that affect spacecraft electronics, materials, and crew exposure.
    Space SystemsSpace Environment →
    Subcontractor
    An organization performing a defined portion of contract scope under agreement with the prime rather than with the government.
    Institutional

    T

    TT&C— Telemetry, Tracking, and Command
    The subsystem and ground service that carries spacecraft health data down, tracks the vehicle, and delivers commands up.
    Space Systems
    TRL— Technology Readiness Level
    A nine-point scale describing technology maturity, from observed basic principles through a system proven in mission operations. Used to frame development risk.
    Research & EngineeringResearch →Advanced Propulsion →
    Teaming Agreement
    An agreement between companies to pursue a specific opportunity together, defining roles, work share intent, and exclusivity ahead of award.
    Institutional

    U

    UEI— Unique Entity Identifier
    The identifier assigned in SAM.gov that a federal entity uses in registration, award, and reporting systems.
    Federal Acquisition
    UAP— Unidentified Anomalous Phenomena
    The current term for observed aerial or space phenomena that remain unexplained after review. Studied here strictly as a data and methodology question.
    Research & EngineeringUap Propulsion Analysis →

    V

    V&V— Verification and Validation
    Verification confirms a system was built to its specification; validation confirms the specification met the actual need. Both are required before flight commitment.
    Research & Engineering

    W

    WBS— Work Breakdown Structure
    A hierarchical decomposition of the total scope of work into manageable elements, used as the backbone for planning, costing, and reporting.
    Federal Acquisition

    This glossary is reviewed on a rolling basis as terminology on the site changes. Definitions reflect general industry usage and are provided for reference only; they are not legal, regulatory, or contractual advice.

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