Chapter 1. Welcome to GMAT

General Mission Analysis Tool

Chapter 1. Welcome to GMAT

The General Mission Analysis Tool (GMAT) is the world’s only enterprise, multi-mission, open source software system for space mission design, optimization, and navigation. The system supports missions in flight regimes ranging from low Earth orbit to lunar, libration point, and deep space missions. GMAT is developed by a team of NASA, private industry, public, and private contributors and is used for real-world mission support, engineering studies, as a tool for education, and public engagement. See the R2018a Release Notes for a complete list of changes in R2018a.

Milestones and Accomplishments

We're excited that GMAT has recently seen signficant adoption for operational misssion support..

  • GMAT is now used as the primary system for maneuver planning and product generation for the Solar Dynamics Observatory (SDO).

  • GMAT is now used as the primary operational tool for orbit determination for the Solar and Heliospheric Observatory (SOHO) mission.

  • GMAT is now used as the primary operational tool for maneuver planning, orbit determination, and product generation for the Advanced Composition Explorer (ACE) mission.

  • GMAT is now used as the primary operational tool for maneuver planning, orbit determination, and product generation for the Wind mission.

  • In April 2018, the Transiting Exoplanet Survey Satellite (TESS) mission is planned to launch. TESS has used GMAT as its primary tool for mission design and maneuver planning from proposal development through operations.

  • In April 2018, the LRO project will hold an operational readiness review to perform final evaluation of GMAT to replace GTDS as the primary operational orbit determination (OD) tool for the Lunar Reconnaissance Orbiter (LRO).

Features Overview

GMAT is a feature rich system containing high fidelity space system models, optimization and targeting, built in scripting and programming infrastructure, and customizable plots, reports and data products, to enable flexible analysis and solutions for custom and unique applications. GMAT can be driven from a fully featured, interactive GUI or from a custom script language. Here are some of GMAT’s key features broken down by feature group.

Dynamics and Environment Modelling

  • High fidelity dynamics models including harmonic gravity, drag, tides, and relativistic corrections

  • High fidelity spacecraft modeling

  • Formations and constellations

  • Impulsive and finite maneuver modeling and optimization

  • Propulsion system modeling including chemical and electric system

  • Solar System modeling including high fidelity ephemerides, custom celestial bodies, libration points, and barycenters

  • Rich set of coordinate systems including J2000, ICRF, fixed, rotating, topocentric, and many others

  • Propagation using CCSDS, SPICE, STK, and Code 500 ephemeris files

  • Propagators that naturally synchronize epochs of multiple vehicles and avoid fixed step integration and interpolation

Plotting, Reporting and Product Generation

  • Interactive 3-D graphics

  • Customizable data plots and reports

  • Post computation animation

  • CCSDS, SPK, and Code-500 ephemeris generation

  • Eclipse and station contact location

Optimization and Targeting

  • Boundary value targeters

  • Nonlinear, constrained optimization

  • Custom, scriptable cost functions

  • Custom, scriptable nonlinear equality and inequality constraint functions

  • Custom targeter controls and constraints

Programming Infrastructure

  • User defined variables, arrays, and strings

  • User defined equations using MATLAB syntax. (i.e. overloaded array operation)

  • Control flow such as If, For, and While loops for custom applications

  • Matlab interface

  • Python interface

  • User-defined functions (sub-routines)

  • Built in parameters and calculations in multiple coordinate systems

Orbit Determination Infrastructure

  • Batch estimator

  • Extensive statistical results reporting

  • DSN data types

  • GN data types

  • Measurement data editing

  • Media corrections

  • Error modeling


  • Fully featured, interactive GUI that makes simple analysis quick and easy

  • Custom scripting language that makes complex, custom analysis possible

  • Matlab interface for custom external simulations and calculations

  • Python interface for custom external simulations and calculations

  • File interface for the TCOPS Vector Hold File format, for loading of initial spacecraft data

  • Command line interface for batch analysis


GMAT has enabled and enhanced missions in nearly every NASA flight regime including enabling new mission types, extending the life of existing missions, and enabling new science observations. GMAT has supported 8 NASA missions and 10+ NASA proposal efforts. The system has experienced broad application and adoption around the world. To date, GMAT has been used by over 30 organizations, with 15 universities and 12 commercial firms publishing results in the open literature.


GMAT is licensed under the Apache License 2.0.

Platform Support

GMAT has been rigorously tested on the Windows 7 platform and we perform nightly regression tests running almost 14,000 test cases for the system core and over 4000 test cases for the GUI interface. The system core has been rigorously tested on Windows 10, but the GUI has only undergone preliminary testing on that platform. Note that R2018a is the last version that will be tested on Windows 10. The Mac and Linux console versions are rigorously tested, but the GUI is provided in Beta form on those platforms. On Mac, the minimum OS version is OSX 10.10 (Yosemite) and testing was performed on OSX 10.12 (Sierra).

The following plugin modules do not run under this release of GMAT on Mac and Linux platforms:

  • Optimizer libFmincon

  • libMarsGRAM

and the Mac release does not support the following plugin:

  • libMsise86

Component Status

GMAT is distributed with production and Alpha/Beta components. Components that are in Alpha/Beta status are turned off by default. The status of plugin components is shown below.

Production quality plugin components:

  • libDataInterface

  • libEphemPropagator

  • libEventLocator

  • libFormation

  • libGmatFunction

  • libNewParameters

  • libPythonInterface

  • libStation

  • libGmatEstimation

  • libMatlabInterface

  • libFminconOptimizer

  • libProductionPropagators

  • libScriptTools

  • libYukonOptimizer

Alpha quality plugin components:

  • libCInterface

  • libGeometricMeasurements

  • libExtraPropagators

  • libPolyhedronGravity

  • libSaveCommand

  • libThrustFile

  • libEKF

Internal-only plugins (not included in public releases):

  • proprietary/libMarsGRAM

  • proprietary/libMsise86

  • proprietary/libNRLMsise00

  • proprietary/libSNOptimizer

  • proprietary/libVF13Optimizer


The Navigation and Mission Design Branch at NASA’s Goddard Space Flight Center performs project management activities and is involved in most phases of the development process including requirements, algorithms, design, and testing. The Ground Software Systems Branch performs design, implementation, and integration testing. External particpants contribute to design, implementation, testing and documentation. We use a collaborative development model that enables innovation and actively involves the public and private sector having seen contributions from 12 commercial firms. External participants for R2018a include:

  • Thinking Systems, Inc. (system architecture and all aspects of development)

  • Omitron, Inc (testing, requirements, specifications)

  • Emergent Space Technologies, Inc.

Past commercial and external contributors to GMAT include:

  • Air Force Research Lab (all aspects of development)

  • Boeing (algorithms and testing)

  • The Schafer Corporation (all aspects of development)

  • Honeywell Technology Solutions (testing)

  • Computer Sciences Corporation (requirements)

  • Korea Aerospace Research Institute

  • Chonbuk National University, South Korea

  • Korea Advanced Institute of Science and Technology

  • Yonsei University, South Korea

The NASA Jet Propulsion Laboratory (JPL) has provided funding for integration of the SPICE toolkit into GMAT. Additionally, the European Space Agency’s (ESA) Advanced Concepts team has developed optimizer plug-ins for the Non-Linear Programming (NLP) solvers SNOPT (Sparse Nonlinear OPTimizer) and IPOPT (Interior Point OPTimizer).