GMAT is a software system for trajectory optimization and mission analysis. Analysts
use GMAT to design spacecraft trajectories, optimize maneuvers, visualize
and communicate mission parameters, and understand a mission’s trade
space. The GMAT project is a collaborative effort between NASA, the space community, and
the open source community. The system contains
new technology and is also a system for future technology development. To
maximize technology transfer GMAT is open source and is licensed under the NASA
Open Source Agreement. In the sections below, we discuss
the high-level technology goals of the GMAT project and discuss some key features and benefits
of GMAT.
The development areas within the mission design discipline
that GMAT addresses include, but are not limited to:
- New technology that does not currently exist
- New applications of existing technology.
- Significant enhancements to existing technology that
- Give new insights into well known problems.
- Improve analyst productivity and software ease of use.
The best way to learn about the features of GMAT is to watch it solve
mission analysis problems. We’ve included more than 20 sample missions in the
distribution. We’ll talk about how to run the Sample Missions first,
and then provide a list of major software capabilities.
To run the Sample Missions:
- Download and install the GMAT application.
- Open GMAT and left click on the yellow folder icon on the toolbar.
- Navigate to the Sample Missions folder which is located in the GMAT root directory.
- Select a script file of your choice and hit ok.
- Hit the green run button located in the toolbar, and watch the mission evolve.
The list below contains a high level description of GMAT’s capabilities and benefits.
Some of these capabilities are common to many mission analysis systems, as they are
fundamental to the mission design process. Some features are less common or unique
to GMAT. This list is intended to give you high level understanding of what GMAT does.
Feature
|
Benefit
|
| Open Source Architecture
|
- provides ability for anyone to develop and validate new algorithms
- enables new algorithms to quickly transition into high fidelity code
- encourages maximum review of code and algorithms
- allows unlimited number of machines with GMAT installations
|
| Platform Independence
|
- runs on Windows, Mac, and Linux
(Windows is in beta form, Mac
and Linux are in alpha form)
|
| Global epoch synchronization of spacecraft
|
- naturally synchronizes epochs of multiple vehicles
- shortens run times by avoiding fixed step integration or interpolation
to synchronize epochs of spacecraft
|
| Coupled propagation of multiple spacecraft
|
- provides unique modeling capabilities of coupled systems of spacecraft
- improves performance and simulation run times
|
| Inline Math using MATLAB’s® syntax
|
- uses industry standard language to maximize compatibility and minimize learning curve.
- enables users to add their own calculations and parameters
- supports user defined matrices, variables, and strings
- supports matrix algebra in script language
|
| Nonlinear Programming
|
- makes defining cost and constraint functions trivial by built-in commands that allow rapid exploration of trade space.
- allows analyst to turn constraints on and off easily, to determine how their inclusion or exclusion effects solutions.
- permits constrained optimization of numerous classes of problems.
|
| High fidelity orbit propagation
|
- permits modeling of numerous flight regimes with high accuracy modeling
- uses models standard in the industry
|
| Boundary value solvers
|
- solves two point boundary value problems using iterative methods
|
| Script and GUI interface
|
- employs one-to-one mapping between script and GUI interface.
- teaches users how to use the script syntax, through a GUI to script translator.
|
| Impulsive and Finite Maneuver Models
|
- permits modeling of spacecraft maneuvers
- permits minimization of fuel expenditure
|
| Reports, 2-D, and 3-D plots
|
- provides report and graphical output so analyst can develop insight into problem trade space
- allows data to be exported to other systems
|
| Control flow
|
- permits system flexibility to simulate new and unanticipated problems
- enables convenient automation of routine tasks
|
| MATLAB® interface
|
- provides access to industry standard analysis system and users' existing routines
- provides an ability to calculate parameters not supported by current GMAT system
|
| Coordinate systems
|
- supports standard coordinate systems used in mission analysis
- permits user to input, output data in useful coordinate systems.
- supports coordinate system dependent parameters naturally in inline math statements.
|
| Built in orbit related parameter calculations
|
- allows users to plot and report relevant orbit parameters for problem insight and understanding
- allows user to use orbit parameters in inline math to generate new parameters not supported internally by GMAT
|
|
