Mission control sequence
A Mission Control Sequence (MCS) tree displays the sequencing and structure of the mission and facilitates the
editing of mission segments. The MCS is a graphical programming language, using mission segments that dictate
how STK/Astrogator will build the spacecraft trajectory. Individual mission segments are added as the building
blocks of the mission, and can be keyed to temporal, orbital or system events, including constrained
inter-visibility opportunities with other satellites or ground stations.
Targeter
STK/Astrogator calculates maneuver characteristics necessary to meet mission requirements by using a mission
segment called a target sequence. Within a target sequence, a differential corrector algorithm adjusts
user-defined control variables to satisfy user-defined constraints. Nested target sequences can meet the most
demanding trajectory designs by solving for segments of the overall trajectory while iterating on the complete
solution. Automatic sequences can be designed to ensure that specific mission control steps are applied every
time user-defined conditions occur, an ideal feature for station-keeping, orbit-raising, and orbit-lowering.
Built-in trajectory optimization
STK/Astrogator provides powerful optimization capability at the segment level via the target sequence.
This optimization profile of a targeter allows for coarse->fine->optimized targeting. The ability to optimize
maneuvers is critical to successfully targeting subsequent portions of the mission via the MCS.
High-fidelity orbit propagation
STK/Astrogator's flight-proven algorithms include force models for third-body effects, solar radiation
pressure, atmospheric drag, geopotential models, thermal pressure and albedo and solid and ocean tides,
as well as the use of JPL planetary ephemeris data for accurate coordinate transformations including
precession, nutation and pole wander. Users can choose from a broad set of numerical integrators.
Component technology
STK/Astrogator includes a Component Browser and Editor for selecting and customize engine models, force models,
propagators, coordinate systems, central bodies, atmospheric models and other elements of a space mission
analysis scenario. These elements can then be used or adapted in any STK/Astrogator scenario. STK's Vector
Geometry Tool builds upon the standard vectors, coordinate systems, state variables and angles to create
unique components for use in building mission control sequences. You can use STK/Astrogator components as
target and stop values, and as the basis for reports.
Scripting/Plugin interface
STK/Astrogator is a fully customizable astrodynamics software platform that can control or be controlled by
outside scripts and plugins. Choose from numerous programming environments (Perl, MATLAB, Excel, VBS, Java,
.NET) and write external scripts to control numerical integration, engine models, spacecraft attitude or
targeter search methods. You can also apply custom logic from within the MCS via a simple scripting interface
in the GUI. This capability allows users to easily solve much more complicated trajectory problems such as
tying multiple maneuvers together or applying a solved-for attitude or a percentage of a required total
delta-v for a given maneuver.
Multiple views of space missions
Using STK's multiple map window capability, STK/Astrogator lets you
view a mission or a mission segment from as many perspectives and distances as your screen allows. In addition,
when used with
STK Professional Edition, you can display multiple 3-D views of the mission. Spacecraft
trajectories can be viewed in inertial, fixed or any user-defined frame, and monitored during successive
calculation iterations of the targeter in 3-D for critical insight into the targeting solution.
Closed-loop maneuver control
Model closed-loop propulsion systems and maneuver control laws to analyze missions which include near-field
rendezvous, proximity operations, station-keeping, planetary landing and formation flying. Analyze fuel
requirements, thruster duty cycles and control-law stability and robustness, among others.
Formation flying
STK/Astrogator models multiple spacecraft flying in formation, thus permitting users to analyze and calculate
complex maneuvers that support formation-flying activities such as imaging, satellite maintenance missions,
gravity field determination and constellation maintenance. To complement numerical results, visualize complex
trajectories in a vehicle-relative coordinate frame with
STK Professional Edition.
Reports and graphs
STK/Astrogator generates a variety of reports and graphs, including reports concerning the numerous elements
of a trajectory at the conclusion of the mission or at any phase during the mission. STK/Astrogator also
reports on the corrections introduced by a target sequence and the extent of its success in achieving the
assigned goals. Building upon the STK/Astrogator component technology, all kinds of data can be output in
customizable fashion.