The Launch Vehicle Object

The Launch Vehicle Object models the properties and behavior of a vehicle that follows an ascent trajectory from a launch point to an orbit insertion point. Select one or more of the following to model a Launch Vehicle, impose constraints, and define the launch vehicle's subobjects:

Basic Properties

Property Description
Trajectory Define the path that the launch vehicle will follow by selecting and defining one of the following propagators:
SimpleAscentCreates an ascent trajectory based on launch and insertion parameters. The trajectory is a simple curve rising vertically from the launch pad that turns over smoothly to insert the launch vehicle into orbit with a zero flight path angle at the insertion point using the specified velocity.
StkExternalEnables you to read the ephemeris for a satellite from a file.
RealTimeEnables you to propagate vehicle ephemeris using near-real-time data received using a Connect socket.

You can also position a launch vehicle or missile by clicking anywhere in the 2D Graphics window. If you use the mouse in the 2D Graphics window to specify the position of the launch vehicle or missile, be sure that the Trajectory properties page is open. You do not need to click OK or Apply after you have positioned the object in the 2D Graphics window. You will need to click OK or Apply if you have made any other changes on the Trajectory properties page. For more information on setting object properties using the mouse, see Mouse Shortcuts.

If you are interested in end-to-end trajectories including boost phase, missile intercepts, and/or missile defense architecture performance, you should explore Missile Tool Kit (MTK). For designers and analysts of ballistic missiles, kinetic interceptors, sensor systems, and integrated missile defense architectures, MTK provides key analysis capability via user interfaces that minimize expertise requirements without sacrificing modeling fidelity.
Attitude Define an attitude profile for the launch vehicle.
Lighting Define the eclipse central body list used for lighting computations.
Ground Ellipses Add a set of ellipses for the launch vehicle.
SEET

SEET property pages enable you to enter values that affect calculations involving the space environment as modeled by the STK Space Environment and Effects (SEET) capability :

  • Environment. Set parameters that affect the magnetic field model and the entrance and exit times and probable fluxes for a vehicle crossing the South Atlantic Anomaly (SAA), a region of space with an enhanced concentration of ionizing radiation.
  • Thermal. Set material properties and average Earth albedo that affect the determination of vehicle temperature exposed to direct solar and reflected Earth radiation.
  • Particle Flux. Set parameters that affect the determination of the level of (damaging) exposure due to meteroids and debris particles.
  • Radiation. Set parameters that affect the expected ionizing dose rate and energetic particle fluxes due to the trapped electron and proton populations, as well as integrated total dose and fluence (flux integrated over time).

SEET radiation computations are also affected by scenario-level settings.

Description Record useful information about the launch vehicle.

2D Graphics Properties

Property Description
Attributes Define color, line style, and other graphics characteristics for the launch vehicle, and opt whether to inherit or override global attributes defined at the Scenario level.
Trajectory Define the graphical display of the launch vehicle's trajectory in the 2D Graphics window.
Contours Define elevation angle contours in the 2D Graphics window.
Range Define range contours representing the various regions of the surface that can see an object at the specified level.
Lighting Define the graphical display of lighting conditions for the launch vehicle during animation.
Swath Calculate and graphically display swath for the launch vehicle.
Ground Ellipses Set the display graphics for a ellipse set defined on the Basic Ground Ellipse page for vehicles.
SEET Environment

Set parameters that affect the display of the magnetic field and the contours of the South Atlantic Anomaly (SAA) in relation to the vehicle, as modeled by the STK Space Environment and Effects Tool.
Radar Cross Section Define the 2D contour graphics for the desired frequency.

3D Graphics Properties

Property Description
Trajectory Control the display of the launch vehicle trajectory.
Trajectory System Set the reference frame or frames used for displaying the launch vehicle's trajectory.
Attitude Sphere The Attitude Sphere is a visualization aid that when combined with vector display constitutes a powerful tool for displaying the launch vehicle's attitude and for tracking attitude changes over time.
Vector Control the display of vectors and other geometric elements related to the launch vehicle.
Proximity Control the position of the launch vehicle in the 3D Graphics window.
Drop Lines Define the display of lines between the launch vehicle's trajectory (the actual path that the launch vehicle follows) and the central body.
Covariance Define the graphical display of a 3D ellipsoid.
Model Specify a model to represent the launch vehicle in the 3D Graphics window, and then scale the model and adjust the position of any model articulations.
Offsets Position a model and marker representing a launch vehicle in the 3D Graphics window by offsetting the launch vehicle from its reference frame.
Contours Define elevation angle contours in the 3D Graphics window.
Range Display range contours for the launch vehicle. Range contours display in accordance with the values set for the 3D Graphics Range Contours for the launch vehicle.
Model Pointing Point parts of the launch vehicle model toward a target, such as the Sun or Earth.
Data Display Display dynamic data for the launch vehicle in the 3D Graphics window.
Vapor Trail Add a vapor trail to the launch vehicle.
Radar Cross Section Control the 3D display of RCS contour lines.

Constraints

Property Description
Basic Impose a variety of standard access constraints (azimuth and elevation angle and rate, range and range rate, propagation delay, etc.) from the launch vehicle to another object.
Sun Impose a variety of access constraints from the launch vehicle to another object based on the position of the Sun and the Moon.
Temporal Impose time-based access constraints from the launch vehicle to another object.
Advanced Impose several advanced access constraints (grazing angle and altitude, doppler cone angle, solar beta angle, etc.) from the launch vehicle to another object.
Zones Use inclusion and exclusion zones to define areas where access is or is not allowed.
Targeting Define the relationship between an object and the target of that object in terms of cross-track range, in-track range, and squint angle.
Vector Constrain access computations with respect to any valid vector or angle.
Special Special access constraints are defined in terms of geostationary belt exclusion, height above horizon, terrain grazing angle, and exclusion of other scenario objects.
CAT Turn off the time slip constraint that is automatically set by the STK's Close Approach capability when its launch window capability is utilized.
Search/Track

Radar Search/Track Constraints property pages enable you to enter minimum and maximum values for several parameters. You can also choose from the following Doppler options:

  • Search/Track. These parameters correspond to the radar's main channel. These parameters account for the polarization mismatch, if you select polarization on the Basic Polarization page.
  • ST w/Jamming. These parameters correspond to the main channel radar receiver that is under the influence of jamming. When the radar receiver polarization is set and the jammers are polarized, the search/track parameters take polarization mismatch into account. Most of these parameters are re-computed under the impact of jamming on the radar receiver main channel. For more information on the effects of jamming on constraints, see Constraints with Jamming.
  • S/T OrthoPol. These parameters correspond to the radar's orthogonal polarization channel.
  • S/T OrthoPolJam. These parameters correspond to the radar's orthogonal polarization channel under the threat of jamming.

You can extend the STK Radar SAR computation and constraints with the Search/Track plugin constraint. See Search/Track User Plugin.

SAR

SAR property pages enable you to impose a variety of constraints on synthetic aperture (SAR) radar.

  • SAR. These parameters correspond to the main channel (SAR).
  • SAR w/Jamming. These parameters correspond to the main channel under jamming. For more information on the effects of jamming on constraints, see Constraints with Jamming.
  • SAR OrthoPol. These parameters are enabled when you select the receiver side orthogonal polarization.
  • SAR OrthoPolJam. These parameters are enabled when you select the receiver side orthogonal polarization. For more information on the effects of jamming on constraints, see Constraints with Jamming.

You can extend the STK Radar SAR computation and constraints with the Search/Track plugin constraint. See SAR User Plugin.

Plugins An interface is provided for defining custom constraints in terms of scripts you supplied created in VBScript and MATLAB.
SEET Special access constraints are imposed based on relationships of the vehicle with, and the effects of, the space environment as modeled by the STK Space Environment and Effects Tool (e.g., debris and meteroid fluxes, radiation fluxes, vehicle temperature, magnetic field, etc.).

RF Properties

Property Description
Environment Apply environmental factors that affect the performance of a communications link or a radar system.
Radar Cross Section Specify the radar cross section (RCS) parameters.

LASER Properties

Property Description
Environment Apply environmental factors that affect the performance of a laser communications link.

Subobjects

You can attach the following subobjects to a launch vehicle: