STK's Space Environment and Effects Tool (SEET) capability evaluates the effects of the space environment on a spacecraft. It provides comprehensive modeling of the near-Earth space environment and its expected impacts on a space vehicle. It also calculates spacecraft exposure to ionizing particles, thermal radiation, and space debris throughout the orbit. This level of analysis is becoming critical as higher levels of debris and energetic natural phenomena (such as solar flare activity) are increasing the environmental risks to spacecraft.
SEET is designed for use by spacecraft designers, analysts, and operators to evaluate the effects of the space environment on their spacecraft. Developed by AGI business partner Atmospheric and Environmental Research, Inc. (AER).
SEET includes the following features:
Trapped Radiation Environment
- Radiation Environment. The SEET Radiation Environment component computes the expected dose rate and total dose due to energetic particle fluxes for a range of shielding thicknesses and materials, and can also compute the energetic proton and/or electron fluxes for a wide range of particle energies. These quantities may be computed for a specified space vehicle as a function of time or for a specified set of spatial of coordinates. Information on vehicle dosing and incident energetic particle flux is important to designers and mission planners because devices on satellites degrade over time due to the total collected dose as well as the instantaneous dose rate, both of which depend on the incident energetic particle flux. SEET allows you to choose from AFRL CRRES or NASA standard models, or you can allow SEET to select the best model for the specific orbit.
- South Atlantic Anomaly (SAA). The SAA is a region of space with an enhanced concentration of ionizing radiation due to the configuration of Earth's magnetic field. Such radiation can damage spacecraft electronics and cause Single Event Upsets (SEU), which can impair the functioning of electronic components. A key feature of SEET is its ability to compute a spacecraft's entrance and exit times through the SAA. The SAA Transit component also computes the energy flux and/or flux contour of SEU relative probability for altitudes between 400 and 1500 km. The model of the SAA is based on data received from the Compact Environment Anomaly Sensor (CEASE) detector flown on the Tri-Service Experiment (TSX-5) satellite during the epoch 2000 - 2006.
Untrapped Radiation Environment
- Galactic Cosmic Ray (GCR) differential and integral fluxes and fluences. Galactic Cosmic Rays (GCRs) can lead to a variety of satellite anomalies, especially single event effects (SEE) that can upset electronic components and software on the satellite. SEET provides three different options for GCR models: CREME86, ISO-15390, and Badhwar-O’Neill 2010
- Solar Energetic Particle (SEP) probabilistic fluences over mission lifetimes. Solar energetic particles (SEPs) can cause similar problems, as well as other effects including increased ionizing dose, leading to long-term failure of electronic components, and damage to solar arrays, leading to loss of power to satellites. SEPs also cause other disruptions to technology such as increased radiation dose to astronauts and airline crews and passengers, as well as degraded HF radio communications. SEET provides three different options for SEP models: JPL-91, Rosenqvist, and Emission of Solar Protons (ESP).
Particle Impacts
Particle Impacts computes the total mass distribution of meteor and orbital debris particles that impact a spacecraft along its orbit during a specified time period. It can also compute the mass distribution of these particles above a satellite surface damage threshold you specify. SEET allows you to define or select from lists of surface materials and properties that may be damaged by high-velocity impact with meteors and orbital debris. The particle impacts algorithms are based on AF-GEOSpace meteor and debris models.
Vehicle Temperature
For vehicle sub-system design and operations, thermal environment energy combined with any internal heat dissipation requirements must be considered. Using thermal balancing equations, SEET determines the mean temperature of a space vehicle due to direct solar flux, reflected and infrared Earth radiation, and the dissipation of internally-generated heat energy. You may specify spherical objects, or planar objects with particular orientation, for the computation of temperature.
Magnetic Field
SEET uses a highly customizable set of conditions to compute the local magnetic field at the current location. The Magnetic Field component provides the total magnitude along the vehicle path using a chosen magnetic field model. Magnetic field data can also be computed on a specified set of spatial coordinates. Field-line tracing for display and magnetic conjugacy computation are also provided. Information about the local magnetic field at the satellite is useful for vehicle designers, mission planners, and operators because the local radiation (energetic particle) environment is organized by the magnetic field, and the measurement of local field direction on the vehicle can sometimes give information about vehicle attitude. This component provides common magnetic field functionality with current AF-GEOSpace magnetic field models, including simply tilted dipole models based on time-interpolated moments of the full IGRF field representation, full time-interpolated IGRF, and full IGRF plus Olson-Pfitzer (1977) external field models. The component can also compute dipole L, McIlwain L, and B/Beq (ratio of magnetic field strength at the current location to that at the magnetic equator).
Specialized Report and Graph Options
Makes available numerous reports and graphs that are customizable. Dynamic displays and strip charts containing SEET calculations can be displayed in real-time as STK animates through a scenario.
For additional background information, consult: SEET: Space Environment and Effects Tool for STK (PDF).
Getting Started
Click SEET tutorials to begin.