ATS6 is an Atmospheric Trajectory Simulation with 6 degrees of freedom. Like ATS3, it generates the ballistic track of a vehicle through a configurable atmosphere, but also generates the evolution of the vehicle attitude. The simulation can be set up to terminate at a predetermined altitude or, when integrated with the Vehicle Fragmentation Model, when specific fragmentation thresholds are exceeded. When integrated with the Aerothermal Heating Module, ATS6 will drive the evaluation of vehicle heating and ablation, providing a prediction of vehicle or fragment demise:

  • Aerodynamics - ATS6 can make use of external aerodynamic coefficient databases, or when linked with the Aerodynamic Coefficient Generator these may be evaluated from the vehicle geometry at runtime.
  • Bridging functions - ATS6 contains a configurable bridging function for the transition between free molecular and continuum flow.
  • Atmosphere models - ATS6 is supplied with a set of static (1976 US Standard, CIRA2012 Jacchia-Bowman 2008 profiles) and dynamic (NRLMSISE-00, Jacchia-Roberts, Jacchia-Lafontaine-Hughes) atmosphere models. Other user defined atmospheres can be described using JavaScript.
  • Gravity models - ATS6 can compute JGM3 gravity harmonics up to 70x70, although the standard configuration of zonal harmonics to J4 are sufficient for most re-entry studies.
  • Accurate - At its core, ATS6 has a standard 4th order Runge Kutta solver, delivering configurable accuracy and enabling a balance to be struck between simulation fidelity and performance. ATS6 is quaternion-based which both increases performance and avoids gimbal-lock issues.
  • Modular - The architecture of ATS6 permits the most appropriate components including the solver, atmosphere, gravity and vehicle heating and fragmentation models to be selected from libraries at execution time.
  • Extensible - Interface definitions are provided for all key components, permitting clients to construct implementations optimised for their specific problem domain.
  • Configurable - All aspects of ATS6 can be configured using JavaScript. This enables sequences of simulations and complex conditional scenarios to be scripted and evaluated without resorting to changes in the core engineering simulation.
  • High performance - Simulation scripts can be constructed to execute several ATS6 simulations in parallel, allowing modern multi-core / multi-processor hardware to be fully exploited.
  • Portable - Written in a combination of Java and JavaScript, ATS6 is fully supported on Windows, Unix / Linux and OS X.