Secondary Flight Safety Models


Distribution-Based Risk (DBRISK) computes risks, in terms of impact probability, P(i), and expected fatality, E(f), from debris impact distribution. This flight safety tool computes the statistical distribution of the debris impacts generated by either IMPACT or MILS and calculates risk contours and casualty expectation for populated areas within the debris footprint. It compiles data files to create maps of the footprint, debris histograms, and risk contours.


Minimax is a process of minimizing the maximum risk. It is supported by automated tools to parametrically vary the nominal impact location in order to minimize the maximum risk to surrounding populations. It is used at the test planning phase of evaluating new programs when the detailed inputs needed to model vehicle dispersions are normally unavailable.


Velocity Search Algorithm (VeSA) matches analytical trajectories to observed parameters. It determines the event-induced delta velocity required to match a known trajectory, based on the event state vector, flight time, and impact point. It will also propagate a trajectory with a delta velocity applied similarly to the Multiple Impact Location Simulator (MILS). This tool was used to conduct the TDT Destruct Debris Analysis for GBI.


Artificial Satellite Analysis Program (ASAP) is a general orbit propagation program developed by the Jet Propulsion Lab to support orbital and planetary mission design. ASAP uses 8th order Runge-Kutta integration with a 40 x 40 gravitational field, atmospheric, lunar, solar, and radiation pressure models for high accuracy prediction of orbital flight paths.

Test Requirements Allocation Database

Developed by APT to support definition of GBI flight test requirements. This tool traces performance requirements to verification methods and launch activities. It also provides requirement traceability for test program and documents requirements verification results. Its purpose is to ensure responsiveness to 1) changing requirements, 2) partially successful tests, 3) revised test plans, and a list of other factors which serve to make the traceability of test requirements difficult.

CASA – Aurora & Horizons

Computes various casualty areas for impacting inert debris accounting for dimensions of a person; wind and trajectory path angle; slide, bounce, and splatter effects; and impacts on either a hard or soft surface.

APT Point of Contact

Bob Baker 256.327.3373