Using Open Standards and NASA Open Source Simulation Tools to Model Artemis Base Camp Mission Timelines

The United States’ National Aeronautics and Space Administration (NASA) has announced that
the Artemis Program will return humans to the Moon, establishing a persistent presence with
the Artemis Base Camp (ABC), and extend human exploration to Mars. The NASA Exploration
Systems Simulations (NExSyS) team at NASA’s Johnson Space Center is using internationally
developed simulation interoperability standards and NASA open source simulation tools to
support Artemis concept, analysis, designs, development, training, and ultimately operations.
The NExSyS team has been tasked to support early ABC architecture and mission analysis using
mission time lines developed by the crew operations mission planning team. The NExSyS team
is developing a distributed simulation framework with initial Artemis element implementations
to model the ABC mission timelines using the international simulation interoperability standard
High Level Architecture (HLA), the Simulation Interoperability Standards Organization’s Space
Reference Federation Object Model (SpaceFOM), the NASA open source Trick Simulation
Environment, and another NASA open source interface package called TrickHLA.
The ABC architecture is composed of a number of key surface elements and resources. Some
examples of modeled elements (also known as entities) are landers, habitats, rovers, logistics
carriers, and astronauts. Some examples of modeled transferable and consumable resources
are power, water, oxygen, nitrogen, scientific samples, and food. These entities and resources
are modeled in a collection of individual simulations called Federates. A coordinated collection
of interoperable federates is called a Federation and when these federates are tied together in
a coordinated simulation run, it is referred to as a Federation Execution. The federates
communicate through HLA using data exchange formats defined by a collection of machine
readable files called Federation Object Models (FOMs). These FOM files are based on
extensions to the SpaceFOM. This enables the instantiation and sharing of objects and
interactions between federates in the federation. These provide for entity and resource
tracking, object transfer, and data collection. Federate interactions are used to trigger events
and notify federates of entity or resource transfers.
For the initial implementation, the constituent federates are Trick-based simulations that use
TrickHLA to provide the required HLA-base interoperability. These Trick-based simulations
provide the required modeling for the individual Artemis elements along with the associated
element resources. These federates provide a means to explore traverses between surface
elements and exploration sites as scheduled in a mission timeline and explore the affects
traverse times have on the overall mission timeline. The mission time lines are modeled using a
Trick input file event handling capabilities. Each timeline operation is handled as individual
simulation events, and triggered based on previous event status, time of operation, and
simulated task completions. In addition, the ABC Federation can be used to perform Monte
Carlo analysis. The Monte Carlo tool can vary the inputs, timings, and malfunctions to show how various contingencies in the mission can affect the mission timeline.