October 30, 2008 Vol. 1, Issue 10
Video game technology is providing the basis for robust visualization and collaboration capabilities at NASA.
How will the Ares I vehicle roll out of the Vehicle Assembly Building to the launch pad? During flight, how will the separation of the different stages of the rocket vary depending on minor adjustments to the trajectory?
Modeling and simulation tools have been essential in NASA’s efforts to design, build, and execute the complex systems that its missions demand. In the case of the Constellation program, these tools are vital for ensuring mission safety and success. In a business where “test as you fly and fly as you test” is the maxim, 3-D simulations can offer the next best thing to actual flight hardware tests — which are not always possible — at a fraction of the cost.
Given the importance of modeling and simulation, the Exploration Systems Mission Directorate (ESMD) has developed a comprehensive strategy for it over the life cycle of the Constellation program that will incorporate a number of different tools capable of using common data. While simulation is often associated with training (think of flight simulators), the ESMD strategy employs modeling and simulation in all phases from planning and requirements definition all the way through operations.
The challenge of making simulations that can be shared among team members is compounded by the fact that projects are spread across NASA’s ten field centers. “If you’re developing a simulation for a large group of geographically distributed stakeholders, it becomes very difficult and very expensive to get them all in the same place at the same time to show them the results of a simulation,” says Bill Little of Kennedy Space Center (KSC).
Little knows this from first-hand experience. He is a technical lead on a team at KSC that runs the Distributed Observer Network (DON), an innovative solution to this problem. The DON enables teams of engineers to view and collaborate on 3-D representations of the environmental, design, and operational data from models and telemetry. Its modular client-server architecture allows for the rapid deployment and visualization of data previously visible only through proprietary simulation software. Each user can view and move within the simulation environment independently. (To use the example of a launch simulation, one user might choose to zoom in on the launch stand while at the same time another might focus on the upper stage of the vehicle.) The collaboration tools also facilitate real-time communication through voice-over-internet-protocol (VOIP) and text chat, as well as long-term communication through saved notes.
The software allows multiple users to connect securely using their desktop or laptop computers and view the simulation results from anywhere on the NASA network. “By using a client server architecture, we can distribute this data more easily than other formats like video. Those files are often large, and good central server space to host them on has not been easy to come by,” explains Rebecca Mazzone, Software Architect for Data Presentation & Visualization (DPV).
DPV is an element of the Constellation Program tasked with providing tools to efficiently and effectively communicate simulation data. DON has been a key piece of its efforts. Doug Craig, ESMD Directorate Integration Office (DIO) Strategic Analysis Manger, has also identified DON as a key component of the Lunar Surface Operations Simulation that is supporting NASA’s Lunar Architecture strategic studies. These studies will help determine the feasibility of potential partnerships and share them across an international team.
The DON is based upon a gaming engine called Torque that was adapted for NASA by Valador, Inc. The engine is a product of GarageGames, the maker of several commercial video games. Valador chose Torque for DON after a NASA-directed study comparing the cost, lifecycle, licensing, performance and handling of large data sets for multiple engines. It first developed the technology as an internal research and development project before partnering with KSC to create the DON.
The DON has been used to visualize a simulation of an Ares I liftoff, ascent, and rendezvous with International Space Station as well as the lunar surface, and it has begun to attract notice: NASA’s Innovations and Contribution Board (ICB) recognized the members of its civil servant-contractor team with a software invention and Tech Brief Award.
Read a short white paper about the DON. (PDF)
