This blog was written by Mr. Tom Bryan ES31\ GNC Hardware Team Lead – RF, Electromagnetic Effects, GNC Hardware Branch, Senior Engineer, Flat Floor Robotics Lab & 6DOF Dynamics Sim Lab for NASA. He worked on the Navigation system for the Artemis SLS system and did the testing for it with our motion base. His words are as follows:

The small compact 6DOF Motion Table was used for the “End to End [Control] Polarity Test” demonstration or as the nickname of “Tilt the SIL”.

For smaller launch vehicles, once all of the sensors and control actuators are installed on the launch vehicle and the final software is loaded, the launch vehicle can be rotated to demonstrate and check that when the vehicle is “tilted”, the polarity from the gyroscopes into the computers and out to the steering actuators actually activate to steer the vehicle back onto the correct course. However, the SLS (Artemis) core stage being the largest launch stage ever built is too big for such a test demo. But here at MSFC, the entire avionics system is built into the SLS Integration Laboratory ( or SIL) including all of the gyroscopes, computers, software, two working Thrust Vector Control Actuators and simulators used to steer the 4 main engines, and the two Solid Rocket Boosters during ascent (liftoff).

Even though earlier standalone tests of the Gyro sensors had been performed in various labs on various motion tables, everyone wanted to run a more thorough polarity test before the first flight. The concept of “tilting” each of the three Gyro sensor packages while they were connected via extension cables to the rest of the integrated avionics was conceived. Servos & Simulation small compact 6DOF Motion Table (PN: 710-6-500-220) was selected due to its flexibility and ability to fit through the available openings in the SIL Lab and have safe motion constraints for the equipment and personnel. The software protocols and table commands were verified in a simulation command development facility before the 6DOF Motion Table was trucked over to the “SIL” lab, bolted to the floor, and aligned to “True” North for accurate Gyro package performance before being connected to the SIL Simulation Control system.

After a carefully modified and isolated version of the SLS Flight Software was loaded into the SLS Avionics Integration Lab, each of the 3 Core Stage gyro packages was taken off of their normal SIL rack mounts. Then they were bolted on to test fixtures mounted to the 6DOF motion table and reconnected back into the avionics. When each of the gyroscope packages was tilted in Roll, then Pitch, and Yaw, everyone watched with anticipation to see the readouts from the avionics, but more importantly, that full-scale Thrust Vector Control Actuators moved according to design to keep the SLS on its proper course. It worked!! We now knew that the polarity and channels of all of the sensor data were correct and that the software correctly processed the sensor inputs into the correct vehicle Control commands to steer the SLS during ascent!

And in the early morning of Nov 16, 2022, as SLS lifted Orion into space for the first Artemis mission, we saw the proof that the “End to End [Control] Polarity Test” demonstration was correct and that Servos & Simulation’s 6DOF motion table allowed NASA MSFC to “Tilt the SIL” one critical piece at a time!

We are honored to have been utilized as a small part of getting Orion and Artemis into space. Thank you Tom Bryan for the write-up.

Applications of 6DOF Motion Base in Aerospace

The 6DOF Motion Base developed by Servos & Simulation, Inc. is engineered for a variety of aerospace applications, providing realistic simulations for testing and training. This technology allows engineers to replicate the dynamic conditions of launch and flight, enabling thorough evaluation of avionics and control systems under simulated environments. Such capabilities are crucial for ensuring the safety and effectiveness of space missions.

For instance, during the Artemis program, the 6DOF Motion Base was utilized to perform critical tests on the SLS core stage. By accurately simulating tilting and other maneuvers, engineers were able to verify the performance of the Thrust Vector Control Actuators, ensuring that the spacecraft would maintain its intended trajectory during ascent. This level of testing is vital for the success of future missions to the Moon and beyond.

Technical Specifications of the 6DOF Motion Base

The 6DOF Motion Base is equipped with advanced sensors and actuators that facilitate precise control over multiple degrees of freedom. This technology is designed to handle the substantial weight and complexity of systems like the SLS, ensuring accurate feedback and response during simulations. The integration of sophisticated software protocols allows for real-time adjustments, enhancing the fidelity of the simulation experience.

Moreover, the motion base’s design is tailored to align with the specific needs of aerospace testing, including high-speed data acquisition and robust performance under varying conditions. By utilizing cutting-edge materials and engineering practices, Servos & Simulation ensures that their motion systems can withstand the rigors of extensive testing, providing reliable results that contribute to mission success.

Future Innovations in Motion Simulation

As the aerospace industry continues to evolve, Servos & Simulation, Inc. is dedicated to advancing motion simulation technologies. The company is actively researching and developing new capabilities that will further enhance the realism and reliability of their systems. This includes exploring the integration of artificial intelligence and machine learning to improve simulation accuracy and efficiency.

Looking ahead, Servos & Simulation aims to expand its offerings to include more versatile motion platforms that can be adapted for a wider range of applications, from commercial aviation to space exploration. By staying at the cutting edge of technology, the company is committed to supporting the future of aerospace innovation and ensuring the success of missions that push the boundaries of human exploration.

We are looking forward to seeing just how far the Artemis program will advance us into the future. Good Luck and God Speed!!

Rachel Baker