Laser Communications Terminal for Artemis II Undergoing Testing
By Matthew D. Peters
September 23, 2020
As NASA prepares to land the first woman and next man on the Moon with the Artemis missions, it will demonstrate the use of a high-speed optical terminal to communicate with Earth using infrared lasers. Expected to fly on the second Artemis mission, the Orion Artemis II Optical Communications System (O2O) is undergoing essential testing to ensure it will withstand the harsh environment of launch and space.
There are several benefits to using optical communications, including additional bandwidth through higher data rates. Optical systems are also smaller, lighter weight, and use less power - leaving more room on spacecraft for science payloads. These additional science instruments will be able to bring back a larger diversity of data.
“O2O will prove exactly how beneficial optical communications beyond low-Earth orbit is for the space exploration and science community,” said Betsy Park, project manager of the Laser-Enhanced Mission Communications and Operational Services (LEMNOS) Pipeline project. “We will be able to send home data from large distances, the Moon and beyond, in volumes not previously possible.” The LEMNOS Pipeline, managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is responsible for maturing optical communications technologies.
Each O2O module will undergo rigorous testing to verify that the components can withstand the stresses of launch, work correctly in space, and not interfere with other instruments on Orion, nor will those other instruments disrupt the terminal.
Any payload traveling to space is subjected to extraordinary vibration from the force and acceleration of an ascending launch. If a module cannot withstand vibrations, the mission risks a part or piece falling out of place. During vibration testing, each module is placed on a shaker table and subjected to twice the vibration it would experience during launch to guarantee plenty of margin for error.
While in space, components on the Orion capsule will face both frigid and scorching temperatures. Those facing the Sun can experience temperatures up to 212° Fahrenheit, the boiling point of water, or even higher. In contrast, components on the opposite side can experience temperatures just a few degrees above absolute zero, the theoretically lowest temperature possible. Heating and cooling systems are put in place to keep the modules at an optimal temperature for operation. The modules are placed in vacuum chambers and subjected to both temperature extremes to test whether these systems can withstand the extreme environment.
Modules also undergo electromagnetic interference and compatibility testing. Interference testing “listens” to the electromagnetic emissions of each module to confirm those emissions will not interfere with any of Orion’s other components. Compatibility testing subjects the modules to the kinds of electromagnetic emissions they will encounter from surrounding elements, ensuring proper operation.
Each O2O module will undergo testing separately by the end of 2020. After testing, NASA will deliver the modules to the Massachusetts Institute of Technology Lincoln Laboratory for integration. Once assembled, the system will undergo the same testing to verify proper functionality as a unit.
When NASA ventures to the Moon, O2O’s increased communications capabilities will enable more data transmitted by a crewed mission from that distance than ever before. The technologies and capabilities proven during the initial Artemis missions will enable a sustainable lunar presence and future crewed missions to the red planet.