GDC’s MoSAIC Instrument Passes Testing Milestones

Dec. 2, 2024

The Modular Spectrometer for Atmosphere and Ionosphere Characterization (MoSAIC) is a key instrument for GDC. It is a quadrupole mass spectrometer — a compact instrument that measures the density, composition, temperature, and wind velocity of both electrically charged and neutral particles in Earth’s upper atmosphere.

Learning more about these properties is necessary to meet GDC’s main science goals of understanding how Earth’s ionosphere and thermosphere react to fluctuations in energy input as well as how this region of the upper atmosphere distributes that energy globally. This characterization will, in turn, greatly enhance our understanding of space weather, thus allowing for better modeling and forecasting.

Main image caption:
Team members pose with the Modular Spectrometer for Atmosphere and Ionosphere Characterization (MoSAIC) instrument at NASA’s Wallops Flight Facility in Virginia. MoSAIC is a quadrupole mass spectrometer, an important part of NASA’s Geospace Dynamics Constellation instrument suite. The project is led by the University of Maryland Baltimore County and implemented by NASA’s Goddard Space Flight Center in Greenbelt, Md. Clockwise from left: Joyce Manning, Draisy Friedman, Marvin Noreiga, Moi Outsa, Mehdi Benna, Victoria Afram, Jaykumar Jatinkumar Vaidya, Mitchell Hamann, Wally Rodriguez.

Image credit: NASA’s Wallops Flight Facility

Pyrotechnic Testing

MoSAIC engineers (left to right) Mitchell Hamann, Wally Rodriguez, and Tom Russell prepare to test the instrument’s bellows at NASA Wallops.

Image credit: NASA/Mehdi Benna

On Oct. 16, 2024, at NASA Wallops, the MoSAIC team tested the break-off mechanism that will remove a cover from the instrument once GDC reaches space. The cover protects MoSAIC’s sensitive internal equipment before and during launch, but it must be removed before the instrument can be exposed to the space environment and gather data.

Using an engineering testing model of MoSAIC, the engineering team successfully used pyrotechnics to demonstrate that the instrument cover deploys correctly and the shock level experienced by the instrument is within safe and expected limits.

As demonstrated in this animated GIF, MoSAIC will use onboard pyrotechnics to remove the cover protecting the instrument’s sensitive internal equipment before and during launch.

Video credit: NASA/Mehdi Benna

Working Toward a Flight Model

MoSAIC’s baffle-scanning mechanism is tested using motor control electronics from Motiv Space Systems.

Image credit: NASA/Anand Mylapore

Later in the month, the MoSAIC team conducted a test of the instrument’s motor control electronics (MCE) system at NASA Goddard. The MCE system controls and provides power to the baffle scanning mechanism, a device that moves two tabs (called baffles) to measure horizontal and vertical winds during flight.

The test was completed successfully, showing that the MCE could command the instrument’s baffles to move through the various scanning patterns, speeds, and angles needed for scientific operations in space.

A detailed performance analysis is now being conducted to refine the system’s design and ensure it meets all requirements for the final flight hardware prototype.

This animated GIF shows a test of MoSAIC's baffle scanning mechanism using motor control electronics by Motiv Space Systems. The baffles were moved through scan patterns expected to be used while in space.

Video credit: NASA/Anand Mylapore