MMS Spacecraft (IMAGE) NASA/Goddard Space Flight Center Caption The four Magnetospheric Multiscale, or MMS, spacecraft (shown here in an artist's concept) have now made more than 4,000 trips through the boundaries of Earth's magnetic field, gathering observations of our dynamic space environment. Credit Credits: NASA/Goddard/Conceptual Image Lab Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.