She is a co-investigator on the Helium, Oxygen, Proton, and Electron Spectrometer on the NASA Radiation Belts Storm Probe mission.

At LANL she was the principal investigator for the Z-Plasma Spectrometer on the Department of Energy Space and Atmospheric Burst Reporting System geosynchronous payload.

[11] In 2018 MacDonald and her team announced the discovery of a new aurora called Strong Thermal Emission Velocity Enhancement (STEVE).

[20] In 2016 in the journal Space Weather, MacDonald and co-workers reported that "citizen scientists are regularly able to spot auroras farther south of an area where prediction models indicated".

[21][22][23] MacDonald leads an interdisciplinary citizen science project called Aurorasaurus, which uses social media to predict the Northern Lights during the current solar maximum.

[27][8][28][29] After noticing a spike in tweets about an aurora borealis in October 2011, she established Aurorasaurus to track such geolocation information in order to improve forecasting, such as that done by NOAA's Space Weather Prediction Center.