Plasma Irregularities at the Equator (PIE) Mission Concept
- Arcfield Marketing and Communications
- May 28
- 2 min read
Anastasia Newheart, Research Scientist

At Orion, we are constantly exploring new frontiers to advance our understanding of Earth's upper atmosphere and the space environment. One of the most intriguing and dynamic regions of study lies in the ionosphere, where a complex interaction of physical processes gives rise to phenomena that impact satellite communications, navigation and global positioning systems. In this novel mission concept, we aim to study the formation and behavior of equatorial plasma bubbles (EPBs) and medium-scale traveling ionospheric disturbances (MSTIDs) through a cutting-edge very low Earth orbit (VLEO) mission.
WHY STUDY EQUATORIAL PLASMA BUBBLES?
EPBs are regions of low-density plasma that form in the ionosphere, primarily in equatorial regions, disrupting radio signals and affecting critical satellite operations. These irregularities are thought to result from generalized Rayleigh-Taylor instability (GRTI), a process that effectively predicts the overall patterns of EPB occurrence. However, GRTI alone cannot explain the day-to-day variability of EPBs, suggesting that other factors—such as seeding by MSTIDs—play a role.MSTIDs are medium-scale disturbances in the ionosphere, characterized by wavelengths of 100–300 km.Our mission aims to investigate whether MSTID activity in the bottom-side F-region of the ionosphere acts as a seeding mechanism for EPBs. By examining the relationship between GRTI growth rates and MSTID activity, we hope to unravel their relative contributions to EPB formation.
THE MISSION DESIGN
To tackle these questions, we propose a two CubeSat mission in a sun-synchronous orbit with a local time of 19:00 and a perigee of 250 km over the equator. These two satellites will work together to provide a comprehensive view of the ionospheric conditions where EPBs are likely to form:
CubeSat 1 will be equipped with an electric field probe, a magnetic field probe, and a Langmuir probe to measure key ionospheric parameters such as electron density and field dynamics
CubeSat 2 will carry a Langmuir probe and a radio occultation (RO) receiver to measure total electron content (TEC) and scintillation
Flying with a small longitudinal separation and approximately 10 km difference in altitude, the CubeSats will observe the density gradient in the bottom-side F-region and directly detect MSTIDs.
CONNECTING MEASUREMENTS TO OUTCOMES
This innovative mission design goes beyond in situ observations. By leveraging the radio occultation receiver on CubeSat 2, the mission will determine whether EPBs have formed in the same longitudinal sector as the CubeSats' prior measurements. This unique capability allows us to directly connect the observed growth rates and seeding conditions to the occurrence—or non-occurrence—of EPBs.
A STEP FORWARD FOR SPACE WEATHER RESEARCH
By dipping into VLEO, this mission will explore a region of the ionosphere that remains poorly understood yet critical for satellite operations and global communications. Our double CubeSat approach will provide a novel way to study the ionospheric processes that underpin space weather phenomena.
Check back often to stay in the know on this mission (and others) as Orion carries on its commitment to advance science and innovation for a more connected and resilient world.
Click the link below to view the poster presentation of this work.
Comments