Aimss snapshot la ur 26 23247 db417

Richard P. Feynman Center for Innovation

Technology Snapshot
Autonomous Ion Mass
Spectrometer Sentry (AIMSS)
A high-resolution ion mass spectrometer
for measuring the space plasma
environment in low-Earth orbit (LEO),
with flight operations on the International
Space Station (ISS).
Value Proposition
Satellites operate in a constantly changing plasma
environment. In low Earth orbit, charged particle
density can vary dramatically over the course of a
single orbit.
These variations can cause electrostatic charging of
spacecraft surfaces, leading to discharges,
interference, and damage to onboard systems.
Plasma density changes can also disrupt
communications, while spacecraft-generated
contaminants can degrade optical systems, thermal
control surfaces, and solar panels.
To manage these risks, operators need accurate
measurements of both the local plasma environment
and the induced environment surrounding the
spacecraft.
AIMSS provides these measurements, enabling
operators to monitor and manage spacecraft
charging, contamination, and plasma-driven
communication disruptions.

Technology Readiness Level 6
Flight instrument completed and flight qualified through ground testing and calibration. The AIMSS payload will
launch to the ISS on May 12, 2026.

Fig 1. AIMSS separates ions by energy and mass as they move through the instrument, with lighter ions bending more than heavier ions before being detected at the imaging anode.

IP Information Continued:

• Patent Pending – Dual Electrostatic Plasma
Analyzer for Tunable Energy Resolution and
Geometric Factor (S-194425)
• Reconfigurable High Voltage Power
Supply – U.S. Provisional Application No.
63/515,283
• Electronics Package for Two-Dimensional
Imaging Spectrometry (application/patent
status to be confirmed)

Overview
Satellite measurements of plasma density and
temperature help predict the intensity of geomagnetic
storms, which can impact satellites, communications,
and power systems. Accurate forecasting requires
knowledge of plasma composition.

Contact: [email protected]

However, typical orbital mass spectrometers have
difficulty distinguishing between nitrogen (N+) and
oxygen (O+) ions due to their similar masses.

IP Information

This limitation makes it difficult to validate modern space weather models, which depend on accurate knowledge
of ion composition in near-Earth space.

This technology is protected under the following