Alaska Satellite Facility - Distributed Active Archive Center

Thruster anomaly affects Sentinel-1 orbit control

An anomaly in a thruster used for Sentinel-1 orbit positioning control has resulted in the “orbit tube” diameter increasing from 100 meters to 200 meters maximum. The effect of this action on interferometric baselines has been predicted:

“The preliminary conclusion, supported by InSAR experts, is that the perpendicular baseline, a key InSAR performance indicator, will remain within acceptable limits. Burst synchronization at data-take start is not expected to be impacted, and degradation within data-take and as well as reduction of spectral overlap due to crossing orbits are expected to be limited.”

Detailed information is available from ESA:

https://sentinels.copernicus.eu/web/sentinel/-/sentinel-1a-change-in-the-orbit-control-strategy
https://sentinels.copernicus.eu/documents/d/sentinel/esa-eopg-eopgmq-tn-2024-12-increase-of-sentinel-1a-orbital-tube