Sentinel-1A

Sentinel-1A is a C-band synthetic aperture radar (SAR) satellite operated by ESA under the Copernicus programme. It launched on 3 April 2014 into a sun-synchronous orbit at 693 km altitude, 98.18 degree inclination, with a 12-day / 175-orbit repeat cycle and a 98.6-minute orbital period. The default Interferometric Wide Swath (IW) mode covers a 250 km swath with dual-polarisation (VV+VH or HH+HV). The satellite has been operating in a degraded state since April 2024, when a thruster anomaly required suspension of out-of-plane inclination manoeuvres and expansion of the orbit maintenance tube from 100 m to 200 m RMS diameter; data acquisition continues and InSAR performance remains within acceptable limits per ESA assessment.[^copernicus-thruster-anomaly][^nasa-earthdata-thruster] ESA's public facts page describes the satellite as operational; the Copernicus operational announcement and eoportal record the degraded designation.[^esa-facts][^eoportal-s1] Sentinel-1C, launched 5 December 2024, now provides nominal constellation coverage alongside the degraded Sentinel-1A.[^esa-constellation] Single-satellite revisit is 6 days; coverage priority is global, with tropical forests, Europe, and Canada scheduled for daily or sub-daily acquisition. The on-board archive supports approximately 12 years of imagery from launch through mid-2026.[^esa-facts] No planned decommission date has been announced; design life is a minimum of 7 years. The spacecraft was developed by an industrial consortium led by Thales Alenia Space and Airbus Defence and Space.