Sentinel-1B

{{Short description|European radar imaging satellite}}

{{Infobox spaceflight

| auto = all

| name = Sentinel-1B

| image = Sentinel 1-IMG 5874-gradient.jpg

| image_caption = Model of a Sentinel-1 satellite (with radar antenna missing)

| image_size =

| mission_type = Earth observation

| operator = ESA

| COSPAR_ID = 2016-025A

| SATCAT = 41456

| website = {{URL|http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-1|Sentinel-1 (ESA)}}

| mission_duration = Planned: 7 years{{cite web|url=http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-1/Facts_and_figures|title=Facts and figures / Sentinel-1 |publisher=ESA|access-date=28 April 2016}}
Elasped: {{time interval|25 April 2016|3 August 2022|show=ymd|sep=,}}{{cite web|url=https://sentinels.copernicus.eu/web/sentinel/-/end-of-mission-of-the-copernicus-sentinel-1b-satellite/1.5|title=End of mission of the Copernicus Sentinel-1B satellite|publisher=ESA|access-date=28 May 2023|archive-date=31 August 2022|archive-url=https://archive.today/20220831002743/https://sentinels.copernicus.eu/web/sentinel/-/end-of-mission-of-the-copernicus-sentinel-1b-satellite/1.5|url-status=dead}}

| spacecraft_type = Sentinel-1

| spacecraft_bus = Prima{{cite web|url=http://www.thalesgroup.com/en/worldwide/space/event/thales-alenia-space-flies-high-space-symposium|title=Thales Alenia Space flies high at the Space Symposium|publisher=Thales Group|date=13 April 2015|access-date=28 April 2016}}

| manufacturer = Thales Alenia Space
Airbus Defence and Space

| launch_mass = {{convert|2164|kg|lb|abbr=on}}

| dry_mass =

| dimensions =

| power =

| launch_date = {{start-date|25 April 2016, 21:02}} UTC{{cite web|url=http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-1/Sentinel-1B_liftoff_delayed_another_24_hours|title=Sentinel-1B liftoff delayed another 24 hours|publisher=ESA|date=23 April 2016|access-date=28 April 2016}}

| launch_rocket = Soyuz-STA/Fregat-M{{cite web|url=http://space.skyrocket.de/doc_sdat/sentinel-1.htm|title=Sentinel 1A, 1B, 1C, 1D|publisher=Gunter's Space Page|access-date=28 April 2016}}

| launch_site = Kourou ELS

| launch_contractor = Arianespace

| disposal_type = Decaying orbit

| declared = 3 August 2022

| deactivated = 12 September 2024

| destroyed =

| last_contact =

| recovery_by =

| recovery_date =

| decay_date =

| landing_date =

| landing_site =

| programme = Sentinel-1

| previous_mission = Sentinel-1A

| next_mission = Sentinel-1C

| orbit_reference = Geocentric

| orbit_regime = Low Earth

| orbit_altitude = 693 km{{cite web|url=https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-1|title=ESA - Sentinel-1|access-date=18 January 2022}}

}}

Sentinel-1B was a European radar imaging satellite launched on 25 April 2016. It was the second of two original satellites in the Sentinel-1 constellation, part of the European Union's Copernicus programme on Earth observation. The satellite carried a C-SAR sensor, capable of providing high-resolution imagery regardless of weather conditions.

The satellite made its first observation on 28 April 2016, capturing a {{Convert|250|km|mi}} wide image of the Austfonna glacier on Svalbard.{{cite web|url=http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-1/Sentinel-1B_delivers|title=Sentinel-1B delivers|publisher=ESA|date=28 April 2016|access-date=28 April 2016}}

Beginning on 23 December 2021, the spacecraft experienced an anomaly which resulted in a loss of data transmission. On 10 January 2022, the European Space Agency confirmed online that a power issue was the root cause of the issue and that initial attempts to fix it had failed. The agency confirmed that efforts to restore the spacecraft's capabilities would continue,{{cite web|url=https://scihub.copernicus.eu/news/News00980|title=Copernicus Sentinel 1-B Anomaly|publisher=Copernicus Open Access Hub|date=10 January 2022|access-date=10 January 2022}} before announcing on 3 August 2022 that efforts to recover the mission would end. The power issue disabled the use of the satellite's payload, but otherwise the satellite remains operable, thus allowing ESA to perform a controlled deorbit.{{cite web |date=3 August 2022 |title=Mission ends for Copernicus Sentinel-1B satellite |url=https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-1/Mission_ends_for_Copernicus_Sentinel-1B_satellite |access-date=3 August 2022 |publisher=ESA}}

Sentinel-1B was placed into a decaying orbit in April 2024.https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-1/Sentinel-1B_journeys_back_to_Earth It will reenter the atmosphere within 25 years.