For more than a decade, the Copernicus Sentinel-1A satellite has quietly orbited Earth, providing radar imagery that scientists, commercial businesses and emergency responders rely on every day. Behind the mission is a dedicated team of engineers, including Mario Sansone, a Mission Planning Engineer at Starion who has worked on the Sentinel-1 programme since before the satellite was launched.
Having been involved in the mission from its earliest preparations through to its final operations, Mario shares his unique perspective on one of Europe’s most important Earth observation (EO) missions as Sentinel-1A reaches the end of its operational lifetime.
When Sentinel-1A was launched in 2014, it marked a significant milestone for European EO. As Mario explains, the satellite was vital in ensuring continuity of remote sensing data for European users following the previous generation of missions. It was also the first satellite launched as part of the European Union’s Copernicus programme.
Uninterrupted access to EO data is essential, and Sentinel-1A strengthened Europe’s ability to monitor its planet, using synthetic aperture radar (SAR) to provide reliable radar imagery regardless of weather conditions or time of day.
Over its operational lifetime, Sentinel-1A has delivered invaluable data to the scientific community, helping researchers study environmental change, monitor the impacts of climate change and respond to natural disasters. “With this satellite, we were able to study what was happening on our planet,” Mario explains. “We were able to monitor natural disasters and understand trends. This was one of the major achievements of the mission.”
Mario’s specific role as a mission planner has been to coordinate observation requests from users across the globe and transform them into feasible operational plans for the satellite. “Mission planning means taking all these requests into account and trying to fit them into a conflict-free plan ready to be deployed,” he explains.
Why has Sentinel-1A been retired?
Now, after exceeding its original design life, Sentinel-1A has reached the end of its operational journey. Although originally only intended to operate for around 7 years, the satellite has instead served for more than 12 years.
The end of a satellite’s life can be emotional for the teams who work on the mission, especially those who have been involved a long time.
“It’s very sad. It’s like when people retire from their work. You think maybe it could work for another year, but in the end, it was time.”
With the arrival of newer satellites in the constellation, ESA has taken the responsible decision to retire the spacecraft while it remains under control.
What happens when a satellite is decommissioned?
Decommissioning a satellite is about far more than simply switching it off. As Mario explains, Sentinel-1A will be carefully manoeuvred into a dedicated disposal orbit where it will not pose a risk to operational spacecraft. This responsible process helps prevent the creation of additional space debris and protects the orbital environment for future missions.
“It is very important to move the satellite in a safe way. If you leave it there and it fails, it can create disturbances for many other missions. Moving it away responsibly helps protect the space environment.”
What next for the Sentinel-1 mission?
While Sentinel-1A prepares for retirement, the Sentinel-1 mission continues. Following the failure of the SAR payload on board Sentinel-1B in December 2021, the next-generation Sentinel-1C and Sentinel-1D satellites have now taken over responsibility for delivering radar imagery to users worldwide, ensuring the continuity of the Copernicus Sentinel-1 programme.
Mario himself is transitioning to work on Sentinel-1C, carrying forward the operational expertise built over more than a decade on the original mission.
Why is it important to continue with Sentinel-1?
The importance of Copernicus missions is perhaps most evident during times of crisis. Mario highlights the use of Sentinel-1 data following the recent earthquakes in Venezuela, where radar imagery supported studies assessing damage and identifying collapsed buildings.
“This data is very important [when it comes to] natural disasters because satellites can really help communities that have suffered,” he explains. “You can assess what happened, identify routes to reach affected areas and help send support to people who are in danger.”
Using SAR instruments, the Sentinel-1 satellites can acquire imagery day and night and through cloud cover, providing critical information when emergency services need it most. From helping responders understand the scale of an earthquake to identifying safe routes during floods, Copernicus satellites continue to demonstrate how space-based data can have a direct impact on life on Earth.
As Sentinel-1A’s mission comes to a close, its legacy will live on through the knowledge it has generated, the communities it has helped protect and the next generation of Copernicus missions that will continue its work.
Main image credit ESA/Mlabspace
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