OHB Wins €554 Million Contract to Develop New Sentinel-3 Satellites
Key Facts
OHB said the European Space Agency had awarded it a €554 million contract to develop the next-generation Sentinel-3 topographic satellite mission, with an option to add a second satellite. OHB System AG will serve as prime contractor and carry out the mission with a European industrial consortium, the company said. The contract puts the company at the center of developing a new European capability to measure sea-surface height and monitor ocean, ice and inland-water topography. OHB described the contract as strengthening its position in European Earth observation. The mission is part of the European Union’s Copernicus program, which provides data and information on the state of the Earth, atmosphere and oceans to support policymakers, scientists, businesses and society.
The new mission will consist of two identical satellites operating in sun-synchronous orbit and carrying altimetry instruments, according to OHB. The configuration will focus on expanding observation of oceans, coastal areas, sea ice and inland waters. The new satellites will provide better coverage and shorter revisit times, along with much more accurate sea-level measurements than current Sentinel-3 satellites, the company said. These improvements combine broader and more frequent coverage with more precise height measurements, key elements in monitoring changes affecting sea levels, ice and bodies of water. The design is based on altimetry, the focus of the new mission, rather than reproducing the current satellite system with all its instruments.
The current Sentinel-3 system comprises two operational identical satellites, each carrying the mission’s instruments, including a radar altimeter and a spectrometer. Their functions include monitoring ocean and ice topography, ocean and land color, and surface temperature. The new mission, by contrast, centers on altimetry, with improved observation coverage, shorter intervals between visits and more accurate sea-level measurements, according to OHB’s description. This development puts measurements of oceans, coasts, ice and inland waters at the heart of the new satellites’ remit. The mission design reflects continued reliance on altimetry while improving its performance compared with the current generation.
An OHB project manager said the mission would bring together “Europe’s extensive experience spanning more than four decades in altimetry missions.” The mission aims to continue the topographic measurements provided by Sentinel-3 while improving measurement capabilities and performance. In a presentation by the European Space Agency, the design was described as aiming to ensure continuity of downward-looking altimeter measurements within Copernicus from 2030 to 2050. That timeframe gives the mission a role in linking current measurements to a longer observation period, alongside improvements in accuracy and performance. OHB’s chief executive said the mission would provide “essential data for climate research, environmental monitoring and the protection of polar ice caps.”
The current Sentinel-3 satellites operate within the Copernicus Earth observation program, which provides information on the Earth, atmosphere and oceans to a range of users, from policymakers to scientists, businesses and society. Sentinel-3A was launched on 16 February 2016, followed by Sentinel-3B on 25 April 2018, according to the European Space Agency. Sentinel-3C joined the sequence on 15 September 2026, placing the next-generation contract within a broader effort to continue and develop the mission. OHB links the practical purpose of the new satellites to providing data for climate research, environmental monitoring and the protection of polar ice caps. The announced observation remit also focuses on oceans, coastal areas, sea ice and inland waters.
The World Meteorological Organization lists the S3NG-TOPO A satellite for 2032 or later in data updated on 14 April 2025. The organization describes its status as “under consideration, not firmly planned, as part of a program or mission proposal,” so the timing remains an estimate based on the listed information. The date falls after the start of the targeted period for continuity of Sentinel-3 measurements, which runs from 2030 to 2050, according to the European Space Agency presentation. During that period, the mission aims to continue altimeter measurements and improve its capabilities and performance. The option for a second satellite is part of the announced contract, while continuing and developing the measurements remains central to the planned mission.