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The case for why ESA shoulc keep Sentinel2-A active after S2-C is commissioned, and a petition https://labo.obs-mip.fr/multitemp/lets-ask-copernicus-to-keep-s2a-operational-after-s2c-launch/

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Hey, Fiona!

Sentinel-2 satellites are designed for an initial nominal mission of seven years. Each satellite carries enough fuel to potentially extend its operational life to a maximum of 12 years, which includes the fuel reserved for end-of-life deorbiting.

Under normal operations, this could stretch the lifespan of Sentinel-2A to around mid-2027. However, since there isn’t publicly available information on the exact fuel consumption to date (as far as I know), it’s possible that the satellite might require deorbiting earlier than 2027 if the remaining fuel is insufficient to continue operations safely.

Given this, I’m not sure the decision to retire Sentinel-2A sooner rather than later was primarily driven by operational costs, as the petition assumes.

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Interesting point..fI wish ESA would make a statement on this. Going over to read the debate on LinkedIn.

I think about how Landsat 5 was able to keep going for, what was it, 20 years long past its mandate, and how valuable that was. It must have had a lot of fuel onboard?

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Landsat 5 was initially designed as a 3-year mission but remarkably spent nearly 29 years in orbit! However, we can't directly compare Landsat 5 to the Sentinel-2 mission because they had different mission requirements.

Sentinel-2 is designed to revisit the same location on Earth every 5 days, often in combination with its twin, Sentinel-2B. Sentinel-2A performs frequent attitude control maneuvers to keep its instruments accurately aligned with its targets. It also needs to maintain a very stable orbit to ensure consistent image quality and calibration throughout its mission.

In contrast, Landsat 5 focused more on providing consistent, long-term data rather than frequent, precisely-timed revisits. As a result, Landsat 5 required fewer attitude and orbit adjustments since its mission did not demand the same level of precision as Sentinel-2A.

Additionally, NASA and the USGS adapted their operations to conserve fuel as Landsat 5 aged. In its later years, they reduced the frequency of certain maneuvers to extend its operational life.

Finally, while Sentinel-2 satellites carry specific fuel reserves for deorbiting, Landsat 5 was not designed with a planned end-of-life deorbit maneuver.

The only way I could see Sentinel-2A spending a few more years in orbit would be if its mission objectives were adjusted, and ESA adapted its operations to a mode similar to that of Landsat-5 in its later years. This could involve reducing the frequency of maneuvers and focusing on more long-term, less precise data collection, allowing the satellite to conserve fuel and extend its operational life.

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Thanks for the insights. I did not know about this difference. You are very knowledgeable! We'll see what happens.

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This makes me wonder about how this affects the harmonization of Landsat and Sentinel-2 (ie the harmonized product) , and the challenges that must entail.

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