Meet The ESA’s Sentinel Satellites Helping Fight Climate Change

Have you ever been curious about what in the universe the nearly 5,000 satellites orbiting Earth are doing? Well, for starters, only about 2,787 are active – talk about a lot of space junk. Each satellite sent into orbit has a different purpose. Some are for communications, and others are for earth observations and scientific research to help us understand climate change. 

Circling the Earth is a squad of European satellites working together and collaborating with other Earth observation satellites to understand the changes on our planet caused by climate change and weather patterns. These little heroes are called the Sentinel satellites. There are currently 8 Sentinels in orbit, which includes the twin pairs, with several more scheduled in the coming years. Together, the Sentinels, part of the EU’s Copernicus Programme, can help us plan for a better future by preparing for and understanding the changing earth systems. 

In 2019, the European Space Agency (ESA) invited me to meet Sentinel 6A in person. I got to suit up and head into the cleanroom to meet 6A before it began final tests and journey to California for a launch on a Falcon 9.

I also got to chat with some of the folks behind the project, learn more about the collaborative efforts, and learn how the satellites benefit European citizens and global populations. So, let’s look at this fantastic posse of satellites working around the clock, or instead around the earth, to help us combat climate change.

About the Sentinel Satellites and Copernicus Program

The EU developed the Copernicus Programme to help governments, scientists, NGOs, businesses, and corporations access free public data to help them adapt and mitigate environmental changes. 

Copernicus is the overarching program that uses Sentinel satellites along with airborne data and ground stations to compile information targeting six areas:

• Climate Change
• Emergency Management
• Land Monitoring 
• Atmosphere Monitoring
• Marine Environment Monitoring
• Security

The information can help anyone worldwide looking to map and understand comprehensive climate formatting and deliver evidence-based climate policy decisions.

Copernicus’s program started in 2010. The first satellite, Sentinel 1, was launched in 2014. There are missions planned well beyond 2030, which means the EU and the world can utilize the data for short and long-term monitoring. Access to this data today and in the future will help governments and communities prepare for and predict what changes lay ahead for the earth.

Each satellite in the series has a unique payload (or observation tools) optimized to collect data and monitor specific things, such as rising sea levels, ice density, air quality, and more. Most satellites will only last 5-7 years, but most have a twin satellite, launched at a later date, aimed to extend their lifespan. The twin continues collecting and enhancing the same data as their twin. For example, Sentinel 6B will launch in 2025 and will continue the vital work for 6A as it nears the end of its productive life cycle.

Up Close with Sentinel 6

Before my introduction to 6A, I had to cover my clothing, hair, and shoes and turn off my phone. Any stray hair or phone signal could compromise the entire satellite, resulting in more tests. I must have checked my phone and tucked my hair behind my cap a dozen times because no one wants to be THAT person. 

I was surprised at how small and compact the satellite was, which makes sense considering the need for efficiency, but it was still a bit mind-blowing to be in the same room as a satellite. One of Sentinel 6’s unique features is its trapezoid shape and “roof” of solar panels. This fully mounted solar range means the 6 twins can capture solar energy from all sides, enabling a stable orientation without turning toward the sun for power.

Most satellites have to turn their solar panels to face the sun, making them less efficient.

Sentinel 6 – ‘Surfing the Seas’

ESA “Fun” Profile: Before being hired as a satellite, 6 was often found at the beach. Many neighbors would whisper during Monday night bridge that 6 was just a beach bum, surfing the waves from dawn until dark. Over time, 6 noticed that the coastline along their favorite beach was changing. Sea levels and temperatures were rising, and sea life was washing ashore.

In a valiant effort to understand the rising sea levels threatening their home, 6 was hired to be the latest in the line of superhero satellites. 6 is looking forward to providing data on the changing ocean to protect coastal communities worldwide.

Mission Stats and Practical Use

Climate Change. Atmosphere Monitoring

To monitor sea-level variability and rising sea levels by mapping 95% of the Earth’s ice-free ocean every ten days.

From its launch, 6A will provide immediate assistance in sustainable ocean resource management for coastal communities and long-term climate forecasting.

• Improved forecasts of ocean currents, wind, and wave conditions
• Clarity on how the ocean stores and redistributes heat, water, and carbon
• Empowers communities to understand the implications of land development

Launch Date:

• November 2020 on a Falcon 9 from Vandenberg, AFB, USA
• 6B launching in 2025

Payloads:

• SAR Radar altimeter records wind speed, sea-surface, and wave height.
• GNSS-RO uses radio occlusion to create tropospheric temperature, pressure, and humidity profiles.

Why is Monitoring Sea Level So Important? Global sea levels have been rising by an average of 3.2mm annually since 1993. However, data shows the average is increasing. Sentinel 6 maps global sea levels every ten days to help us understand long and short-term projections for coastal communities.

Six will also provide valuable information on the impact of global greenhouse gases and how reducing them might help.

Disappearing Belgium

At the current rate of sea-level rise, Belgium’s coast will be submerged by 2050. This will displace thousands and create an economic disaster, causing future erosion and ecosystem degradation, threatening biodiversity and food and housing security.

Belgium, together with Europe, must make a conscious effort to combat climate change, restore natural defenses, and plan for rising levels. Data from Sentinel 6 will help Belgium and many other coastal countries protect their citizens.

Indigenous Arctic Communities

During the Sentinel event, I asked how Alaskan (my home state) communities might use this data. Alaska has the first climate change migrants in the United States. Many at-risk communities are Indigneous villages that rely on ice for subsistence hunting. They are experiencing extreme impacts from melting permafrost and rising sea levels, causing flooding, erosion, and loss of subsistence foods.

Arctic communities and Indigenous peoples can access the data to help plan and potentially move their villages before a disaster. The data can also help them project sea ice loss, which will be valuable in determining any future loss of subsistence hunting.

Meet the Rest of the Team

Sentinel 1 – ‘Radar Vision’

ESA “Fun” Profile: During a tragic lab accident that was redacted, 1 came down with a strange case of ‘radar vision.’ After being rejected by society for their creepy and off-putting stare, 1 wandered the streets gazing up through the clouds, dreaming of using their strange new superpowers for good.

Their dreams came true after being picked up by a large unmarked white van in a dark alleyway. Some people in suits offered 1 the chance to launch into space. While orbiting the Earth, they use their radar vision to peer down through clouds and help scientists create detailed maps of the planet, regardless of weather.

Mission Stats and Practical Use

Climate Change. Marine Environmental Monitoring. Land Monitoring. Emergency Management. Security. 

These polar-orbiting twin satellites work day and night, whether rain or shine. Utilizing advanced radar technology (SAR), Sentinel 1 creates images of the Earth’s surface by mapping forests, bodies of water, agricultural land, sea-ice areas, and the Arctic and land surfaces. It can do all this even when cloudy, revolutionizing our understanding of the planet.

The first of the Sentinel series is a handy tool. It is a jack of all trades and a powerful land management tool. Advanced radar is key to mapping ecosystem health and function, helping us prepare for and understand disasters.

• Forest mapping helps forest service isolate and control the spread of disease and manage wildfires. 
• Water and soil mapping helps manage flood risk and response.
• Oil spill tracking helps monitor the spread, enabling fast and efficient response.
• Offers timely sea ice maps to help with shipping and cargo plan routes. Ships can use real-time data to monitor wind and waves for safe passage. 
• It provides a detailed polar map, as polar regions are typically cloudy; SAR technology can help us “see through” the clouds.
• Urban planning for coastal communities and flood plains.
• Monitoring and predicting volcanic activity.
• Quick and consistent imaging helps humanitarians with crisis response.

Launch Dates: 

• 1A launched in April 2014 on Soyuz from Kourou.
• 1B Launched in April 2016 on Soyuz from Kourou.
• Sentinel 1C & D – coming soon!

Payload: 

• C-Band SAR sends advanced radar MicroWaves to the Earth. When they return, it creates an image.
• Sentinel C& D will have a SAR augmentation for marine surveillance applications.

Sentinel 2 – ‘Color Vision’

ESA “Fun” Profile: While studying mantis shrimp’s unique abilities, 2 created a pair of supercolor glasses so humans could enjoy high-resolution color for the first time. 2 became a world-renowned artist who used colors only seen through their exclusive glasses.

Surrounding themselves with elitists and the type that sells banana peel art for billions of dollars with a martini in hand, 2 began to wonder if this was too vapid a life for them. Approached by a woman in a dark suit at their latest showing, 2 was never seen in the elite art circle again. Word is they use their color technology while orbiting Earth, creating images to monitor vegetation levels.

Mission Stats and Practical Use

Climate Change. Land Monitoring. Emergency Management. Security. 

Sentinel 2 creates high-resolution images of the Earth every five days to track and monitor changes in land use and vegetation levels. Sentinel 2 helps us understand how agriculture, logging, urbanization, and natural disasters impact biodiversity and land use. It also can record pollution levels along coastal communities.

Its unique capability to create geophysical maps allows us to see details such as chlorophyll and water content in vegetation, which can help us predict the impacts of drought and fires.

• Leaf content images help monitor plant growth, are vital to farmers during the growing season and support reforestation efforts. 
• Provides critical information to optimize crop yield, improving food security
• Offers crisis responders with accurate information during natural disasters 
• Land managers worldwide can use the information to detect fungus or pest control early by identifying problem areas.
• Accurate pictures of volcanic eruptions and landslides for disaster mapping and aid.

Launch Dates: 

• 2A Launched in June 2015 on VEGA from Kourou, French Guiana.
• 2B Launched in March 2017 on VEGA from Kourou, French Guiana.
• Sentinel 1C & D – Coming Soon

Payload: 

• A multispectral instrument (MSI) optical imager
• Creates high-resolution images of the Earth.

Sentinel 3  – ‘Surf and Turf’

ESA “Fun” Profile: 3 was once a humble Benihanas chef. Their only claim to fame was creating the lip-smacking surf and turf combination on every menu around the United States.

But, deep in their heart, 3 always knew there was a special connection between land and sea and wrote deeply found poetry about this connection. Their private notes detailing their hypothesis were found by the Benihanas CEO, who had a distant relative at the ESA. 3 was last seen taking their 20-minute break outside the restaurant and is likely orbiting space to monitor the changes to both land and sea.

Mission Stats and Practical Uses

Climate Change. Marine Environment Monitoring. Land Monitoring. Atmosphere Monitoring. Emergency Management.

The twin satellites provide two-day global coverage for monitoring oceans and land. The twins’ unique tools allow for colorful data, including temperature from marine and land systems. The colorful topographic measures provide detailed maps of ice and fresh-water systems and pollution levels over bodies of saltwater.

• Improves ocean forecasting for maritime safety
• Enhanced predictions for storm surges and flooding
• Early forest-fire detection for better response and crisis management

Launch Dates: 

• 3A launched in 2016 on Rockot from Plesetsk, Russia.
• 3B Launched in April 2018 on Rockot from Plesetsk, Russia.

Payload: 

• Ocean and Land Color Instrument
• Sea and Land Surface Temperature Radiometer  

Sentinel 4 – ‘EU Air Defender’

ESA “Fun” Profile: 4 wasn’t like the other Europeans who always had a cigarette in one hand and a stack of papers ready to roll in the back pocket. Suffering from chronic asthma, 4 often stood on the sidewalk with a cardboard sign advocating for better air quality.

All 4 wanted was the right to clean air. After working their way through the EU bureaucratic command, they were given the opportunity to launch into space, piggybacking on an MTG-S to monitor European air quality. Finally, 4 can fight for clean air for all Europeans—even if they refuse to quit smoking.

Mission Stats and Practical Uses

Climate Change. Marine Environment Monitoring. 

Sentinel 4 will provide hourly data while monitoring European air quality from a geostationary orbit. This is a Visible Near-Infrared spectrometer payload on the MTG-S satellite in a geostationary orbit. It will complement the onboard InfraRed Sounder

Copernicus will use the data to understand and report on air quality, pollution, and climate monitoring. 

• Monitors trace elements of Nitrogen Dioxide, Formaldehyde, and Aerosol in high spatial resolution for better forecasting and air quality monitoring
• Provides information on ozone and solar radiation for better UV forecasting and climate monitoring
• Enhance the monitoring of the North African Sahara as well as Europe

Launch Dates: 

• Planned launches in 2023 (A) and 2030 (B)
• 4A and 4B launch with Meteosat Third Generation Sounder satellites.

Payload: 

• Main Optical Unit (MOU) contains optical and detection chains.

Sentinel 5 and 5p – ‘Global Air Defenders’

ESA Profile: 5 and 5P were twins separated at birth. After meeting at a science summer camp, in a story that surely inspired Parent Trap, the twins bonded over their poor health due to particulate matter in their home countries.

The twins put their heads together and won scholarships and awards for their fight for clean air. Not long after, they were picked up from a science fair in a suspiciously familiar dark van. They now monitor global air quality, hoping children won’t grow up with chronic illnesses.

Mission Stats and Practical Uses

Climate Change. Atmosphere Monitoring. 

5 continuously monitors air quality worldwide at a high resolution and from a low orbit. 5P is a simplified precursor to Sentinel 5, providing air-quality measurements until 5 is ready for launch. There are six planned satellites in the 5 series. 

Together, they will provide long-term global measurements and projections on atmospheric variables, monitor greenhouse gasses, and track how air pollutants move through our atmosphere.

• Provides global policymakers with a better understanding of air quality for evidence-based decisions to tackle climate change.

Do you remember when China first went into lockdown in 2020 after the outbreak of COVID-19? News outlets were reporting about the sudden and real-time improvement in air quality. That data was collected from 5P!

Launch Dates: 

• 5P was launched in 2017 from Plesetsk, Russia.
• Planned launches in 2021 (A) and 2022 (B)
• Additional launches scheduled for 2028

Payload: 

• Includes five different spectrometers to test for greenhouse, aerosols, and reactive gasses.  

The Future Sentinels

The ESA just released more details about Sentinel 7. It will continue monitoring air quality with a specific focus on CO2. CO2 mapping will help determine if countries meet their Paris Agreement goals regarding air quality, greenhouse gas emissions, etc. The satellite’s construction will begin soon; hopefully, we can expect a launch date in 2025. 

There may be no end in sight to the Copernicus Programme. There are rumors that a Sentinel 8 will have a thermal infrared sensor to help us better understand volcanic activity, forest fires, and drought. Sentinel 9 is rumored to focus on polar ice, including thickness, and provide better weather imaging.

Real Ways the Satellites Help

Free Data for Everyone!

All data collected by the Copernicus program is free and available for anyone to access. Ensuring the data is open and accessible has allowed governing bodies, conservation groups, land managers, farmers, and citizens to plan for a changing climate based on scientific data.

The data has helped manage the spread of disease in forests, track deadly algae blooms, monitor glacier recession, respond to emergencies, develop climate apps, and protect cultural heritage sites. Let’s take a look at some of the real success stories. 

Emergency Relief to Latvian Farmers

The sentinel data can be beneficial for long-term monitoring. However, the accurate and real-time data allows for fast and instant relief during a climate emergency, such as in Latvia.

In 2017, unexpected flooding due to climate change devastated Latvia’s farmland, resulting in a state of emergency. Latvian farmers needed immediate financial relief due to yield loss. The government struggled to distribute funds as the floods made most roads inaccessible.

Overlapping optical data from Sentinel 1 & 2 mapped the flood zone every few days. This data saved the Latvian government time and money, and 3,100 Latvian farmers received compensation for loss of yields within two months. Previously,the Latvian government would have waited to distribute funds after clearing the roads, causing financial insecurity.   

Glacial Monitoring in Iceland

Iceland contains most of Europe’s glaciers. Monitoring these glaciers is critical to global sea levels. The rivers flowing from the glaciers fluctuate annually and are subject to large-scale outbursts of water flow due to the region’s volcanic activity. Floods block roads, putting tourists and locals at risk.

Eighty percent of Iceland’s energy is renewable from hydropower. Understanding the changes in glacial rivers is vital to securing the future of renewable power in Iceland. It is far too expensive and complicated for such a small population to use traditional means (airplane surveys) to map glaciers. Sentinel 2A mapped ⅔ of Iceland in 2017, and its frequent updates help locals respond to road flooding and energy use and keep tourists safe while visiting glaciers. 

If you’re interested in accessing this free data, you can follow these easy steps provided by GIS Geography to look at the Copernicus Data. You can also reach out to the Research and User Support team. 

A Collaborative Effort

The European Space Agency is not working alone on these missions. At the Sentinel 6 event, Sandra Cauffman, the inspiring woman directing NASA’s Earth Science division, discussed NASA’s involvement. Many missions will continue or lend data to NASA satellites in space. NASA contributed a GNSS-RO to Sentinel-6, the payload that creates tropospheric temperature, pressure, and humidity profiles, hinting at future collaborations with NASA and the ESA. 

Several women are involved in the Copernicus Programme. Being a woman at the 6A press event and seeing Sandra Cauffman, NASA’s Earth Science Director, Astrid Christina Koch, the head of the European Commissions Copernicus Programme, and Simonetta Cheri, the head of strategy programs for Copernicus, was inspiring. After chatting with the women, they made it clear that there is space for women at the ESA and Copernicus Programme, and it is exciting to see what the future holds for women in space.  

Also present at the Sentinel 6 event were Airbus, IABG, CMEMS, LEGOS, and EUMETSAT, highlighting how many people come together from around the world to ensure the global population has access to free climate data and resources to help plan and prepare for future climate change.

Discuss, Share, Engage

Discuss

• Has your country used Sentinel data to help in a climate-related crisis? You can read some inspiring case studies from Africa to Iceland to see how this free data helps people worldwide! Let me know in the comments if your country has used this data.
• Which satellite is the most important for helping us understand climate change? Why?
• If your country hasn’t used the data, let me know in the comments some areas they might be able to use this information.
  • You can even write a local politician and let them know about the free data provided by the Sentinel satellites.

Share

I hope you enjoyed reading about this fantastic team of satellites helping us combat climate change. The Sentinel Satellites and the Copernicus Programme give us a fighting chance to adapt to our planet’s changing climate. Make sure you share this so your friends and family can learn all about the Sentinel Satellites.