Climate satellite
“Earthcare” scans the atmosphere – “No one else has that”
Esa employees have been training for weeks in the control center in Darmstadt for the launch of the earth observation satellite “Earthcare”. photo
© Boris Roessler/dpa
Knowledge about the Earth’s atmosphere is patchy. A new ESA satellite is intended to close these gaps. Preparations are in full swing.
Rows of numbers and tables flicker on dozens of monitors. Error and danger reports are sent to the specialists from the basement. Space debris or sandstorms, in an emergency you have to react quickly. Employees of the European Space Agency (ESA) have been training in the control center for weeks Darmstadt for the launch of the new earth observation satellite “Earthcare” planned for the end of May.
The mission is intended to enable global interaction between clouds, aerosols and solar radiation on the atmosphere and thus enable better climate models and weather forecasts. “Nobody else has that,” says Nicolaus Hanowski from the ESA Directorate for Earth and Environmental Observation in Frascati near Rome.
New dimension in earth observation
“Earthcare is one of the most sophisticated Earth explorers we have,” says Hanowski. For the first time, a 3D model of the atmosphere can be created across the entire height profile. “The European-Japanese earth observation mission “Earthcare” will significantly advance our understanding of climate and weather phenomena,” says the German Aerospace Center (DLR), which is involved in the mission.
The aim of the mission and the measurements is to understand how the atmosphere behaves across the entire altitude profile, said Hanowski. It’s about dynamic movements, physical and chemical properties and how the atmosphere changes globally over time. You could also do this with a weather balloon, but then you would only get a selective image, a column so to speak. “We make the column three-dimensional by examining the entire earth’s surface,” says the ESA specialist about the mission, which has so far cost a good 500 million euros and has four instruments on board.
New possibilities for weather forecasts
“The data that is collected is used by various organizations to specifically optimize weather forecasts,” says Hanowski. This means that storms such as the deadly flood disaster in the Ahrweiler district in 2021 could probably be better predicted. Short-term warnings of such events are not possible, even with the new data.
The aim is to improve forecasts, and this requires an understanding of the dynamics of clouds, low pressure areas and the atmosphere. Climate models obtained from the data could perhaps also be used to predict impending droughts. But: “We know too little about the interaction between solar radiation and the different layers of the atmosphere.”
The instruments on board “Earthcare” (Earth Cloud Aeorosol and Radiation Explorer) are now intended to measure and record density profiles, the water content of clouds, the chemical composition and the type of molecules in order to investigate interactions between clouds, aerosols and solar radiation. According to Hanowski, the comprehensive models created from this are very valuable: “You have everything in context.”
Highly complex instruments on board
According to DLR, when its solar panels are unfolded, the orbiter is around 17 meters long, 2.5 meters wide and 3.5 meters high. The instruments on board would send pulses of light and analyze the reflected signals. The Japanese space agency Jaxa contributed a cloud profile radar that can be used to examine the inner workings of clouds. There is also an instrument that takes high-resolution images in the visible and infrared light spectrum. The fourth instrument measures the reflected solar radiation and the thermal radiation emitted from the Earth.
Three steps for a successful start
The head of the control center in Darmstadt, Simon Plum, and his teams are preparing for the launch with a Falcon 9 rocket from the US space company SpaceX in Vandenberg, California: “We are also training for the failure of the control center.” In an emergency, decisions would have to be made quickly. A smooth start to the mission is also important for the satellite, which weighs around two tons.
According to Plum, there are three steps that have to take place on the way there: first, the launch itself, then aligning the solar panels with the sun to generate energy, and finally establishing communication with the orbiter. If something goes wrong here, the control center on launch day won’t say “We have a mission.”