James Webb: why the European Space Agency launches its rockets from South America

It is a small territory in continental South America, with only 83,846 square kilometers.

But within its borders it houses one of the most important spaceports in Europe: that of Kourou, jointly managed by the European Space Agency (ESA), the French National Center for Space Studies (CNES) and the Arianespace company.

French Guiana, with some 259,109 inhabitants and a very low population density, is a key center for the space race, not only in Europe, but also globally.

And it is from here precisely where it will take off this Saturday, December 25 James Webb telescope aboard the Ariane 5 rocket.

Considered the successor to NASA’s Hubble Space Telescope, the James Webb has been designed to look deeper into the Universe and, as a consequence, detect events that occur further back in time, more than 13.5 billion years ago.

Scientists also hope to use their more advanced capabilities to study the atmospheres of distant planets in the hope that they can detect signs of life.

With a cost of US $ 10 billion dollars and a construction of more than 30 years, the project is led by NASA in conjunction with ESA.

Shortly after launch, the rocket will launch Webb onto a path that will take him to an observation station about 1.5 million kilometers from Earth. On this trip, which should last a month, the telescope will deploy its 6.5-meter-diameter primary mirror and a shield to protect its observations of the cosmos from the Sun’s light and heat.

Webb’s goal is Obtain images of the first objects that were formed after the Big Bang.

And everything will be managed from the control room located in Kourou.

“I can say that (the European Spaceport) has one of the best locations in the world in terms of suitability for launching into space,” Julio Aprea, one of the mission managers, tells BBC Mundo.

European territory in South America

In 1964, France had to choose a site from which to launch its satellites. The European country no longer had Algeria, which had become independent in 1962.

14 locations were analyzed until the experts chose Kourou, a town within French Guiana located 55 kilometers from the capital, Cayenne, and 500 km from the Equator line.

There were many aspects that were evaluated, from historical, political and even technical.

This region, inhabited by European settlers since the 17th century and once a penal center, officially became an overseas department of France in 1946.

The geopolitical aspect is very important. That French Guiana is part of the European continent – the official language is French and the currency is the euro. Despite being in the northeast of South America, it simplifies things.

Finally, in 1975, the French government made the decision to share its Centre Spatial Guyanais with the newly created ESA.

A port in the middle of the jungle

But it is its strategic position on the map that is ideal for space scientists and engineers.

More than 90% of the country is covered by tropical forests. This represents a safety advantage in the event of accidents.

It is also not affected by cyclones or hurricanes, since these form more towards the Caribbean Sea.

French Guiana, on the other hand, has the north and east coast bathed with the waters of the Atlantic Ocean. With this it has a launch angle of 102 degrees, allowing it to carry out all possible space missions.

Aprea explains: for pitches to the geostationary transfer orbit, which is where most of the communication satellites are located, the rockets have to take off in an easterly direction.

But on its way to space, the rocket “shed” layers that fall on unpopulated places. In the case of French Guiana, this place is about the ocean.

But it is also easy to launch polar orbits from here, heading northwest. These orbits are synchronized with the Sun, which means that the satellite in this orbit will pass over the same point on Earth at the same time every day.

“If the Sun is always in the same position, the shadows will always be the same, then you can better analyze the different changes. If instead you go through the same point, but have different positions of the Sun, the shadows change and it is much more. difficult to analyze what you are seeing, “explains Aprea.

Some of the most important launches from Kourou have been the first of them (1968), the launch of the rocket Europe 2 (1971), the Ariane 1 (1979, ESA’s first successful rocket), the launch of the Soyuz (2011) and Vega (2012).

Slingshot effect

Another advantage of the European Spaceport is what scientists know as “slingshot effect“, or” slingshot effect “(slingshot, slingshot or sling in some countries).

And this happens precisely because the proximity of the port with the equatorial line.

The “slingshot effect” is the energy created by the speed of rotation of the Earth around the axis of the poles.

But the following happens: the closer an object is to the Equator, the faster it moves.

This happens because an object in the middle of the world has to go around faster than one located at the poles of the planet.

The rotation time of the Earth is approximately 24 hours. But depending on the latitude in which it is, the speed that is used for an object to complete the rotation in that time can change.

The Ecuador line measures 40,075 kilometers. But as we head toward the poles, the circumferential line gets smaller, so less speed is used to complete the turn in 24 hours.

This energy gives an initial thrust for the rockets at lift-off time. “Imagine you have two cars that you have to accelerate to 100 km / h. You have two ways: one you start from 0 km / h and the other from 30 km / h. Obviously the 30 will arrive faster. That is what gives you Ecuador “, explains Aprea.

This initial boost is very useful for space launches, since saves fuel and weight.

If the launch is made in other latitudes, the effect changes and more fuel is consumed. It would also add a considerable amount of weight, up to hundreds of kilos, which makes “a huge difference,” in Aprea’s words.

“Going up and down is very easy. What takes more work is going into orbit because you have to go very fast to get to such a speed that you stay in orbit,” says the specialist.

ESA is already developing the Ariane 6 rocket with which it intends to increase the number of launches. The French space agency is preparing the facilities in Kourou for the debut of this rocket for the second quarter of 2022.

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