South America’s Rivers Hit Record Lows as Brazil Drought Impact Spreads 

The Paraguay River is pictured, amid smoke coming from wildfires in neighboring countries, as the river has hit a record low water level due to a major drought, in Villeta, Paraguay September 7, 2024. (Reuters)
The Paraguay River is pictured, amid smoke coming from wildfires in neighboring countries, as the river has hit a record low water level due to a major drought, in Villeta, Paraguay September 7, 2024. (Reuters)
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South America’s Rivers Hit Record Lows as Brazil Drought Impact Spreads 

The Paraguay River is pictured, amid smoke coming from wildfires in neighboring countries, as the river has hit a record low water level due to a major drought, in Villeta, Paraguay September 7, 2024. (Reuters)
The Paraguay River is pictured, amid smoke coming from wildfires in neighboring countries, as the river has hit a record low water level due to a major drought, in Villeta, Paraguay September 7, 2024. (Reuters)

South America's Paraguay River, a key thoroughfare for grains, has hit a record low in Paraguay's capital Asuncion, with water levels depleted by a severe drought upriver in Brazil that has hindered navigation along waterways in the Amazon.

The depth of the Paraguay River, measured versus a "zero" index rather than the riverbed, has dropped below minus 0.82 meter, breaking the previous record low in October 2021, data from the national Meteorology and Hydrology Directorate shows. The body expects the river will keep falling with no rain forecast.

The Parana River in Argentina is also near year lows around grains hub Rosario. Both the Paraguay and Parana rivers start in Brazil, eventually joining and flowing into the sea near Buenos Aires. They are important routes for soy, corn and other trade.

"In the northern section (of the Paraguay waterway), navigation is practically halted due to the extreme drop in water levels," the Paraguayan oilseed and grain crushing chamber CAPPRO told Reuters in written comments.

The chamber, whose grain-trader members handle some 60% of Paraguay's soybean exports, said the low river was hitting shipments, though the impact was capped as it was not peak trading season.

"Vessels have had to transport volumes below the average of their normal cargo capacity," said CAPPRO. "This has generated delays and made travel times longer." The chamber's members include ADM, Bunge and Cargill.

EXPECTED RAINS NOT ENOUGH

The Paraguay-Parana system is a waterway of more than 3,400 kilometers (2,113 miles) that runs through Argentina, Brazil, Uruguay, as well as landlocked Paraguay and Bolivia.

Paraguay is the world's No. 3 soybean exporter and roughly 80% of grains travel along waterways to seaports downriver. Argentina is the top exporter of processed soy, most of which goes down the Parana from around river port city Rosario.

Paraguay's deputy director for the Meteorology and Hydrology Directorate, Jorge Sanchez, said the outlook for river levels in the coming months was not encouraging, even with the traditional October-November rainy season ahead.

"This would alleviate the level of the river, but it's not expected to be enough," Sanchez said.

Less rain than normal is expected in the second half of the year due to the La Nina weather phenomenon, which brings drier, cooler conditions in Paraguay and Argentina, though it usually heralds wetter weather farther north in Brazil.

Sanchez said this year, however, La Nina was delayed and its effects would be seen only between October and November. "There is a lot of variability due to climate change," he added.

In Brazil, where record wildfires have also occurred, the low water levels are leaving some communities in the Amazon isolated, as well as hitting soy and corn shipments in center-west states such as Mato Grosso, Brazil's number one grains growing area.



What is Helium and Why is it Used in Rockets?

India's Geosynchronous Satellite Launch Vehicle Mk III-M1 blasts off carrying Chandrayaan-2, from the Satish Dhawan Space Centre at Sriharikota, India, July 22, 2019. REUTERS/P. Ravikumar/File Photo Purchase Licensing Rights
India's Geosynchronous Satellite Launch Vehicle Mk III-M1 blasts off carrying Chandrayaan-2, from the Satish Dhawan Space Centre at Sriharikota, India, July 22, 2019. REUTERS/P. Ravikumar/File Photo Purchase Licensing Rights
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What is Helium and Why is it Used in Rockets?

India's Geosynchronous Satellite Launch Vehicle Mk III-M1 blasts off carrying Chandrayaan-2, from the Satish Dhawan Space Centre at Sriharikota, India, July 22, 2019. REUTERS/P. Ravikumar/File Photo Purchase Licensing Rights
India's Geosynchronous Satellite Launch Vehicle Mk III-M1 blasts off carrying Chandrayaan-2, from the Satish Dhawan Space Centre at Sriharikota, India, July 22, 2019. REUTERS/P. Ravikumar/File Photo Purchase Licensing Rights

Two NASA astronauts aboard Boeing's (BA.N) Starliner will stay on the International Space Station for months, because of a faulty propulsion system whose problems included helium leaks. Back on Earth, SpaceX's Polaris Dawn mission has been delayed because of helium issues on ground equipment.

Boeing's Starliner spacecraft landed uncrewed in a New Mexico desert late on Friday.

Past missions have that have been affected by pesky helium leaks include ISRO's Chandrayaan 2 and ESA's Ariane 5. Why do spacecraft and rockets use helium, and what is so tricky about it?

WHY HELIUM?

Helium is inert - it does not react with other substances or combust - and its atomic number is 2, making it the second lightest element after hydrogen.

Rockets need to achieve specific speeds and altitude to reach and maintain orbit. A heavier rocket requires more energy, not only increasing fuel consumption but also needing more powerful engines, which are more expensive to develop, test, and maintain.

Helium also has a very low boiling point (-268.9°C or -452°F), allowing it to remain a gas even in super-cold environments, an important feature because many rocket fuels are stored in that temperature range.

The gas is non-toxic, but cannot be breathed on its own, because it displaces the oxygen humans need for respiration.

HOW IS IT USED?

Helium is used to pressurize fuel tanks, ensuring fuel flows to the rocket's engines without interruption; and for cooling systems.

As fuel and oxidiser are burned in the rocket's engines, helium fills the resulting empty space in the tanks, maintaining the overall pressure inside.

Because it is non-reactive, it can safely mingle with the tanks' residual contents.

IS IT PRONE TO LEAKS?

Helium’s small atomic size and low molecular weight mean its atoms can escape through small gaps or seals in storage tanks and fuel systems.

But because there is very little helium in the Earth's atmosphere, leaks can be easily detected - making the gas important for spotting potential faults in a rocket or spacecraft's fuel systems.

In May, hours before Boeing's Starliner spacecraft made an initial attempt to launch its first astronaut crew, tiny sensors inside the spacecraft detected a small helium leak on one of Starliner's thrusters that NASA spent several days analysing before deeming it low-risk, according to Reuters.

Additional leaks were detected in space after Starliner launched in June, contributing to NASA's decision to bring Starliner back to Earth without its crew.

The frequency of helium leaks across space-related systems, some engineers say, have highlighted an industry-wide need for innovation in valve design and more precise valve-tightening mechanisms.

ARE THERE ALTERNATIVES?

Some rocket launches have experimented with gases such as argon and nitrogen, which are also inert and can sometimes be cheaper. Helium, however, is much more prevalent in the industry.

Europe's new Ariane 6 rocket ditched the helium of its predecessor Ariane 5 for a novel pressurization system that converts a small portion of its primary liquid oxygen and hydrogen propellants to gas, which then pressurizes those fluids for the rocket engine.

That system failed in space during the final phase of Ariane 6's otherwise successful debut launch in July, adding to the global rocket industry's long list of pressurization challenges.