Hexbyte Glen Cove America has sent five rovers to Mars—when will humans follow? thumbnail

Hexbyte Glen Cove America has sent five rovers to Mars—when will humans follow?

Hexbyte Glen Cove

Radiation will also be challenging on the planet, because of its ultra thin atmosphere and lack of a protective magnetosphere, so shelters will need to be well shielded, or even underground

With its impeccable landing on Thursday, NASA’s Perseverance became the fifth rover to reach Mars—so when can we finally expect the long-held goal of a crewed expedition to materialize?

NASA’s current Artemis program is billed as a “Moon to Mars” mission, and acting administrator Steve Jurczyk has reiterated his aspiration of “the mid-to-end of the 2030s” for American boots on the Red Planet.

But while the trip is technologically almost within grasp, experts say it’s probably still decades out because of funding uncertainties.

Mars is hard

Wernher von Braun, the architect of the Apollo program, started work on a Mars mission right after the Moon landing in 1969, but the plan, like many after it, never got off the drawing board.

What makes it so hard? For a start, the sheer distance.

Astronauts bound for Mars will have to travel about 140 million miles (225 million kilometers), depending on where the two planets are relative to each other.

That means a trip that’s many months long, where astronauts will face two major health risks: radiation and microgravity.

The former raises the lifetime chances of developing cancer while the latter decreases bone density and muscle mass.

If things go wrong, any problems will have to be solved on the planet itself.

‘It’s the details’

That said, scientists have learned plenty of lessons from astronauts’ missions to the Moon and to space stations.

“We have demonstrated on Earth orbiting spacecraft the ability for astronauts to survive for a year and a half,” said Jonathan McDowell, an astronomer for the Harvard–Smithsonian Center for Astrophysics.

Astronauts bound for Mars will have to travel about 140 million miles (225 million kilometers), depending on where the two planets are relative to each other

The general ideas of how to execute a Mars mission are in place, but “it’s the details” that are lacking, he added.

One way to reduce the on the journey is getting there faster, said Laura Forczyk, the founder of space consulting firm Astralytical and a planetary scientist.

This could involve using nuclear thermal propulsion which produces far more thrust than the energy produced by traditional chemical rockets.

Another could be building a spacecraft with water containers strapped to it that absorb space radiation, said McDowell.

Once there, we’ll need to find ways to breathe in the 95-percent carbon dioxide atmosphere. Perseverance has an instrument on board to convert carbon dioxide to oxygen, as a technical demonstration.

Other solutions involve breaking down the ice at the planet’s poles into oxygen and hydrogen, which will also fuel rockets.

Radiation will also be challenging on the planet, because of its ultra thin atmosphere and lack of a protective magnetosphere, so shelters will need to be well shielded, or even underground.

Risk tolerance

The feasibility also comes down to how much risk we are willing to tolerate, said G. Scott Hubbard, NASA’s first Mars program director who’s now at Stanford.

During the Shuttle era, said Hubbard, “the demand was that the astronauts face no more than three percent increased risk in death.”

“They have now raised that—deep space missions are somewhere between 10 and 30 percent, depending on the mission, so NASA’s taking a more aggressive or open posture,” he added.

That could involve raising the permissible level of total radiation astronauts can be exposed to over their lifetimes, which NASA is also considering, said Forczyk.

Musk has been developing the next-generation Starship rocket for the purpose—though two prototypes blew up in spectacular fashion on their recent test runs

Political will

The experts agreed the biggest hurdle is getting buy-in from the US president and Congress.

“If humanity as a species, specifically the American taxpayer, decides to put large amounts of money into it, we could be there by the 2030s,” said McDowell.

He doesn’t think that’s on the cards, but said he would be surprised if it happened later than the 2040s, a conclusion shared by Forczyk.

President Joe Biden hasn’t yet outlined his Mars vision, though his spokeswoman Jen Pskai said this month the Artemis program had the administration’s “support.”

Still, the agency is facing budget constraints and is not expected to meet its goal of returning astronauts to the Moon by 2024, which would also push back Mars.

SpaceX wildcard

Could NASA be beaten to it by SpaceX, the company founded by billionaire Elon Musk, who is targeting a first human mission in 2026?

Musk has been developing the next-generation Starship rocket for the purpose—though two prototypes blew up in spectacular fashion on their recent test runs.

These might look bad, but the risks SpaceX is able to take, and NASA as a government agency can’t, gives it valuable data, argued Hubbard.

That could eventually give SpaceX an edge over NASA’s chosen rocket, the troubled Space Launch System (SLS) which is beset by delays and cost overrun.

But not even one of the richest people in the world can foot the entire bill for Mars themselves.

Hubbard sees a public-private partnership as more likely, with SpaceX providing the transport and NASA solving the many other problems.



© 2021 AFP

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Hexbyte Glen Cove South America ravaged by unprecedented drought and fires thumbnail

Hexbyte Glen Cove South America ravaged by unprecedented drought and fires

Hexbyte Glen Cove

In this file picture taken on September 13, 2020 a man gestures in a burnt area of the Pantanal in Brazil, part of a large area ravaged by fires

Under stress from a historic drought, large swathes of forest and wetlands in central South America known for their exceptional biodiversity have been ravaged by devastating fires.

Experts say the wildfires in a region that spans Argentina, Brazil, Bolivia and Paraguay—especially the region between the Paraguay, Parana and Uruguay rivers—have become critical in 2020.

“There has been a dramatic increase in fires. In Argentina there has been an increase of around 170 percent, it’s very serious,” said Elisabeth Mohle, an environmental politics researcher at Argentina’s San Martin National University (UNSM).

She says it’s part of a wider problem affecting multiple regions around the world this year, including in Brazil’s Amazonas state, Australia, California, and the Gran Chaco, South America’s second largest forest after the Amazon.

The Pantanal—the world’s largest wetlands that span Brazil, Bolivia and Paraguay—is experiencing its worst drought in 47 years.

The Parana river—one of the most powerful on the planet that originates in Brazil and empties into the River Plate estuary—is at its lowest level since 1970.

In August it was down to 80-centimeters in Rosario, eastern Argentina, rather than the usual 3-4 meters for that time of year.

It’s the same thing with the Paraguay river that is at its lowest level “in half a century,” according to Paraguay’s national weather center in Asuncion.

The fires have killed wildlife, including this alligator beside the Transpantaneira park road in the Pantanal wetlands in Brazil

‘Desert of ashes’

The fires are being fanned by ideal conditions, including , temperatures over 40 degrees Celsius (104 Fahrenheit) and the dry season in which farmers use slash-and-burn techniques to try to regenerate the soil.

In Paraguay, “the fires … at the end of September and first week of October, broke all records,” Eduardo Mingo, a top official at the national weather center, told AFP.

The number of fires were up 46 percent in 2020, according to authorities.

Paraguay’s capital Asuncion and several towns in northeastern Argentina and southern Brazil spent days and even weeks submerged under a thick fog due to the intense fires.

And without the usual rainfall that moistens the soil, the wetlands have been particularly badly affected.

Images from the Brazilian Pantanal of the charred carcases of birds, snakes, caimans and trees have shocked the world.

In this file picture taken on September 27, 2020 a ring tailed coati receives medical attention from vets at the Guilherme de Arruda Environmental Education and Inspection centre in the Transpantaneira area of the Pantanal in Mato Grosso State, Brazil

A quarter of the area was devastated between January and September, while the Paraguayan Pantanal had already been badly affected by fires in 2019.

The Parana Delta that is home to species such as the jaguar, Pampas cat and several rodents, has been hit by fires of an unprecedented intensity since January, leaving a “desert of ashes” over tens of thousands of hectares of wetlands.

“Reptiles, migratory birds, and tortoises have died,” Cesar Massi, a naturalist in Argentina’s Santa Fe province, told AFP.

“I remember that during the last drought in 2008, there were fires. But this year they’ve been stronger, more intense and lasted longer.”

Reduced protection budgets

Agriculture is a massive source of income for the countries in this region but the slash-and-burn techniques used aggravate the situation.

In the north of Argentina “despite COVID-19 restrictions, between March 15 and September 30… twice the area of Buenos Aires was deforested,” according to Greenpeace.

Red glow from fire is seen at the wetlands of Pantanal in Brazil on September 13, 2020

The Mighty Earth NGO says that Paraguay’s dry forests are “one of the main sites of deforestation in the world, mostly due to the expansion of pastureland and more recently soyabean plantations.”

Argentina’s government has accused cattle farmers of setting fires to “increase pastureland area” in the Parana Delta.

One problem is that NGOs don’t have the necessary funding from governments to enforce rules and instigate large restoration or protection projects.

“The provincial government has less and less of a budget for prevention, there are no surveillance posts, the environmental police have been disassembled,” Alfredo Leytes, a member of the Ambiente en Lucha environmental collective based in Cordoba, Argentina, told AFP.

In Brazil “there has been a 58 percent decrease in ‘Brigadistas’ contracts,” said Alica Thuault from the Centro de Vida institute, referring to the volunteers that mobilized to tackle fires. She attributes blame firmly at the feet of President Jair Bolsonaro, a climate change skeptic.

Mohle wants different players, including farmers and ecologists, to work together “to regulate the use of land to ensure a more sustainable development than currently exists.”



© 2020 AFP

Citation:
South America ravaged by unprecedented drought and fires (2020, October 24)
retrieved 25 October 2020
from https://phys.org/news/2020-10-south-america-ravaged-unprecedented-drought.html

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part may be reproduced without the written permission. The content is provided for information purposes only.