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By Guest Nicole
The US space agency Nasa has landed a new robot on Mars after a dramatic seven-minute plunge to the surface of the Red Planet.
The InSight probe aims to study the world's deep interior, and make it the only planet - apart from Earth - that has been examined in this way.
Confirmation of touchdown came through on cue at 19:53 GMT.
It ended an anxious wait in which the robot radioed home a series of updates on its descent.
Nasa's mission control at California's Jet Propulsion Laboratory (JPL) erupted into cheers when it became clear InSight was safe on the ground.
Read more: https://www.bbc.com/news/science-environment-46351114
For the first time, the European Space Agency (ESA) has tested a novel air-breathing electric thruster that could allow near-Earth orbiting satellites to stay in space almost indefinitely. The thruster, designed to harvest atmospheric molecules and use them instead of onboard propellant, could also make future Mars exploration easier, ESA officials said.
Satellites need propulsion to hold their position or move around in space. Conventionally, satellites use rocket-like chemical propulsion, but electrical thrusters are becoming increasingly popular due to their better efficiency. However, current electrical propulsion systems still need to use a propellant,Â such as xenon, and their mission lengths are therefore limited by how much propellant they can carry. Due to weight constraints, satellites can carry only a limited amount. Those orbiting close to the Earth, in the range of a few hundred kilometers (about 125 miles), consume it at a higher rate, as they need to compensate for the atmospheric drag that slows them down and pulls toward the Earth.
Instead of carrying its own propellant, a satellite using ESA's new system would skim air molecules from the top of Earth's atmosphere. The molecules turn into plasma when compressed. An electric field is then used to accelerate the stream of plasma to provide thrust for the satellite.
"Providing atmospheric drag compensation without the use of carry-on propellant, this kind of electric propulsion would let satellites orbit at very low altitudes around Earth for very long operational time," Louis Walpot, who leads the project at ESA, told Space.com in an email.
"Normally their orbit would decay rapidly and they'd reenter the atmosphere," Walpot said.
Together with the thruster, ESA tested an innovative collector that captures incoming air as it hits the thruster at the staggering orbital speeds of about 4.9 miles per second (7.8 kilometers per second). The collector strips nitrogen and oxygen molecules from the air, and turns them into fuel. It's this collector that makes the system the first of its kind, demonstrating how an air-breathing thruster would actually work in orbit.
"This design of the collector was challenging because the air molecules tend to bounce out again, rather than be retained and compressed to a point where they turn into plasma, capable of being accelerated with an electric field," Walpot said. "The collector-plus-thruster design is entirely passive in nature Â— the air enters the collector due to the spacecraft's velocity as it orbits around Earth. All it needs is electric power to ionize the compressed air."
The electric power, he said, could be easily obtained from solar panels.
Walpot said the system would also work at the outer edges of the atmosphere of Mars, harvesting carbon dioxide molecules that make up the Red Planet's atmosphere instead of Earth's nitrogen and oxygen.
"This is more than a hundred times less dense than Earth's atmosphere of course, so any such air-breathing spacecraft would fly lower Â— about 120-180 km," Walpot said.
ESA, which funds the thruster's development through its Technology Research Programme, started working on the project in 2015 in collaboration with the Polish firm QuinteScience and Italy's Sitael. Researchers tested the technology in a vacuum chamber in Italy, simulating the surroundings at 200 kilometers (120 miles) altitude, according to the statement.
The agency now plans to scale up the technology to a more realistic flight configuration.
"This would increase the Technology Readiness Level," Walpot said. "Efforts will start to look at potential applications for the technology, future missions where it would be a good fit."
He said the air-breathing thruster would work up to altitudes as low as 160 km (100 miles), since it can only operate in vacuum or near vacuum. For comparison, ESA's Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) orbited at about 250 km (150 miles). GOCE used a similar electric thruster to keep itself in the orbit, but its thruster relied on the propellant xenon. The mission ran out of fuel after four years and seven months, after which the spacecraftÂ plunged into the atmosphere.
Using air as a propellant "opens up near-Earth space for new missions, which could be used for instance for very high-resolution imaging, or even to studyÂ the ever-changing conditionsÂ prevailing at the top of the atmosphere," Walpot said.
By Guest Nicole
Scientists cooking up test with potato pros in Peru; 65 varieties, red desert dirt
NASA says the Pampas de La Joya Desert in southern Peru has soil conditions like Mars. PHOTO: RYAN DUBE/THE WALL STREET JOURNAL
PAMPAS DE LA JOYA, Peru—As humans prepare to blast off to Mars, there is still the question of what they’ll eat once they colonize the red planet. Scientists who have traveled here to the Peruvian desert say they have the answer. Potatoes.
Researchers at the Lima-based International Potato Center and scientists at the National Aeronautics and Space Administration are studying which type of potato could be best suited for extraterrestrial farming to support a human settlement on Mars. If everything goes as planned, the Martian colonies could be munching on french fries, chips and mashed potatoes one day.
“It’s got to be a Martian potato that tastes good,” Julio Valdivia-Silva,a Peruvian astrobiologist with NASA, said while surveying the reddish-brown desert on a trip to collect soil. “It’s a big challenge to take a living organism somewhere else. We’ve never done this before.”
The idea is literally science fiction, included in the Hollywood blockbuster “The Martian,” where Matt Damon played a stranded astronaut and botanist who plants potatoes to survive on Mars. It’s also not so far-fetched.
Mars One, a Dutch nonprofit foundation, plans to send individuals to the planet in about 10 years on a one-way trip to establish a permanent colony. Inventor Elon Musk says his spacecraft company, SpaceX, also hopes to send humans within a decade but warned during a startup conference in Hong Kong in January that it would be “hard and dangerous and difficult in every way you can imagine.”
NASA, which landed the Curiosity rover on Mars in 2012 and found last year that water flows there, has recently announced plans to land astronauts.
That will be when the potato comes in handy.
“When humans go to Mars, they will want to grow things. They’ll need food,” said Chris McKay, a planetary scientist at NASA’s Ames Research Center in California and participant in the potato study. “I think we’ll be able to find varieties of potatoes that will grow at cold and low-pressure conditions. That would be interesting to know for Mars applications.”
The potato is a major global crop thanks to its ability to adapt to a variety of climates and its abundance of carbohydrates, as well as protein, vitamin C, iron and zinc. Peru, birthplace of the humble tuber, is home to over 4,500 varieties, more than anywhere else, according to the International Potato Center. Potatoes here also have another advantage: They’re not just for eating.
Reddish, purple and yellow spuds are used as dyes. Potatoes can be used as a battery. In Peru’s rural highlands, a lumpy potato called “the weeping bride” is given by the groom’s mother to the bride-to-be to test how good a wife she will be (it all depends on how neatly she peels the hard-to-peel spud).
In ‘The Martian,’ Matt Damon played a stranded astronaut trying to grow potatoes on Mars. PHOTO: 20THCENTFOX/EVERETT COLLECTION
Peru is good for the experiment because of the Pampas de La Joya Desert, one of the driest spots on Earth, which receives about a millimeter of precipitation a year. It is part of South America’s vast Atacama Desert that has long been studied by NASA for its Mars-like conditions, in particular its dirt.
For the potato study, scientists selected 65 varieties of spuds known to be the most resilient.
The first step will be to plant the tubers in over 1,300 pounds of soil transported from this desert to Lima. If they grow successfully, the potatoes will then be planted in a simulator that factors in the atmospheric conditions on Mars.
Walter Amoros, a Peruvian scientist at the International Potato Center, said he thinks half of the potatoes will grow in the desert soil, but only about 10 will yield a good-sized tuber. The flavor could change under the stress, he warned, which is common on Earth when potatoes are exposed to severe drought and high temperatures. That sometimes makes them so bitter they are inedible.
On Mars, the temperature averages minus 84 degrees Fahrenheit, with lows of minus 284 degrees, according to NASA. It has high levels of radiation and over 60% less gravity than Earth. Its atmosphere has 96% carbon dioxide, with only a tiny amount of oxygen. Then there are the dust storms and salty water.
Mars and Peru. The landscape is very similar.PHOTOS: NASA, RYAN DUBE/THE WALL STREET JOURNAL;
The potatoes “are going to pass through an acid test. I’ve done tests under stressful conditions, but never so stressful,” Mr. Amoros said. “I don’t think they’ll grow in the open air [on Mars]. They will have to plant them under controlled conditions, in domes.”
Early space travelers relied on paste-like food squeezed from aluminum tubes. Today, astronauts have a more appetizing menu: chicken, beef and even salmon jerky. Salt and pepper are provided in liquid form, to prevent them from floating away. There is coffee, orange juice and lemonade, consumed through straws.
NASA’s plant studies are currently focused on leafy greens like lettuce, which has been grown in small plant chambers on the international space station. They also plan to study Chinese cabbage and dwarf tomatoes. While less nutritious than potatoes, researchers hope the greens will be able to complement astronauts’ diet during space flights.
Scientists say growing food—should humans colonize Mars—would reduce costs and mitigate risks of transporting food by shuttle.
“If something goes wrong, if you can produce some of your own food in situ, then you have that as a means to sustain yourself,” saidRaymond Wheeler, a plant physiologist at NASA.
Until cultivating begins, scientists foresee transporting potatoes to Mars in refrigerated tubes. They could be planted by machines in a controlled environment before humans arrive. If Martian soil proves to be too hostile, there are options of growing them without soil by hydroponics and aeroponics, which deliver nutrients in water and air, respectively.
They will still need fertilizer, which scientists say could be resolved on Mars by recycling nutrients from urine and inedible plant parts.
“This will be important for achieving sustainable-type systems,” Mr. Wheeler said, “regardless of the approach.”
Abel Yapo, a student volunteer who helped dig up the desert soil, said he hopes one day to eat potatoes on Mars. “It would be a dream,” he said. “With my potatoes from the results we get here.”