Tuesday November 21, 2017
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Decades’ worth of man-made junk is cluttering up Earth’s orbit, posing a threat to Spaceflight and Satellites

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FILE - A piece of metal, presumably from doomed US rocket SpaceX Falcon, recovered from the sea off the Isles of Scilly in Britain, is seen in this handout provided to Reuters on Nov. 27, 2015. VOA

Decades’ worth of man-made junk is cluttering up Earth’s orbit, posing a threat to spaceflight and the satellites we rely on for weather reports, air travel and global communications.

More than 750,000 fragments larger than a centimeter are already thought to orbit Earth, and each one could badly damage or even destroy a satellite.

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Last year, a tiny piece of debris punched a gaping hole in the solar panel of Copernicus Sentinel-1A, an observation satellite operated by the European Space Agency, or ESA. A solar array brought back from the Hubble Telescope in 1993 showed hundreds of tiny holes caused by dust-sized debris.

Experts meeting in Germany this week said the problem could get worse as private companies such as SpaceX, Google and Arlington, Virginia-based OneWeb send a flurry of new satellites into space over the coming years. They said steps should be taken to reduce space debris.

Getting all national space agencies and private companies to comply with international guidelines designed to prevent further junk in orbit would be a first step. At the moment those rules — which can be costly to implement — aren’t legally binding.

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ESA’s director-general, Jan Woerner, told The Associated Press on Friday that so-called mega-constellations planned by private companies should have a maximum orbital lifetime of 25 years. After that, the satellite constellations would need to move out of the way, either by going into a so-called `graveyard orbit’ or returning to Earth.

That’s because dead satellites pose a double danger: they can collide with other spacecraft or be hit by debris themselves, potentially breaking up into tiny pieces that become a hazard in their own right.

The nightmare scenario would be an ever-growing cascade of collisions resulting in what’s called a Kessler syndrome — named after the NASA scientist who first warned about it four decades ago — that could render near-Earth orbits unusable to future generations.

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“Without satellites, you don’t have weather reports, live broadcasts from the other side of the planet, stock market, air travel, online shopping, sat-nav in your car,” Rolf Densing, ESA’s director of operations, said. “You might as well move into a museum if all the satellites are switched off.”

Even if future launches adhere to the guidelines, though, there’s the question of what to do with all of the debris already in orbit.

“We have to clean the vacuum, which means we need a vacuum cleaner,” Woerner said.

Just how such a device would work is still unclear. Proposals include garbage-cleaning spacecraft armed with harpoons, nets, robotic arms and even lasers to fry really small bits of debris.

Luisa Innocenti, the head of ESA’s “clean space” initiative, said a mission is already in the works to bring down a very large piece of debris.

“It’s a very complex operation because nobody wants to fail,” she said. “Nobody wants to hit the debris and create another cloud of debris.” (VOA)

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India to launch new Cartosat-2, 28 foreign satellites in December

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ISRO
India to launch new Cartosat-2, 28 foreign satellites in December

India would launch its latest remote sensing satellite in Cartosat-2 series along with 28 foreign satellites riding piggy-back in December, a top space official said on Monday.

“In the next launch, we have a Cartosat along with 28 international commercial satellites, which we will launch in the second half of December,” said S. Rakesh, the Chairman and Managing Director of Antrix Corporation Ltd, the commercial arm of state-run Indian Space Research Organisation (ISRO).

There will be 25 nano satellites and three micro satellites from the US and other countries as co-passengers along the space firm’s own satellite of the Cartosat-2 series, he said.

The satellites will be launched into the orbit onboard the Polar Satellite Launch Vehicle (PSLV), Rakesh added.

The next launch will be keenly watched as it comes after ISRO’s PSLV rocket failed to deploy a spare navigation satellite on August 31. The rocket’s heat shield had failed to separate leaving the satellite inside the shield.

The Cartosat-2 is an earth observation satellite that is capable of providing high-quality images.

Imageries from Cartosat-2 series are used for cartographic, urban and rural applications, coastal land use and regulation, utility management like road network monitoring, water distribution, creation of land use maps, change detection to bring out geographical and man-made features and other Land Information System (LIS) and Geographical Information System (GIS) applications.

The previous satellite (Cartosat-2E) in the series was launched on February 15 this year from the spaceport at Sriharikota in Andhra Pradesh, about 90km northeast of Chennai.(IANS)

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Can Flourishing Islamic State (ISIS) be Stopped in Afghanistan?

The truth about IS and Afghanistan is definitely no picnic

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Taliban fighters react to a speech by their senior leader in the Shindand district of Herat province, Afghanistan, May 27, 2016.
Taliban fighters react to a speech by their senior leader in the Shindand district of Herat province, Afghanistan, May 27, 2016. The rise of IS in Afghanistan has become such a priority that U.S. and Afghan forces sometimes support the Taliban while battling IS, VOA
  • Depending on the location, the proliferation of IS has drawn varied resistance from the Afghan military, U.S. air support and ground troops, local militias, Taliban forces and other militant groups
  • Afghan army planes on Wednesday night accidentally air dropped vital supplies of food and water to IS militants in the Darzab district of northern Jouzjan province instead of to their own besieged troops
  • In the Tora Bora area, where IS has made a strong stand in recent days, local villagers and militias joined with Taliban to rout IS

June 25, 2017: The Islamic State group is rapidly expanding in parts of Afghanistan, advancing militarily into areas where it once had a weak presence and strengthening its forces in core regions, according to Afghan and U.S. officials.

Depending on the location, the proliferation of IS has drawn varied resistance from the Afghan military, U.S. air support and ground troops, local militias, Taliban forces and other militant groups.

Attacking IS has become such a priority in the country, that disparate forces sometimes join together in the ad-hoc fight, with Afghan and U.S. forces finding themselves inadvertently supporting the enemy Taliban in battling IS.

Confusion leads to mistakes

All too often, officials say, mistakes are made due to confusion on the ground.

Afghan army planes on Wednesday night accidentally air dropped vital supplies of food and water to IS militants in the Darzab district of northern Jouzjan province instead of to their own besieged troops, provincial police chief, Rahmatullah Turkistani told VOA. The supplies were meant to help Afghan forces that are countering twin attacks by IS and Taliban militants but were used instead by IS.

“It’s not getting better in Afghanistan in terms of IS,” U.S. Chief Pentagon Spokeswoman Dana White told VOA this week. “We have a problem, and we have to defeat them and we have to be focused on that problem.”

Reinforcements for the IS cause reportedly are streaming into isolated areas of the country from far and wide. There are reports of fighters from varied nationalities joining the ranks, including militants from Pakistan, India, Iran, Iraq, Syria, Russia and Central Asian neighbors.

Confusing scenarios

Still, the Islamic State-Khorasan (ISK) as IS is known in Afghanistan remains a fragmented group composed of differing regional forces with different agendas in different parts of the country.

“IS-K is still conducting low-level recruiting and distribution of propaganda in various provinces across Afghanistan, but it does not have the ability or authority to conduct multiple operations across the country,” a recent Pentagon report said. But where it operates, IS is inflicting chaos and casualties and causing confusing scenarios for disparate opponents.

In the Tora Bora area, where IS has made a strong stand in recent days, local villagers and militias joined with Taliban to rout IS. IS regained ground after a few days, leading to U.S. military air attacks on IS positions in conjunction with Afghan intelligence instructions and army operations.

IS fighters reportedly have fled from mountain caves of Tora Bora, where al-Qaida’s leader Osama bin Laden hid from U.S. attack in 2001.

Families displaced

IS fighters were also reportedly advancing in neighboring Khogyani district, displacing hundreds of families, according to district officials. It is one of several areas in Nangarhar province, near the Pakistani border, where IS has been active for over two years.

Fierce clashes in the Chaparhar district of Nangarhar last month left 21 Taliban fighters and seven IS militants dead, according to a provincial spokesman. At least three civilians who were caught in the crossfire were killed and five others wounded.

“IS has overpowered Taliban in some parts of Nangarhar because the Taliban dispatched its elite commando force called Sara Qeta (Red Brigade) to other parts of the country, including some northern provinces to contain the growing influence of IS there,” Wahid Muzhda, a Taliban expert in Kabul, told VOA.

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Recruiting unemployed youths

IS has also expanded in neighboring Kunar province, where, according to provincial police chief, it has a presence in at least eight districts and runs a training base, where foreign members of IS, train new recruits.

Hundreds of miles from Nangarhar, IS is attempting to establish a persistent presence in several northern provinces where it has found a fertile ground for attracting militants and recruiting unemployed youths, mostly between the age of 13 and 20.

IS has been able to draw its members from the Pakistani Taliban fighters, former Afghan Taliban, and other militants who “believe that associating with or pledging allegiance” to IS will further their interests, according to the Pentagon report.

Hundreds of militants have joined IS ranks in northern Jouzjan and Sar-e-Pul province where local militant commanders lead IS-affiliate groups in several districts.

Darzab district

Qari Hekmat, an ethnic Uzbek and former Taliban militant who joined IS a year ago, claims to have up to 500 members, including around 50 Uzbek nationals who are affiliated with the Islamic Movement of Uzbekistan (IMU) — previously associated with al-Qaida and Taliban in Afghanistan.

IS and Taliban are reportedly fighting over the control of Darzab district in Jouzjan which they stormed this week from two different directions and besieged scores of government forces. The Taliban has reportedly captured the center of the district while IS militants control the city outskirts.

Afghanistan faces a continuing threat from as many as 20 insurgent and terrorist networks present or operating in the Afghanistan-Pakistan region, including IS, the Pentagon said.

“In areas where the government has limited influence and control, IS attempts to emerge and expand there,” Ateequllah Amarkhail, an analysts and former Army general in Kabul told VOA.

Hit-and-hide strategy

IS has also claimed responsibility for several recent attacks in urban areas, however, with a hit-and-hide strategy that is proving effective. And it is engaging too in more skirmishes with U.S. forces that initially were sent to the country to help Afghan forces halt the spread of Taliban.

Three American service members based in eastern Afghanistan were killed in April during operations targeting IS militants, according to the Pentagon.

“ISIS-K remains a threat to Afghan and regional security, a threat to U.S. and coalition forces, and it retains the ability to conduct high-profile attacks in urban centers,” the Pentagon said. (VOA)

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Satellite sends First Quantum Signal to Earth

This is a big step towards achieving a secure and developed way to encrypt communications because ever-improving computer algorithms can not crack them

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Micius
Micius satellite. wikimedia
  • An orbiting satellite has sent the first entangled pair of photons to Earth
  • It is a big step towards achieving a secure and developed way to encrypt communications
  • They can not be cracked by ever-improving computer algorithms

June 18, 2017: It was reported by scientists today that an orbiting satellite has sent the first entangled pair of photons to Earth. It is a big step towards sending quantum keys from satellites — an approach that has been heralded as a secure and developed way to encrypt communications because ever-improving computer algorithms can not crack them.

A laser on China’s Micius satellite, which was launched last year and is dedicated to researches related to quantum satellite communications, spit out pairs of entangled photons from its position, 500 km above Earth. Then two telescopes on Earth – about 1200 km apart — had 5 minutes each day to look for them as the satellite passed over both telescopes. It was found that paired photons survived the journey through Earth’s atmosphere. They detected 1 entangled pair per second out of the 6 million sent in that time.

So how exactly does all this work?

A quantum key needs to be generated first by two people who are looking to communicate. Then, one person receives one of the entangled photons in the pair, the other person receives the other. When the received photons have measured the photons, they obtain bits of information strung together to create a key that they both have. That key can be used to encrypt and decrypt a message. The users can also share a portion of the key publicly to check if it has been compromised. In case if someone tries to intercept the communication at any point, they would then notice a difference between their strings.

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There is a certain set of problems as well. Caltech’s John Preskill believes even though it is an important proof of concept, the feat doesn’t address one of the biggest problems with quantum communications. Currently, these messages can’t be sent long distances. Photons, using an optical fiber to carry a quantum signal, can only make it about 100 km before the dissipation of the light.

Quantum systems are similar to optical telecommunications here on earth and need repeaters that are able to amplify the message so it can be passed long distances. But amplifying a quantum message in the same way optical ones are done would effectively result in the destruction of the information. That is why satellite-based communication are being eyed by researchers. The reported 500 km from space is an improvement over optical. Quantum signals were measured in another study published today from a satellite 38,000 km away to a single point. But in deploying a global network which would likely be able to combine optical fiber and satellites, the repeater problem still stands.

Preskill has predicted that it is more likely we will first come up with another form of encryption for communication. “There will be other ways of doing classical public key cryptosystems that we won’t know how to break with quantum computers,” he added.

– prepared by Durba Mandal of NewsGram. Twitter: @dubumerang