30 octobre 2024 | International, Terrestre
North Korean troops likely to join Ukraine war, Pentagon says
Some North Korean soldiers heading toward Kursk have received Russian uniforms and equipment.
14 août 2018 | International, Aérospatial
New Spy Drone Flies Non-Stop for a Month
Airbus's Zephyr solar-powered drone flew for 25 days straight during a test-flight over Yuma, Arizona beginning on July 11, 2018. The flight represented a record for aircraft endurance, breaking the previous 14-day record also set by a Zephyr back in 2015.
The long flight has big implications for military surveillance. Drones like Zephyr could loiter over a low-intensity battlefield far longer than current drones can do. The latest high-endurance Reaper drone maxes out at 40 hours in the air.
The propeller-driven Zephyr belongs to a class of aircraft known as “high-altitude pseudo-satellites,” or HAPs. Flying as high as 70,000 feet for weeks or even months at a time, HAPs perform many of the same missions that low-orbiting satellites do.
“The main HAP applications are in telecommunications and remote sensing, both civilian and military,” Flavio Araripe d'Oliveira, Francisco Cristovão Lourenço de Melo and Tessaleno Campos Devezas wrote in a 2016 paper.
Compared to comms satellites, HAPs have the advantages of lower latency and the ability to land for maintenance or reconfiguration, d'Oliveira, de Melo and Devezas explained. For surveillance missions, HAPs unlike satellites can linger over a particular area and could produce images with better resolution, since they fly lower than satellites do.
HAPs could be more vulnerable to enemy defenses, however. Where satellites orbit many hundreds of miles over Earth, beyond the reach of most conventional weaponry, Zephyr — so far the only HAP undergoing realistic testing — attained a maximum altitude of 70,000 feet, well under the ceiling for modern air-defense missile systems such as the Russian S-300.
Also, the drone is slow, with a cruising speed of just 20 miles per hour.
Zephyr and similar pseudo-satellite drones could be best-suited for operations over lightly-defended territory. In 2016, the U.K. ministry of defense bought three Zephyrs for around $6 million apiece in order to evaluate them for potential use by the military and other government agencies.
“Zephyr is a cutting edge, record-breaking piece of kit that will be capable of gathering constant, reliable information over vast geographical areas at a much greater level of detail than ever before,” then-defense secretary Michael Fallon said in a statement.
Airbus is still refining Zephyr, in particular its power-consumption. During daytime, the lightly-built solar-powered drone — which features an 82-foot wingspan and yet weighs just 165 pounds — can fly as high as 70,000 feet while also charging its batteries.
After the sun goes down, Zephyr runs on batteries ... and slowly loses altitude. During the record-setting Yuma flight, the drone dipped as low as 50,000 feet at night.
The challenge for Airbus is to balance weight and power-consumption to produce the optimal flight profile for a particular task. “You have to find the right equation between flying altitude plus battery life, maintaining this or that power,” said Alain Dupiech, an Airbus spokesperson.
It's unclear just how long Zephyr could stay aloft under the right conditions. The drone's lithium-ion battery eventually dies, forcing it to land for maintenance. But battery technology is advancing rapidly, driven in part by consumer demand for electric cars, d'Oliveira, de Melo and Devezas wrote.
In the short term, a maximum endurance of several months is not inconceivable. But longer flights might not be particularly useful for surveillance and comms missions, Dupiech said. “At this stage, most of those missions are not calling for a year and half up there.”
Airbus has scheduled Zephyr's next test flight for October in western Australia.
http://warisboring.com/new-spy-drone-flies-non-stop-for-a-month/
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US Space Force sorts through industry ideas to boost satellite sensors
Space Systems Command is sifting through an influx of ideas from companies to determine how they might shape future space domain awareness requirements.
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11 mai 2020 | International, Aérospatial
Greece and Israel deal spotlight leasing model for military UAVs
By: Seth J. Frantzman JERUSALEM — Greece's Hellenic Ministry of National Defense will lease unmanned aerial vehicles from Israel, in a deal that offers up an alternative to pricey acquisitions amid budgetary constraints. The Heron long endurance drones, manufactured by IAI, will be used for border defense under a leasing model that IAI said may grow more appealing with the new pandemic dynamics that countries face. Executive vice president and general manager of AIA's Military Aircraft Group, Moshe Levy, praised the new deal with Greece as "yet another example of the successful leasing model promoted by IAI in many parts of the world.” Greece will have an option to purchase the Herons after the lease term ends in three years. The Heron is one of the most popular of IAI UAVs, which have collectively seen 1.8 million operation flight hours with over fifty partners worldwide, the company says. IAI could not comment on the overall value of the lease agreement. The twin-boom Heron comes in several models, including the smaller tactical Heron unveiled in 2019, and the longer endurance Heron MK II unveiled this year. With development roots in the early 1990s, the larger Heron UAVs have been active with the Israeli Air Force since the early 2000s and been used by countries such as Turkey, India, Australia, Singapore, Azerbaijan and Germany. Greece and Israel have become closer partners in defense and maritime relations over the last decade. The Heron lease for Greece will include a unique maritime configuration with sensors and communications designed to monitor the extensive water borders of Greece. Levy says that Israel sees this maritime security model as an important market. The coronavirus pandemic has made countries increasingly aware of the need to control borders, Levy said, creating newfound demand for large surveillance UAVs like Heron. The flexibility of lease agreements with operations outsourced allows customers to get the data they need to secure borders, but without the overhead of ownership or the large logistical footprint. Levy points to previous lease agreements, such as a $600 deal in 2018 with Airbus and Germany to lease Heron TPs. Those leased Herons saw more than 30,000 hours of flight time in Afghanistan. “We supply the birds [UAVs] and the maintenance and another company takes the bird and puts it in the air," Levy said. “The customer just does the mission and get the data.” Lease agreements were signed with Australia and Canada over the last decade as well. “We assume after coronavirus, budgets will shrink and people will look for different solutions and things that are simpler, and less costly, so the lease option can meet the needs,” Levy said, particularly for states that want only a few large UAVs, without the overhead of operations and training. Israel was the world's largest exporter of drones through 2013, bringing in more than $4.6 billion in sales between 2006 and 2012 and selling UAVs to more than two dozen countries. However, China has rapidly increased its military drone sales to become one of the largest exporters last year. At the same time, UAV sales are increasingly a smaller percent of Israel's overall defense exports, illustrating a changing market. “We have to adapt and manage our portfolio. We are offering a wide variety of platforms,” says Levy. The new Heron MK II, with a wingspan of 16 meters, weighs 1,300 kg and can reach an altitude of 35,000 feet for up to 45 hours. It has a new more powerful Rotax 915 iS engine, says Levy, who pointed to increased demnd for versatile vertical-takeoff and landing (VTOL) options or UAVs that require only a short runway. https://www.defensenews.com/global/europe/2020/05/08/greece-and-israel-deal-spotlight-leasing-model-for-military-uavs/