Situational awareness of potential hostile targets and of friendly forces is considered to be a key component in obtaining and sustaining military superiority over adversaries. Military requires persistent ISR 24 hours a day, seven days a week, 365 days a year, good weather or bad weather.
Near space has long been seen as a promising frontier for intelligence services, but has remained relatively untapped because it is too high for most aeroplanes to operate, and too low for satellites. Until now, the Northrop Grumman RQ-4 Global Hawk, limited to an altitude of about 19km, has been the highest flying drone in use. The RQ-4 Global Hawk provided outstanding surveillance and reconnaissance in Afghanistan and Iraq, though the number of aircraft was insufficient to provide 24/7 coverage.
China in Feb 2018 completed a test of a solar-powered drone capable of flying at extremely high altitudes more than 65 Kms for more than half a day straight. And it can also shoot missiles. In June, China Aerospace Science and Technology Corporation flew a large, solar-powered drone at an altitude of 20,000 metres for 15 hours. The Caihong T4 aircraft, with a wing span of more than 45 metres, could be equipped with radar and communications equipment to provide early warning for Chinese military aircraft, according to state media reports.
The goal of scientists is to develop a durable near space vehicle capable of observing large areas for weeks, months or even years on end. Drones, which would cost just a fraction of what a satellite with comparable abilities would cost, are seen as one of the best ways of reaching that goal. Near space, begins at about 20km above sea level, has until now been regarded a “death zone” for drones – thin air at this altitude makes it hard to generate lift, while extremely low temperatures mean electronic components like batteries are prone to fail. However, a new type of Chinese-developed drone that is undergoing testing appears to have overcome such difficulties, marking a significant step towards China’s ambitions of exploiting near space for purposes of military intelligence.
At a research facility in Inner Mongolia, two drones were attached to a weather balloon and deployed at 30,000 feet and 82,000 feet. Roughly the size of a bat and weighing about as much as a soccer ball, the drones were launched by an electromagnetic pulse sling shot that catapulted them out at 60 mph.
The drones coasted to targets over sixty miles away, automatically adjusting their flight path and sending data back to a ground station. Operating at 12.5 miles above sea level or higher, China’s new drones can break through air defenses, avoid radar detection, and collect valuable intelligence while staying well beyond the range of anti-aircraft fire.
All these developments implies that china has militarized the near space domain with capability to conduct intelligence , drop cluster bombs and shoot enemy missiles while remaining out of the range of most of current ballistic missile defense.
China tests new spy drones in near space ‘death zone’
Each of the drones, which are about the size of a bat, was launched using an electromagnetic pulse that accelerated them from zero to 100km/h within a space about the length of an arm. “It shot out like a bullet,” said Yang Yanchu, lead scientist of the project with the Academy of Optoelectronics at the Chinese Academy of Sciences in Beijing.
The drones then glided towards their targets more than 100km away, adjusting course and altitude in flight without human intervention. On-board sensors beamed data back to a ground station. Significantly, throughout their flights, the drones barely left traces on radar due to their small size. “The goal of our research is to launch hundreds of these drones in one shot, like letting loose a bee or ant colony,” Professor Yang said.
The near space drones being developed by Yang’s team, on the other hand, are projected to cost as little as a few hundred yuan. The drones are small enough to fit in a shoebox and weigh about the same as a soccer ball. They are made with composite materials and are designed to withstand the forces involved in electromagnetic launches.
The wings and body are blended into one flat, tailless fuselage to produce sufficient lift in the thin air. The sensors include a terrain mapping device and electromagnetic signal detector to locate military presence or activities. But the drones would not carry cameras, Yang said, as the transmission of photo or video data over long distances requires bulky antenna unsuitable for near space launches. Some models, including the early prototype tested in last month’s experiment, did not even have a power motor but would drift to their destinations as a glider would.
Yang Chunxin, a professor at the school of aeronautic science and engineering at Beihang University in Beijing, said there were still many challenges in developing high altitude drones. “One of the biggest headaches is the near-vacuum environment, where electric currents can produce a spark. This can lead to shortages and damage electronic equipment,” he said. “This is why high altitude drones are more difficult to build than lower-flying variants. Whether they can play a practical role in military operations remains an open question,” he said.
The high altitude drone is part of a project called the Scientific Experiment System of Near Space, a strategic pilot project of the Chinese Academy of Sciences. Yang Yanchu said China was a latecomer in the race to near space, but the technical progress it had made in recent years was stronger than that of most other countries. “We expect to achieve some major breakthroughs by 2020. They will be stepping stones towards massive applications,” he said.
China plans space-based, solar-powered telecom drones
China is planning to build a space-based, solar-powered drone telecommunications network capable of providing week-long emergency assistance on the ground, according to a state media report today. A research institute affiliated with China Aerospace Science and Industry Corp is developing the project “Feiyun,” which means “flying cloud,” the Global Times reported, citing another report in the Science and Technology Daily.
The network will be based in “near space”, it said, adding the system will be able to provide week-long emergency communications access and likely to go on trial this year. The drones can fly as high as 20 kms above the ground for days – somewhat like a telecommunications satellite – and can undertake remote sensing and relay signals, the report quoted Ma Hongzhong, head of the institute, as saying.
Experts believe the technology can play an important role in aiding rescuers in the aftermath of natural disasters. However, they warned that the severe environment in “near space” – 20-100 kms above sea level – poses a challenge to the UAVs as the thin air inhibits the functioning of fuel- powered aircraft engines. The high-flying drones are easy to maintain and control, and can better provide high-resolution data than satellites.
China’s Solar-Powered Drone Test-Fires Missiles in Near Space
The People’s Liberation Army tested a variant of its CH-4 Rainbow drone for six days, the People’s Daily reported February 12, conducting live-fire trials in extreme weather conditions. “The capacity and variety of its ordnance indicate the CH-4 can conduct effective air strikes on more targets, from longer distances with faster reactions, which lays the foundation for future models and their aligned payloads,” the news outlet adds.
The drone flew for 15 hours 20 kilometers above sea level. While it remained quite far from the Karman Line 100 km above Earth, which represents the bridge between the planet’s atmosphere and outer space, the aircraft was well within “near space,” a non-technical term referring to regions roughly between 18 and 100 km above ground.
The plane is designed to reach altitudes of 65 km and fly for weeks on end, Popular Science reported last June. This was the first time the latest variant of CH-4 has fired weapons, according to Xinhua. Developers at China Aerospace Science and Technology Corporation (CASC) involved in the CH-4 project insist the plane has better “basic performance” than the MQ-1 Predator, Xinhua noted.
The plane can shoot 50-kilogram cluster bombs and an assortment of guided missiles, Asia Times noted. Planes that release weapons at such heights are susceptible to unexpected weather events interfering with a weapon’s flight pattern and are also vulnerable to enemies who might use electronic jamming methods to throw off their guided munitions. According to Asia Times, developers believe they will be able to overcome these obstacles
Near space drones are not immune to ground based threats
Constellations of NSVs hovering over the battlefield are not immune from various ground-based threats. Depending on their altitudes, NSVs could find themselves under attack by high performance interceptor aircraft, for example MiG-25s or MiG-31s. The MiG-31 is can reach altitudes exceeding 67,000 feet before launching radar guided air-to-air missiles. Based on current threats, NSVs at altitudes above 100,000 feet should be relatively immune from current airborne interceptors.
The threat to aircraft like Global Hawk or other aircraft with a relatively high ground speed is real. However, airships and balloons with their near zero ground speed might escape a radar missile attack because they occupy the Doppler notch of the radar preventing tracking at slow speeds.
Other threats do exist in the form of surface-to-air missiles (SAMs). The most lethal threats today are the Russian S-300/400 and Antey-2500 systems, which can engage targets at a range of altitudes and ranges up to 200 km. Jane’s claims several of the missiles used with the operational S-300PMU can reach up to 38 km (98,400 ft).
Even the veteran S-200 (SA-5 Gamon) SAM with its square pair engagement can destroy targets as high as 40 km (131,200 ft) or as far as 300 km. The only protection that NSVs may have is potentially slow relative velocities with respect to the engagement radars. If that velocity is below the minimum velocity cut-off for the radar, the radar cannot track the NSV without a software upgrade.
Another potential threat is from ground-based lasers. Countries like US, Russia and China all have developed laser weapons which have been tested successfully against airborne drones. The next generation laser weapons shall have enough power to disrupt / destroy near space vehicles.