Military Seeing Different Applications, Wider Use of Aerostats and Airships
On the U.S. border with Mexico near El Paso, Texas, a similar tethered system employs sensors looking for drug smugglers and illegal migrants.
Aerostats and airships are old ideas that are in vogue again in military and homeland security applications. Two programs that used aerostats for perimeter defense in Iraq and Afghanistan are making the transition to an Army program of record.
Meanwhile on Capitol Hill, House members have formed a bipartisan Cargo Airship Caucus to promote the technology’s use in the transportation industry and military.
Airships and aerostats have been around since the dawn of the aviation age. They were employed in both World Wars, mostly for intelligence, reconnaissance and surveillance.
“Traditionally, aerostats have been used for ISR. You throw a camera up there and you get a wider view and longer range,” said Drew Shoemaker, director of the Washington office for Aeros, a small business based in Montebello, California, that develops aerostats and airships.
But the military has used them recently for any application that benefits from being at higher altitude such as communications relay, atmosphere testing and radio frequency jamming, he said.
Aerostats, as the term suggests, are tethered and remain in one place. The lines keeping them in one spot can also serve as communications and power links, as is the case with the joint land attack cruise missile defense elevated netted sensor system (JLENS) currently being deployed at Aberdeen Proving Grounds.
“Aerostats have unmatched persistence,” said Doug Burgess, Raytheon’s JLENS program director. “JLENS stays aloft for 30 days at a time before they have to come down for minor maintenance, and because there are two of them in an orbit, you can stagger the downtime, so you have radar coverage 365 days a year. And because JLENS’ operators are on the ground, you don’t have to worry about crew endurance or those type of issues.”
Raytheon integrated the radar onto the aerostat, which is manufactured by TCOM L.P. of Columbia, Maryland.
JLENS is a strategic missile and air defense system and is not envisioned to change locations often, he said. Smaller aerostats over the last dozen years have been used in more tactical applications, particularly at forward operating bases (FOBs), Burgess noted.
Several vendors such as Aeros, Lockheed Martin and Raytheon responded to urgent needs for aerostats with surveillance capabilities in Iraq and Afghanistan.
Raytheon’s rapid aerostat initial deployment (RAID) program used a 55-foot-long platform to search for insurgents near bases.
“Our RAID program is a good example of using aerostats for ISR applications. Early on in the war, commanders were using unmanned aerial vehicles to protect FOBs. But that was not the best use of that resource, and it didn’t offer persistence. So RAID came about because it made more sense to use an aerostat-borne ISR platform to protect the static FOB, and send the UAVs out into the field to help protect mobile forces,” he said.
Aeros has a suite of five aerostats ranging from the SkyCobra — a small, man-portable platform about five-feet long that can be transported in the back of a Humvee — to the Aeros 3200, which is 127-feet-long and can carry heavier payloads such as radars. The larger the aerostat, the larger the payload and longer the endurance, Shoemaker noted. While they can be lofted with helium, the company also sells field hydrogen generators so there is no logistical tail for the gas.
Rob Smith, Lockheed Martin vice president of C4ISR, said, “The size of the aerostat is pretty important when it comes to what you can do with it.”
Smaller ones are more maneuverable and easier to transfer from location to location, however, they can’t carry large payloads. Larger aerostats can fly higher and carry larger payloads. They can also operate in high winds, whereas smaller aerostats have problems in rough weather.
Lockheed Martin is the prime contractor for the Army’s persistent threat detection system (PTDS), which has been used by the service since 2004 for perimeter surveillance at vulnerable bases. Customs and Border Protection has taken a small number of surplus PTDS aerostats and deployed them in Texas. The pilot program began in 2013, but has been extended.
The knock on aerostats has been survivability. They were employed in more permissive environments in Iraq and Afghanistan. But will they survive where an enemy’s offense or defense is more robust? Aeros has tried to convince customers that they are not a “soft target.”
“Most people don’t understand that aerostats are very different material from a party balloon,” said John Kiehle, Aeros director of communications. “It’s more like a shirt. If it gets a small hole it is not going to rip across the material.”
A bullet hole will not bring it down immediately. “In certain situations, you can put duct tape over the hole and keep it going until a more permanent solution is available to fix it,” he said.
Shoemaker added: “If you are in small arms fire of the aerostat, you are well within detection range.”
Smith shrugged off small arms fire. “We have aerostats that get shot. We have to repair them. We’re able to do that in the field,” he said.
Burgess said, “I can tell you that JLENS does have a robust protective suite, but I really can’t get into greater detail for security reasons,” he added.
A 2012 Government Accountability Office report, “Future Aerostat and Airship Investment Decisions Drive Oversight and Coordination Needs,” said the military had spent $1.3 billion on various aerostat and airship programs that fiscal year alone. It also criticized the lack of coordination on programs between the services.
Smith said the Army and Navy are now combining their two forward operating base surveillance aerostats into one program of record under the Army. The PTDS and the Navy’s persistent ground surveillance system will become the “persistent surveillance system-tethered.”
“From my perspective, the future of the aerostat is bright,” Smith said. Even with the U.S. wars winding down, there is still a huge global demand for persistent surveillance and communications in austere environments, he added.
“I think a lot of our international partners have seen the value of our PTDS system and some of its capabilities,” he said. Many of them are looking to aerostats to employ in the wake of natural disasters. They can quickly be deployed for situational awareness or as temporary communications towers. “They haven’t been used that way in the U.S., but I think it is a potential market going forward,” he added.
Airships, also known as blimps, have also been used in military applications. They were used in coastal patrols during World War II.
Aeros offers the SkyDragon D, a 266-foot aircraft that can carry a one-ton payload. It flies at about 35 to 65 knots per hour, he said. The company is developing a more advanced E model, he said.
There is no reason why a sensor or communication suite cannot be placed on one and flown around, other than they would be highly vulnerable in an anti-access/area denial scenario, said Shoemaker. All of the blimps the company offers are manned. Converting them to robotic systems would be relatively easy, he ventured, although there is no demand for that currently, he said.
Lockheed Martin is developing an unmanned high-altitude airship designed to fly above the jet stream in a fixed position in order to provide surveillance.
Another promising application for airships is cargo supply.
Aeros is developing an airship several times larger than the SkyDragon. The new airship could carry 66 tons. Aeros has a Defense Advanced Research Projects Agency contract to develop a buoyancy management system.
The proposed cargo aircraft would be 550 feet long. The 66-ton payload fills a niche, he said. That’s more than a speedy commercial cargo airliner can transport, but less than a slow cargo ship. The tough problem DARPA has asked Aeros to solve is how to keep the blimp from flying off once that heavy cargo is unloaded.
Airships haven’t traditionally done well as cargo transporters because of ballast exchange requirements, Shoemaker said. For every 100,000 pounds offloaded, another 100,000 pounds has to go on, or the airship would fly away like a toddler’s wayward balloon at a county fair.
A buoyancy management system keeps the airship in one place as it is offloaded. The company has already demonstrated the system and is continuing to develop it with an eye toward introducing the airship in about two years.
Transporting cargo in that 66-ton range to hard-to-reach places is where there might be efficiencies, Kiehle said.
For example, a large piece of mining equipment today must be hauled through several transfer points by rail and then a truck to make it to its final destination in the mountains. An airship could pick it up at the factory and take it directly there.
The technology is promising enough for two congressmen, Rep. Brad Sherman, D-Calif., and Rep. Tom Rooney, R-Fla., to create the Cargo Airship Caucus in the House of Representatives “to encourage the development of these potentially revolutionary aircraft for military and civilian use,” they said in a statement.
Airships can travel at speeds many times faster than ocean-going cargo, they noted. “This could provide the military the capability to carry large cargos to the theaters in which they operate faster than via maritime shipping, while eliminating much of the risk of casualties and disruptions that accompany the need to truck cargo overland after arrival at the sea and air ports,” the statement said.