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Article updates (July 12/10)
The rise of modern terrorism, sharply increasing costs to recruit and equip professional soldiers, and issues of energy security, are forcing 2 imperatives on modern armies. Modern militaries need to be able to watch wide areas for very long periods of time. Not just minutes, or even hours any more, but days if necessary. The second imperative, beyond the need for that persistent, unblinking stare up high in the air, is the need to field aerial platforms whose operating costs won’t bankrupt the budget.
These pressures are forcing an eventual convergence toward very long endurance, low operating cost platforms. Many are lighter-than-air vehicles or hybrid airships, whose technologies have advanced to make them safe and militarily useful again. On the ground near military bases, Raytheon’s RAID program fielded aerostats, and then surveillance towers. Lockheed Martin has also fielded tethered aerostats: TARS along the USA’s southern border, and PTDS aerostats on the front lines. The same trend can be observed in places like Thailand and in Israel; and Israeli experience has led to export orders in Mexico and India. At a higher technical level, Raytheon’s large JLENS aerostats are set to play a major role in American aerial awareness and cruise missile defense, and its ground and air scanning ISIS radar was developed under a DARPA project, to pair with Lockheed Martin’s fully mobile High Altitude Airship.
The Army’s LEMV project fits in between RAID and HAA/ISIS, in order to give that service mobile, affordable, very long term surveillance in uncontested airspace. Its technologies may also wind up playing a role in other projects…
- The Army’s LEMV [NEW]
- Surveillance Options, and the Rise of the LTAs
- Contracts & Key Events
- Additional Readings [updated]
The Army’s LEMV
The LEMV isn’t really a blimp. Technically, it’s something called a hybrid airship, which gains lift from 3 different sources. One is the same aerostatic lift that a blimp gets, from the same onboard helium. Another is aerodynamic lift, now that composite materials allow rigid, shaped hull designs that aren’t just balloons. The final element is vectored thrust from 4 diesel engines and vector vanes, which builds on aerodynamic lift.
That combination is very helpful, because it can eliminate one of the biggest problems with blimps: sensitive equilibrium. A conventional blimp must have more buoyancy than payload, in order to fly. If it has too much buoyancy, however, it becomes very difficult to land. That isn’t a big problem if the mission is fly over a local football stadium, but if you’ve just offloaded many tons of cargo, or finished up a 3-week mission and burned about 18,000 pounds of fuel, it’s a different story. For a blimp, the problem could be solved with ballast, but it’s an inefficient approach that creates its own hazards and difficulties. A hybrid airship has more options, hence more flexibility. Ongoing research into technologies like hovercraft/suck-down skirts would offer even more flexibility on the ground.
Northrop Grumman Director of Airship Programs Alan Metzger told The Engineer magazine that he expects LEMV to have about 3 weeks endurance, carry 2500 pounds of payload, and travel at speeds between 30 – 80 knots/ He added that:
“When you do the maths on that you’re talking about $20,000 to keep the vehicle in the air for three weeks. It’s vastly cheaper to operate than many conventional aircraft today…. Some of the characteristics of our vehicle allow you to make trades between how long you’d like to stay in the air and how much cargo you’d like to carry. We have the ability to trade 23 days to go 1000 miles and carry 15, 20, 30,000 pounds…. We’re green, we use a quarter of the fuel as the same payload of cargo aircraft… there are fewer moving parts. there’s less maintenance…. Now we have the opportunity to show that a vehicle of this class and size can carry the required payloads, create the endurance and persistent surveillance that war-fighters are looking for.”
Fortunately, these 3 week missions won’t require a crew, but deploying to the mission zone at home or abroad means flight through civil airspace. For now, that means manned flight options, in addition to remote piloting or autonomous modes. Piloting it has been described as being closer to operating a ship than to flying a plane, and winds above 23 mph or so will be a challenge for the design team to tackle.
Their team crosses the Atlantic, and includes Northrop Grumman as lead, plus:
- Hybrid Air Vehicles Ltd. in Bedford, UK (HAV304 airship platform)
- Textron subsidiary AAI Corp. in Hunt Valley, MD (Makes the US Army’s OneSystem UAV/surveillance aircraft control & information distribution stations)
- DERA spinout Blue Bear Systems Research in Bedford, UK (flight control algorithms)
- ILC Dover in Kent County, DE (Airship manufacturer and designer)
- SAIC in McLean, VA
- Warwick Mills in New Ipswich, NH (Fabrics engineering)
Surveillance Options, and the Rise of the LTAs
There are already many ways to perform aerial surveillance. Fighter aircraft can and do equip advanced surveillance and targeting pods. In Iraq, they often found themselves used in overwatch roles for short periods of time, and piled up a considerable number of flight hours doing these “non-traditional missions.” At $10-20 thousand dollars per hour operating cost, however, plus an additional $10 thousand or so per flight hour in recapitalization costs, fighters are not an affordable option.
Scout helicopters are more affordable, and can intervene like fighters if weapons are needed, but they are noisy and vulnerable, have very low endurance, and are still not cheap to operate.
UAVs can offer much lower operating and recapitalization costs than fighters or scout helicopters, and larger models are able to stay on station for 20-36 hours. That’s still a limited period of time, however, and their payloads are likewise limited by weight and aerodynamic restrictions. Those limitations have also traditionally meant limited fields of view, though heavy UAVs like the MQ-9 Reaper are beginning to field products like ARGUS-IS and Gorgon Stare to expand their view. At present, UAVs also crash much more often than manned aircraft.
Manned propeller planes are a useful intermediate option between fighters and UAVs, with more carrying capacity, a much wider human field of view, and much better endurance and operating costs than fighters or helicopters. Iraq has used, and even armed, Cessna 208B Caravans for this role. HawkerBeechcraft’s MC-12 King Air twin-turboprops are quietly becoming stars of the Iraq and Afghan wars.
Integrating these 4 options with precision artillery fire, via organizational structures like the USA’s Project ODIN, has paid big dividends on the front lines.
So where do hybrid airships fit in?
The answer is tied to what they do best. They can operate from any small forward base, like a helicopter. Their operating cost is likely to be better than any other surveillance option, and so is their endurance, which can be measured in weeks. Modern airships have long since stopped using hydrogen, and the growth of composite structures gives them very interesting design options they’ve never had before. Unlike aerostats, they will be mobile rather than fixed. Speed will be less than any aircraft or even UAV option, however, so airships will perform best covering specific high-value areas, or assigned stations.
In that role, they can serve as steady communications relays, for instance, ensuring the groups of soldiers in mountainous areas never lose contact with one another, even if they don’t have direct line of sight to each other. They can track important convoys, key roadways, or other key infrastructure as semi-permanent overwatch escorts, monitor an urban area of interest to prep for major battles or enforce security, or focus on shutting down border chokepoints.
By restricting its focus to very achievable goals, the US Army will be funding a system whose sensors and surveillance equipment go well beyond RAID’s proven gear, without being anywhere near the bleeding edge of technology like HAA/ISIS. Within the Army, it will provide a level of overwatch that goes well beyond its top-end MQ-1C SkyWarrior UAVs, offering heavy surveillance payload options like the USAF’s MQ-9 Reaper, but with much longer endurance. Finally, the Army’s move will fund operational hybrid airships, proving out the concept, and growing the industrial base for obvious future LTA projects like cargo lift.
Contracts & Key Events
June 14/10: Northrop Grumman announces a $517 million contract to develop up to 3 LEMV (long-endurance multi-intelligence vehicle) hybrid airships for the US Army Space and Missile Defense Command/Army Forces Strategic Command. The 3 LEMVs will be designed, developed and test with their surveillance payloads within an aggressive 18-month time frame, then transported to the front lines for assessment and use by the military.
The LEMVs are not small airships, and are described as “just larger than the length of a football field” (about 100m). per the solicitation, they’ll have to sustain altitudes of 20,000 feet for a 3-week period, while carrying up to 2,500 pounds of sensors and communications equipment. Northrop Grumman designed their system to integrate into the Army’s existing common ground station command centers, and equipment used by ground troops in forward operating bases. See also: WIRED Danger Room.
Feb 11/10: U.S. Army Space and Missile Defense Command issues solicitation #W91260-10-R-0005 for a “Long Endurance Multi-Intelligence Vehicle.” The solicitation is amended several times, but its core is issued under Section 845 of the National Defense Authorization Act (NDAA) for Fiscal Year (FY) 1994, Public Law 103-160, as amended (Title 10 United States Code (USC) Section 2371). That long citation exempts the purchase from many US federal acquisition regulations and processes, with the intent of fostering the participation of companies that do not traditionally do business with the Department of Defense.
“The anticipated LEMV OTA will be for a (5) year technology demonstration inclusive of the fabrication of a LEMV airship, integration of payload and ancillary systems, test, and support for (5) years. The schedule requires performance testing within 18 months followed by additional test and demonstration conducted in Afghanistan over the remaining OTA term. The basic performance requirements for the LEMV airship include: optionally unmanned; 3 week endurance; 2500 pound payload capability; operating altitude of 20,000 feet above mean sea level, 16 kilowatts of payload power; multi-intelligence capable; supportable from austere locations; 80 knot dash speed and 20 knot station keep speed.”
Dec 30/09: Flight International reports on the US Army’s interest in a hybrid airship it calls LEMV (long-endurance multi-intelligence vehicle). Though much smaller than a HULA, LEMV would be a hybrid buoyancy/lift craft that would likely end up proving out associated technologies. The US Army aims to test the airship’s performance during the first 18 months, and deploy the airship into Afghanistan as a super long-endurance surveillance platform.
Space and Missile Defense Command will reportedly issue an RFP on Jan 29/10 (actual date: Feb 11/10), and an acquisition notice posted on Dec 29/09 asks for an “optionally manned” craft that can fly for up to 3 weeks, carry multiple intelligence payloads weighing up to 2,500 pounds/ 1,134 kg, provide 16kW onboard power, and reach speeds up to 80 knots/ 148km/h.
- US Army Stand To! (July 21/09) – Long Endurance Multi-Intelligence Vehicle
- DARPA – Next Generation Aerostructures [PDF]
- Hybrid Air Vehicles – Products: SkyCat Overview. The SkyCat would be an amphibian, thanks to its hovercraft skirt.
- The Engineer magazine (July 12/10) – Meet LEMV: the first of a new generation of advanced military airship
The Lighter than Air Trend
- DID – Walrus/HULA Heavy-Lift Blimps Rise, Fall… Rise? If hybrid airship technology proves out, maybe. SkyCat definitely has its eyes on airships of that size – and they’re not alone.
- DID (July 1/09) – Canada Ordering Aerostats and Towers
- DID – Boeing’s Skyhook Shot: Redefining the Aerial Heavy-Lift Market? Their Skyhook 40 partnership aims to create a commercial airship in the 30-ton cargo class.
- DID (March 2/07) – Return of the Navy Blimps?
- DID (March 17/06) – Energy Conservation Moving Up Pentagon’s Agenda. The Army Corps of Engineers forecasts that fuel availability and cost may become an important constraint on future operations. That has implications for transport and aviation.
- DID (July 6/05) – USAF Looking at “Near-Space” Blimps. Interest takes the next step via a positive formal report to the USAF.
- DID (Apr 26/05) – USN, DARPA See Blimps & HULAs Rising
- DID – DID – Task Force ODIN: In the Kingdom of the Blind…