Drones, Future Tech

On the Wings of the Sun? Harnessing Solar Power for Aviation

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Solar Impulse HB-SIA in flight
         It may be a little gangly, but that’s just a sign of growth spurts

A few months back we had a guest post from NavalDrones on the site discussing power needs for drones, focusing on the advantages of batteries compared to today’s combustion engines. Engines are noisy, limiting drones’ stealthiness, and both engines and batteries require refueling/recharging. Thus, lengthy, days-long on-station operations aren’t in the cards for today’s drones. (For example, the Global Hawk can fly continuously for about 28 hours.) A balloon or dirigible could stay aloft for longer periods, but at the expense of maneuverability and speed. For reasons like these, harvesting solar power during flight has captured the attention of many aerospace engineers.

One challenge terrestrial solar-powered vehicles face is the variability of cloud cover. In contrast with its grounded brethren, solar aircraft can often negate a cloudy day by just climbing to a sufficient altitude. However, night is, of course, still an obstacle to long-term flight (or short-term missions not in the daytime).

Nevertheless, with the aid of batteries, today’s solar drones and UAVs can fly non-stop for weeks. The British-US aerospace and defense company QinetiQ developed the drone Zephyr, which stayed aloft for 14 days in July 2010 (h/t to Solar Impulse). Zephyr is not small (12-m [39-ft] wingspan), as one can see in the following video, but it is light—only 27 kg, or ~60 lbs, hence the hand-launch. It reached an altitude of 21.6 km (13.4 mi) on that first flight, boosting its observational capabilities.

 

[youtube http://www.youtube.com/watch?v=ejXaAwsIDoI&w=560&h=315]

Meanwhile, the goals of the Solar Impulse team might be even more audacious: a solar-powered flight around the world in 2015— with a pilot. While it’s perhaps not the most agile, the HB-SIA has already demonstrated 24-hr flight in the past year (with a battery system) from Switzerland to Morocco. And the team has strong backing; it was launched by Bertrand Piccard, who made his name in aviation by circumnavigating the world in the Breitling Orbiter balloon in 1999. Industrial partners include Solvay, Décision, and Bayer MaterialScience, who increased their funding for the project in October [h/t to Flightglobal]. In contrast to Zephyr, HB-SIA’s mass is 1600 kg (3500 lb), about as much as a car, and its 63-m (208-ft) wingspan is about 60% longer than Global Hawk’s – necessary to fit enough solar cells to lift that mass.

So what’s next for solar aircraft? A higher-density storage system than batteries would help by extending flight time. NASA tested a series of solar UAVs in the early ’00s, including Helios, which included an “experimental fuel cell system” that used solar power to regenerate its fuel, storing more energy per pound than batteries. Unfortunately, a crash in 2003 destroyed Helios, but a fuel-cell system remains a possible avenue of advancement. Surface-based lasers can also offer additional illumination for a power boost (also covered in Naval Drones’ post).

Increasing the efficiency of solar cells is another route. Aircraft using solar cells require large wings whose size and shape are driven in part by demands for enough surface area to power the aircraft. These designs limit maneuverability and high-performance (i.e. high-power-demand) attributes like sudden acceleration and changes in direction. Unfortunately, physics principles constrain just how much efficiency can increase. Solar Impulse uses cells with an efficiency of 22.7% — higher than most commercial modules in solar farms. But using only one kind of material in the cell to absorb light means it can harvest only part of the sun’s light, at maximum about 33% (something called the Shockley-Quiesser limit).

Multi-junction cells can capture more slices of the solar spectrum, but in practice their complex assembly limits them to two or three absorber materials. So far they are mostly used in spaceflight, where low weight is a bigger driver than low cost. Still, according to the U.S. National Renewable Energy Lab, the record triple-junction cell (without concentrators, which are another topic) has 35.8% efficiency. So assuming for the sake of estimation that these triple-junction cells weigh about the same per unit surface area (not true at present, according to Solar Impulse), they could reduce wing area by about 37%.  Or, depending on the requirements, they could produce 58% more power.

And power is the big difference between a solar airplane like HB-SIA and a fuel-burner like Global Hawk. HB-SIA’s electric engines produce a maximum of 30 kW (40 hp), whereas Global Hawk’s engine produces at peak 7600 lbs of thrust at a top speed of 357 mph, which works out to 5.4 MW (7200 hp). In part we could say that HB-SIA is more efficient, so it doesn’t need as much power, but on the other hand, Global Hawk can carry a 1360-kg (3000-lb) payload, whereas HB-SIA can carry… one human.

Doing the math shows the upper limit of improving power capture. The sun provides, at midday, 1.3 hp per square meter (of land surface). This handy figure gives you an idea of the maximum solar power wings of a given size could produce (with magical 100% efficient cells). Thus, performance improvements may come from vehicle lightweighting, rather than ratcheting up solar cell efficiency. For example, batteries make up one-quarter the total mass of HB-SIA (400 kg, or 800 lb). And while modern aircraft bodies are increasingly made of carbon fiber (instead of aluminum), companies such as Nanocomp and TE Connectivity are also beginning to manufacture data and power cables made of carbon nanotubes (CNTs) on the scale of miles. CNTs can match the conductivity of copper while saving ~70% of the weight.

Even if it doesn’t displace the combustion-engine in aviation when speed and heavy lift are required, solar power’s promise of nearly indefinite sustained flight is likely to expand its role in aeronautics in the near future.

Dr. Joel Abrahamson holds a PhD in chemical engineering from the Massachusetts Institute of Technology (MIT), where he created nanomaterials for lightweight, high-power electricity generators. He currently researches materials for thin-film, flexible solar cells at the University of Minnesota. The opinions and views expressed in this post are his alone and are presented in his personal capacity. They do not necessarily represent the views of the University of Minnesota.

Future Tech

Foaming at the Abdominal Chest Cavity

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A New Darpa Advance Mass Might Offer Hope for Shipboard Injuries

A DARPA announcement today touted the initial results of the Wounded Statis Sytem. The pre-clinical tests showed injecting a polyurethane polymer foam into the chest cavity of an injured servicemember suffering from internal hemorrhaging could increase stoppage of blood loss 6-fold, and boost chances of survival at three hours post-injury from ~8% to 72%. Removing the foam in a singular solid chunk reportedly takes less than one minute after making a small incision.

While the press release is geared toward ground-combat survival, medical departments in the U.S. fleet would surely be just as interested in having a few of these injections on hand in the event of a singular of mass casualty incident requiring a medical evac for just this reason:

The Department of Defense’s medical system aspires to a standard known as the “Golden Hour” that dictates that troops wounded on the battlefield are moved to advanced-level treatment facilities within the first 60 minutes of being wounded. In advance of transport, initial battlefield medical care administered by first responders is often critical to injured servicemembers’ survival. In the case of internal abdominal injuries and resulting internal hemorrhaging, however, there is currently little that can be done to stanch bleeding before the patients reach necessary treatment facilities; internal wounds cannot be compressed the same way external wounds can, and tourniquets or hemostatic dressings are unsuitable because of the need to visualize the injury. The resulting blood loss often leads to death from what would otherwise be potentially survivable wounds.

 

DARPA launched its Wound Stasis System program in 2010 in the hopes of finding a technological solution that could mitigate damage from internal hemorrhaging. The program sought to identify a biological mechanism that could discriminate between wounded and healthy tissue, and bind to the wounded tissue. As the program evolved, an even better solution emerged: Wound Stasis performer Arsenal Medical, Inc. developed a foam-based product that can control hemorrhaging in a patient’s intact abdominal cavity for at least one hour, based on swine injury model data. The foam is designed to be administered on the battlefield by a combat medic, and is easily removable by doctors during surgical intervention at an appropriate facility, as demonstrated in testing.   

Up next is clinical testing, and before long, someone you know may have an interesting memento bearing the faint impression of their internal organs.

 

LT Scott Cheney-Peters is a surface warfare officer in the U.S. Navy Reserve and the former editor of Surface Warfare magazine. He is the founding director of the Center for International Maritime Security and holds a master’s degree in National Security and Strategic Studies from the U.S. Naval War College.

 

The opinions and views expressed in this post are his alone and are presented in his personal capacity. They do not necessarily represent the views of U.S. Department of Defense or the U.S. Navy. 

 

Future Tech

The Royal Navy’s Type 26

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Concept image of the Type 26 Global Combat Ship.

In 2020, the first of the new Royal Navy frigates – the Type 26 Global Combat Ships – will enter service, replacing the current fleet of 13 Type 23s. The ships are designed to be versatile and adaptable, making them useful within a broad range of strategic, operational, and tactical circumstances.

The First Sea Lord, Admiral Sir Mark Stanhope, said of the ships: “The T26 Global Combat Ship (GCS) will be a multi-mission warship designed for joint and multinational operations across the full spectrum of warfare, including complex combat operations, maritime security operations such as counter-piracy, as well as humanitarian and disaster relief work around the world… It will be capable of operating independently for significant periods or as part of a task group and will play a major role in the defence of this country for many years”1.

The Minister for Defence Equipment, Support and Technology, Peter Luff, also said of the ships: “The Type 26 Global Combat Ship will be the backbone of the Royal Navy for decades to come. It is designed to be adaptable and easily upgraded, reacting to threats as they change”2.

As individual units, the Type 26 frigates will no doubt be potent warships. The intended fleet of 13 Type 26 frigates do indeed represent a flexible and adaptable platform, ideal for ever-changing technological, diplomatic, strategic, operational, and tactical contexts. The proposed armament bears this out:

  •          Anti-air missiles
  •          Anti-ship, submarine and land-attack missiles
  •          Anti-submarine torpedoes
  •          Guns
  •          A hanger to accommodate a Merlin or Wildcat Helicopter (and underwater, surface and air drones)
  •          Additional accommodation for Royal Marine detachments

The frigates is a concept, not just a particular type of ship. It is one that emphasizes wide-ranging utility, speed and cost-effectiveness. These fundamental functions have barely changed throughout the Royal Navy’s history. This quote from blogger Gabriele Molinelli posted on the Defence Management website supports this notion, “The Type 26 is going to reverse the Type 45 situation by adopting proven, legacy solutions for 80 percent of the design, and only innovating in the remaining 20 percent. This is an effort to stay within budget and get a minimum of 13 hulls into the water. Using existing and proven solutions whenever possible does not make the Type 26 obsolete. The ship will still be a great leap forwards in capability as it will be, effectively, the first true multi-mission ship of the “age of the drones” for the Royal Navy.’3. Considering the flexible nature of these warships and their obvious utility, they are understandably an exciting prospect for the Royal Navy and will represent the backbone of the fleet of the future.

But my concern is with numbers, concerns also felt at the highest levels of the military. Recent comments made by Chief of Defence Staff, General Sir David Richards, at an Oxford University talk revealed one of his biggest concerns in relation to Britain’s modern armed forces is the number of frigates and destroyers the Navy has4. We often hear talk of how advanced and flexible modern warships are, however, no matter how advanced a warship may be, numbers are of critical importance – there is quality in quantity – for a nation that wishes to retain global influence. With the Royal Navy due to commission two 65,000 tonne Queen Elizabeth-class aircraft carriers in 2016 and 2018, there is a chance of a distorted allocation of resources from the wider surface fleet.

Concept image of the Queen Elizabeth aircraft carrier.

A current American carrier battle-group is at a minimum often comprised of, but not limited to, the carrier itself, two guided missile cruisers, 1-2 ASW destroyers or frigates, and up to two attack submarines. To lose one of the new carriers would be unthinkable, even more so because the loss of one would halve Britain’s seaborne strike capacity (or all of it if one of the carriers is sold to the French!). It would thus be fair to assume that the Royal Navy will need levels of protection similar to that which the American Navy affords their carriers when on deployment (additional protection in time of conflict or crisis). When you consider that there will be only 6 destroyers and 13 frigates (Type 23, then 26) for the foreseeable future, factoring in periods in re-fit, ships returning from operations and the sheer importance of these assets, deployment of just one carrier would seriously hamper the Royal Navy’s ability to meet its wider global commitments. Consider the analogy of a football team; a side consisting of only a few world-class players will still struggle to compete against a full team of average players; unable to respond to every manoeuvre on the pitch. If a warship is thousands of miles from a crisis, technological superiority counts for nothing. It is all well and good having an adaptable and flexible warship, but a flexible fleet is vital.

Limited numbers also means that should any ships be lost during a crisis, regenerating forces to replace those loses becomes problematic. We only need to recall the loses sustained during the Falklands; the modern Royal Naval fleet could not sustain such damage. With procurement timelines as they are (many sailors who serve on the new carriers and frigates were not yet born when they were first conceived), it is important the service fights tooth and nail to get its full allocation of 26s in the first round; the MOD and the Navy must learn from the Type 45 fiasco, where construction delays led to spiraling costs and a halving of the initial building programme of 12 ships. Unlike days of yore, we can’t acquire several new warships after an afternoon sparing with the French.

In addition to the routine but important ‘kinetic’ tasks carried out by Royal Navy frigates and highlighted by Admiral Stanhope in the quote above, maintaining influence through ‘showing the flag’ missions remains of critical importance. For a nation disillusioned with liberal interventionist principles, with little thirst for future foreign policy entanglements and yet a desire, and duty, to influence events abroad, soft-power should be of primary consideration for British policy-makers; something the Navy can uniquely provide. The Type 26 will be a valuable asset for providing such diplomatic leverage.

Unlike the Type 45, the Royal Navy must secure its full allocation of Type 26 warships to ensure Britain has the ability to shape events abroad, both in times of peace and conflict. Britain must not allow the fleet to shrink any further, otherwise London must accept its global influence will continue to diminish.

 

Simon Williams received a BA Hons in Contemporary History from the University of Leicester in 2008. In early 2011 he was awarded an MA in War Studies from King’s College London. His postgraduate dissertation was entitled The Second Boer War 1899-­1902: A Triumph of British Sea Power. He organised the Navy is the Nation Conference, which was held in April 2012 in Portsmouth, UK. The aim of this event was to explore the impact of the Royal Navy on British culture and national identity.

 

[1] ‘Design unveiled of Royal Navy’s future warships’ 20 Aug 2012

http://www.mod.uk/DefenceInternet/DefenceNews/EquipmentAndLogistics/DesignUnveiledOfRoyalNavysFutureWarships.htm accessed on 20/11/2012

[2] ‘Design unveiled of Royal Navy’s future warships’ 20 Aug 2012

http://www.mod.uk/DefenceInternet/DefenceNews/EquipmentAndLogistics/DesignUnveiledOfRoyalNavysFutureWarships.htm accessed on 20/11/2012

 

[3] Gabriele Molinelli ‘The Type 26 will usher in the age of the drones for the Royal Navy’ 21 August 2012 http://www.defencemanagement.com/feature_story.asp?id=20530 accessed on 24/11/2012

[4] Kirkup, J. ‘Defence chief General Sir David Richards attacks Armed Forces cuts’ 14 Nov 2012 http://www.telegraph.co.uk/news/uknews/defence/9679243/Defence-chief-General-Sir-David-Richards-attacks-Armed-Forces-cuts.html accessed on 14/11/2012

Strategic Outlook

More Than Words: Australia-Indonesia Strategic Relations

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Australia-Indonesia Joint Patrol

By Natalie Sambhi

Australia’s leaders from both sides of politics have been paying greater attention to Indonesia; there’s been more official engagement, as well as new diplomatic and defence initiatives in the past year. And we’ve been describing Indonesia, as our Defence Minister has during his Jakarta visit last week, in more important terms like ‘strategic partner’.

But it looks like that there’s some way to go before ‘strategic partner’ becomes more than just a term of endearment. If we look at the 2009 Defence White Paper (for the time being still the government’s defence strategic policy), we find a curious ambivalence towards Indonesia. According to the White Paper, we have a ‘fundamental interest in controlling the air and sea approaches to our continent’ (paragraph 5.5). But in reference to a secure immediate neighbourhood, it says we should prevent or mitigate ‘nearby states [from] develop[ing] the capacity to undertake sustained military operations within our approaches’ (paragraph 5.8). There’s a contradiction there; as Hugh White notes in his Security Challenges essay (PDF), it may very well be those same capabilities Indonesia requires to ensure its own security in its northern approaches that could be instrumental in both Indonesia and Australia securing their strategic interests.

In short, the language of the 2009 Defence White Paper simply doesn’t match our statements of Indonesia as a strategic partner. And although there are asymmetries in our capabilities, a strategic partnership means allowing and encouraging Indonesia to grow in a way that complements our strengths and compensates for our weaknesses so that we can work together; if Indonesia is to play an important role in our strategic future, then actively mitigating or preventing particular capacities isn’t the way to go.

This position might have been justifiable in white papers released after Konfrontasi (during which Australia and Indonesia found themselves on opposing sides of the conflict) or shortly after the 1999 East Timor intervention, during which relations with Indonesia were more fractious and the military (TNI) was only just exiting Indonesian politics. But times have changed.

On the domestic front, Indonesia is a much more stable, democratic state. In economic terms Indonesia is now starting to flex its muscle. Its GDP grew by an annualised 6.4% in the second quarter of 2012, its economy is now larger than Australia’s in purchasing power parity terms, and its middle class is larger than Australia’s population. TNI no longer exerts the same level of direct influence on politics and there’s a greater commitment to crack down on corruption. In regional terms, Indonesia enjoys greater clout and has attracted the attention of international partners such as the United States, the United Kingdom and China. Recent participation in RAAF-hosted Exercise Pitch Black 2012 (see image) shows Indonesia’s willingness to engage with partners such as Australia by sending their newest aircraft to build person-to-person ties and to dispel doubt as to their military intentions.

Barring a significant change in Indonesia’s trajectory of growth and domestic transformation, this is likely to become an enduring externality for Australian policy. Nonetheless, it’s worth thinking through the factors that could cause problems for Indonesia down the track: these include slowed growth, a change of leadership to one that is more internally focused, and deteriorating domestic stability. The question is whether these eventualities would adversely affect the Indonesia–Australia relationship in the long-term or would merely slow the engagement temporarily. That said, the relationship between Indonesia and Australia seems to be on an unstoppable path of growth. A nationalist President of Indonesia would be a concern but wouldn’t necessarily require a radical rewrite of Indonesia’s place in our strategic interests. In any case, as one RSIS commentator notes (PDF), nationalism at present is not a call for concern.

Likewise, Australia can cause ructions over livestock, people smuggling or the incarcerations of Australians, but the fundamental shared interests should ultimately prevail. In terms of shifting regional geopolitics, Australia and Indonesia might have more in common in the future Asia as we both navigate China’s rise and the US rebalance. A Defence Cooperation Agreement signed recently between Australia and Indonesia provides a framework for practical cooperation on common security matters, but it’s time to work together as well on bigger, long-term strategic questions about the region.

Indonesia demands different handling in the next Defence White Paper, which is as much an opportunity as the Asian Century White Paper to correctly recognise Indonesia’s place. Language matters, because it sends a strong signal to both the Australian and Indonesian people about how we see each country’s place in the region. And while the majority of everyday people in each country may not delve into the pages of the White Paper, setting the tone for political interaction as well as doing away with ambiguous language remains important. Hopefully the 2013 White Paper will articulate Indonesia’s importance and elevate it to partner status rather than a subordinate. That sort of constructive language would remove the disparity between language of the 2009 White Paper and the increasing importance of close defence relations and alignment of strategic interests between the two nations.

The White Paper might start by recognising the complementarity across our capabilities, strengths and weaknesses. Or it could, as Hugh White suggests, create a heading for Indonesia separate from the rest of ‘our neighbourhood’ to recognise the important role it plays in our strategic environment. While there’s no prospect of an alliance between our countries in the foreseeable future, it would provide a more robust basis in our national policy to give a broader context to initiatives such as the recently signed Defence Cooperation Agreement.

Defence Minister Smith assures us that he is ‘committed to regular, open and transparent discussions with Indonesia on the development of Australia’s 2013 Defence White Paper’. Let’s hope the final cut pays them the same due respect.

Image courtesy of Department of Defence.

Natalie Sambhi is an analyst at the Australian Strategic Policy Institute, editor of The Strategist and co-editor of Security Scholar. She is also a Hedley Bull Scholar and graduate of the Australian National University.

This article appeared in its original form and was cross-posted by permission from The Security Scholar.

Fostering the Discussion on Securing the Seas.