Huge US command-&-control airship gets quantum optics
Fibre-fat pipage for 'Blue Devil' aerial computer warship
Pentagon boffinry powerhouse DARPA has announced plans to fit a giant new US military command and control airship - known as "Blue Devil Block 2" - with through-the-air optical links offering bandwidth normally achievable only by fibre cables. This is to be done using newly-applied technology developed in the 1990s for use in astronomical telescopes.
Soon to be doing 'God's work' alongside Blue Devil Block 1 (see Bootnote below.)
We learn from a federal no-competitive-tender announcement issued last week that the Blue Devil airship under development by military intelligence contractor MAV6 is to be fitted with "up to two Free-space Optical Experimental Network Experiment (FOENEX)" systems.
FOENEX is a system which uses line-of-sight lasers to communicate between aircraft and ground stations, which on the face of it is nothing new. However FOENEX achieves much, much better reception and transmission fidelity, almost as good as if the laser light were travelling along an optical fibre rather than through miles of turbulent air and clouds: so good that single photons can be picked up, potentially allowing for through-the-air quantum cryptography, if desired, as well as massively increased bandwidth in normal fibre style.
FOENEX achieves this by using adaptive-optics technology, a trick originally developed in the 1990s for use in high-powered astronomical telescopes to eliminate distortions caused by viewing through the Earth's atmosphere. Adaptive-optic telescope mirrors measure distortion of an incoming photon stream very fast and use piezoelectric actuators to warp the shape of the mirror to tolerances of one fifty-thousandth of a millimetre every millisecond. This lets the mirror produce an image approaching theoretical perfect performance - the sort of performance you need to start dealing in in single quanta/photons, the sort of performance you normally need fibres for. The Reg has previously reported  on the project which developed FOENEX, under the auspices of US air force lab boffins.
The Blue Devil Block 2 is perhaps an ideal candidate for deployment of the fibreless optical pipes into the field, as it is intended to handle enormous amounts of information. It's billed as a "C4ISR aerial fusion node", C4ISR standing for "Command, Control, Computers, Communication, Intelligence, Surveillance and Reconnaissance" - the latest in a long strong of military acronyms which long ago replaced the simple phrase Command and Control. Like many modern-day airship projects it's intended to exploit a dirigible's long endurance by using the ship to sweep large areas of ground with high-resolution sensors including man-tracker radar and infrared video surveillance: but even more than this the Blue Devil is expected to act as an airborne command and communications netywork hub tying together a fleet of Reaper drones and other aircraft all deploying so-called "wide-angle" spy payloads, which look at many places at once (so minimising the so-called "drinking straw" problem where ordinary single-lens optics can look at only a small area in any detail.
For those who might be more interested in the ship than the payload, the Blue Devil is no less than 370 feet long (ie roughly of a size to fill up the interior of the Notre Dame cathedral in Paris) and boasts diesel-electric propulsion for flights lasting up to 9 days at altitudes of 20,000 feet - and furnishing up to 96 kilowatts of power for the payload hardware. It's a simple blimp in construction, using internal envelope pressure rather than any rigid structure to maintain its shape - though it's very large for a blimp, with volume of just over 1.3 million cubic feet, almost seven times as much as today's Goodyear ships. (The largest non-rigids ever built were the US Navy's 1950s ZPG-3Ws, which carried a large distant early warning radar inside their envelopes, at 1.5 million feet3). The ship, as opposed to the more-expensive payload, is provided by TCOM of North Carolina.
Not unmanned - Optionally manned
The Blue Devil is "optionally manned", able to fly with a crew if required (as when transiting civil-controlled airspace, for legal reasons) or without (as will probably be the case on most operational missions). The big ship is now inflated with helium and floating moored inside MAV6's North Carolina hangar while company technicians fit it out with payload and systems: it's expected to fly and then deploy to the warzone next year.
It's big alright.
True to the acronym C4ISR, the Blue Devil is also intended to offer some hefty computing grunt, acting as an airborne server for ground troops with mobile network terminals (and offering more services to "advantged users" in forward bases etc with better kit). The "processing pallet" in its payload car will be of supercomputer grade, which should reduce the strain on the pipes relaying sensor data down to the ground - though with the addition of FOENEX, those pipes will be a lot fatter.
Interestingly, we also learn from the new DARPA announcement that Blue Devil is referred to at the Pentagon as "the USAF/Big Safari Blue Devil Block 2". "Big Safari" is a magical phrase in this context, referring to long running and generally highly secretive airborne spookery efforts by the US Air Force and partner agencies. Big Safari has put many strange-looking secret spy planes, drones etc into the sky over the decades: it would seem it is now getting into the airship business as well.
Other parts of the US military also plan to use airships above Afghanistan as airborne spyeyes and comms relay posts. The US Army's Long Endurance Multi-Intelligence Vehicle (LEMV) uses a more sophisticated "hybrid" design from British engineers which should means it will be more economical with helium, and thus is of more interest to airship buffs (the more so as it could potentially carry heavy cargoes at lower altitudes): on the other hand it was supposed to have made its first flight some months ago now, and instead there has been ominous silence from the programme.
At $517m, LEMV is a much more expensive project than the $86m Blue Devil 2, but it could be that the Blue Devil will actually beat it into the air.
There's also one final aspect for airship fanciers to ponder: MAV6 advertise their big blimp not only as a C4ISR node, but also a "weapon system platform". It could be that the days of the armed aerial warship are about to return. ®
For those noting the term "Blue Devil Block 2" and wondering what "Block 1" might be - perhaps supposing that an earlier giant spyship is already in the air above Afghanistan - a MAV6 blog post  provides the answer:
Blue Devil Block I is a fixed-wing aircraft based, multi-INT capability currently doing God’s work.