Not where you would expect to see it. but Israel's Elta brought its EL/K-1981 satellite communications system to the US Army show in Washington DC this week. This is the satcom fitted to Israeli F-16I Sufas, to provide wideband beyond line-of-sight communications. Now where would that have come in useful recently, I wonder?
Satcom antenna (left) is housed under the bump in the dorsal spine (right)
Elta says it has used airborne radar technology to produce a steerable planar-array antenna small and light enough to fit in a fighter, and agile enough to track the geostationary satellite throughout combat manoeuvres. It says the Ku-band system is also used on Israeli AH-64 Apaches, where it has to look through the rotor.
"Satcom on the move" is still a rarity on fighters and helicopters, but not for much longer.
Orbital Outfitters has unveiled what it claims is the world's first commercial spacesuit. The catchily named Industrial Suborbital Space Suit Crew, or IS3C, is intended for those "lucky" enough to fly the first suborbital spaceships. The company says it has a contract to deliver the first set of suits to XCOR Aerospace, which is developing the Xerus suborbital vehicle. Orbital Outfitters says the suit "is by intent a bit conventional in appearance, if not retro". Well, we all know retro is very now-tro, so it should sell like hot cakes. Meanwhile, to help you choose here are some iconic spacesuit designs from science fiction.
I am thinking of starting an occasional series on "visual aerodynamics" - images that show the air at work, creating lift and generating drag. What better way to start than these stills from high-speed video of the US Naval Research Organisation's January 31 test of the world's most powerful electromagnetic railgun. Not aviation perhaps, but aerodynamics certainly. As the projectile leaves the railgun with a muzzle velocity almost Mach 7.5 you can see the "lens" effect caused by the shockwave. Remember, the projectile is unpowered - the flames are generated by friction...
Blackswift breaks cover - DoD funds hypersonic aircraft
The Pentagon boffins have been keeping mum, but the DoD's fiscal year 2009 budget request lifts the lid on Blackswift - DARPA's prototype hypersonic aircraft. Formerly the Falcon HTV-3X, and being designed by Lockheed's Skunk Works, the unmanned Blackswift is intended to take off conventionally on turbojet power, transition to scramjets, cruise at Mach 6 for an extended period, then return to a runway landing. If it succeeds, Blackswift will be a worthy successor to the Skunk Works' Blackbird.
Sharon Weinberger at Wired's Danger Room was first to blow Blackswift's cover, and in January alerted us to an InsideDefense story that DARPA was to seek $750 million for the demonstration programme. DARPA's FY2009 request is for $70 million on top of the $35 million to be spent in FY2008. Here's what DARPA's budget documentation has to say:
"The Blackswift Test Bed program will develop an extended duration hypersonic test bed which will allow for the study of tactics for a hypersonic airplane that includes a runway take-off, Mach 6 cruise and runway landing. This test bed is an evolution of the reusable Hypersonic Cruise Vehicle developed under the Falcon program.
"Key technologies that will be demonstrated include efficient aerodynamic shaping for high lift to drag, lightweight and durable (reusable) high-temperature materials and thermal management techniques including active cooling, autonomous flight control, and turbine-based combined cycle propulsion.
"It is envisaged that flying this hypersonic aircraft test bed in a relevant, flight environment will permit the futire development of enhanced-capability reusable high-speed vehicles for intelligence, surveillance, reconnaissance, strike and other national need missions. This program will transition to the Air Force following completion of flight-testing."
DARPA's Falcon programme continues, with two unpowered, rocket-boosted HTV-2 hypersonic test vehicles scheduled to be flown in FY09 to pave the way for Blackswift. The Skunk Works, meanwhile, is to complete the Blackswift preliminary design and ground test the integrated high-speed turbojet and scramjet propulsion system by the end of FY09. No news yet on when Blackswift might fly, but it should look like this...
First flight for PDE = pretty darned extraordinary
It's not every day a new form of propulsion makes its first flight: the turbojet in August 1939 (Heinkel He178), the ramjet in April 1949 (Leduc 010), the scramjet in July 2002 (University of Queensland HyShot). Now it's the turn of the pulsed detonation engine (PDE) - a simple, lightweight powerplant that promises efficient operation over a wide range of speeds from 0 to Mach 4.
In a PDE, combustion is supersonic (detonation) rather than subsonic (deflagration), resulting in the more efficient conversion of fuel into thrust. PDEs have few moving parts. A fuel/air mixture is injected into a tube and ignited, creating a supersonic detonation wave that travels down the tube and is expelled, producing a pulse of thrust. Grouping several tubes together and firing each many times a second produces constant thrust.
It's taken a few years longer than planned, but the US Air Force Research Laboratory and partners ISSI and Scaled Composites finally accomplished the first PDE-powered flight in late January. The modified Long-EZ was powered by a four-tube PDE, each tube firing 20 times a second, producing 200lb peak thrust. The flight was short, just a few tens of seconds, taking place within the length of the Mojave runway, but it was a first.
On the subject of PDEs - pulse detonation engines - General Electric has just been assigned a US patent for a turbofan that uses a rotating pulse-detonation system, rather than low- and high-pressure turbines, to drive the fan and compressor. Basically, each turbine stage is replaced by a radial array of raked and angled pulse-detonation tubes.
According to the patent, the first ring of PDE tubes (58) is fired first to start the booster compressor (28) turning. Once the booster is up to speed it provides compressed air to the remaining PDE rings (59), which then fire up to drive the fan (20).
As a PDE ring turns, each tube sequentially passes first a port (50) allowing air into the tube, then a fuel injector (52), then the igniter (54), which initiates a supersonic detonation wave (66) to power the ring's rotation.
I have a soft spot for the blended wing, and Swift Engineering is keeping the dream alive with its cool-looking Killer Bee UAV. Not surprisingly, perhaps, as Swift's chief scientist Mark Page was technical programme manager on McDonnell Douglas' Blended Wing Body. Boeing and NASA continue to work on the BWB, flying the X-48B unmanned demonstrator, but the Killer Bee promises to be quite a different beast:
