Sharp-eyed Nick Cook of Janes has spotted a new classified UAV program. He refers to this Pentagon budget document which says "the J-UCAS program to split into two separate programs: one Air Force classified program and a navy UCAV [unmanned combat air vehicle] program". Some $1.7 billion is to be spent on these developments over five years.
The new craft is referred to as Penetrating High Altitude Endurance (PHAE), and is thought to be able to cruise at 70,000-80,000 ft, similar to the U-2 (Global Hawk has a ceiling of 65,000 ft). ‘Penetrating’ means operating over defended territory, so unlike Global Hawk high degree of stealth will be essential. Being derived from the armed J-UCAS program, strike missions and SEAD are also possible. Cook says:
One report refers to the aircraft using engines from an inventory that has been in storage since the 1970s. This almost certainly refers to the General Electric J97-GE-3 engine for the Teledyne Ryan AQM-91 Compass Arrow UAV (a project terminated in 1971). In 1998, a NASA paper reported that 24 J97 engines were in storage at the agency's Ames research centre...the J97 was rated at around 25 kN and the new UAV is probably a twin-engine design.
Compass Arrow, otherwise known as the Ryan Model 154 Firefly, weighed in at 5,000 lbs with a wingspan of 48 feet and carried a payload of over 300 lb. It was very stealthy for its day, with rounded fuselage and inward-canted tailfins, with a coating of RAM (radar absorbing material) to reduce radar returns. The engine was mounted above the fuselage to minimize the infrared signature.
Compass Arrow could cruise at 80,000 feet, and was intended to be used over China. For political reasons it was mothballed without ever being used.
Compass Arrow Arrow was single-engined, so a twin-engined PHAE is likely to be somewhat bigger.
The PHAE concept has been studied before , with a view to roles including countering WMD, attacking fixed and mobile targets, and suppressing air defences. It’s not clear what weapons might be used from this sort of altitude, though a guided kinetic penetrator would make quite an impact from sixteen miles up. A stealthier approach would be for PHAE to act as a ‘mothership’ for smaller UAVs (such as the 100 lb Dominator) killer UAV or miniature munitions. The US Navy has already experimented with launching the FINDER UAV from a Predator drone for close-in reconnaisance, as well as the miniature CICADA Close-in Covert Autonomous Disposable Aircraft which would be dropped in large numbers for electronic attack.
The endurance of PHAE will be limited by fuel supply; serious long-endurance drones with mission times measured in weeks or months will be solar powered. High-altitude long-endurance drones will find many more applications in both the civilian and military worlds - there’s more on this topic in my book Weapons Grade.
-- David Hambling
UPDATE – Check out the new Special Report on Weapons & Warfare on the New Scientist magazine website, a feast of dozens of weapons tech articles with an ‘instant expert’ overview by a DefenseTech regular.
While it would be nice to have long-range, highly sensative UAVs that were small, the technology isn't there yet.
UAVs have to be large enough to carry their sensor payload and an energy supply. Their size, then, is based on being large enough to create enough lift to carry the payload and fuel for a long endourance mission.
Radar and electro-optical cameras with sufficient power or clarity aren't small enough for a small UAV yet.
Energy sources would either be batteries (heavy) or aviation fuel (also heavy in sufficient quantity for a long mission). Even if solar power was used to power the craft, a sufficient number of "solar panels" would still make for a larger aircraft.
So, micro, stealth, long-range UAVs sound perfect, be we ain't there yet.
Just two cents....
Posted by: DITBOY at December 13, 2008 06:05 PM