RQ-180 drone leaks continue ahead of Mach 6 "Son of Blackbird"

The clandestine RQ-180 drone developed for secretive electronic surveillance and strike missions for the US Air Force has been further detailed, though military officials still refuse to confirm the leaked $2bn project. First revealed earlier this month as part of an Air Force project to operate high-altitude remote missions in hostile airspace, the RQ-180 will fly as high as 11 miles up, it's suggested, and be the first in a new breed of super-fast, super-stealth drones slowly becoming public.

Test flights of the RQ-180 for the US Air Force are said to have already begun, with operations pencilled in from 2015. The project is said to have been underway since 2013, and contracted with manufacturers Northrop Grumman as early in 2008.

According to US officials speaking to CNN, the RQ-180 drone is expected to boast flight times of 24 hours, besting existing drones for long-distance surveillance. It will also have an advantage over traditional satellite monitoring, ramping up the frequency of the pass-overs.

Believed to have a wingspan more than double that of the existing X-47B drone, another Northrop Grumman project, the RQ-180 would also dwarf the RQ-170 Sentinel widely used by the Air Force today. Built by Lockheed Martin Corp. and first put into operation back in 2007, the RQ-170 is believed to have a wingspan of at most 90ft wide.

It was notably used for the 2011 raid on Osama bin Laden's compound in Pakistan, which killed the al-Qaida chief.

RQ-180 is only the first of a new line of super-stealth, high-speed hardware the US government is investing in, however. Lockheed Martin Corp. is already working on a new "Son of Blackbird" hypersonic jet, which could potentially travel three times the speed of existing fighters, and be equipped with light weapons for raids.

The Mach 6 jet, codenamed the SR-72, would be unmanned like the RQ-180 drone, though Lockheed plans to also use the hypersonic technology on missiles as a testbed of sorts. They could be operational by 2018, though the SR-72 itself – if it gets the green-light overall – is unlikely to be ready for some years after that.

Whether that green-light will be given depends in no small part on budgetary considerations. Lockheed has been attempting to use off-the-shelf parts for the design, it's said, in an attempt to minimize expensive custom components, including a combined turbine and scramjet-engine system to drive the craft to hypersonic speed. The Mach 6 top speed was selected as a compromise between performance and the demands for tougher shielding and other materials, too, though Lockheed still declines to say how much it envisages any final jets actually costing.

Reuters last month