SENTINEL R1 - ASTOR (AIRBORNE STAND-OFF RADAR)

The Airborne Stand-off Radar (ASTOR) is a new British capability for operations over and around the battlefield. It is to form the UK equivalent to the US E-8 Joint Surveillance Target Attack Radar System (JSTARS).

ASTOR is to provide a long range all weather theatre surveillance and target acquisition system capable of detecting moving, fixed and static targets. It is designed to meet a joint Army and RAF requirement.


The production contract was signed in December 1999 for the supply of 5 x air-platforms, 8 x ground stations, and contractor logistic support. The principal elements of ASTOR are the Bombardier Global Express aircraft and the Raytheon ASARS-2 side looking airborne radar used on the U-2.

The radar operates at high altitude and in all weathers to provide high resolution. ASARS-2 has been reported to provide images of the battlefield at ranges of 160 km, at altitudes up to 47,000 feet.

High speed data links transfer the data from aircraft to ground stations in near real time. The system has directional and broadcast data links which are interoperable with existing US U-2Rs, JSTARS and command and control networks.

Number 5 (Army Cooperation) Squadron was reformed on 1st April 2004 at RAF Waddington and will operate the 5 x modified Bombardier Global Express long-range aircraft and 8 x ground stations. In RAF service, the aircraft type will be known as the Sentinel R Mk 1, with the R acknowledging its Reconnaissance role.

The first Sentinel R1 arrived at RAF Waddington in 2007 and in February 2009 the aircraft made its operational debut in Afghanistan. The projected procurement cost is just over £1bn.

The 2011 UK SDSR announced the intention of the MoD "withdraw the Sentinel airborne ground surveillance aircraft once it is no longer required to support operations in Afghanistan." However, in February 2013 it was announced that it might be possible to retain Sentinel after 2015 and that a decision would be made as part of the next SDSR

In 2013 Sentinel were deployed in support of French operations in Mali.