Written evidence from Raytheon UK |
The Airborne Standoff Radar (ASTOR) program that
includes the Sentinel R Mk1 as the aircraft element was launched
in December 1999 as a key component of the Armed Forces Intelligence,
Surveillance, Target Acquisition and Reconnaissance (ISTAR) capability
to become the country's future key ground surveillance capability.
It meets the joint RAF/Army threefold requirement in one airframe
for: surveillance over a wide area; the ability to focus on a
discreet area of interest; and identify moving targets. Using
a business jet enables the sensor to be flown much higher than
larger aircraft thus greatly extending the range of radar coverage.
Raytheon delivered the programme to the original
target cost of £850 million and went from concept to operational
capability, deployed in theatre in just over eight years, a significant
achievement for what was an extremely complex and technically
The Strategic Defence and Security Review (SDSR)
announced the retirement of the RAF's fleet of five Sentinel R
Mk 1 aircraft on completion of the support to ongoing operations
in Afghanistan circa April 2015.
The Defence Select Committee is investigating the
SDSR and National Security Strategy (NSS). One of the areas for
investigation is to identify the capability gaps that will be
created as the SDSR policies are implemented, the assessment process
that led to these decisions, and the impact this may have on the
UK's defence planning assumptions and the ability to adapt to
changing threats or unforeseen occurrences.
The Sentinel R Mk1 aircraft passed 300 successful
operational missions in theatre milestone last October. It is
now achieving a rolling average Duty Carried Out (DCO) rate in
theatre of 95%: this with only two aircraft, one ground station,
very lean staffing and a supply chain using UK Main Operating
Base criteria. It compares very favourably to the significant
cost and infrastructure required by coalition forces to keep their
equivalent ISTAR capability in theatre.
Reports from in theatre, openly available, demonstrate
that Sentinel is a proven life saver and route protector in the
current battle space, with a capability unmatched by other platforms.
Its ability to scan very large swaths of land over great distances
in very short time provides information and pattern of life intelligence
that would take hours, even days, to compile using other UK platforms
in theatre. Its pattern of life intelligence has therefore become
a vital tool in the battle against Improvised Explosive Devices
The Sentinel R Mk1 has been an operational success
story, delivering a wide area surveillance capability that is
relied upon by UK, US and other coalition forces in Afghanistan
today. Sentinel is one of the few systems that the UK deploys
that the UK is able to add real value to the coalition's overall
The Strategic Defence and Security Review announced
the retirement of the RAF's fleet of five Sentinel R Mk 1
aircraft on completion of the support to ongoing operations in
Afghanistan circa April 2015.
This decision leaves the UK without a viable wide
area ground surveillance capability. Raytheon's understanding
is that the MoD believes that wide area surveillance can be provided
by a combination of the Scavenger capability, currently in procurement,
and the Joint Strike Fighter (JSF).
However, whilst these programmes may provide a ground
surveillance capability, they are intended to provide coverage
complementary to Sentinel's wide area capability. JSF and Scavenger
will be optimised for local area surveillance provided by smaller
sensors and less powerful processing capability. Unmanned assets
like Scavenger need cueing from very wide area pattern of life
based product libraries and without Sentinel, another means will
be needed to update these databases in near real time. We are
not aware of MoD plans to provide this capability.
With the JSF not due to enter into service until
between 2017 and 2020 and Scavenger not planned to deliver an
operational capability until 2018 at the earliest, there remains
a risk of no capability in this area for a significant period
The Sentinel system also has a valuable role in communications.
The Ground Station currently provides the coalition forces with
the only means of interoperation with JSTARS which will be lost
when Sentinel is retired.
Furthermore this loss will have an effect on potential
plans for the long range deployment of UAVs, for which radio relay
of data may be required, especially if SATCOM bandwidth is limited
or not available. Sentinel's high altitude ceiling has been utilised
in this way by the USAF using the original ASTOR demonstrator
GEX 9001 as a trials aircraft operating out of Afghanistan.
In addition to its pattern of life picture that Sentinel
currently provides, the system could assist further in the battle
against IEDs due to the inherent quality of the raw data provided.
Offboard post processing trials have proven that there is the
capability to identify disturbed earth and cue the identification
of IED locations. The Sentinel aircraft does not require any modifications
in order to deliver this near real-time IED detection capability.
Therefore, with minimal additional outlay, further trials could
be undertaken with in theatre data to refine this capability,
and potentially help to reduce the casualty figures in theatre.
Such a capability is considered essential given the
latest trend in warfighting scenarios, and would be valuable,
not just for current operations, but wherever the next theatre
of interest lies. Afghanistan has proven that terrorism will likely
continue to revolve around insurgency and IED based threats, a
scenario that the current platforms have difficulty in addressing
over wide areas.
The ASTOR System has untapped capability that with
incremental investment could deliver significantly enhanced capabilities.
This spiral capability development would be a more cost effective
and lower risk way of delivering new capability, rather than investing
in the development and entry into service of new platforms.
The SDSR decision to cancel the Nimrod MRA4 leaves
the UK with maritime capability gaps that the Sentinel R Mk 1
capability could address, including:
sea search and rescue maritime target detection;
of Action presence for maritime emergencies beyond the range of
current Sea King helicopters;
naval force protection; and
area submarine threat detection.
The Sentinel Dual Mode Radar Sensor (DMRS) could
be modified to accept a high sea state target detection capability
that would match and possibly even surpass that lost by the cancellation
of the Nimrod MRA4. This capability is already in service in the
In addition the ASTOR Ground Station could be upgraded,
with relatively little investment, to provide a multi ISTAR hub
for the reception of information feeds from Watchkeeper, Reaper
and, in the future, Scavenger. This would fit well into the future
plans for the Solomon programme, as we understand them, maximising
reuse of existing assets, saving valuable resource and costs.
The SDSR decision to retire Sentinel leaves the UK
with capability gaps covering significant wide area pattern of
life surveillance, long range target detection and coalition force
interoperability. It also offers cost effective opportunities
to plug maritime surveillance gaps and high altitude wide area
IED detection. Some of these may be filed in the 2018-24 timeframe,
but not all.
In addition spiral development of the proven Sentinel
capability could deliver solutions to future capability gaps such
as maritime search and rescue, and deep sea threat detection at
significantly lower cost and risk, than developing and deploying