FARNBOROUGH – A British surveillance aircraft system, controversially scheduled for an early retirement in parliament's 2010 defense review, is getting a new lease on life.

The Royal Air Force's Airborne Stand-Off Radar (Astor) system is based around five Sentinel R1 aircraft. The Bombardier Global Express business jets are equipped with a dual-mode ground, moving-target indicator (GMTI) and synthetic aperture radar (SAR) supplied by prime contractor Raytheon. The aircraft had been scheduled for a post-Afghanistan retirement.

However, Sentinel was granted a reprieve, according to a speech given by British Prime Minister David Cameron at the Farnborough air show earlier this month. Cameron's announcement had been widely expected following successful deployments to Libya, Mali, and Operation Pitchpole, a mission supporting the U.K.'s environmental agency following severe flooding in southern England earlier this year. One RAF Sentinel has deployed to Africa, supporting efforts to find schoolgirls kidnapped by Boko Haram, while other aircraft have been supporting ground forces in Afghanistan since February 2009.

The system has become increasingly valuable to the British military and its allies, and as an army cooperation squadron expands its utility, Raytheon is looking to sell versions of the Sentinel capability to other customers in a variety of configurations and on different platforms.

Raytheon has been planning a number of major upgrades for Sentinel, which the company and the squadron hope will be funded now that the system's future has been secured. Of most urgency are structural checks and airframe life-extension maintenance that had been delayed pending the decision. An upgrade of mission-crew software also is necessary, but may now be folded into a larger project to develop and fit completely new workstations and computers.

The current concept for the new mission system is called Overseer, and it is among the items that will dominate discussions between the contractor, the squadron and the defense ministry over where the new money will be spent. The squadron and Raytheon also have a prioritized "shopping list" of other work to carry out. This includes refinements to the radar and an evaluation of additional sensors.

"We're considering the implementation of a long-range optical sensor, which we can then integrate with the radar and provide a much better surveillance capability," says Paul Francis, Raytheon U.K.'s business development director. "[We are also considering] the implementation of a signals-intelligence capability on the platform, to pick up and highlight some of those areas where, just with the radar, it's difficult to form identification."

That there is a significant market for surveillance systems based on business-jet platforms, with low cost of ownership, a quick route to technology being fielded, and a wide operational envelope is key to the appeal, company officials say.

"Two customers are looking for a turreted [EO/IR] capability to be able to move down quickly from altitude, which the business jet uniquely allows you to do," says Jim Hvizd, vice-president of international strategy at Raytheon's space and airborne systems division in the U.S. "We're leveraging technology that we developed on Global Hawk, where we have an integrated long-range camera capability."