According to reports, it has about 1400 T/R modules. Searchwater 2000, the main maritime surveillance radar for the now defunct Nimrod MRA4 programme, developed by Thales UK. The AEW variant is currently fitted to the UK's Westland Sea King AsaC7 helicopters. Seaspray 5000E, Seaspray 7000E and Seaspray 7500E, developed by Selex ES, have found widespread use in various applications. The Seapray 7000E has been selected for the AW159 Wildcat and the Seaspray 7500E has been selected by the United States Coast Guard for its C-130s. The range for these radars is given as more than for the Seaspray 5000E, for the Seaspray 7000E and for the Seaspray 7500E. Vixen 500E, a small AESA radar developed by Selex ES for small lightweight fighter aircraft. It is currently under development and has so far no customers. It has approximately 500 T/R modules. There is also a variant with 750 T/R modules under development. The range of the Vixen 500E is given as . Picosar radar, a very small AESA radar also developed by Selex ES with a range of about 20 kilometres and a weight of around 10 kg. Its market is mainly seen as a cheap, small radar for UAVs. Satellites Galileo satellite navigation system, intended to rival the American GPS system, is supported by the United Kingdom and its industry has a significant workshare in the development of the system. Disaster Monitoring Constellation, a five satellite constellation with the first satellite being launched in 2002, to monitor disasters around the globe. Every satellite has been funded by a different country and SSTL has built and operates them. Currently, there are another three satellites under construction, one for Nigeria, one for the UK and one for Spain. Airbus UK satellite manufacture business Skynet family of military communications satellites Solar Orbiter, amongst the largest research satellites built in Britain Spaceplanes British company Reaction Engines Limited is currently developing a SSTO spaceplane called Skylon with funding from The European Space Agency (ESA). The British Government partnered with the ESA in 2010 to promote Skylon. This design was pioneered by Reaction Engines Limited, a company founded by Alan Bond after HOTOL was canceled. The Skylon spaceplane has been positively received by the British government and the British Interplanetary Society. As of 2014 the precooler technology for the engine design has been demonstrated and test flights are expected within a decade. The Company Bristol Spaceplanes