It was funded by NASA and tested in the Atacama Desert in the early 2000s. Urey was selected by NASA for further development in support ExoMars or any future Mars mission that could use Urey along with Mars Organic Molecule Analyzer, or Moma in 2007, funded with 1.5 million USD total (750k each). Urey was a suite of instruments that built on 15 years of research into detecting organic molecules. Urey is a design for in situ biomarker detection, and it was tested in the early 2000s. The device would also study the mysterious oxidants in Mars regolith.
Urey was previously included on ExoMars rover in one of its iterations, and would have searched for organic compounds in Martian rocks and soils as evidence for past life and/or prebiotic chemistry. Starting with a hot water extraction, only soluble compounds are left for further analysis. Sublimation, and capillary electrophoresis makes it possible to identify amino acids. The detection would be by laser-induced fluorescence, a highly sensitive technique, capable of parts-per-trillion sensitivity. These measurements would be made at a thousand times greater sensitivity than the Viking GCMS experiment, and would significantly advance our understanding of the organic chemistry of Martian soils. Urey would follow up on the Viking results which were inclusive and only sampled the very near surface.
Urey had been selected for a time to be on the Pasteur payload of the ExoMars rover, however, it was developed for any Mars mission not necessarily ExoMars and was funded independently by NASA.