In the aerospace context, "UHV" stands for "Ultra-High Vacuum." UHV refers to a vacuum with a pressure of less than 10^-9 pascals (Pa), which is an extremely low pressure. UHV environments are typically used in research and testing applications, where the lack of air or other gases can be used to simulate the conditions of outer space or to conduct experiments that require a very low pressure.
The UK Astronomy Technology Centre (UKATC) is a research and development organization that is part of the Science and Technology Facilities Council (STFC), a UK government agency that supports research in a variety of scientific fields. The UKATC is based in Edinburgh, Scotland, and it is focused on the development of new technologies and instruments for astronomy and astrophysics.