Cosmic microwave background (CMB) astronomy is concerned with observations of the Universe about 380,000 years after the Big Bang. At this time the CMB, relic radiation from the Big Bang, had very faint temperature and polarisation fluctuations imprinted on it as structure formed in the early Universe. By mapping the fluctuations, astronomers can test cosmological theories and determine the fundamental constants of the Universe. Making these measurements, in particular measurements of the extremely faint polarisation properties, demands extremely sensitive and carefully-designed telescopes. The particular expertise of the NUI Maynooth group is in the design and verification of such instruments, both ground- and space-based. We are involved in several projects to observe the CMB such as MBI and QUaD which has already taken world-leading data from the South Pole. We are also involved in the Planck Surveyor satellite of the European Space Agency, which will be launched in 2009. The exquisite sensitivity of the Planck measurements and the deep space environment in which it will observe will ensure quality data that will have a revolutionary impact on the science of Cosmology.