Radio telescopes allow astronomers to study the celestial objects that give off radio waves. With radio astronomy, astronomers study astronomical phenomena that are often invisible or hidden in other portions of the electromagnetic spectrum, because there is no other way to ‘see’ these objects. It is a segment of the electromagnetic spectrum that lets astronomers look at the cold Universe, which is also very, very old. Astronomers studying the cold Universe really are seeing it in its earliest stages.When complete in the late 2020s the SKA will be made up of hundreds of radio telescope dishes and thousands of antennas spread across two continents. Each of the thousands of elements will have to have identical performance characteristics and be built to last in a harsh environment – South Africa’s Karoo region and Western Australia’s Murchison Shire.