Alma radio telescope: How to move a giant antenna
3 October 2011 Last updated at 10:38 BST
The world's most powerful radio telescope has begun scientific operation.
The Alma (Atacama Large Millimetre/Submillimetre Array) telescope array, high up in Chile's Atacama desert, has commenced its quest to view the formation of the first stars in the Universe.
Building it has also been a remarkable feat of engineering.
Science correspondent Pallab Ghosh has been speaking to one of the leading engineers involved in the project, Pascal Martinez, about the technical challenges involved.