Science: The low oxygen levels on the Chajnantor plateau in Chile where the Atacama Large Millimeter/Submillimeter Array (ALMA) telescope is being assembled have presented a challenge for engineers. The thin air can wreak havoc not only on the humans working to install the Correlator supercomputer that will process the telescope’s data but also on the computer itself. A standard supercomputer operating at some 5000 m above sea level would be prone to overheating, and its data storage drives would likely fail. So the engineers worked to optimize the design and placement of all the Correlator’s components to reduce energy use and facilitate cooling. In addition, for additional redundancy, the data from the telescope will be transmitted down to a support facility located at just 2900 m above sea level. Although the computer’s design is specific to ALMA’s needs, some aspects could be applied to future supercomputers, says Correlator subsystem manager Alain Baudry of the University of Bordeaux in France.