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Hauling an ALMA Telescope

31 December, 2009 / Read time: 2 minutes

In this 3 minute-long video, we can see how is an antenna transported in the Atacama Large Millimeter/submillimeter Array (ALMA), from the unplug to the relocation.

This video shows how the antenna is lifted up safely from its mounts, then is unplugged from its power and control sockets and plugged into the Transporter. The Transporter's hooks then crawl up its sloped ramps, pulling the telescope up with them.

Why do we need to move te antennas?

ALMA can change the way it watches the sky, depending on whether the object being studied calls for high sensitivity to faint light, high resolution for seeing fine details, or some combination of both. To make high sensitivity maps of large structures (such as gigantic stellar nurseries), the telescopes need to be close to one another. To spot the pinpoints of once-hidden objects (such as planets going around other suns), the telescopes should be spread far apart. To switch between these set-ups (or to head down the mountain for maintenance), ALMA's telescopes must be carefully hauled for miles across the desert landscape in Chile.

The Transporters

Lifting and moving a 115-ton telescope requires a beast of a vehicle -- half crane and half tank. Built in Germany, ALMA's two monster trucks are named "Lore" and "Otto" and are incredible feats of engineering known as Transporters. Each is 33 feet (10 m) wide, 66 feet (20 m) long, and 20 feet (6 m) high, and uses twenty-eight tires to drive its 130-ton mass up to 20 mph.

Loaded with a telescope, one of these giant trucks can attain speeds of up to 12 mph. With an engine rivaling that of two Formula One racecars, the Transporter can take up to seven hours to carry its burden carefully up from the telescope testing area to the observatory site. In part, this is because the engine loses half of its fuel-burning power as it climbs into the thinner air at the observatory, 16,000 feet (5,000 m) above sea level.

Credits: National Radio Astronomy Observatory (NRAO)