After a 17-mile trek up to a plateau in the Chilean Andes, scientists installed the first of 66 giant antennae on the European Southern Observatory’s Atacama Large Millimeter/submillimeter Array (ALMA) telescope this week.

The antenna, which weighs about 100 tons and measures 40 feet in diameter, was carried to its operations site at 16,400 feet by a massive, custom-built transporter. Eventually, the antenna will be linked with dozens of others to form a single, enormous telescope. Scientists hope the extremely dry air on the Chajnantor Plateau will help ALMA study some of the coldest and most distant objects in the observable universe.

But because of the harsh conditions on the plateau, each antenna must be built at a base camp at 9,500 feet and then transported up to its concrete pad at the observation site. Once there, the array must be able to survive harsh winds and freezing temperatures, while still maintaining enough precision to point out a golf ball from about 10 miles away.

The first antenna began its journey when one of the two ALMA transporters, affectionately called “Otto,” hoisted the enormous white disk onto its back (below).

While the transporter can theoretically travel more than seven miles per hour with an antenna on its back, the vehicle moved extra carefully on its first trek, taking a total of seven hours to travel 17 miles across the Chilean desert.

Once the antenna reached its new home, the transporter used laser-guided steering and ultrasonic collision detectors to guide the disk into its docking station, a concrete pad equipped with power and fiber optic connections.
As more and more antennae are added to the array, the transporter’s special sensors will be crucial to keep it from accidentally colliding with an antenna. Even after ALMA is fully operational, ESO scientists say they’ll use the custom-built transporters to move antennae between the concrete pads, which will adjust the telescope’s view of the sky