 Colossal. Heavy. Ultra precise. Extremely manoeuvrable. Super rugged. Whenever an ALMA transporter moves a fragile high-tech antenna, there is a lot at stake. This is demanding work for both man and machine. The two huge ALMA transporters named Otto and Lore crawl across the magnificent landscape of the Chilean Atacama Desert, moving the sensitive antennas with the precision of the finest Swiss clockwork. The capacity to relocate the antennas is a crucial aspect of the operation of the powerful ALMA array. This is the ESOcast, cutting-edge science and life behind the scenes of ESO, the European Southern Observatory, exploring the ultimate frontier with our host Dr. J, a.k.a. Dr. Joe Liske. ALMA, the Atacama Large Millimeter Submillimeter Array, is the world's most powerful telescope for observing the cool universe. It consists of 66 high-precision antennas that can be placed up to 16 kilometres apart. Now, being able to move and reposition each of these antennas individually is precisely one of the reasons why ALMA is such a powerful science machine. But moving the antennas requires a sophisticated vehicle that had to be custom-built for the job. The ALMA Transporter is an engineering wonder, 20 metres long, 10 metres wide and 6 metres high. It has 28 wheels fitted in pairs, which can turn independently in any direction, providing astonishing manoeuvrability. This behemoth weighs 130 tonnes and is powered by two 700-horsepower engines, giving a top speed of 20 kilometres per hour or 12 kilometres per hour when carrying an antenna. The driver's cabin is set low down to ensure that the driver has a perfect view. The transporter can also be controlled remotely, allowing the operator to stand outside the vehicle and watch the machinery during critical manoeuvres. The sole purpose of the ALMA Transporters is to move the antennas around and to place them with millimetre accuracy. Now that's not bad considering that each of these antennas weighs in at more than 100 tonnes. Now an antenna trip can range anywhere from a few hundred metres, from one antenna pad to the next, to some 28 kilometres from the base camp up to the Chachlandour Plateau at 5,000 metres above sea level. The powerful engines of Otto are fired up. Whenever an antenna move is scheduled, the utmost attention of the transporter team is required. Picking up a colossal ALMA dish will never become a matter of routine, as the slightest mistake could result in a fatal accident. The U-shaped frame of the transporter spreads the load evenly. Carefully, the movers bring the transporter to an optimal position and prepare the antenna for the trip. Two angled rails secure the antenna as it is lifted onto the transporter's back. The ALMA Transporter keeps the antenna, earthquake safe, in an ultra-rigid grip. The antenna is positioned with incredible precision at its new location. But transporting an antenna from the base camp up to the Chachlandour Plateau is an entirely different sort of challenge. It's a 28 kilometre climb up the mountain, with an altitude difference of some 2,100 metres. The long drive up the winding road is a test of both driver and engine, and tension in the team is high. At a maximum speed of 12 kilometres per hour, the transporter creeps along the custom-made road. It is equipped with a unique suspension system that copes with the washboard pattern of the road, keeping the fragile load safe at all times. This high altitude driving is not a leisure trip. As the air thins, the operators struggle to breathe and need to use supplementary oxygen. Likewise, the power generated by the vehicle's engines drops dramatically. Finally, the plateau is reached, and the antenna is lowered with great precision onto its foundation pad to increase the observational power of ALMA. At first, these transporters may seem to be just bulky monster trucks bulging with power. But of course, there are much more. Their ability to handle the fragile ALMA dishes with such incredible care and precision makes them a simply indispensable tool for ALMA. And what's more, they do it in harsh environmental conditions and with unfailing reliability. And so, these giants aren't just trucks. In a way, they're actually part of a telescope. This is Dr. Jay, signing off for the ESLcast. Join me again next time for another cosmic adventure.