One of the keys to the VLA is that the antenna are movable. This allows for simplifed maintenance and a scalable aperature. There are 28 antennas at the VLA. At any one time, up to 27 are making observations and one is in the antenna barn. This is a large enclosure where the spare antenna can be repaired so that it can be ready as a hot replacment should one go down. The array itself can be confured in one of 4 diameters known as configurates A though D. Configuration A is the largest at almost 25 miles in diameter, with the D being the smallest only 8 miles across.

There are a collection of pre-surveyed mounts along the Y shaped double railroad tracks. Special hydraulic engines can jack up and antenna and move it to a new mount in about 30 minutes. With 3 such transporters working together the array can be reconfigured in 4 to 6 hours. Normal obervations are schedule to minimize the need for such reconfigurations. Since radio astronomy can be conducted day or night, the VLA is a 24 hour a day operation.