Behind the controls of one of the Very Large Array’s Transporters, is the gentle giant trucks that carefully lifts and moves the antennas.
VLA’s Miles of Old Tracks
Over 80 miles of train track, re-purposed from old, discontinued rail lines around the United States, allow the Very Large Array to be reconfigured. Throughout the year, the antennas are carried on the backs of one of two Transporters and hauled along these tracks to a new powered pad. Changing the size of the array changes how much detail it can see.
VLA Subreflector
The Very Large Array dish antennas focus their radio waves to a second reflector (seen here). It is placed exactly where the radio waves come to a focus after reflecting off of the 25-meter parabolic dishes. The so-called “subreflector” bounces the collected radio waves straight through the throat of the dish where multiple receivers could be placed. It is mounted on a swivel, so that it can rock to aim waves directly into different receivers.
Train skills required for laying the VLA tracks
With over 80 miles of track to keep in service, the Very Large Array needs the skills of a railway crew. Here, the gravel ballast is combed around the rails.
Inside an azimuth bearing of a VLA telescope
Over time, the azimuth bearing of a Very Large Array antenna needs cleaning out and repairing. Here, technicians work inside the base of a separated antenna to remove worn rollers. The upper, dish half of the antenna is braced on the dark platform at far left where another technician inspects it for wear and tear.
On top of VLA antenna
Engineers are required to wear safety harnesses when performing routine inspections on the VLA’s telescopes. Here we see an engineer attached to the antenna’s feed.