Expanded VLA

Almost any science fiction fan can identify an image of the Very Large Array (VLA) radio telescope. This impressive collection of 27 mobile antennas was the opening backdrop for "Contact", a screen adaptation of Carl Sagan's popular novel, starring Jodi Foster. In the movie, Jodie's character detects the first signals from an alien species while relaxing in the shadow of the array.

The VLA sits on the Plains of San Agustin, a desolate plateau in western New Mexico, more than 50 miles from the nearest city. They make for a spectacular scene as you crest hills circling the plateau. Each of the telescope's white dish antennas measures 25 metres in diameter and weighs a hefty 230 tons. They ride on railway tracks, which enable them to fan out into a Y-shape configuration up to 37 km apart. Two of the three rail arms even extend across local highways.

The complex was originally authorised by the US Congress in 1972. It officially opened in 1980 after more than 16 years of steady construction. The US National Radio Astronomy Observatory (NRAO), a joint venture between the nation's universities and the National Science Foundation, maintains the facility and controls its use.

In 2001, the NRAO began work on the US$98 million Expanded VLA (or EVLA) project. The project, due for completion next year, is an extensive technology upgrade designed to make the telescope ten times more sensitive to faint radio frequencies. Its 1970s-vintage electronics, analogue data transmission systems and computing technology are being replaced by modern optical fibre technology and a new, powerful supercomputing that can process in an hour the same volume of data collected by the VLA during its first thirty years of service.

Garry and I visited the EVLA today en route to Arizona. We couldn't have picked a better day to visit. The array is currently being transitioned from its most compact formation. This meant we could see all 27 antennas in close proximity and watch its special red transporter unit carefully relocate the gleaming white dishes. Visitors can take a self-guided walk around the facility, including a close-up look at one of the active dishes. We were also lucky enough to see a dish undergoing repair in the facility’s giant workshed.

Lunch today was hosted by Pie Town. This unassuming town was founded by Clyde Norman in 1922, who was known for baking pies for passing travellers. Several cafes still offer pies as their signature dish. However, Garry and I stuck with our regular picnic lunch at a shaded table in the town park. We’ve just missed the annual Pie Town festival and pie-eating contest. It was held a week ago on Saturday, 10 September.

This evening we're staying at a clean but rather nondescript Best Western Sunrise Inn in Eagar, Arizona. Tomorrow we turn north and head for the Painted Desert, and what's left of the immortal Route 66.  We also clocked up our first 500 miles this afternoon. We'll do at least another 600 before we're done.