Builders of the biggest radio telescope in the world, the Square Kilometer Array, are borrowing techniques from the makers of shopping carts and coat hangers to stay in the project's budget.
The radio telescope is made up of 3,000 radio dishes and several million non-dish antenna elements located in two different countries — one array in South Africa and the other in Australia. Each array will be arranged in five sprial arms, extending out to distances of 3,000 kilometers from a center, and are being built to detect electromagnetic radiation emitted by objects in space.
Construction of the arrays will start in 2016 and is expected to be completed by 2024. The product development company, Cambridge Consultants, needs to build each antennae for less than 75 euros (U.S. $92) for a total budget of 1.5 billion euro or U.S. $1.84 billion. But back when they starting pricing out the original prototypes for the antennas, the cost was too high. That's because precision antennas used for astronomy are custom-designed, rather than mass-produced. They have to be the right shape and size to reduce background noise, pick up faint signals and work in relatively narrow frequency bands.
To stay within budget, Cambridge Consultants and the organizations building the SKA looked to the makers of coat hangers and shopping carts, as well as television aerials. Their mass productions techniques made efficient use of metal during manufacturing, bringing down the cost.
Gary Kemp, who led the project for Cambridge Consultants, told Discovery News that some of the savings came from simplifying the assembly technique. When making coat hangers, or shopping carts, the metal is taken in large batches and rolled into shape, rather than having each piece built individually.
"TV aerials are basically a bent tube stuck into a metal rod," Kemp said. That kind of technique — adapted to more precise work — was used to build the thousands of antenna elements.
The group also had to think about how to make the antennas durable. "This has to be reliable in the field," he said. "It has to be out there for, like, 50 years."
Andrew Faulkner, an astrophysicist at the University of Cambridge, said one of the big targets will be the three-dimensional structure of the neutral hydrogen in our part of the universe. "If you extend looking back in time with neutral hydrogen, eventually you get to the epoch of re-ionization," he said. That's the era between about 300,000 years after the Big Bang and the point where we see the first galaxies and stars, about a billion years later. The structure of the hydrogen will tell scientists how the universe lit up.
Other targets include rare pulsars. "We'll be able to see the holy grail of pulsars, a millisecond pulsar around a black hole," he said.
Photo: Gary Kemp (right) of Cambridge Consultants, with Drs. Nima Razavi Ghods (left) and Dr. Andrew Faulkner (center), among the low-frequency antenna array.
Credit: Cambridge Consultants