Scientists in Western Australia think they've cracked a way to use FM radio emissions from a youth station to track man-made garbage in low-Earth orbit. The boffins have demonstrated the technique using the International Space Station as a target.
The newly built Murchison Widefield Array (MWA) in remote Boolardy sheep station in Australia's western outback region uses radio transmissions from nearby youth-orientated station Triple J to detect objects in space. It has picked up the station's signals reflected off the ISS, but the team says the same reflections could be refined down to serve a more useful purpose.
"We have shown that we are able to detect approximately 10 pieces of space junk simultaneously. Over time this means we are in a position to monitor a significant fraction of the space junk that is in Earth orbits," said Professor Steven Tingay, chief investigator in the Australian Research Council Center for All-sky Astrophysics (CAASTRO).
"An early warning system has the potential to protect the billions of dollars' worth of vital infrastructure orbiting the Earth but also prevent collisions that will result in even more space debris being generated, such as what happened in the case of the Iridium 33 satellite in 2009."
Space debris is certainly a problem. Mankind has been littering Earth's orbit for more than 50 years and the situation is getting worse. NASA has had to upgrade rocketry control systems on the ISS so that it can dodge debris in six hours, instead of over a day in the original designs, due to the number of close shaves.
That said, the MWA isn’t designed for this kind of work. The telescope is one of the first operation stages of the Square Kilometre Array (SKA) project, a $2bn radio telescope that will be the largest array in the Southern Hemisphere when it comes online in 2024, if current building schedules permit.
The SKA consists of a concentrated one square-kilometer heart of dishes and dipole radio receptors, with refining receivers spread up to 3,000 kilometers further out. It will work faster and image galaxies farther out than any other Earth-bound radio telescope.
One of its key tasks is to look back into the very early stages of the universe's development, about 350 to 800 million years aft the Big Bang. This period, known as the Epoch of Reionization, saw the very first stars and galaxies form, and the Aussie telescope may be able to provide vital clues about what fired up the universe as we know it. ®