A Russian Soyuz rocket has successfully launched a controversial satellite into orbit, which will become one of our brightest stars in a few days – and may hamper astronomical observations.
Mayak is a cubesat, a small satellite about the size of a loaf of bread. But once in position about 600 kilometers (370 miles) above Earth, it will unfurl a giant pyramid-shaped sail made of Mylar that’s designed to reflect the Sun. It will span 16 square meters (170 square feet) and is apparently 20 times thinner than human hair.
The goal of the mission is to inspire people to look up to space, as well as testing technology to de-orbit satellites. Using an app on their phone, backers of the project can track its location and find out when it’s flying overhead.
The satellite will remain in orbit for at least a month, although at such a high altitude, there’s a possibility it could stay there for many more months if it’s orbit does not properly degrade as planned.
By their calculations, the company says it will shine with a magnitude of -10, third only to the Sun and the Moon. Our calculations suggest it will be -3, making it the fourth brightest object in the night sky after Venus.
Astronomers often have to deal with other artificial objects, including satellites that occasionally shine brightly when they reflect the Sun. Some of the brightest of these are known as iridium flares. But these are an annoyance in of themselves; astronomers certainly don’t want other objects to hamper their observations.
Michael Wood-Vasey, from the University of Pittsburgh, said Mayak was “quite unlikely to be a problem for astronomers.”
He added: “Mayak is orbiting just above the day/night terminator line – it’s always sunrise/sunset below where Mayak is orbiting. It will thus be too low on (or even below) the horizon when it really gets dark enough for astronomers to observe.”
However, there are undoubtedly other ways to test this technology without also causing a nuisance. One of these alone might not be an issue. But if this set a precedent for more in future, that probably wouldn’t be great.