The smallest spacecraft ever launched are successfully travelling in low Earth orbit and communicating with systems on Earth, scientists have announced.
Known as “Sprites”, the miniature satellites are just 3.5cm square and carry radios, sensors and computers, with each device powered by sunlight and weighing just four grams.
While nanosatellites known as CubeSats have previously been sent into space, such systems have a mass thousands of times that of the Sprites, weighing more than 1kg.
Scientists say the latest development is an important a precursor to an ambitious attempt to send space probes to planets beyond our solar system, dubbed Breakthrough Starshot.
“This is a new frontier of tiny, gram-scale spacecraft” said Professor Avi Loeb of Harvard University, chair of the advisory committee for the Breakthrough Starshot Initiative.
The Sprites, Loeb adds, are also cheap. “Each of them is only tens of dollars in cost,” he said.
Announced last year by Stephen Hawking and Russian entrepreneur Yuri Milner, who has put $100m into funding the first five years of the project, Breakthrough Starshot’s goal is to develop chips with a weight of roughly one gram and fit them to a lightweight sail before propelling them through space with a 100-billion watt laser.
“The reason one needs to push the weight down is because in order to reach the nearest stars within our lifetime, the spacecraft needs to move at a fraction of the speed of light – a fifth of the speed of light or so,” said Loeb.
While Sprites have previously been carried on board the International Space Station, this is the first demonstration that it is possible to launch such a lightweight miniaturised satellite into space and communicate with it.
The Sprite project is led by Zac Manchester, now a researcher working with Loeb at Harvard University, who began work on the spacecraft almost a decade ago, before the project became part of the Breakthrough Starshot effort.