Star travel will no more be a distant dream; the idea is increasingly coming closer to reality. Scientists have announced that the world’s smallest spacecraft launched are successfully traveling in low Earth orbit and communicating with systems on Earth.
During the ISRO’s PSLV C38 launch on June 23, the launch vehicle not only carried Cartosat-2 series satellite for earth observation, but it also had 30 more satellites on board. Amongst these 30 smaller satellites, there were 6 prototypes of interstellar spacecraft. Also known as Sprites, they are the smallest spacecraft ever launched.
Minature satellites — Sprites
Created by the Breakthrough — Starshot program and funded through a 2011 Kickstarter campaign — Sprites measure just 3.5-by-3.5 centimeters and weigh only four grams. The miniature satellites carry radios, sensors and computers, with each device powered by sunlight.
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.
Exploring the future
The whole idea behind launching such tiny spacecraft to planets orbiting nearby stars is to collect data which could help to shed light on the possibility of life beyond Earth. However, the immediate aim is to reach our nearest star system, Alpha Centauri. In this system, there is a star called Proxima Centauri which in turn contains the planet Proxima b. This planet has been very interesting for scientists all over the world, because it contains similar features like Earth, raising questions of a possibility of “extraterrestrial life”.
The mission will also explore the concept of solar sail propulsion in which spacecraft can be powered by using the sun’s radiation. These tiny satellites also mark the next step in the field of spacecraft miniaturization that can contribute to the development of centimeter and gram-scale StarChips envisioned under the Breakthrough Starshot project.
Though currently only prototypes of interstellar spacecraft have been launched for preliminary tests, Breakthrough Starshot wants to use lasers to launch the sprites deep into space.
The Sprites, once accelerated by laser, will reach up to 15% to 20% of the speed of light. Even with such great speeds, it will take over 20 years for a sprite to reach Alpha Centauri.
Once there, the Sprites will capture images of the star and its planet Proxima b, and send images back to Earth. Scientists expect to launch thousands of Sprites to study the Earth’s magnetic field and atmosphere, and this could become a reality within the next decade.
“This is a new frontier of tiny, gram-scale spacecraft,” said Professor Avi Loeb, Harvard University, chair of the advisory committee for the Breakthrough Starshot Initiative in an interview to the Guardian.
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 $100 million 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 miniaturized satellite into space and communicate with it.