When it comes to travel, it is logical to assume that the nearest goal will be the fastest to reach. In any case, if we are talking about the same roads. In space, this may not be the case.
Introduced to the general public about a year ago, the Breakthrough Starshot startup intends to send a fleet of several thousand miniature ships to our space neighbor, the Alpha Centauri star, in the foreseeable future. Equipped with a solar sail and accelerated by a laser from Earth, a boat weighing about a gram should reach a speed of about one-fifth of the speed of light. In this case, the path to the goal will take him about 20 years. Upon reaching its destination, the boat uses its sail as a reflector to transmit the collected data. Perhaps (and even probably) not all will fly - that is why there will be so many devices.
The coming years will show whether this concept will be implemented in practice. While it is being discussed, calculated and criticized. The project has so far proved viable enough to withstand the first wave of criticism. It looks like there really is a chance of reaching the destination. So what is next?
It will take several hours to fly through the entire Alpha Centauri system at a speed of one-fifth of the speed of light. It is impossible to reduce the speed - our boat has no brakes, and they do not fit into one gram of mass. Waiting for this event for two decades, not counting the time to develop probes, is perhaps too luxurious. Perhaps, in order to get some meaningful result, it is worth staying in the system under study longer.
This is how the concept of a ground-based booster station of the Breakthrough Starshot project looks like today.
After this, somewhat protracted, introduction, you can move on to the heart of the matter. Two astronomers - René Heller from the Institute for Solar System Research. Max Planck in Göttingen (Germany) and independent researcher Michael Hippke - propose to change the project, changing its purpose. Reaching the stars in it will remain, but instead of the nearest Alpha Centauri, Sirius will become the target of the flight. Being twice as far away (eight light years instead of four), Sirius glows 16 times brighter, so its light, if desired, can be used to decelerate the probe.
According to Heller's calculations, in principle it is possible to put the probe into orbit around Alpha Centauri, but the flight in this case will take about 140 years. It takes just 69 years to get to Sirius, slow down and stay in orbit.
The idea is “innovative and interesting,” says Avi Loeb of Harvard University. "However, it will take a very thin sail if the goal is truly to achieve a fraction of the speed of light."
“We need a very lightweight, durable, temperature-resistant and highly reflective sail material that can cover an area of several hundred square meters,” says Heller. The material could be based on metamaterial-coated graphene, he said. "If it works, then humanity can indeed become interstellar."
It should also be noted that, according to modern data, the age of Sirius is only slightly more than 200 million years, so there is absolutely no chance of finding brothers in mind or at least a formed planetary system there.
A preprint of the article by the authors of the new idea is available at arxiv.org.