Alpha Centauri is our closest star system and also offers the possibility of finding extraterrestrial life. The problem is that even being the closest, it is 4.37 light years away and getting there, with current technology, would take thousands of years . It’s an idea that presents all kinds of technical and engineering challenges.
The Breakthrough Initiatives project founded in 2015 has been exploring the possibility of reducing these figures to just a few decades, allowing scientists traveling on the mission to live to see the results and not require a generational ship as we have seen so many times in science fiction . Now, in a new study published in the Journal of the Optical Society of America B, they have shown to have cleared one of the main hurdles (although more remain).
Scientists from the Australian National University (ANU) have unveiled the prototype of a new type of spacecraft propulsion system as part of this international initiative with the aim of exploring the worlds surrounding Alpha Centauri. The project is based on a laser-powered sail, an ultra-light spacecraft, which acts like a sail, which would allow it to travel with unprecedented speed and reach the star system in 20 years.
The best option, from Earth
Experts say that the light needed to propel the candle will come from the surface of the Earth: a giant laser array with approximately 100 million lasers that act in unison to illuminate the candle and push it on its interstellar journey.
“To cover the vast distances between Alpha Centauri and our own solar system, we must think outside the box and forge a new form of interstellar space travel,” clarifies Chathura Bandutunga of the Applied Metrology Laboratories at the ANU Center for Gravitational Astrophysics. Light missions could be given an immensely powerful boost and left to travel alone.
“Once on its way, the sail will fly through the vacuum of space for 20 years before reaching its destination. During its flyby of Alpha Centauri, it will record images and scientific measurements that it will transmit to Earth.”
This recently presented energy matrix is accompanied, in turn, by the spacecraft, which requires a gram-scale nanotechnology equipped with small sensors, thrusters, a camera and a radio antenna that would be towed by a dinghy scale of a meter measuring 4 x 4 and accelerated by the 100 gigawatt (GW) laser array. This would allow the spacecraft to reach speeds of up to 20% of the speed of light. Slightly slowed by the gravity of the Sun and the interstellar medium, the spacecraft could reach Alpha Centauri in about 22 years.
Is the atmosphere not a problem?
The adaptive optics used by telescopes to compensate for atmospheric distortion can be used in reverse, scientists say. Bandutunga says that a small laser mounted on a satellite pointed at Earth can be used to measure atmospheric effects in real time, which would allow much more powerful lasers located on the ground to adjust, keeping their focus safely on the probe. space. Thus, the guide satellite would be placed in the orbit of the Earth and would act as a conductor to unite all the lasers.
“The next step is to start testing some of the basic components in a controlled laboratory environment. This includes the concepts of combining small arrays to make larger arrays and atmospheric correction algorithms, ”the researchers clarify.
Alpha Centauri is home to three stars: Centauri A, Centauri B, and Proxima Centauri. Proxima Centauri is 4.2 light years from Earth and has two confirmed planets, a Jupiter-like gas giant and a rocky world called Proxima b in the habitable zone.
Referencia: Photonic solution to phase sensing and control for light-based interstellar propulsion Chathura P. Bandutunga, Paul G. Sibley, Michael J. Ireland, and Robert L. Ward Journal of the Optical Society of America B Vol. 38, Issue 5, pp. 1477-1486 (2021) DOI: https://doi.org/10.1364/JOSAB.414593
