One of the major roadblocks to interstellar travel is the immense distance involved. We can design rockets that can escape the force of Earth’s gravity, even reach Mars in a matter of 8 months. but outside our Solar System? Forget it. The fastest speed we can reach in is not enough to propel us outside the Solar System in a reasonable time frame, which is why rendering proper exploration outside it is impossible. Engineers and researchers have been grappling with this speed limit for some time now, and apparently a feasible solution has been announced.
Last month, British cosmologist Stephen Hawking, Russian billionaire Yuri Milner and Facebook pioneer Mark Zuckerberg announced the $100 million ‘Breakthrough Starshot project’, which is a technology with the potential to accelerate spacecraft at approximately a fifth of the speed of light: 60,000,000 ms-1. This velocity is achieved using ‘nanocraft’ or tiny 1 gram rockets accelerated with lasers from a high altitude point on Earth. These nanocraft will hitch a ride on meter wide sails called light sails.
The basic idea was developed by astrophysicist Philip Lubin of the University of California, Santa Barbara. It uses a large number of solar powered lasers (which emit a 100 gigawatt beam for a few minutes). This is around the same energy as that required for launching a standard rocket using chemical propulsion. These lasers propel the postage stamp sized nanocraft into space at incredible speeds.
It is being estimated that using nanocraft and the laser technology developed by Lubin will make it possible to reach the closest star system to our solar system, the Alpha Centauri system in approximately 20 years.
To put this into perspective, chemically propelled space crafts like the Voyager 1 (which was launched almost 40 years ago), in the current state of technology, would take 100,000 more to reach the Alpha Centauri star system.
But that is not everything one can achieve using the nanocraft.
Apart from providing the fastest means of travel humans can possess in the near future, the same technology, according to Lubin, can be used to propel heavier and larger crafts with proportionately sized lightsails.
By using this technology, it is also possible to cut short the journey to Mars (which usually takes numerous months) by a few weeks or even days. This brings us closer to the current mission of agencies like NASA of putting human footsteps on the surface of Mars.
Lubin also mentions other potential applications of this technology, like beaming power supply to distant space craft, ‘trapping’ asteroids and other celestial bodies for mineral composition analysis and study, de-orbiting space debris and modifying other planets to make their conditions similar to those on Earth (a process called terraforming).
Interestingly, in the event of a possible collision between Earth and an asteroid, the same technology could be used to change the asteroid’s orbit and prevent a catastrophe.
While this is the most feasible and effective idea to make interstellar travel a reality, some economic and engineering obstacles still remain. Making it feasible requires a drastic fall in costs of laser power and equipment, photovoltaic cells and access to space.
When asked about it, Philip Lubin remarked, “We cannot find a reason we can’t do it. This doesn’t have to be science fiction.”
