Interstellar travel is studded with colossal challenges and a one-way trip would take 80,000 years to travel the four light-years to the star system nearest our Sun, Alpha Centauri, according to a US researcher.
The current propulsion technology is only able to move spacecraft at 0.005 percent of the speed of light.
Sidney Perkowitz, Candler Professor of Physics Emeritus at Emory University, Atlanta, US, reported his findings from the 100 Year Starship Study (100YSS) conference and discussed the challenges that interstellar travel presents.
Delegates at 100YSS - from ex-astronauts to engineers, artists, students and science-fiction writers - looked at the range of issues facing scientists who would like to make the "mad and glorious aspiration" a reality.
Starting with the development of a rocket engine that can reach high velocity, humans are not short of initiative, but, as Perkowitz has described, even with engines based on photon-powered sails or nuclear fusion, we are still a long way from reaching the speed of light.
Some theoretical models present tantalizing options, such as Miguel Alcibierre's idea to contract space-time in front of a spaceship and expand space-time behind it to create a bubble that would propel the spacecraft at any speed without violating special relativity.
Picking on this example, Perkowitz explained that the maths is impeccable but that the model requires negative mass, which, to the best of our knowledge, doesn't exist.
Accepting that interstellar travel will, at very best, take decades, some are now considering using suspended animation, or even carrying the DNA and other resources necessary to recreate humans on an unmanned ship.
"With the exploration of the solar system by the US space agency NASA and others well under way, and with the discovery of hundreds of exoplanets orbiting distant stars, it may be time to contemplate the next great jump outwards," Perkowitz wrote.
The study has been published in Physics World. (ANI)