Is Interstellar Spaceflight Possible?
With current space travel limited to just a few robotic probes visiting nearby planets, how realistic is it to think about reaching the nearest stars? For the short term, not very – especially when we speak of manned missions. But the long term - 50 or even 100 years - chances are good mankind will have missions, unmanned to start with, traveling to stars in our galactic neighborhood.
Actually, we already have space craft venturing into interstellar space. Pioneer and Voyager probes, 2 each, have reached the sun’s escape velocity and are now forever outward bound. The fastest, Voyager 1, is traveling at 62,000 kilometers per hour (39,000 mph). Even at that tremendous speed it’s painfully slow when interstellar distances are involved. Voyager 1 would take over 17,000 years to get Proxima Centuari, our nearest neighbor at 4.22 light years distance.
With a theoretical speed limit imposed by Einstein's Theory of Relativity at 1,079,252,848.8 km/h, or the speed of light, even the closest stars are very far away indeed.
But if you take in to consideration the rapid pace of technological advancement, things look brighter. The Wright brothers’ first feeble flights advanced to a man on the moon in just 50 years. In less than 100 years, we can travel 1,000 times faster. If this rule holds true for the next hundred years, we will be able to travel to the nearest stars with relative ease.
Predicting this future, however, is not easy. We simply lack even the basic theories to travel at above light speed making the engineering of an interstellar drive even further away. There are however, some interesting ideas on the drawing board that are within current theoretical limits.
A study by NASA in 1998 identified 3 potential propulsion technologies that might enable exploration beyond our solar system. Antimatter, fusion and light sails.
Story continues: physorg.com.