NASA late last year outlined a three-phase plan to send astronauts to Mars. The ambitious undertaking, much of which involves ongoing space research and developing methods to harvest resources from Mars to sustain human life, is on schedule to unfold over the next several years.

Those challenges aside, perhaps the most pressing question then becomes how to transport astronauts to the red planet in the most efficient - and of course, safe - manner. Although Mars is one of our closest neighbors, it would still take a modern spacecraft several months to get there using traditional thrust-based propulsion methods.

Philip Lubin, a US Santa Barbara physics professor and NASA employee, believes the key to timely space travel lies in an alternative propulsion technology known as photonic propulsion.

In its simplest explanation, Lubin proposes a spacecraft with a reflective sail that could be pushed through space at an incredibly high speed (a significant fraction of the speed of light) by firing a laser directly at the sail. If successful, Lubin believes the method could send a 100 kilogram robotic craft to Mars in just three days. A larger craft occupied by humans could make the trip in about a month.

As Wired notes, photonic propulsion could allow us to explore other solar systems in search of potentially habitable planets. Maintaining communication with a robotic craft that far away, however, would still be a problem given modern technology.

Lubin says there's no known reason why we could not do this although there are several hurdles that must be overcome beforehand. For example, how would we slow down a spacecraft as it approaches its destination?

Those interested in delving deeper into Lubin's proposal can check out his 52-page paper on the matter by clicking here.