Since the beginning of spaceflight, humans have accomplished wonderful feats of exploration and showcased their drive to understand the universe.
Yet, in those 60 years, only one spacecraft, Voyager 1 (launched in 1977) has left the solar system. As remarkable as this is, humans will never reach even the nearest stars with out current propulsion technology. Instead, radically new strategies involving the technology already available must be used.
We propose a roadmap to a program that will lead to sending relativistic probes to the nearest stars.
To do so requires a fundamental change in our thinking of both propulsion and our definition of what a spacecraft is. In addition to larger spacecrafts capable of human transportation, we consider “wafer sats”, wafer-scale systems weighing no more than a gram. The wafer sats would include integrated optical communications, optical systems, and sensors. These crafts, combined with directed energy propulsion, could be capable of speeds greater than 0.25 c.
This program has applications for planetary defense, SETI and Kepler missions.
At about four light-years from the sun, Alpha Centauri is the closest star system to the solar system. While that may seem relatively close, it would still take humanity thousands of years to reach, based on current propulsion technology.
In fact, it took Voyager 1, which was launched in 1977, 37 years to reach the outskirts of the solar system. That spacecraft flew at 17 km/sec, less than 0.006% the speed of light.
“We have to radically rethink our strategy or give up our dreams of reaching the stars in a way romanticized in books and movies,” wrote Philip Lubin, of Univ. of California, Santa Barbara’s Physics Dept.
In his paper, “A Roadmap to Interstellar Flight,” and in a video from NASA 360, Lubin states that photonic propulsion, or the propulsion of objects through light particles, could help humanity achieve quick interstellar travel, turning science fiction into science fact.
Currently, NASA estimates that it would take humans roughly six months to travel to Mars. According to Lubin, his theoretical technology could propel a 100 kg robotic craft to Mars in a few days, and a shuttle-sized craft in about one month. The former robotic craft would travel around 1,200 km/sec.