In 2069 we start for Alpha Centauri
The centenary of the lunar landing could be the year of the departure of the first interstellar mission. The goal (far) is to reach a speed equal to 10% of that of light.
The 100th anniversary of the moon landing could mark a new venture in space exploration. According to the New Scientist report, 2069 would have been chosen as a symbolic date for the departure of the first interstellar mission.
The project presented by NASA’s Jet Propulsion Laboratory (JPL) at the 2017 American Geophysical Union conference in New Orleans on December 12. Is so new and ambitious that it does not yet have a name. For now, there is a basic idea. Send a probe into the orbit of the nearest exoplanet, looking for other life forms. But the technology is lacking to implement it.
THE INITIAL IDEA.
The impulse to aim so high (and far) started from a double political request advanced to NASA in 2016 and never became a law. To study an interstellar means of transport that can reach 10% of the speed of light, and use it to reach Alpha Centauri, the star system closest to us (at 4.3 light years). With the technology we have today, it would take hundreds of thousands of years to complete such a journey.
The JPL scientists took the task seriously and tried to draw up the first list of objectives. To characterize the atmosphere of the “target” exoplanet (one could be Proxima b). To look for signs of artificial structures, modifications of the landscape and luminous emanations. During the journey could test the properties of matter and radiation that meet and verify the validity of the general theory of relativity.
In order to achieve the desired speed, it could be possible to resort to propulsion methods based on matter-antimatter collisions, nuclear propulsion or laser-light-powered sails like those conceived by the Breakthrough Starshot initiative: all technologies currently not available.
LIKE STAR TREK.
The most interesting is that which would exploit the annihilation of matter and antimatter. That is the energy that is freed when particles of matter meet with their “different twins” of antimatter. The “different twin” have the same mass but opposite electric charge. The encounter between a hydrogen atom and an anti-hydrogen atom causes a flash of energy that makes nuclear fusion look like a small fire. The problem is to produce antimatter. On Earth, we can do it with great difficulty in particle accelerators. Then, keep it separate from matter until the right time.
One way to do that is in a 2003 study by Steven Howe and Gerald Jackson of the Chicago Fermilab. The two researchers imagined a reservoir composed of a series of cells, each containing a packet of anti-hydrogen atoms separated from the rest by an electric field; the tank is connected to a source of electricity, which periodically causes a discharge and causes a little fuel to come out of the cells, directing it towards a “veil” in carbon covered with uranium. When the anti-hydrogen meets uranium, there is the annihilation, which produces a boost on the sail.
According to the two researchers, with an engine of this type would suffice 17 grams of anti-hydrogen to get to Alpha Centauri in 40 years, reaching a speed equal to one-tenth of that of light. The problem is that 17 grams are enormously more than all the antimatter so far produced on earth. Furthermore, even if one could achieve such an engine, a political problem similar to that of nuclear would resurface. Because, in principle, antimatter is terribly effective even as a weapon.
LAST OBSTACLES: BRAKING.
If the star system is reached, pointing to the orbit of an exoplanet would require tens of years more to brake and maneuver the probe. The mission would end up lasting a few centuries.
But dreaming does not cost anything. Above all, because applying to such an ambitious goal could help to improve the exploration of our solar system and make it faster to reach Mars.