The more we look into the Universe the more obvious it becomes that our Solar System and potentially our own Earth is not as unique as we once thought. Just this week NASA released news about Kepler-452b which is very similar to Earth both in size, its parent Star and its distance from the star.
Today we are going to take a look at three of the technology breakthroughs we would need to make to be able to visit other Solar Systems.
At present all communications are limited to the speed of light 186,000 miles per second (mps) therefore the further we move away from Earth the longer it takes to communicate information back. Take for example the recent visit by NASA New Horizons which just pasted the planet Pluto, a signal from the spacecraft when at Pluto took 4.5 hours. The nearest star to ours is Proxima Centauri which is 4.2 light years away (more than 24 billion miles).
There are significant challenges when dealing with communicating at the speed of light over vast distances, for the purposes of this article we are going to use laser-based communications not radio-based.
1) Location of receiver – If you send a signal towards Earth today which wasn’t expected to arrive for 4.2 years we would never receive it because Earth would not be in the same location by the time the signal arrives. Therefore we would have to calculate where Earth should be when the signal is expected to arrive.
We would also need to calculate how much data could be returned before the signal would be lost again.
2) Data Corruption – The chances of data corruption over the vast distances involved are significant, therefore we would have to build a system that would provide a way of compensating for this corruption, this would result in less actual data being returned as each packet of data would have redundant information from other packets.
3) The long wait – With New Horizons we only had to wait a relatively short amount of time for signals, when we have to wait 4.2 years for a signal to arrive things will be much more intense.
In order for us to overcome these challenges we are going to need to find a way to break the light speed limitation on communications.
One technology that could allow this is Quantum Entanglement where two or more particles interact in ways that the quantum state of each cannot be described independently. If a device was able to measure and control the state of each particle then it may be possible to transmit data. This is purely theoretical at present based on a limited understand of how it works.
At present the fastest vehicle we have travelling in space is the Voyager 2 which is travelling at 17 kilometers per second (kps) relative to the sun. This translates to approximately 38,000 miles per hour or 0.0057% the speed of light.
The New Horizons probe that was launched in 2006 more than nine years to get to Pluto and it currently travelling a little slower than Voyager 2 at 16.26 kps.
Based on these speeds it would take a spacecraft 73,000+ years to get to our nearest neighbor Proxima Centauri.
We believe there are two technology breakthroughs needed for transportation:-
The first breakthrough would be to significantly increase the speed at which spacecraft travel within our Solar System. The long term goal would be to increase the speed by a factor of 10,000 allowing us to travel at 57% the speed of light. While this doesn’t sound too bad it comes with big risks, including how to avoid debris, how to navigate around the solar system at those speeds and ensuring we slow down when approaching the target. There is a lot of research going on at present to help increase the speed of spacecraft, and these could well achieve the desired speed increase however it would take many years of continuous thrust to get there. For more information on current research check out the following (not exhaustive list) of companies/agencies researching.
Ad Astra – VASIMR
NASA – Ion Propulsion
NASA – NEXT
UCLA Plasma & Space Propulsion
The second and biggest would be to breaking the light speed barrier, and while there is research being done into this it could be many years before we can do this, if ever. The possibilities that would be open to us if we were able to achieve faster then light travel are almost limitless, however it is very unlikely that in our lifetimes we are going to be able to achieve this.
At present we have two ways to provide power to spacecraft Solar and Radioisotope thermoelectric generator (RTG), the problem with these is they have limited applications.
Solar is very useful for applications nearer to our Sun but once we start getting into the outer solar system they are harder to justify. RTG’s can provide power for many years however in general they provide a very small amount of power typically between 100-450 watts.
For long term missions that cannot rely on these power sources, for example a mission to Europa’s Ocean or to Triton, we need to come up with another source of power that can provide what is needed.
One concept in design by NASA is a Sterling Engine, this uses the same fuel as an RTG but because of the design it can produce more power. However because it has moving parts there was concern that it could damage sensitive instruments. More information on the design can be found here.
So in summary while we can explore the universe using the amazing telescopes that we currently have and that exploration will only get better with new scopes in development or being planned. Going physically beyond our own Solar System is not something that is going to happen for many years yet. We would love to be proven wrong on this and for a breakthrough to come that would enable it however realistically we will be stuck to a low % of light speed travel probably for most of this century.
The views expressed in this article are the authors and any feedback would be welcomed, if you know of any research into these technologies we would be happy to update the article to include details on the research and links to any publications from the team.