Nuclear powered rockets : future of conquering cosmic infinity

The moment we launched sputnik 1 , the first man made object to reach space , the space era begun......   

World countries racing against eachother to take man into space  and they believed that living in space will be the future of mankind

           ( credits : nasa , www.nasa.gov)

The most powerful , wonderful and useful technology that humans have ever built is rocket technology. 

Without this huge looking thing we would have not made it into space .

With the current rocket technology ( chemical and liquid engines) we are capable of reaching moon in three days and mars in 9 months.... seems like a lot of time right .

Spending this much time in space costs us more money as space industry it self is costly and space environment has tons and tons of radiation and we need to carry more life support system for the astronauts to survive which brings in mass as a big factor to be considered and it is the biggest enemy of rocket .if lets say a crew of astronauts are going to mars and in their journey to mars they have to face radiation which is not good for health .

So how can this problem be fixed......?

Maybe by reducing the time taking to reach the destination.  For that if we talk in terms of rocket science we have to increase the ISP which is the specific impulse of a rocket ( this thing says how fast the rocket would travel or we can say that how long in seconds 1 kg of propellant can give 1 kg of thrust ) . In chemical rockets the ISP is around 450. As the by product of burning rocket fuel and oxygen is water vapour it is heavy so it decreases the speed of exit velocity and hence the ISP is also less. Scientists after breaking their head with this came to a conclusion that we can use nuclear energy to do this . Sounds interesting right , but this is not a new concept

In the 1960 Scientists developed a nuclear powered rocket engine . The idea was like there will be a pressure plate and below that there will be literally nuclear explosion going on , 1st blast it will go forward 2nd blast again and it will move forward,  like that there will be a series of blast and that thing will propell in the forward direction,  but some time after the launch the whole thing got blasted . This was the initial encounter that space Scientists made with nuclear science .

But we are in 2021 and the whole concept of this thing got developed.  Now we are having ion thruster ( nuclear electric powered) in this type of rocket engine it will release xenon or krypton atom into the ionization chamber we will bombard the xenon atom with a high energy electron which produces  a positively charged xenon atom  and more electrons and the positive xenon atoms will move towards the grid ( there will be two grids 1 . Screen grid and 2 . Accerator grid ) walls of the chamber , the potential difference between the two grids causes the positive ions to shoot out at higher acceleration .  which is way more powerful that the existing chemical rocket as the exit velocity is upto 40 km /s and that of chemical rockets is 3.5 km/s  . 

But the problem here is we have to power  the ion drive . Currently we depend on solar panels to power them up but the regions after the planet Saturn do not get enough sunlight to power the entire system. So we need an alternative method and nuclear thermal powered rocket engines are the only way to do that as in nuclear thermal we generate our energy by nuclear reactions.

            ( credits: NASA, www. Nasa.gov )

And in the not so distant future we will be using the technology of nuclear fission ( nuclear thermal powered ) in which we will let a neutron to hit a  heavier atom and that heavier atom will get split into two lighter atoms and in this process, a lot of heat energy gets released. this is how a typical nuclear reactor on earth works in that a neutron will hit a uranium 235 atom and that uranium 235 atom will absorb the neutron and will become uranium 236 which is highly unstable so to make it stable it will split into two lighter atoms, with the released heat energy they will heat the water in the reactor and the water will turn in to steam and that steam will make the turbine to rotate and will generate electricity. but in the nuclear thermal rocket engine instead of water we will pump hydrogen fuel into the reactor core and using the same process the hydrogen fuel gets heated to an extreme temperature and it becomes a superheated gas and when it accelerates out of the rocket nozzle, as hydrogen is the lightest element in this universe its exit velocity is great and as a result, we get more ISP.

              ( credits: NASA, www.nasa.gov)

And the rocket engine with fission technology has an ISP of und 900 which is double the amount that a chemical engine gives us with this we can reach mars in just three months and future we will have the technology of fusion which gives out more heat energy than fission.

But even if we use nuclear-powered rocket engines it has its disadvantages as it is highly radioactive and we need a lot of protection against that and we can't use these nuclear-powered rocket engines in the booster stage that is in the initial launch stage as we don't want to make our planet not a safe place to live so the traditional chemical rockets will do the heavy lifting job for us. 

So let's believe that space travel will one day be very accessible to a common man and maybe who knows you can also get a ride into space even to mars or beyond our solar system.