A guide to rocket propulsion. 🚀
Mars is 52.225 million miles away from Earth. Alpha Centauri is 4.367 light-years away from Earth. Icarus, the farthest known star is 5 billion light-years away from Earth.
With our current chemical rockets, it would take 9 billion years to reach Icarus! Not only that but companies like SpaceX charge $62 million to send a commercial satellite to space. Clearly, these rockets are not efficient, cost-effective, or powerful enough to make space travel feasible.
These reasons have prevented space travel within deep space, but to combat this, new methods of propulsion are currently being explored to make space exploration and inhabitation a reality.
When ion thrusters, rockets are able to produce ions by adding and removing electrons.
The propellant is ionized by a process called ion bombardment:
High-energy electrons collide with the propellant atoms resulting in them losing electrons.
As more and more ions are created through this process, plasma is produced which has properties of gas that are affected by magnetic and electric fields.
There are subcomponents to the ion propulsion system within a rocket:
- The power processing unit (PPU) converts the electrical power generated from solar cells or a nuclear source of heat into voltages which provide the currents needed to create the ion beam.
- The propellant management system (PMS) is responsible for lowering the pressure of the newly produced gas from the higher storage pressures to a level that is measured by the LPA (low-pressure assembly).
- The digital control and interface unit (DCIU) monitors the entire system’s performance and undergoes communication functions with the rocket computer.
NASA has been working towards ion propulsion development since the late 1950s and even tested this technology via the Space Electric Rocket Test 1. In fact, ion propulsion allowed for the Deep Space I mission using NSTAR (NASA Solar Technology Application Readiness) system.
Nuclear thermal propulsion harnesses the heat produced by fission reactions to accelerate the spacecraft at extremely high speeds.
This form of propulsion is currently being investigated mainly because of the reduced flight time it provides for astronauts traveling to Mars. The trip from Earth to Mars that would take 7 months using current-day chemical rockets would be shortened to 3–4 months using nuclear propulsion. With their travel time cut into half, their exposure to harmful radiation would be greatly minimized.
The specific impulse, which is
the change in momentum per unit mass of propellant ~NASA
is very high which allows for such a quick trip to Mars from Earth.
Systems are being developed to implement low-enriched uranium as the source of fuel because it is more cost-effective and allows for already established rocket engine testing facilities to be modified to test nuclear thermal propulsion systems. In fact, BWXT Nuclear Energy, Inc. is fabricating specialized fuel that is undergoing testing.
In order to test the full-fledged NFP system, engine ground facilities would be required.
But imagine, if rockets powered via nuclear propulsion became a reality, modern space flight would become extremely efficient and would greatly aid in the development and utilization of advanced fission systems in space.
I’m sure you’ve heard of matter… but antimatter??
Antimatter is essentially the opposite of matter. So, antimatter subatomic particles have numerous properties opposite to the normal subatomic particles that we commonly know such as neutrons, protons, and electrons.
Antimatter is sometimes called the mirror image of normal matter because while it looks just like ordinary matter, some properties are reversed.~ NASA
Antimatter fuel is the most powerful and efficient fuel known thus far.
Matter-antimatter reactions are 1,000 times more powerful than the nuclear fission produced in nuclear power plants and 300 times more powerful than nuclear fusion energy. ~Bonsor
There are three main parts to the matter-antimatter engine:
- The magnetic storage rings allow the antimatter to be separated from the normal matter by providing magnetic fields for the antimatter to go around until energy is needed to be created.
- The feed system releases the antimatter which then collides with normal matter to release energy.
- Magnetic rocket nozzle thrusters consist of an elongated magnetic nozzle that moves the newly made energy through a thruster to power the spacecraft.
When antimatter and matter come together they annihilate each other creating an unchecked amount of energy which is why it can be such a great fuel. New designs implementing antimatter propulsion will use positrons, making it a safer alternative because the gamma rays produced are very harmful to health.
100% of the mass of the antimatter and matter is converted into energy making it very effective as well.
Additionally, it would cost $250 million to produce enough fuel to last three years on a space mission to Mars versus the billions more required to merely send a satellite into space.
NASA’s Work with these Technologies
NASA has been conducting research on all of these propulsion systems and they have been able to make much progress throughout the years. In fact, NASA’s Space Electric Rocket Test I (SERT I) was able to operate its ion thrusters for a little over 30 minutes, while the Dawn Spacecraft consists of ion propulsion systems.
NASA’s Nuclear Engine for Rocket Vehicle Application (NERVA) program has recognized the potential of nuclear thermal propulsion systems and has been working towards making them a reality in order to reduce transit time from Earth to Mars specifically.
Although NASA has not yet been able to implement antimatter propulsion systems into their spacecraft, the NASA Institute for Advanced Concepts (NIAC) has funded a team to design a new antimatter-powered spaceship.
Why does this matter? 🤔
Whether we realize it or not, the realization of space travel and inhabitation will provide numerous benefits to the human civilization. In fact, we have already seen the benefits of using space to its fullest. Satellites such as SMAP, which detects soil moisture levels to enhance the farming industry, have already improved life here on Earth. The vast and endless outer space will act as our backup plan if anything bad were to happen on Earth allowing us to colonize and thrive elsewhere. With space, the possibilities are truly endless and we will truly be able to reach new heights as a civilization if deep space travel is accomplished.
- The current rockets we use today will not be the rockets we use in the future. They just aren’t good enough.
- Innovators are looking into ion propulsion, nuclear propulsion, and antimatter propulsion to make space travel more efficient than ever before.
- Ion propulsion has been something that scientists have looked into for the past few decades and is definitely achievable. Missions that are not possible with our current chemical rockets will be achievable with ion propulsion.
- Nuclear thermal propulsion would enable us to implement advanced fission systems and reduced radiation exposure due to shorter flight leading to safer and cost-effective space travel.
- Antimatter propulsion systems are the most disruptive thus far and will provide the most energy for space travel out of all the said propulsion systems.
Major steps towards improving our current state with regards to outer space are being taken. One day we will be able to cultivate the best rockets making space travel easier and more widespread than ever before. And who knows maybe someday we’ll be taking vacations to outer space? 😉