How NASA and Aerojet Rocketdyne AEPS Laser Propulsion means Interstellar Travel in Days

Finally, NASA has decided to go with electric propulsion for their next generation of satellites and probes.

They've awarded a $67 million contract to rocket engine manufacturer named Aerojet Rocketdyne to build this electric propulsion as announced April Wednesday 20^th, 2016  reported in the article “NASA contracts Aerojet Rocketdyne to develop a new electric system for deep-space vehicles”, published April 20, 2016 By Loren Grush, The Verge.

Electric Propulsion isn't intended for launching rockets. Rather it's intended to be used for deep space exploration of the planets and outside of the solar system.

Asteroid Redirect Mission and their NASA’s Journey to Mars initiative will benefit from this new form of propulsion, which would be based on the RS-25 engines, a chemical propulsion unit as described in “NASA invests $67 million into solar electric propulsion for deep space exploration”, published April 22, 2016 by Emily Calandrelli, Techcrunch. 

NASA has had past experience with electric propulsion, having used one for the Dawn spacecraft orbiting Ceres in the asteroid belt. NASA has given Aerojet a 36-month contract to develop an AEPS (Advanced Electric Propulsion System) ten (10) times more efficient than the one used in their Dawn spacecraft.

As part of their contract, they've given the contractor a prototype thruster and power system to use as a template to build the electrical propulsion system to their specification. So how does an electrical propulsion system work?

NASA and Aerojet Rocketdyne - How Fleming's Left Hand Rule helps in Deep Space Exploration

To understand this form of propulsion, we'll have to recall Newton's Third Law. This law states that when one objects exerts a force on a second object, the second object exerts and equal and opposite force on the first object.

Aerojet's system will have the following components:

1.      Thruster

2.      Power system

3.      Propellant Flow Module 

A spacecraft using an electrical propulsion system would convert solar energy into electricity.

This electricity is then used to aerosolize and then ionize an onboard propellant stored in a propellant tank whose flow is controlled by the Propellant Flow Module as noted in the article “Aerojet Rocketdyne Wins $67M Contract for Solar-Electric Drive for Missions to Mars”, published April 23, 2016 by David Z. Morris, Fortune.

As the gas is ionized, it’s then accelerated down the thruster chamber using Fleming's Left Hand Rule to determine the direction of the magnetic field.

Remember that the charged ions will most likely have a net positive charge, as it’s usually easier to strip off electrons for the atoms of a propellant than to add electrons. Also, the propellant has to be a fuel that can be easily ionized and of a significant mass so as to generate enough momentum to push a large spacecraft along.

The Thruster chamber will have the magnetic field designed in such as manner as to accelerate the charged ions out the back of the aircraft, creating thrust. The genius of an electric propulsion system is that it works the same way like a typical chemical rocket engine but uses way less fuel, as it doesn't need to carry oxygen to burn another propellant i.e. hydrogen.

It's also suitable for deep space missions, albeit further away from the Sun might present some problems, being as radiation from the Sun that far out into space is not as strong.

Directed Energy Propulsion and Electric Propulsion Units - Interstellar Travel in days not years

One idea is to use a gigantic Maser array on the Earth or in space in earth orbit.

It would collect the solar energy and then converted it into a very intense tight laser beam that the Spacecraft could receive and harness as energy, effectively a form of directed energy propulsion as described by UC Santa Barbara physics professor Philip Lubin in the article “Could a spacecraft really make the journey to Mars in 30 minutes? One physicist says yes”, published February 26, 2016 By Rick Stella, Digitaltrends.

Because a Laser or Maser (Microwave Laser) is a tight concentrated stream of energy, it would make it possible for NASA to use a Solar Sail similar to the one described in my blog article entitled “The Planetary Society LightSail Cubesat deploys Solar Sail – Why Surfing the Solar Wind is now on @NASA agenda” 

Directed Energy Propulsion would make travel across the solar system take days, instead of years. It would also solve the power problem at distance further away from the Sun, as the spacecraft can switch over to using the solar panels to pick up the radiation from space based Maser Array to power the AEPS. In so doing, the spacecraft could get all the radiation energy needed to power its way across the solar system and eventually into interstellar space.

NASA needs to look beyond the Asteroid Redirect Mission and their Mars initiative towards Interstellar space, where humanity true destiny lies.