For as long as humans have walked on this earth, we have stared into the black expanse
of space.
Wondering where our place in the universe was and why we are here.
The rhythm of the moon’s phases has guided humanity for millennia, but Galileo was the
first to point a telescope towards it and identify its mountains and craters.
Not just that he saw that those distant heavenly bodies had moons of their own, a discovery
that shook the religious world’s view of our place in the universe.
Fast forward 300 years and we have landed 12 men on our moon.
An achievement that was largely driven forward in a world living in the shadow of the threat
of global nuclear war.
Since that threat has subsided our race to expand into space has waned.
The Mars society put it best with their founding statement.
Civilisations, like people, thrive on challenge and decay without it.
The time is past for human societies to use war as a driving stress for technological
progress.
As the world moves towards unity, we must join together, not in mutual passivity, but
in common enterprise, facing outward to embrace a greater and nobler challenge than that which
we previously posed to each other.
Pioneering Mars will provide such a challenge.
One man has embraced that challenge like no other and his name is Elon Musk.
Today we are going to investigate how will Space X get us to Mars.
Elon Musks ultimate goal is to reduce the cost of space travel.
He believes if he can get the cost of a ticket to Mars down to around half a million USD,
the overlap of people who actually want to go to Mars and the people who can actually
afford it will be great enough to fund a Mars colony.
The most efficient way, that is the one that uses the least amount of fuel, to get to Mars
from Earth is with the Hohmann transfer method, named after Walter Hohmann, who first proposed
the idea in 1925.
With this method you wait for earth to be at it’s closest point to the sun and then
launch.
Mars needs to be about 44.4 degrees ahead of earth so that Mars will be at it’s most
distant point from the sun when the vehicle arrives.
This alignment happens once every 26 months.
This is not the short or fastest path to Mars, but it requires the least amount of energy
input.
When getting the cost of travel down, this is the deciding factor.
As I mentioned in my last video, the Space Shuttle could transfer one kilo to low earth
orbit for 18000 dollars, the falcon 9 can do the same for just 2700 and Space X is continuously
working to reduce that cost.
Let’s take a look at the falcon 9s launch sequence to learn some of the ways Space X
has reduced the cost of operation.
The Falcon 9 first stage is powered by 9 Merlin engines.
These engines have the highest thrust to weight ratio of any booster engine ever made at 155:1.
This means the engines can lift more with less fuel and do it faster.
At launch the 9 engines produce 7900 kN of thrust lifting the 550 tonne rocket of the
ground and gradually accelerating it to 5 times the speed of sound.
This section, called the interstage, houses another Merlin engine that is designed to
work optimally in the vacuum of space.
The first stage now separates about 75 km above our planet’s surface and reveals the
second stage engine.
It’s interesting to note that the interstage remains connected to the first stage, after
seperation.
This was not the case for the Saturn V, as the interstage needed to wait for the engines
of the second stage to fire before separating using pyrotechnic charges.
This ensured a clean separation, as there were worries that the interstage would collide
with the engines as it separated.
due to clearance issues.
This is not a problem with the Falcon 9, making the interstage reusable and again saving money.
The Merlin engine of the second stage is designed to be shutdown and restarted multiple times
to deliver the payload to the appropriate orbit, or increase the velocity enough to
perform the Hohmann transfer to Mars.
The payload is stored inside this composite fairing, which is big enough to fit a school
bus.
When the time is right, the fairing splits in half and drifts away from the second stage.
The payload is now released into orbit around earth.
Meanwhile the first stage has begun its decent back down to earth.
Cold gas thrusters fire to flip it around, once this maneovre is complete the engines
will fire again to bring the speed down for re-entry and give it an appropriate trajectory
to reach the landing site.
Upon re-entry the grid fins deploy which provide aerodynamic control allowing it to steer.
These are fantastic little devices that provide excellent control at supersonic speeds.
This mesh structure provides a huge amount of control surface area in a small amount
of space, which allows them to be easily stowed away during launch to reduce drag.
Grid fins are also much shorter than conventional planar fins, so they generate less hinge moments
meaning they need smaller motors to control them in high speed flow.
As the first stage descends closer to sea level, the cold thrusters, grid fins and merlin
engines work together to control the precise landing on the drone ship barge.
The reason Space X uses this barge is another cost saving measure.
The falcon 9 launches from land towards the sea for safety reasons, when the first stage
separates it’s over open ocean and if it needed to return to land it would need to
slow down, turn around and use more fuel to get back to where it started.
Instead the drone ship can place itself at the predicted landing zone and wait for the
first stage, this way the falcon 9 just needs a little bit of extra fuel to slow itself
down to land.
Most people see Space Xs true innovation in their reusable rockets, but their innovation
in the manufacturing field is just as significant.
Space X was the first space company to employ a method called vertical integration to manufacture
their rockets.
This means that Space X designs and manufactures nearly all it’s components itself.
The Merlin engines, the aluminium-lithium fuel tanks, the composite fairing for holding
the payloads, the dragon spacecraft, the flight control computers and the coding that goes
into them.
They are all designed manufactured by space X.
Comparing this to the Space Shuttle.
Rockwell developed the orbitor, Lockheed Martin developed the external tank and ATK developed
the solid rocket boosters.
Each of these companies have their own subcontractors too..
Each subcontractor adds a markup percentage to their selling price in order to make their
own profit.
Manufacturing everything yourself eliminates all of these price markups.
It cuts out the middlemen, like buying popcorn as kernals and cooking them yourself, rather
than buying them from the cinema for 10 dollars.
It has the added benefit of allowing you to have full control of your quality control
and creates an efficient product development system.
All of your employees can speak and collaborate to improve and develop new designs.
Elon insists on open plans offices to remove any communication barrier.
He himself works in a cubicle.
This creates the perfect environment for continual innovation and if we want to get to Mars that
is going to have to happen.
So you may be wondering what is next for Space X.
They will be launching their Falcon 9 heavy variant at the end of this year.
According to Space X the falcon 9 can currently launch 1 kilo to Mars for 15400 dollars, but
the heavy variant can launch one kilo for about 6600 dollars.
The average American weighs 80 kg, ignoring all other costs like how you will live on
Mars and how you will survive journey there, the raw price for a one way trip to Mars will
be half a million dollars.
Musk aims to bring the price of a round trip, including all other expenses, to Mars, down
to half a million total.
In 2010 Space X presented concept designs for future heavy lift rockets, that will help
towards that goal.
They are also planning to replace the 9 Merlin engines of the Falcon 9 with one incredible
powerful engine, dubbed the Merlin 2, that will increase the thrust to weight ratio even
more.
I, for one, am really excited to see what Elon Musk and his incredible employees have
in store for us.
Thanks for watching!
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