In December twenty fifteen, SpaceX landed an orbital Falcon nine rocket booster back on
the Earth for the first time in the history of human spaceflight, and in
the eight years since, SpaceX remains the only rocket provider who can accomplish this
feat. In fact, no one else has even tried. So what's the
deal with that? How did SpaceX come out of nowhere and leap frog over
companies that had already been launching rockets for decades. Could it be that Elon
Musk is an unprecedented super mega techno genius. Yeah, maybe, But we
think that there's a much more fascinating and satisfying answer to be found here,
So let's get into it. This is the space race. If there is
one defining factor that sets SpaceX apart from the rest of the aerospace industry,
it is the reusable rocket. SpaceX has completely reinvented this technology in a way
that no one has ever dared to dream. But that's not entirely true,
is it. Obviously someone down the line must have had the thought that maybe
it would be better to try and keep these gigantic rocket boosters instead of just
sending them to the bottom of the ocean every time. And we all know
that the Space Shuttle was already reusable. Right, Even Blue Origin can land
their rocket booster the same as a Falcon nine. If you ask other leaders
in the aerospace industry, they'll try to tell you that reusable rockets are not
actually any more economical or sustainable than the traditional method, and that landing a
booster is more of a parlor trick than an innovation. So what is it
that really sets SpaceX apart? Then? To find the answer, we have
to go back to the beginning. The first rocket boosters to ever send a
payload into outer space were simply reconfigured intercontinental ballistic missiles. The Titan two,
which served as the launched booster for NASA's Project Gemini, was originally designed to
send a nine megaton nuclear warhead halfway around the world. So there's only so
much and realistically expect them to do. When it came time for the Apollo
missions to the Moon, NASA was ready to design their first bespoke orbital rocket,
the Saturn five. It was a humongous vehicle that to this day still
dwarfs nearly every rocket ever produced, and yet only the relatively tiny crew capsule
at the very top ever returned to the Earth. The rest was either dumped
in the ocean, left floating in space, or abandoned on the surface of
the Moon. This seems like a waste of money and resources, but in
reality, it was the preferred option for NASA to make the Saturn five entirely
disposable. This was the most economic choice at the time because the Saturn five
was only ever intended to fly around a dozen missions, and it was calculated
that the cost to build twelve disposable rockets would still be cheaper than developing just
one reusable rocket. Besides, the engineers at NASA were already looking towards the
future even before the first person set foot on the Moon. NASA was developing
their space Shuttle concept, a fully reusable rocket plane and booster system that would
be the true answer to sustainable human spaceflight. NASA's chief architect of the Saturn
five, Werner von Braun, perfected his concept for the Faery rocket back in
the mid nineteen fifties. The former Nazi rocket scientist would come to be known
in America as the father of space travel. We didn't really find out about
the Nazi thing until after he was dead, so we can only appreciate how
screwed up this was in hindsight. Anyway, the Faery Rocket was going to
be the vehicle that brought human space flight to the main stream. The three
stage rocket would be fully reusable, with the two first booster cores coming down
softly on parachutes and the third stage orbiter gliding back to Earth for a runway
landing. We should probably do a full video someday just on the Fairy rocket
concept alone. What do you think? Let us know in the comments below.
Anyway, you'll notice that this all sounds pretty similar to what the Space
Shuttle ended up being, yet still quite di frint in the fundamental design.
While the Space Shuttle has generally been built as a reusable space plane, the
more correct terminology is generally considered to be refurbishable. But what's the difference.
If you go to an airport, you can watch a plane land, unload
its passengers and cargo, then get rapidly cleaned, restocked, and refueled before
taking on a load of passengers and lifting off into the sky. Yet again,
that all happens within the span of about an hour or maybe even less,
so we can safely say that a commercial airplane is reusable. Now if
that same airplane had to be fully disassembled, inspected, serviced, and put
back together after every single flight, does that still fit the same definition of
reusable. Not so much, and it certainly doesn't sound like a sustainable way
to operate a commercial airline. That is the issue that NASA faced with their
Space Shuttle. It could technically be reused, which fit the initial criteria that
the agency was granted by US Congress when Shuttle was funded back in nineteen seventy
two, but the procedure involved to actually get a Space Shuttle and its twin
booster engines back on the launch pad after being flown just one time ended up
totaling around six hundred and fifty thousand hours of combined labor spent on transporting and
refurbishing the system. Obviously that all happened simultaneously, not sequentially, Otherwise it
would take seventy four years to refurbish one Space Shuttle. The thing about reusable
rockets is that they are only valuable if the frequency of launches is great enough
to outweigh the cost of developing and utilizing the technology. So, like we
were saying, before. This is how NASA decided it was cheaper to launch
twelve disposable rockets instead of developing one reusable system. And at what point does
a reusable rocket actually start to make sense economically? How many launches does that
take? NASA never really had the chance to find out. Not only did
the Space Shuttle need more work to refurbish than had been expected, it never
flew anywhere near as frequently as NASA envisioned either. In the end, it
would have been cheaper or at least just as expensive for NASA to throw every
Space Shuttle in the garbage after one flight and build a whole new one.
So, if you want a good answer as to why none of the commercial
rocket companies ever tried to develop their own reusable vehicle, it's because they already
saw what happened with the Space Shuttle, not only the most expensive rocket ever
developed, but also the most dangerous and probably the least successful at fulfilling its
original design concept. And if NASA couldn't do it, then obviously no one
else would even stand a chance. Right then along came SpaceX, who decided
that they will succeed where all others have failed. Now, to be fair,
SpaceX did come at the problem from a much different angle than NASA had
taken with the Shuttle, and in many ways their approach with the Falcon nine
does make a lot more sense from a logistics standpoint. Something that SpaceX had
envisioned from the very start of their development with a Falcon one rocket was recovering
and reusing both the first stage booster and the upper stage vehicle by having them
execute a propulsive return to launch site and landing maneuver. Now, they gave
up on recovering the second stage pretty early on, and that's a reasonable concession
to make, because with a conventional rocket, the upper stages a relatively simple
vehicle that consists of just one engine, a couple of small fuel tanks,
and a platform that holds the payload until it's time to deploy. But recovering
the first stage booster is a much more valuable proposition as long as you can
make that booster fully reusable, not just refurbishable, and then fly it often
enough to make the extra effort worthwhile. Of course, SpaceX opted for the
most technically challenging recovery method there is, the propulsive landing. This was unprecedented
territory back in Werner von Bron's old ferry rocket concept. The booster stages would
fire their engines on the return to Earth as a way to help slow them
down, but ultimately would land in the ocean water under giant parachutes. And
NASA had successfully recovered the Space shuttles twin booster engines by simply parachuting them back
down following stage separation. So why didn't SpaceX use parachutes on their Falcon booster
Short answer, they tried, but physics wouldn't allow it. Parachuting the shuttle
boosters worked for two reasons. One, they were pretty small and pretty light,
being solid rocket boosters. Once all of the propellant is burnt up,
they're basically just empty metal tubes. Two, the shuttle boosters separated at a
relatively low altitude and therefore a relatively low velocity of just around forty eight hundred
kilometers per hour. They were only really necessary to get the shuttle off the
ground and through the thickest part of the atmosphere. After that, the shuttle
still had three incredibly powerful hydrogen burning RS twenty five engines that continue pushing to
reach orbital velocity in a single core two stage rocket like the Falcon nine,
that one booster has to impart a tremendous amount of velocity into the upper stage
so that the final vacuum engine can continue to accelerate the payload into orbit.
This means the Falcon booster will fly much higher and faster, reaching a speed
over eight thousand kilometers per hour at stage separation. The formula for kinetic energy
is one half mass times velocity squared, which, in the case of a
Falcon nine booster that just released an orbital payload, equals way too much energy
for any parachute to withstand. That is why von Braun envisioned the hybrid of
engine d acceleration combined with parachute assisted landing. But this is Elon Musk philosophy
we're talking about now, and the best part is no part. The rocket
already has engines, so why bother adding parachutes to lower velocity when the engines
can do the exact same thing. The engines on the Falcon nine also serve
a dual purpose as a free heat shield to protect the booster as it re
enters the atmosphere. So in the case of a drone ship land ending scenario,
the Falcon nine booster is going to coast up and clear through the atmosphere,
crossing over the carbon line and technically being in space for about a minute
or so. But since it's not traveling at orbital velocity, the booster is
eventually going to fall back down. As this begins to happen, the booster
is going to flip around and point its engines in the opposite direction to perform
a re entry burn. The maneuver is going to start killing a ton of
the booster's velocity, which is important, but even more critical, the thrust
from the engines will create a force field underneath the rocket that protects the metal
from the extreme heat of reentry. That's when you see the crazy jellyfish looking
cloud of smoke and fire build up underneath the rocket as it's coming back down.
It looks awesome. Then the booster will coast down through the atmosphere,
losing more velocity to friction as it's guided in by aerodynamic gridfins. At the
last moment, the engines will reignite one more time to make sure that the
booster velocity reaches zero. At the moment that the landing legs touched down on
the floating platform. This is a procedure that SpaceX has now repeated well over
a hundred times, and these days they make it look pretty easy, but
that was not always the case. It took SpaceX a lot of trial and
error and multiple upgrade cycles to the Falcon nine before they could truly stick the
landing. Most people might not realize that the Falcon nine was not a genuine
reusable rocket until SpaceX achieved its final form in twenty eighteen, known as the
Block five. Most rockets don't really go through an active development cycle once they
begin operation. The design they have on the first successful launch is more than
likely going to be what they stick with throughout the life cycle of the product,
and that's because rockets are very temperamental and dangerous vehicles. Anytime you change
a design, you introduce an unknown variable which could then in turn lead to
a failure, and no one wants that unless your SpaceX. Another of elon
philosophy, if things are not failing, you are not innovating enough. Let's
start with the Falcon nine Version one. The first iteration of this rocket was
actually a lot smaller, at just about forty six meters in total length and
a lot less powerful at just one point one million pounds of thrust. Even
though SpaceX had already intended to make falconine a reusable booster, this version didn't
receive any of the necessary gridfins or landing legs to make that possible. They
wanted to make sure that it went up properly before they thought too much about
getting it back down. This Falcon nine flew five missions, including one to
send a cargo Dragon capsule to the ISS. Next up is Falcon nine Version
one point one. This variant grew significantly to over sixty eight meters in length.
It was the first to utilize the Merlin one D engine and the circular
octaweb engine layout. This increased the total thrust to one point three million pounds
total. That extracize and power made this the first Falcon nine capable of a
controlled return to Earth, because it could get a payload into orbit with enough
fuel left over to perform the necessary re entry and landing burns. SpaceX began
experimenting with this capability in small scale tests, where they would attempt to bring
the rocket down for soft landings over the open ocean. It wasn't until the
CRS three mission to resupply the ISS. In April twenty fourteen that the Falcon
nine received its first set of landing legs, and then for CRS five in
January twenty fifteen, the first set of gridfins were added to achieve more precise
control when free falling through the atmosphere. This gave SpaceX the confidence to attempt
their first ever drone ship landing on that same flight. It didn't work,
but they got surprisingly close for something that was thought to be genuinely impossible at
the time. None of the Version one point one rockets ever successfully landed,
and then in June twenty fifteen, the Falcon nine experienced a mid air failure
and broke apart. This gave SpaceX enough pause to shut down operations until they
were able to come back with another revision to the booster design. Falcon nine
Version one point two is also sometimes referred to as Falcon nine Full thrust,
just slightly longer, now reaching seventy meters in length and getting a massive increase
in power to one point seven million pounds of thrust. Most of this power
gain came from SpaceX cooling their liquid oxygen and rocket fuel to lower temperatures,
which increases their energy density. This is where SpaceX really followed through on their
promise to learn through failure, because the first launch of the Falcon nine full
thrust also marked the first successful landing of an orbital rocket booster in the history
of spaceflight, with the booster touching down onto a SpaceX landing pad at Cape
Canaveral. The full thrust went through a series of small tweaks and variations over
the years as SpaceX prepared to finalize the rocket into its ultimate form. The
reason that they had to do this in order to get the Falcon nine crew
raided by NASA. It's fine to play around with variables when there is only
money and equipment on the line, but once it's agreed that a rocket is
safe to carry human beings, then you have to stop messing with it.
So we arrive at the Falcon nine Block five. It's the exact same size
as the previous version and only slightly more powerful at one point eight million pounds
of total thrust. The most obvious visual que to identify these variants is the
black paint in the middle and on the landing legs. The real upgrades here
are being made to increase the overall reusability of the rocket booster. Remember we
talked about the difference between reusable and refurbishable. The Falcon nine full thrust was
refurbishable in some situations, but for the most part SpaceX only recovered those boosters.
They didn't reuse them very often. The first SpaceX launched to use a
refurbished Falcon nine happened in March twenty seventeen, and it made use of a
booster that had been recovered over one year prior. As far as changes with
the Block five, SpaceX upgraded the turbopumps inside their Merlin engines when it was
discovered that the units formed very small micro cracks after being launched and recovered.
The grid fins on the side of the rocket were also made stronger with an
upgrade from aluminum to titanium metal. At the time, these fins were the
largest single pieces of forged titanium ever made and therefore incredibly expensive, but this
gave them a much greater resistance to the heat of reentry and greater control over
the rocket's angle of attack as it coasted through the air. The entire body
of the Falcon nine was given a thermal protective coating that reduced heat absorption across
the entire rocket. In addition, a new reusable and replaceable liquid cooled heat
shield was added to the base of the rocket for greater protection of the engines
and plumbing system. The Block five landing legs were upgraded to allow them to
both extend and retract. The previous legs actually couldn't fold back up after the
rocket was recovered. They had to be unbolted and removed. SpaceX also made
an improvement to the cpovs on the Block five. These are ultra high pressure
tanks that are wrapped in carbon fiber. They are used to store helium gas
that maintains pressure inside fuel tanks as they empty. And a COPV failure was
linked to both of the previous Falconine explosions, one in air and one on
the launchpad. It's been five years now since SpaceX made all of those reusability
upgrades to the Falcon nine, So what do they have to show for it?
Did they make a truly reusable rocket earlier this summer? On July tenth,
SpaceX successfully launched and landed Falcon nine booster B one zero five eight for
the sixteenth time. This is the same booster that launched astronauts Dug Hurley and
Bob Benkin to the International Space Station in May twenty twenty, the first time
a crew had ever flown on a SpaceX rocket. So that's sixteen flights in
just over three years. SpaceX had a ridge only believe that the Falcon nine
Block five would be good for up to ten launches and landings, but that
lifespan projection increased to fifteen launches in twenty twenty two, and right now SpaceX
has certified B one zero five eight for up to twenty launches, and based
on extended life vibration testing by SpaceX engineers, they think that the Block five
could withstand as many as sixty launches and landings. For comparison, the Space
Shuttle Discovery completed thirty nine missions, more than any other Shuttle in the fleet.
On average, there were only between five and eight Space Shuttle launches in
any given year, with one hundred and thirty five total missions spread across thirty
years and five vehicles, So that's not a whole lot of precedent to work
with, But according to the numbers that we do have, yeah, the
Falcon nine is an extremely reusable rocket. Booster, and a good one at
that. So now all we have left to do is sit and wait for
the next leap forward to begin. The Starship take reusable rockets to the next level.