- Hi it's me, Tim Dodd
the Everyday Astronaut.
It's fall of 2018 and you know
what time fall is, it's BFR time.
That's when Elon Musk
is going to update us
all on SpaceX's plans to going to Mars
with their big Falcon rocket.
Now last year they changed
quite a few things on us.
So this year we're going
to find out what's new here
at SpaceX headquarters,
I'm going to go inside
I'm going to learn and listen with my ears
and then we're going to come outside
and I'm gonna tell you about
what changed and all the
big details and speculate
on all the other fun things.
So let's get in there,
let's learn some stuff.
(smooth music)
- We are inside SpaceX's
headquarters, this is where
they action manufacture
of the Falcon nine rocket
and notice behind me is the
actual Falcon nine that's
being worked on and there's
another one over there,
but here's the crazy thing.
Look how much bigger
the BFR is going to be.
That is insane and there
is a reason why they have
to build those things out
on the port because they
wouldn't be able to get
that thing out this door.
So yeah, I can't wait for these details.
Elon is going to be talking
in about 10 minutes.
I better get going.
(smooth music)
- We have so much to talk about.
Okay, I'm here at TMRO Studios to talk
about what we just learned.
The presentation wasn't as
technical as I had hoped for.
I really like all those
nitty gritty details,
however it was incredibly inspiring,
especially the opportunity
that Japanese billionaire
Yusaku Maezawa is offering to artists,
okay that actually made me tear up.
So we can talk about
that or we can sit here
and we can talk about cool things
like the new reentry
system, and how the fins
need to actuate in order
to basically belly flop
through the atmosphere,
or we could talk about
why does this stuff keep
changing every single year
and talk about that evolution process.
So I think that's what
we're going to do today.
And then in future
videos I'll get into some
of those other things as well
because they are really cool.
Okay first of all, let's go
ahead and pop up all three
versions of the BFRs we know it now.
Now don't forget in 2016, we
didn't call it BFR publicly.
It was called the Interplanetary
Transportation System,
or ITS, so I might call it that sometimes
but I might also just call it BFR.
As you can tell it's changed every single
time they make an announcement.
It used to be a 122 meters
tall then last year it shrank
down to 106 meters tall, and now this year
it's standing at 118 meters tall.
Now just for funzies lets
go ahead and compare that to
the Saturn five, which was 110 meters tall
and the Falcon Heavy,
which is 70 meters tall.
Okay then there is the width.
It started off at 12 meters
wide then last year it shrank
down to nine meters wide,
which it still is today
except for those folding
landing legs slash fins
that stick out a little
bit more on the BFS.
We'll talk about that more in a second,
but of course it is still
a little bit skinnier
than the Saturn five, which
was 10 meters wide and
it's a lot wider than the
current Falcon Heavy cores or
the Falcon nine cores
which is 3.7 meters wide.
One think that we don't
know too much more about
is actually how many
engines are on the booster.
So in 2016 it had 42 Raptor
engines and then when
it shrunk down last year it ended up with
31 engines and since
the diameter is the same
I'm guessing it will still
have 31 Raptor engines
but that's quite a few
more than the Saturn five
which had five F1 engines
bit it's not that much
more from Falcon Heavy,
which has 27 Merlin engines.
Assuming there's the same number of
Rapture engines on the Booster 31.
Now Elon says each engine is
capable of 200 tons of thrust
which is equal to 1,962
kilonewtons times the 31 engines
and that means it will have
60.8 meganewtons of thrust.
Now that up from last
year's 52.7 meganewtons
but that's still way down
compared to the original
aspirations of 128
meganewtons of the 2016 ITS.
But then again it's
all a lot more powerful
than the Saturn five that
had 35 meganewtons of thrust
and is about two and a
half times more powerful
than the Falcon Heavy, that's insane.
So now payload capability,
this has changed
a lot over the years,
initially ITS was capable
of 300 tons to low earth orbit
and that changed last year
to 150 tons and now we're at 100 tons.
So it's shrinking but at the
same time 100 tons is still
an insane amount especially
when you're talking about
fully reusing a rocket.
Now of course the Saturn
five was capable of 135 tons
to the low earth orbit but the
entire vehicle was expendable.
Then you have things like
the Falcon Heavy which is
90 percent reusable and
in that configuration
it can only take about 30
tons to low earth orbit.
So it's a lot more capable
than the Falcon Heavy.
So now we need to talk more about the BFS,
the big Falcon ship or
the upper stage portion.
This again has changed a lot.
This probably changed the
most and Elon's talked over
and over again about how this
is going to take the most
design work and the most engineering
because it has to tackle
a lot of problems.
Okay so easily the most
obvious addition is the fins.
Now I need to be really clear about these.
These are not wings, they
aren't there to provide lift
they're more there to provide drag
and increase the surface area.
So think about these
more flaps or air breaks
and less like wings.
Elon mentioned this thing
reenters more like a
skydiver does than an
airplane does and it does this
by changing the amount of
drag basically on those flaps
in order to provide control authority.
So this is really important
because you actually
want to bleed off as much
speed as humanly possible
through the atmosphere
and this is a really,
really good way of doing that.
This is super different
from the Falcon nine,
which reenters butt first
and it's only going about
a quarter of the speed of
orbital velocity and despite
this it still needs to do a
really healthy reentry burn
slowing itself down about half before
it reenters the atmosphere so
the atmosphere doesn't destroy it.
Now the BFS isn't going
to try to lower its speed
to one eighth using retro-thrust
that would be an insane
amount of delta v fuel wasted.
So instead it wants to use that
atmosphere to its advantage.
Because the atmosphere can
remove almost all of the
velocity of the vehicle
the trick is you want the
atmosphere to do as much work as possible
without destroying the vehicle.
We'll go way more in dept with
this crazy reentry system.
Because it's completely unique
in the aerospace industry.
I've never seen anything like this.
Meanwhile check up on my video title
'Will Falcon nine be reusable
or just refurbishable,'
which goes into some of
the physics of reentry
and talks about why you can't
really compare a booster
to an upper stage or spaceship.
Okay now back to the BFS
and those fins real quick.
Now those fins are also the landing legs,
which is important because
they're going to have
the dry mass of landing legs anyway.
That's going to take away some
of the payload capability.
But the thing is, you might
as well make it so they do
other things like a lot
of people talk about
when the Falcon nine
reenters why don't they use
the landing legs to pop out and
they kind of work as air breaks.
Well, that's basically what this is doing.
It's using the landing
legs as air breaks so
it's almost like bonuses instead
of some kind of detractor.
The engines on the BFS
has changed all the time.
Initially in 2016, we saw six vacuum
optimized rapture engines
and three sea level engines.
Then last year it changed to
four vacuum optimized engines
and two sea level and
then Elon updated it like
three weeks later on Reddit
saying it's actually three
sea level engines and now out of nowhere
we see seven sea level engines.
What is the deal, well
someone out there had enough
nerve to ask Elon Musk what
is up with this new design.
- Hey Elon, Tim Dodd the
Everyday Astronaut here.
I see that you changed the
engine configuration for the BFS.
Can you talk a little bit
about it there still engine out
capability, is it vacuum
optimized but still
mandible on sea level can they function
as an an abort system,
can you just tell us
about your decision making on that.
- [Elon] Oh yeah, that's a
good thing to notice, good eye.
- Oh shucks did you hear
that, someone has a good eye.
But as someone with different
colored eyes now I'm
unselfconscious about
which one is the good one.
Okay, but this new seal
level only configuration is
pretty confusing to me, last
year Elon talked over and over
about how important it is to
have engine out capabilities
for landing to minimize pucker factor.
This new configurations
doesn't seem to be too privy on
engine out capabilities
for landing, or does it?
So now if you look closely
the engines are really, really
close to the center, which
is actually really good for
landing burns cause Elon
did say they're still
planning to use three engines to land.
Now say the outer engine would
go out in the middle of landing.
I think they're close enough to the center
that you could offset
thrust by gimballing enough
to actually make it so the
vehicle doesn't totally tip over.
So I believe it could probably
still land on just one engine
but the light three for
redundancy purposes.
For now, we're not going to see a vacuum
optimized Rapture engine
and that's pretty weird
but honesty it's because they can now
streamline manufacturing and
just crank out one engine
over and over, but also
because quite frankly,
it might be good enough
with just sea level engines.
The specific impulse of
the sea level engine or
how efficient the engine
is, is about 330 seconds.
Now that's pretty good but
it's not as good as 380 seconds
they would be able to get out a vacuum
optimized rapture engines,
which they could sport on
later versions and they
might be able to kind of
change out which kind of ship they use,
depending on the mission needs.
Now some of the nerdy details
of the Rapture engine.
Is this is a full flow
stage combustion engine
that burns methane and
liquid oxygen and has a
crazy high chamber pressure of 300 bar.
Let's not go into the details
about what chamber pressure is
right now but just to
compare how insane 300 bar is
let's look at some other engines.
I believe the current king
of high chamber pressure
is the RD-180 from
Russia which is 265 Bar.
Then we look at the chamber
pressure of the RD-170
that Russia used on their Energia rocket,
That was 250 bar, the RS-25
engine on the space shuttle was
206 bar, the space engine's Merlin engine
that they currently use are 97 bar
and the F-1 engine on the
Saturn five was only 70 bar.
So 300 bar is crazy.
The last big change is the
internal cargo volume of the BFS.
Now last year I believe
it was sporting 800
cubic meters and now
they're looking at over
a thousand cubic meters of cargo volume.
This is interesting maybe
the team decided they'd
rather have more internal
cargo volume than
actual payload mass capability.
Just one of those trade offs that might be
valuable when you're flying humans who
require a lot of moving room
compared to just satellites.
Another thing they added as AFT cargo.
What's AFT Cargo?
Well it's unpressurized
portions of the ship,
kind of like the trunk from the dragon
capsule and why would you want this?
Well think about it, if you
land on another planetary body
and you need to get
things like solar panels,
you need to get fuel pumps
to make new fuel out of the
atmosphere using in situ resource
utilization or maybe you need a rover.
It's a lot easier if you have
to reach up from the bottom
and put it on the ground as oppose to
say having a cargo bay up top and
unloading using cranes or something.
It's actually a pretty good idea.
This is where having those
smaller sea level engines
make room for those AFT cargo base.
So then it's a pretty
good compromise when it
actually comes to practicality
and that's almost where
this whole thing comes together.
There's been a lot of big
changes to BFR and you
might go why, why is it every
single year we see basically
an entirely different
rocket, how seriously can we
actually start taking this
stuff when every time we get
a glimpse of it, it's totally different.
Well, Elon actually said
something extremely enlightening
that gives us a really good
perspective on some of the
problem-solving that goes into
making a vehicle this groundbreaking.
- [Elon] This is a stupidly hard problem,
and SpaceX engineering, I think done
a great job with this design.
I don't think most people
even in the aerospace
industry, know what questions to ask.
It took us a long time to even
frame the question correctly.
But once we could frame the
question correctly the answer,
I wouldn't say was easy,
but the answer flowed once
the question could be
framed with precision.
And framing that question with
precision was very difficult.
- Here's where we maybe got
the biggest glimpse into
SpaceX's design process for the BFR.
SpaceX is doing something
that almost no other aerospace
company ever gets to do and that's start
with a completely blank canvas.
Now I'm not saying this
has never been done before,
but to not have some outside
requirements that kind
of gets in the way of your physics
lead design, is pretty unusual.
You know, normally it's like
we have this heritage hardware
we need to use or
something, but in this case
SpaceX is starting from scratch.
And they can let physics do the talking.
Look at the space shuttle for example.
NASA had so many requirements
from so many different people
when they had to design that thing,
it was really compromised.
The Air Force said we need the payload bay
to be this big and to be able
to carry this much weight
for our spy satellites they
also needed to be able to
build the International
Space Station with it
and carry up to eight astronauts.
SpaceX doesn't have any of those outside
requirements when designing this.
So instead, SpaceX gets to
first come up with a question
of what does this actually need to do
and how do we make it do that the best.
And this could lead to
getting over some fears
like Elon's fear of wings because,
"Wings are useless, in
space," of course he's right
it's just dead mass when
it's up there in space
but if they can scrub off a
lot of velocity and save you
a lot of Delta V on reentry and
landing, maybe they are worth considering.
What we're witnessing is
something incredibly unique
I can't think of any other
company that's ever let
you in on the design process.
Can you imagine if Apple
is like, "Hey we're working
"on a new iPhone and show
you some tweaks along the way
"before it comes out," or what
if Lockheed Martin is like
"Hey we're coming out
with this new fighter jet,
"and every year we're going
to let you know what's changed
"in our design process
before it comes out."
That just wouldn't happen,
so this is actually
really exciting, we're
watching the tweaking
and the molding of a brand new rocket.
It's a really cool
demonstration of engineering.
We're actually getting to
see them tweak and tweak
and tweak and make it better which is what
engineering is you just often
don't actually get to see it.
So I guess the only real
question I have remaining
at this point is will they
be tweaking the BFR once they
start making it, kind of like
they did with the Falcon nine.
So SpaceX basically never
made two Falcon nines the same
because they are constantly
tweaking it, adjusting it
making it better and
able to do things like
oh I don't know, land, be
recovered and then reflow.
It's something that's
never been done before.
Will they be tweaking the BFR constantly
and making it better once they start?
I'm sure they will, it's SpaceX after all.
And unfortunately those are
all the nitty gritty details
we got this time, maybe
we'll learn a little bit more
when Elon does that
Reddit AMA I asked for,
you're welcome, how about
as a return favor let's
all get on Twitter and ask Elon Musk
to do a sit down interview
with me, I promise
I'll ask all the good questions.
While we're talking about
favors, thanks to TMOR
for letting me use their
amazing studio space here.
If you guys don't watch TMOR on YouTube,
What are you doing?
It's the best space show period.
That's YouTube.com slash TMRO.
They film every Saturday live at 18 UTC
and you can join and have
your comments in the show.
They have interviews,
the do up to date news,
It's just the best, so make sure and go to
YouTube.com slash TMRO.
But of course, I owe the
biggest and most sincere
thank you to my Patreon supporters.
If it wasn't for you guys I wouldn't
be able to come out here
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Check it out
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Oh and thanks to my friend Patrick Lawler,
who helped shoot this event with me.
I mean his stuff is just incredible.
You should check it out,
he's all over the internet.
Thanks everybody that does it for me.
I'm Tim Dodd the Everyday
Astronaut bringing
space down to earth for everyday people.
(smooth music)
