- Hi, it's me Tim Dodd, The Everyday Astronaut.
As you probably know by now,
SpaceX is building a massive, massive rocket
down in Boca Chica, Texas
that's never going to go to space.
No, this isn't some clickbait headline,
this particular rocket will never go to space
because it's not designed to.
Now this is just a hopper version
of their upcoming Starship that some people are calling
the Starhopper.
And at first this thing's only gonna fly
a couple meters at most
but don't get me wrong, I, of course,
am fully confident that SpaceX will eventually
get an actual Starship flying and get it up to space
and into orbit, but for now, that's not what this is.
So today we're gonna do a quick little
history rundown on SpaceX's Hoppers,
we're gonna explain why they build them,
you know, why they're building this one,
why they did with these things
and then we're actually going to build one
Kerbal Space Program and show what we hopefully will see
the Starhopper do in 2019.
Let's get started.
- [Announcer] Three, two, one.
- [Mission Control] All systems running
lift off, we have a lift off.
(inspiring music)
- Okay, now right off the bat let me do a friendly reminder
that I'm not here to speculate.
I'm not here do to do any rumor or any,
you know, oo, upcoming things about Starship
because it's constantly changing.
At this point, literally, almost everyday
we get something new about Starship.
The super heavy booster,
the upcoming new Raptor engines,
the stainless steel actively cooled skin.
And at this point, it's just constantly changing so much
that I'm not here to speculate,
I'm just going to be teaching you guys
what we actually know about Starhopper.
So, before we actually start,
we need to do a really quick brush up
on all the names and the name changes
because this stuff is confusing
and we just want to make sure
we're all on the same page here.
So, back before November 20th of 2018,
SpaceX's upcoming mega rocket was called the BFR
or the Big Falcon Rocket.
The upstage/spaceship portion was called the BFS
or Big Falcon Spaceship
and the booster was called the BFB
or Big Falcon Booster.
But since the Elon announced a name change
of the upper stage/spaceship that's now called Starship
and the booster is no called Super Heavy
and together some people are calling it Starship Super Heavy
but it's really hard not to just call
the entire rocket still just the BFR.
So let's start of with just a quick overview
of what's been going down at Boca Chica.
So we first saw some glimpses of SpaceX's latest vision
for their Big Falcon Rocket at the Deer Moon event
in September of 2018.
Now, at that Deer Moon event, Elon mentioned
that they planned to do some suborbital hops
by the end of 2019.
Well, fast forward to December 8th
and Elon just causally mentioned in four weeks
they would have cool pics of the demo Starship
that will fly suborbital hops.
Four weeks.
This was surely just Elon time, right?
I mean there's no way they would have pictures
of a hopper ready in four weeks.
But before you know it, people on NASA Space Flights forums
start showing pictures of a water tower company
building a water towerish thing
that just so happened to be exactly nine meters wide.
And of course people were just going crazy
says there's no way this is any kind of Starship mock up,
it's clearly just a water tower.
Well, those people were wrong
because on December 22nd, Elon let the cat out of the bag
that this is indeed the actual hopper
that will perform those suborbital hops.
So this leaves us with a few things we need to explain.
So, first off, it's kind of like a flying,
boiler plate mock up or maybe just a shell of a Starship
over a small, little suborbital hopper.
But having it look like the Starship is a bit functional
so the aerodynamics and the weight distribution
are representative of Starship.
But this is also so SpaceX can start taking
some pretty pictures and give the public
a glimpse of just how massive and gorgeous
this thing's going to be.
But it's not just her to take some pretty pictures with,
if we want to understand what SpaceX is doing
in the future, all we have to do is look back in the past.
Because SpaceX has literally done
this exact same thing before.
They built some hoppers for their Falcon 9
as they prepared to try and land them propulsively
during actual missions for their Falcon 9.
So let's rewind to 2011 where some journalist noticed
some FAA filings for some suborbital hops
at SpaceX's McGregor site beginning in 2012.
SpaceX took a single Merlin 1D engine
in a Falcon 9 version 1.0 tank,
they attached some fixed landing legs
and began to learn how to fly,
or more importantly how to land.
Hello Grasshopper.
Grasshopper took its first flight on December 21st, 2012
and that lasted just three seconds
and it went 1.8 meters in altitude.
So, all though this was just, literally almost nothing,
SpaceX had to learn how to crawl
before they could walk.
I mean, now think about what's actually going on
during even a small hop like this.
They have to spin up the turbo pumps,
they have to throttle up until the thrust
is just slightly more than the weight of the vehicle
and then they have to throttle down,
nice and slow and gently, so it descends slowly
and controlled.
So I mean, yeah, just starting with
a little three second hop is probably a pretty good idea.
They continued to use the Grasshopper
to take bigger and bigger steps for a full year
and they flew it eight times in total
with a maximum altitude of 744 meters.
But perhaps, the most important things
that grasshopper did was perform a landing
with the thrust to weight ratio greater than one.
And this is called doing a hover slam or suicide burn.
And this was absolutely vital for the success
of the Falcon 9 landing.
And that's because when the Falcon 9 comes in
for its final landing burn, it weighs so much less
than it did at takeoff.
So not only has obviously let go of the upper stage
and the payload, it's also burnt through most of its fuel.
So even with just one out of the nine engines
at its minimum throttle setting,
the Merlin engine is still producing more thrust
than the entire vehicle weighs.
So this means if the Falcon 9 were to light its engine
too early, it would actually zero out its velocity
before it got to the ground.
And since its thrust is higher
than the weight of the vehicle,
it wouldn't hover, it can't hover,
its thrust is too high.
Instead it would actually go,
start going back up, it'd start ascending
and that's a very bad thing.
So performing this precise maneuver
was vital in SpaceX actually being able
to successfully cover Falcon 9 boosters.
Which, in my opinion, is still, honestly,
one of the single, coolest things you could watch.
I mean, I could honestly just sit here
and just watch these every single day.
So next up, SpaceX built a more realistic
and properly scaled version of the Falcon 9
to practice landing an this was called the F9R.
And this thing looked a lot more like a Falcon 9
and it even had retractable landing legs
that looked like the iconic ones we're now familiar with
the Falcon 9 and it would eventually test out
some steerable grid fins as well.
As a matter of fact, the tank on this unit
was actually a full blown qualification test article
from a Falcon 9, so it was the full length,
meaning this thing stood about 50 meters tall.
The F9R flew five times, first 250 meters,
then to 1,000 meters and then it tested
the actual grid fin so SpaceX could learn how to steer
and control the booster.
But then there was one more flight
and then on the fifth flight on August 22nd, 2014
the Falcon 9 dif. one, took off for it's last time.
Now unfortunately, the booster had to be remote terminated
when it suddenly veered off course.
And that's because there was a blocked sensor
that caused the anomaly.
But SpaceX still moved forward confidently
with the Falcon 9's landing attempts
Since the Falcon 9 has redundant versions of those sensors.
But the good news is these hoppers were very successful
in teach how to do hover slam maneuvers,
how to precisely throttle through a landing phase,
and how to maneuver around using only an engine gimbal.
Now, back to Starhopper, it's not going to be the first time
they've tried to propulsively land an actual spaceship
because don't forget, they tried to do propulsive landings
and hovering with their Dragon 2 capsule.
Now, unfortunately they ended up
canceling propulsive landing for Dragon 2,
I already have a video all about that,
it's a little bit older, so bare with me.
But it's still a really good explanation
of why they actually canceled propulsive landing
here on earth and of course on other bodys as well.
And just like with the Grasshopper and the F9R,
you always want to test real life hardware.
I mean, when you have new engines
on a brand new platform, with wildly different geometry,
you want to test it
and you want to test it a lot.
So, that's where we're at today.
We're seeing literally the new version of Grasshopper
but this time it's for Starship.
And just like how Grasshopper didn't have any
aerodynamic control services such as grid fins,
this first version of Starhopper
won't feature probably anything more than
a trio of Raptor engines with gimbals.
And just like Grasshopper,
this Starhopper only needs to kind of look the part.
You know, it's really just about learning how to hop,
fly, and land with a brand new set of engines
and a new, much, much larger fuselage.
And the fact that it's covered in roughly bolted on
or riveted stainless steel plates
is simply to make it look a little bit the part.
Because Elon likes everything, even test things
to look pretty.
And we don't really know what's inside the shell,
most people think there's another set of tanks
and that's where the Raptor engines are bolted onto,
so you'd almost think of it as a F9R
inside the shell of Starhopper, maybe.
But that's kinds of getting into speculation land.
The engines currently on the hopper
are a blend of Raptor development and operational parts.
But they'll soon be replaced by a quote unquote,
radically redesigned Raptor.
And I can't wait to hear more about that.
And now lastly, we know that SpaceX applied with the FAA
and the FCC to do high altitude flight tests
of an experimental, vertical takeoff
and vertical landing vehicle
that can go up to 5 kilometers in altitude
for up to six minutes.
And this of course means we're getting really close
to actually seeing this thing fly.
So in order to get a better sense for things to come
and what they're going to be doing with Starhopper,
let's pull up Kerbal Space Program
and I'm gonna show you what we can actually expect.
(upbeat music)
And welcome to Kerbal Space Program
and like I always say,
this is basically 50% rocket designer, 50% flight simulator,
9000% explosion factory.
Now this is with all of the realism overhaul mods installed
which makes it a lot more realistic,
a lot harder to use.
Uses a real earth, all these other things.
I'll link in the description how you can try to get
the realism overhaul mods, it's a longs story,
it's really hard to get working on your computer.
But that's what I'm using here.
And what I'm gonna do is I'm going to take
basically just the avionics,
I'm gonna stick a three meter internal tank,
of which, again, is maybe a little bit speculation.
But just for building this hopper, it's good enough,
just a three meter tank, that'll I'll have,
that'll be pressurized for the fuel.
We're gonna stick three engines on this thing
and then were going to slip
this big, beautiful, stainless steel aeroshell
right down on top of this
and this looks just perfect.
Alright, so first off, we better just learn how to,
just fly a tiny little bit,
just little, baby tiny hops.
So this is all about precise throttle control
and one of the hard things about realism overhaul
is there is a delay between throttle inputs.
So you'll throttle up or down
and it doesn't change right away,
like it normally does in Kerbal Space Program.
So, it's a lot, a lot harder.
It's very realistic, so doing this stuff,
it might look easy but it's really not.
And so, this is just a quick little hop up
to a little over 50 meters in altitude.
And the hard part is that these landing legs here
are about the same width as the takeoff/landing pad
so actually performing a quickly little over
is quite difficult.
And again, all throttle inputs are delayed.
So right when you think it's stopping,
all of a sudden, ugh, it's just really, really hard.
So here we go, trying to center it a little bit better
on this landing, on the takeoff and landing pad
but it looks like we're doing just about fine.
Viola, there you go,
not bad.
So that's probably pretty close
to what we're going to see for the first couple flights
of the Starhopper.
Just little hovers, nothing out of the ordinary,
up and down, nice and slow, nothing scary.
And now, before you know it, we're probably gonna see them
doing higher and higher and higher flight tests.
Like probably up to, you know, say 500 meters or so
And not only going just straight up and straight down,
but we'll probably start to see them divert
and actually go sideways.
You know, they did this same thing with the Grasshopper
and with the F9R, they went up and would scoot over
and come back down.
Or, I guess, if they're, you know,
really feeling brave and bold,
they can sure aim themselves directly at
the vehicle assembly building or that tent down there
in Boca Chica and they too, can try to land the Starhopper
right on top.
I think that's
pretty good idea in my opinion, as you can tell.
Ah yeah.
(upbeat music)
I mean, come on, if I can do this,
SpaceX can do this, right?
I dare you, land it on a building.
Actually, to be perfectly honest, they are going to have to
have more precise landings than this even,
especially with the, you know,
with the booster portion, with the Super Heavy booster,
they plan to land that thing directly back on the launchpad,
so they better be practicing like this.
I mean, yeah, I'm sitting here kind of joking about
landing on the vehicle assembly building
but they're gonna have to be insanely precise.
We're talking down to, you know, half a meter
precision of landing in order to kind of
get into some guide slots here.
Now, you're gonna notice I'm struggling,
personally, not struggling, I'm succeeding.
(chuckling) In landing on the vehicle assembly building.
But this is kind of relevant, actually.
Dang it, I definitely should of kept scooting over,
but hey, that's what the stairs are there for.
Not bad, not bad.
Okay, so next up, let's take this thing up
quite a bit higher, about 700 meters in altitude.
And we are going to work on
turning off one of the three Raptor engines.
And that's because this is something
that they'll probably be practicing
with Starhopper is making sure,
the reason it has three engines to land with
is not because it requires three
in order to have enough thrust,
it's so you have redundancy.
You know, Elon talked about to minimize pucker factor,
they're going to end up with three engines
that are fully redundant.
So that way if one of them goes out
it's no big deal but that means they are going to,
they're gonna have to practice that, you know.
That's, you can model that all day long
but actually getting it to work in real life
is probably gonna be a lot harder than the,
you know, obviously now your thrust is offset,
you're going to have to, you know,
throttle to compensate and gimbal in
towards the center of mass
with your center of thrust now super out there.
It's actually really hard and hmm,
as you maybe seeing here, I wasn't exactly very good at it.
(chuckling) I hope a computer is better at flying than I am,
I don't know if I,
I don't know if I believe in that statement though.
But as you can see, two engines,
of course it is controllable ish,
you still have a decent amount of roll control
but it is going to have to fly a little bit crooked
in order to actually stay maintaining its orientation
and doing a nice, slow touchdown.
It's going to be difficult but it's something
they're going to have to practice
is what if an engine goes out, you know.
How, that's something that the Falcon 9 currently,
if the center engine goes out,
they're pretty well screwed.
Sometimes they do three engine landing burns
but I don't believe they have any contingencies yet
or they've ever practiced
what if one of those three in the middle of
the landing burn goes out.
I don't know what the Falcon 9 can do.
The Starship on the other hand,
has to be able to do that, you know,
we're eventually talking about this landing on Mars.
We're talking about his landing potentially,
point to point earth transportation.
We're talking about his thing
needing to be airliner like reliable
and if you can't have a, you know,
an engine failure in the middle of your landing burn,
and survive and have it really be no big deal,
then that's not reliable.
So this is something they're going to have to practice
and I hope they do a lot better than I did
because, yeah, this,
I know it looks pretty easy but it's,
a computer is obviously going to have to
be doing a lot better job than I am.
Because yeah, look at that.
(laughing)
It took me a couple times
and I had to add some better landing gear
but yeah, I eventually got a soft touchdown
with just two engines.
But again, I think they'll be doing
a lot better job than I will be.
Now one thing to keep in mind here is
that they're going to have to go pretty slow on descent
at least with the fixed legged on the Starhopper
because although, you know, this is pretty stable
going up, when you're coming back down,
now you basically have wings or fins
at the front of your rocket.
And the actual Starship will have the ability
to bring those legs in, not fold them
but kind of fold them in dihedraly.
And that will help eliminate
a lot of those aerodynamic effects.
But on Starhopper, you know, they're gonna have to be nice
and slow because they don't really have
any other aerodynamic control services
to control and compensate for
the center of lift/center of drag
being, basically, in the front of the vehicle
when it's coming back down.
So they're gonna have to go nice and slow,
take it easy.
Which, there's a lot of stuff they can test out
with the Starship Hopper
and it's gonna be really cool.
I really hope it doesn't end like the F9R
but there is going to be a lot of really cool tests
they're gonna be doing with this thing.
So this brings up the fact that clearly SpaceX
will eventually be building
a much, much more advanced version
that has aerodynamic features
and large control thrusters.
So they can start practicing that absolutely,
ridiculous belly flop to tail down maneuver
that's going the to be the key to Starship's success.
Of course I've already done a video all about how Starship
will reenter belly first and then go tail down
so if you need more on that,
definitely check this video out.
But we do know that at some point,
maybe even by the end of 2019,
we'll actually see a stainless steel Starship,
complete with the giant flap air brake things,
the moving forward fins
and large, powerful control thrusters.
And Elon mentioned that eventually
they're going to be doing supersonic reentry
of the Starship down at Boca Chica,
they're gonna fly out over the gulf of Mexico,
turn around, come back super fast
and practice that landing sequence.
That will be absolutely amazing.
And fun reminder, last we know at least,
the control thrusters won't be cold gas thrusters,
at least according to Elon.
Tim Dodd, Spaceflightnow,
in the mars entry, you showed the craft
coming in kind of on the long side of it.
- That's right, broadside.
- [Tim] So how does it have that, enough control,
authority to get that pitched up
and actually put the tail down?
Can you talk a little bit about,
will you having thrusters that can do that?
- Yeah, yeah, they'll be heavy duty control thrusters
on the spacecraft.
It'll be, they won't be cold gas,
they'll be gaseous methane-oxygen.
And we're putting pretty powerful
for as attitude control thrusters goes.
I mean we're talking, 10 ton thrust type thrusters
or if not more.
- So, for today, that's all I want to talk about
with Starship and Starhopper,
at least until we get some more concrete information.
I mean, like I said, at this point,
this info has just kind of trinkling in all randomly.
And it'd be literally a full-time job right now
to stay on top of all these little changes
and speculations and rumors.
There are really good resources
for other groups of people and other organizations
that are doing a really, really good job
of digging into this stuff
and finding out all these fun things.
Like the ones that I pay attention to the most
are Nasaspaceflight.com, reddit/r/spacex,
of course the SpaceX group on Facebook.
There is Teslarati.com and then, of course,
Scott Manley is doing a phenomenal job as well
staying on top of this stuff.
So I'm actually gonna wait until we hear
and learn more about the actively cooled
stainless steel heat shield
and talk more about, you know,
things like the radically redesigned Raptors
that might have dual expansion nozzles
and all these other rumors and speculation.
I'll wait until Elon does a presentation
or really gives us some hard facts to talk about.
But meanwhile, we have a lot of stuff
to look forward to in 2019.
So, stick around, I have got plenty of videos coming,
I have a list that's literally ever growing,
I can't seem to chip away at it fast enough.
But of course, I wouldn't be able to do this stuff full-time
if it wasn't for my Patreon supports,
so if you want to help support what I do,
head on over to Patreon.com/everydayastronaut.
But also, while you're online,
be sure and check out my brand new web store
where I've got really cool, new exclusive shirts
and some fun hats and mugs and prints
of rocket launches, grid fin not-a-coaster,
lots of fun stuff.
Check it out and while you're there
you can click on music where you can stream my music
anywhere you listen to music, on Spotify and iTunes
and all that stuff.
Or right here on YouTube, I've got a playlist,
so check that out while you're online,
let me know what you think.
Thanks everybody, that's gonna do it for me,
I'm Tim Dodd, the Everyday Astronaut
bringing space down to earth for everyday people.
(mellow rock music)
Không có nhận xét nào:
Đăng nhận xét