Can SpaceX Reuse a second stage?

Can SpaceX Reuse a second stage?


Hi it’s me Tim Dodd the Everyday Astronaut! We’ve all seen SpaceX land the first stage
of their Falcon 9 rocket and now Elon Musk says he wants to try and land the second stage… In order to understand why his engineers were
probably crapping their pants when he said this, we’re going to go explain why recovering
something from orbit is significantly harder than recovering the first stage. We’re also going to show you some options
for second stage reuse including one option to just keep it up in space where it might
be a better use than back on earth. Now bare with me on this one, it’s going
to be a little bit more technical and a little longer, but with a little help from Kerbal
Space Program, I think we’ll be just fine! SpaceX has gotten so good at recovering the
first stage of their Falcon 9 that we forget how almost impossibly hard it is. Right up until they actually landed their
first first stage on December 21st, 2015 for mission Orbcomm 2, it was still thought by
most people in the industry to be simply impossible. We’ve previously talked extensively about
how SpaceX lands and also gotten into some fundamentals of determining if they’ll have
enough margins to land their Falcon9 on land or on the drone ship in the ocean. So if you don’t understand those things,
please check out those videos before watching this one. This one’s going to get a little more technical
but we’ll try and make it as easy as possible. So let’s start off with a few numbers here
before we get into some examples. The first stage of a typical Falcon 9 will
get up to speeds of around 5,000 mph (which is about 2.3 km/s). As you hopefully are aware, even at this speed,
the first stage still needs to do a fairly substantial entry burn as the stage enters
the atmosphere so the heat of reentry does not tear the stage apart. This requires the first stage to use up a
portion of its already scarce fuel in order to survive hitting the atmosphere. The second stage on the other hand is traveling
much much faster. An object in low earth orbit is traveling
at around 17,500 mph or 7.8 km/s. Then we have missions where the second stage
needs to loft its payload up into geostationary transfer orbit. This requires it reaches speeds of 22,000
mph or 9.8 km/s! So as you can see, depending on the destination
of the payload, the second stage may end up to 4 times faster than the first stage. This is a big problem when trying to recover
it. The primary reason being heat on reentry increases
by speed cubed! Or in other words, this means if the reentry
of the vehicle goes from 2 km/s to 8 km/s heat would increase by 64 times. So now I hear you saying, “But we bring
stff down from space all the time, why is this any different?” To answer that question, let’s take a look
at some common reentry systems. We’ll start with what’s probably the most
common. A capsule. The reason a capsule works so well is because
it’s the simplest, safest and most stable of all designs. The blunt leading edge and tapered walls create
an exceptional environment to dissipate heat and stay pointing heat shield first. Next most common is what the space shuttle
was, a lifting body. A lifting body allows for the vehicle to stay
in the upper atmosphere longer, allowing the vehicle to slow down for a longer period of
time, which keeps peak heating and g forces to a minimum. This also allows for a lot of control when
coming in, so the space shuttle and others like it, have a great cross range capability
leading to flexibility and reliability in hitting its intended landing area. The space shuttle isn’t the only lifting
body used. There’s the upcoming dream chaser by Sierra
Nevada and Boeings secretive X37B both of which sort of look like mini space shuttles. They’re similar by concept, but are even
more of a lifting body since they don’t have delta wings like the Space Shuttle did. And lastly, although not currently used for
orbital flights on Earth, is using retropropulsion like SpaceX uses for the first stage. The primary reason we can’t use retro propulsion is because it would take as much fuel to slow the vehicle down prior to reentry
as it took to speed the vehicle up to orbital speeds. This means even after the second stage has
completed it’s long burn to speed up, it would have to somehow have enough fuel to
turn around and do that entire burn again… which just simply isn’t happening. Some of the other major problems facing second
stage reentry is stability. The vehicle will want to enter heavy end first,
or in the case of an almost empty second stage, engine first. Say we put a heat shield up on the top of
the stage, it would take some serious design considerations for the vehicle to maintain
its proper heat-shield-first orientation during reentry. Believe it or not, SpaceX actually released
this video in 2011 which showed the second stage with a heat shield on the front of it. Another issue is when it comes to landing,
the second stage cannot simply use its engine at sea level. With its massive nozzle, it would be too unstable
at sea level, meaning we can’t actually use the Falcon 9’s vacuum Merlin engine
for its final landing. But perhaps the biggest enemy is weight. Sure, we can solve any of these issues if
we tack on a spare set of engines for landing, a set of wings for orientation, additional
thrusters for maneuvering, a heat shield to survive reentry and some landing gear… The problem here is for each pound we add
to the second stage, we will have to remove a pound from the payload. By the time we add all of this new hardware,
there’s a chance we won’t have any margin for payload at all! Think about it, the 2nd stage pushes its payload
all the way to its intended destination. All of the mass of the 2nd stage is literally
joined to the payload right up until its mission is complete and it lets go of that payload. This is different from the first stage. The first stage doesn’t take nearly as much
of a payload penalty for each pound added. Elon Musk quoted it’s only about a 5:1 ratio
for first stage. This means they could add about 5 pounds to
the first stage before you have to remove one pound from the payload. This is why the first stage of the Falcon
9 can have large landing gear, nitrogen thrusters and grid fins and still put a substantial
payload into orbit. So let’s take this over to the computer
game Kerbal Space Program where I’ve set up some examples of how SpaceX just
might pursue second stage reuse and just how hard it actually is. Alright, so we’re here inside the vehicle
assembly building at Kerbal Space Center and I’m building a rocket that’s similar to
a Falcon 9. We’re going to call it the Falcore5. For those of you unfamiliar with Kerbal Space
Program, it’s basically a game / simulator that will suck the life out of you. Do you have a significant other? Do you want to keep that significant other? If the answer is yes, then you should not
play Kerbal Space Program. It is that addicting. Because we want this to be somewhat realistic,
I cranked the gravity up two times in this game. So this will make our margins a little bit
thinner and that much more realistic. Our payload for this mission is the start
of a new space station and it weighs 4.8 Metric Tonnes. With this bog standard Falcore5, it will just
barely be able to push this thing up into low Kerbin orbit at an altitude of about 250
KM. So that will leave us with only enough remaining
fuel to de-orbit ourself and that’s it. Now for reference sake only, do notice that
the vehicle is showing as having 7,828 m/s of DeltaV. This is only a reference, this doesn’t really
line up to anything kind of in real life, it doesn’t really line up to most things in
Kerbal, but we’re going to use that as we change the mission profile later. We’re just going to remember what we started
off with. Ok let’s put this baby out on the pad. Full disclosure. I’m using a mod called MechJeb which will
actually fly the rocket for me. It’s not very fun but it at least will keep
all of our missions exactly consistent and it will compare apples to apples so that we
kind of eliminate the variable of me flying it. Alright here we are, we’re loaded up on the
launch pad ready to go! All systems go, 3, 2, 1, HIP HIP! Alright I’m gonna speed this up because we’re
going to be doing this many times and I don’t want to have to watch every single second
of every single mission. Alright here’s our gravity turn, and there’s
Max Q, and now we have stage separation that first stage has enough fuel to try and land. Fairing deploy. And now you can see we’re getting into orbit. Alright now we’re going to coast up to its
highest point or apogee and do one more burn to circularize so that will put us parked
in our 250 km orbit. And now let’s deploy our payload. Ok it’s good to go! Now notice how little fuel we have left. This was at the absolute upper end of what
our standard Falcore5 is capable of pushing into orbit. So we’re going to do our deorbit burn and
we’re going to get down to about 50 km’s into the atmosphere so it blows up on reentry. And there we go, kaboomy. So now we have two options. Since we had literally no fuel remaining to
attempt any kind of recovery at all, we can either do one of two things. We can shrink the payload down or we can build
a bigger rocket. I think we all know the answer to this one… Introducing the FALCORE HEAVY!!! Ok so we’re putting that exact same payload,
that space station, up into the same place in space in the same orbit. But now we’re actually starting off with 9,296
m/s of Delta V as opposed to just 7,828 m/s. So let’s see how much fuel we have remaining
at the end of this mission to see if we have any chance of recovering the second stage
at all. Ok here we go 3, 2, 1 HIP HIP! Alright gravity turn, Max Q, those side boosters
deploy and they have enough fuel to land back at land now the center core when it separates
that will have to try to land out at sea on the drone ship. Ok now we’re going to get into orbit. Let’s see how we’re doing. Ok so the payload deploys and we have a decent
amount of fuel. Let’s see how much fuel we have left over
and try to recover the second stage after our deorbit burn. Ok so we have just over 1,200 m/s of Delta
V to slow ourselves down as we enter the atmosphere. Now as the stage heats up I’m going to throttle
up to help slow ourselves down so the compression from the freestream air behind the bow shock
doesn’t heat us up too much. It’s a lot of technical stuff but basically
that’s the stuff that will kill us. After a good entry burn we still have around
400 m/s left over, now will this be enough to slow us down as we get into denser atmosphere? Ahhh throttle back up! Ahhh no. Bye bye! There she goes! So uh, we just simply cannot slow ourselves
down enough. So just as we had talked about earlier. We need to slow ourselves down enough to survive
reentry which we just simply don’t have the margins to do. So let’s use that atmosphere to our advantage. Let’s stick a big ole heat shield up on the
nose of that stage. And then we’ll try and point it nose first
as it goes through the atmosphere to slow us down. Our biggest problem here is we know that engine
is going to want to go first because its the most massive part of that stage. So we’re going to try to keep it oriented
using those thrusters and stuff like that, but we’ll see how it works. Let’s check this out. And WA LA! We now have a large heat shield at the nose
of the second stage. See that beautiful pizza crust looking thing? Oh yeah there it is, between the second stage
and the payload. It is just delicious! We’re going to go ahead and skip to payload
to deploy and watch our reentry. Now notice after our deorbit burn we’re left
with only 675 m/s. Having to push around that big heavy heat
shield really took its toll. So now we had 1,200 m/s on that last reentry…
so hopefully we won’t need to use our engines at all to slow us down so let’s see how this
goes. Ok so our RCS thrusters are keeping us oriented
nose first. Heating up… it’s getting spicy! Ohh! Oh shoot yeah. There we go and that’s what happens. The RCS thrusters were not strong enough to
keep it oriented. It would take a lot of RCS thrusters to keep
it oriented like that. Ok it’s time to get serious. That last attempt didn’t even have an engine
that could land on sea level anyway or landing gear. So let’s go all in on this one. Ok I’m adding fins for stability, Some separate
engines to land with and some large landing gear that will allow us to land upside down. Now again, this is only for reference, but
by the time we add all this recovery hardware onto the second stage, we’re looking at only
8,093 m/s of DeltaV. That’s a ways down from the 9,296 m/s that
the original Falcore Heavy had. Ok so we’re going to put this into orbit and
deploy the payload. Let’s see how things go on reentry. Well look at that those fins are keeping it
oriented heat-shield-first. Eh yikes. Oh ooo! Wow ok. They’re barely keeping it oriented. Woah ok. Eee! Ok we only have 100 m/s left over to land
with. We’re traveling over 200 m/s, I can see where
this one is going. Into the drink. BOOO! So remember before when we had to decide either
to make a smaller payload or a bigger rocket? Let’s make a smaller payload on this one. Introducing a large tele communications satellite
that weighs in at exactly half the mass of the space station piece at just 2.4 Metric Tonnes. We’re only showing 8,219 m/s which is up from
that 8,093 m/s we had with that larger payload. But the interesting note here is we won’t
have to use as much going up, so it does mean we’ll have a decent amount more to work with
on the way down. Ok so boom we’re in orbit. Payload deploy and now we’re deorbiting. Ok much better. We now have 605 m/s left over to try recover
this baby. Eeeee that’s a spicy meat ball! Ok and let’s and flip it over here. Oop woah! Getting real spicy down here… Annnd alright let’s do our landing burn here. Annnnd full throttle! Annnnd touchdown! Yeah! Oh that took me way too long. I don’t wanna tell you how many times. Ok now don’t forget Kerbal is not a perfect
analogue, but it at least helps illustrate some of the challenges involved in trying
to recover a second stage. Ok so moral of the story is, yes, there is
potential to land the second stage. It ISN’T impossible. It will require some MAJOR design changes
and even if they get are to get it to be recoverable, there might be such little remaining margins
that they might not be able to launch a significant payload. They might end up using the Falcon Heavy to
launch cube sats or something all for the sake of reusing the second stage, which would
not be economical. Only time will tell and I’m really excited
to see what they come up with for their solution. Now, before the comments get blown up with
“BUT THE SPACE SHUTTLE” I did want to point out that the orbiter portion of the
Space Shuttle was essentially a recoverable second stage. It fully succeeded in bringing home those
expensive and wonderful RS-25 main engines. The problem is it took such a big payload
penalty. Despite having almost the same amount of thrust
at sea level, the space shuttle could only put a 28,000 kg payload into orbit, which
is nothing compared to the Saturn V which could put 120,000 kg’s into low earth orbit. This is because about 100,000 kg’s of weight
was the orbiter itself with its wings, and engines, cargo bay and landing gear, this
greatly reduced how heavy of a payload it could actually deliver. Now I did mention there’s another proposal
for keeping a second stage in orbit and reusing it while it’s up there. United Launch Alliance better known as ULA
which is a joint venture between Boeing and Lockheed Martin has a really cool idea for
the second stage of their upcoming Vulcan rocket. They propose the idea that why try and bring
a second stage back down at all. Why not keep them in orbit eventually they
can populate a large number of 2nd stages with some extra fuel in them. Then they would then be able to dock them
and top off a single stage so you could eventually have a full second stage sitting in orbit
waiting to be used. This means you could push a substantial payload
way beyond Earth orbit on just the fumes of otherwise doomed stages! It’s a pretty brilliant idea and I’m excited
to see them work on this concept. Unfortunately we won’t see their Advanced
Cryogenic Evolved Stage or ACES fly until 2023 at the earliest. Regardless, it’s really exciting to see
companies taking this stuff seriously. My hope is that within the next decade we’re
going to see FULLY reusable rockets that help bring the cost of space down significantly,
that’ll be a really exciting time! If you have any other questions about second
stage reuse or any other question about rockets in general, leave them in the comments below. Make sure and hit subscribe so you know when
I make more fun, funny and factual content. Be sure and check out my web store where you
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people.

100 thoughts on “Can SpaceX Reuse a second stage?”

  • Aerobraking is an option due wich the second stage has a low amound of fuel but enough to re -enter the atmoshere wich were it will slow down in it and when it slows down enough for landing it will deploy parachutes .To resist re-entry it needs a heat shield!

  • What I do in ksp is , I put a parachute on my rockets to save it . Why on earth and in space do spaceX not do this ? I mean you would need a lot but still .

  • willyouwright says:

    Seriously its not rocket science. he launches another of his millions of spare older falcon 9s to bring it back.. How is that even difficult..
    COMPLETELY OBVIOUS

  • I'd imagine the second stage would look like a mini starship. Probably use cryogenic surface cooling aswell. It would probably make sense to come down belly first instead of nose first because you get more drag that way. The nose will probably still need some sort of sheild assuming that the area underneath the payload faring can't be cryogenetcally cooled. I think at this point they'd have to use parachute recovery as there is no reason to include a second set of sea level optimized engines. Alternativily, they could sacrifice some delta-v and use hybrid sea level vaccum engines (did STS do that?). Either way I'm interested to see what they come up with. I would think that they would sacrifice the second stage on really high orbits and only try to recover for stuff in LEO.

  • man and with the secret space program the carry anything they what – the tr3b alone is big as an footballplace

    youtube.com/watch?v=IAjUE38PaK4

  • Thomas Sutrina says:

    The problem with the second stage is the aspect ratio with a heat shield. Collapse the tanks. The deployment antennas on satellites already us origami means to open and those same structures can be reversed to collapse back. The origami forms for a collapsing cylinder have long existed. The tanks can be winched down to compress the vapor in the tanks to the initial tank pressures. And continue to collapse them as more fuel is burned. Thus on reentry, stabilization burning, and retro landing burn and landing the aspect ratio will be favorable. https://asunow.asu.edu/20180219-creativity-asu-origami-mechanical-engineering-hanqing-jiang

    http://mechanicaldesign.asmedigitalcollection.asme.org/article.aspx?articleid=2211799

    https://www.sciencedirect.com/science/article/pii/S0020746204001581

    Also many youtube of collapsible origami cylinders exist for viewing.

  • What about using an aerospike on the second stage? This will eliminate the need for a second engine for the landing burn.

  • Where Elon has gone wrong is with the military orientation of what a "Company" can do. The taxes from the general public, along with the lives of the sons and daughters is what got us here ; now Elon wants to use only the minds of the elite few who have made it to "Company Employee" status to achieve intellectual property contribution status. Even EveryDayastronaut guy compliments "what 'Companies' are doing". This leaves contributions from non-military citizens in the garbage heap. This is where the "belonging" dies along with the enthusiasm of being a taxpayer. I have some ideas for this but why throw them away? Regardless; in brief: put some fold-able heat shield platters in orbit like a stack of LP records and when its time to recover a 2nd stage merge a platter with a 2nd stage and drop it near a barge in the ocean.

  • I think you should use only inflatable heat shield (IHS), 4 thursters, probe core, batteries, solar panels (optional) and some parachutes to land it (Apollo way or KSP way). It would only be around more than 1,5 tons heavier. The more lightweight the better. It would be easier to point the IHS (put at the top of the upper stage) at the prograde direction and let the atmospere do the rest of the job, instead of a 3,75m HS and some heavy meltable wings. BUT, the not-so-good fact is that if the second stage is too LONG , it could tip over and could end up being destroyed. Trust me, I tried in KSP. In that case, put the IHS at the back of that stage, near the engine SOMEHOW . It would make that stage a lot more stable during reentry, but it is also mean that the upper stage would be a lot more HEAVIER to be carried around, since 2 IHS would have a total weight of exactly 3t.

    It's just my own opinion. Feel free to share your own. And don't judge or critize each other's.

  • The Orion capsule in the last test was not looking all that stable.
    After they solve the second stage reentry issues, they can capture small satellites and return them for repairs, then launched back into orbit.

  • It seems to me and my novice opinion that a low earth orbiter refueling station/docker is answer to a lot of these problems and that would be resupplied by reusable first stage re-fuelers

  • Italianduck21 says:

    Just wondering on a scale of 1 to 10 how it the idea of changing the refueling idea and using that weight margin to bring some equipment to deorbit large pieces of space junk along with the second stage on its way down

  • This video got me thinking…
    Why do they jettison the fairings in the first place? Just elongate those along the whole upper stage right to the interstage. At this point attach them to arms so they can swing out and around the bottom of the stage to shield the engine. Now you have a giant snowfflake-style airbrake of about 40m diameter with your center of mass perfectly located right at the center and depending on how you build it, the nozzle extension might poke out at the very tip. You can now vent residual fuel out of the nozzle during descend to cool that and produce an atmosphere of anti-oxidising gas around your vehicle.

  • Jason Hamilton says:

    All that fuel being left in orbit from spent second stages, wouldn't that run the risk of turning solid or going high pressure and bursting the tanks while in orbit? That's my question for the reusable 2nd stages. They would probably need to orbit a way-station that had thermal management facilities to service the spent modules and to "park" the empty modules for later de-orbit or reuse in some construction. Are there any public discussions about these things I've brought up?

  • no offense but youtube intros are becoming so annoying lol. i wish videos like this would just get down to business without the unnessesary long intro`s …

  • Taras Wertelecki says:

    This doesn't look feasible at all, but building the second stage so it can remain in orbit with communication, power, attitude control and propulsion systems so it can act like a orbital transfer vehicle is much more practical. That is the ultimate goal of the program to develop and field the ACES second stage.

  • Maybe the heat shield could be carried up on the “light” (non-engine) end, but then robotically moved to the “heavy” (engine) end before re-entry.

    And don’t forget that (expendable) parachutes can bleed off a little low-end speed also.

    (It appears I need to get into this Kerbal business myself.)

  • Maybe the heat shield could be carried up on the “light” (non-engine) end, but then robotically moved to the “heavy” (engine) end before re-entry.

    And don’t forget that (expendable) parachutes can bleed off a little low-end speed also.

    It appears I need to get into this Kerbal business myself.

  • What about doing what the space shuttle did, bring back the most expensive part. The engines and computer hardware could be recovered and mated to a new set of fuel tanks.

  • How about if the heat shield was portable and locked together (think pizza slices coming together to make a whole pizza)? Then you could attach it around the engine faring and have the heat shield come together under the engine bell, which would solve the weight distribution problem. After the second stage descends far enough, the heatshield can be dropped and caught like the payload faring while the engine burns like it would for first stage recovery.

    Clever use of Aerogel in a structured network could really lighten the heatshield and save on payload mass loss, and a parachute-assisted landing burn (deploy parachute, then burn for final touchdown) could save on fuel losses.

  • It only makes sense to save recycle the second stage for later space structures and spacecraft, just like they did in Skylab with the Saturn V second stage.

  • Dude, let me give you a tip, skid off the atmosphere a couple of times (like a flat stone on watersurface) before you do re-entry…that makes all the difference
    Skids for the win in 2020

  • Question never seen adequately answered:
    All non-gyroscope attitude maneuvers in space start by using propellant to rotate the craft in the three axes. The craft turns to the desired orientation and thrusters then fire in the opposite direction to stop the rotation. Unless the retro fires are exact—and nothing is exact—the craft will have some residual rotation and inevitably drift out of proper orientation. Now another firing will be required to correct this misalignment. And that firing won’t be exact… and this cycling will continue.
    How does one not burn through all attitude control propellant on a mission to say Pluto?

  • just keep all the stage 2 engines in a special orbit and every once in a while send a big recovery ship to catch them all and bring back safely to ground :/? im newb but this sound cool

  • Why can’t re-useable SRB’s like the STS used be added to whatever booster your using so the first stage delivers more D-V and the second stage completes insertion with more fuel onboard to make return possible. They could make up for the added weight the second stage would have to make a return possible.

  • I just want to thank you for making these informative videos! I've always wanted to learn about rockets but I didn't know where to start or it was confusing. You explain things so well! I've learned so much for you. 🙂 Thank you!

  • Ravikumar Meshram says:

    Hey Everyday Astronaut, why don't you suggest your idea to SpaceX?
    It will be so helpful to them.

    Bdw I am impressed by this.
    All the best 👍

  • what about skimming the karmen (Can't remember spelling) line multiple times to use the atmosphere to slowly slow the rocket to a manageable rate for descent over multiple orbits?

  • I'm starting to learn how to make things that work in KSP.

    Good thing I have no friends anyway.

    oh and somehow (have no idea how) I can control my self and not play KSP (sometimes I plan to play it and end up forgetting)

  • why not make a whole space station out of second stages and some models to have the stages somewhere to dock and some solar panels

    you could use this station as a refueling station for rockets (maybe even the Starship)

  • Aventureiro Paulek says:

    Elon Reeve Musk é um empreendedor, filantropo e visionário sul-africano-canadense-americano. Ele é o fundador, CEO e CTO da SpaceX; CEO da Tesla Motors; vice-presidente da OpenAI; fundador e CEO da Neuralink; e co-fundador e presidente da SolarCity. Este homem será o responsável por salvar milhares de pessoas. A Nasa vem a anos estudando pra explorar um planeta e chega Elon Reeve Musk em pouco tempo já conseguiu reaproveitar  seus foguetes de lançamentos. Fazendo com isso a viabilidade de exploração deixar de ser um sonho e tornar realidade. Hoje estou aqui escrevendo a minha opinião sobre esta  realidade. Elon Reeve Musk você vai passar por várias  barreiras, mas nenhuma delas serão o suficiente para que façam desistir dos outros planetas. No universo existe sim vida além de nós. Podem ser iguais ou diferente de nós, mas isso não importa o objetivo e migrar para outro planeta porque o nosso aos poucos esta se modificando com os passar dos anos. Não podemos dormir e esperar que tudo sempre continue como esta a cada dia que passa modificações acontecem. Precisamos buscar outro caminho além das estrelas. Neste imenso universo existe sim vida igual a nossa sim! Apesar de que algumas pessoas defendam que isso é impossível. Você Elon Reeve Musk acredita que existe vida em outros planetas? Então acompanho sempre seus passos sou super fã admiro sua coragem em perder seu tempo precioso em busca de uma solução para humanidade. Quero lhe agradecer e lhe dizer que você vai encontrar o que procura em breve neste universo imenso. A humanidade só tem a lhe agradecer por nos ajudar. Talvez eu e você Elon Reeve Musk não estaremos aqui pra ver a conquista espacial no futuro. Mas estaremos na história eu Luiz Paulek por escrever esta carta a você Elon Reeve Musk por conquistar o espaço e salvar a espécie humana. Bom meu amigo Elon desejo todo sucesso do mundo a você e nunca desista vá em frente. Precisamos de você lembra disso. O primeiro passo você, já deu o segundo será pousar em Marte com seres humanos a bordo de uma nave que você vai construir. Marte é só o começo da exploração espacial de longa distância. Lembre de mim quando for lançar as pessoas rumo a Marte. Que Deus te abençoe em sua jornada espacial. Que a humanidade sempre lembre de você como o responsável por salvar a raça humana. Lembra desta frase "AVENTUREIRO PAULEK" no lançamento da Starship. Obrigado Elon Reeve Musk e muito sucesso com a Spacex!

  • I think the starship should go up and grab the second stages that are left up there, stick them in the truck, and return with several at once

  • What about landing with parachutes instead of propulsivly? I used an inflatable heatshield and parachutes and was able to recover the second stage, even using realism overhaul/real solar system mods.

  • Michael Blue Whale says:

    Brilliant i was thinking to retrieve the second stage just build a space ship with a net and retrieve it at low atmosphere ..second stage

  • As everything in spaceflight gets better why can’t the second stage be de-orbited by atmospheric drag. It’s an old concept. I don’t see another way anytime soon.

  • how much do the 2nd stage engines cost? how much would it cost to launch a resupply station and fuel into LOE? then have the boosters refuel and then land? would the math/dollars work if you use an booster that's been launched 10 times and written off? could you keep the 2nd stage engines in orbit as tugs?

  • make an orbit of around 80 km above kerbin, that way you should be at around 2200 m/s. The descent would require way less delta V that way.

  • Hey Tim you dor get that they think to use an indlatable heat shield In the payload adapter and the shield can make it stable and there is also a simulation game kerbal built Marcus house video how SpaceX can reuse the second stage .

  • Use second stages as unmanned cargo pods to send them to Mars. Or build a drydock to build a long range space craft and use engine's from second stages to put on the space craft. A purpose-built spacecraft go to Mars.

  • seems to me if it takes a launch system to go from earth to orbit it will take another system to return the second stage from orbit to a transfer point for return to earth. Time is a consideration when going up but if its a mostly empty second stage then taking a month to bring it back down is not that big of a deal. So why not use a Ion powered return module that locks on to the second stage and bring it down to a return to earth transfer point. This gives you the most efficient burn back possible, there are still many issue to fix but those seem doable if you can get over this rather large hurtle.

  • Seen your content ever since this video, I had just got out of sixth grade and was feeling really bored one day so I scrolled through youtube and saw this video on my recommended. That day, you became my favorite youtuber. I am now a freshman in high school and I still watch your content, luckily, your content has made subjects become more easy to understand while being fun and engaging. The best part about you is that you actually care about your content, which is seen only in a few people today. Thanks for truly bringing space down to earth like everyday people like me.

  • Sometimes the music gets in the way. I like the information you give but sometimes it is hard to hear you because of music. I don't understand why everyone thinks there must be music. I can't speak for others, but for me I would like it better without the music. Not saying the music is bad. I like music, but come here for information not music.

  • Maybe if we made a new space station that operated as a rocket repair facility, we wouldn’t need to have second stages at all. Just keep anything going that fast in space. They could use bigger single stage boosters to transport fuel and materials into orbit. Anything that needs to go further into space can be launched into a higher orbit or geo, or whatever from that station

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