/sci/ - Science & Math

WIR

Anyone her has built a rocket, even small? How expensive it was, and what was the max height reached?

>>14857425
If Von Braun was so smart, why didn't he think to use a monocoque structure?

>esa's new rocket is heavily based on spacex
will they pull it off?

>>14857435
stop shilling it it's bad and has nothing in common with starship

>>14857425
WIR WERDEN GEHEN

>>14857438
that's clearly a falcon derivative

Eighth for air-launch is BASED

>>14857438
Seething SpaceX stan scared of the Sussy Baka and what it will do to their bottom line.

>>14857435
It seems like they got the proportions wrong. That Falcon 9 booster looks too wide.

>>14857362
Reposting here.

Yes, I know about the S1.5400. I use it for some interplanetary missions in KSP RSS even, but material science has not evolved too much in regards to rocket engines, or at least to in making them less heavy. The material science that has evolved since then is more about alloys being able to handle hot oxygen better and changes to the metallurgy processes. And in regards to manufacturing it has become cheaper, faster and require less parts but not necessarily better performance. You still have engines designed and produced in the 60's that mog pretty much any engine today besides the Raptor (like NK-33, RD-57 and RD-270 to mention a few).

For a modern example Rocket Factory Augsburg has made a kerolox ORSC engine named Helix at 100kN, but its pretty heavy for that class iirc.

Zubrin

>>14857279
bigmike really doubled down on being a "SLS stan" yesterday

>>14857430
Learn to speak english

>>14857470
Don't bully the ESL-frens

>>14857439
WIR SUCHEN DICH

>>14857454
It's a 5m booster
>>14857457
I already replied in the old thread

>>14857476
You mean Themis?

>>14857476
The expander cycle problem and aerospike problem are almost perfect inverses of each other so you could probably make a meganewton class expander cycle aerospike with the right spike materials and proonted-in cooling channels.

>>14857481
I mean the thing you were looking at and calling too wide.

>>14857482
The problem there becomes, now you are building an aerospike, which makes you gay and retarded. Also, goodbye nice stage mass fractions and 2.5% of your Isp compared to a bell nozzle.

>>14857476
Ok, answer here then

>>14857467
In regards to making engines lighter, not really. The material science that has evolved has more been related to being able to handle the extreme environments a rocket engine demands better. And frankly the metallurgy processes and metal alloys that existed half a century ago are pretty equal to modern ones, the difference is more in the economy of it all.

I'm not convinced that making a 300kg FFSC hydrolox engine would actually be feasible because of it.

>>14857467
SpaceX could, but they don't build engines for other people to use and there's not really any place in their plans for a 100 kN hydrogen engine. Mitsubishi or Ursa Major might be willing to take a shot at it, but the market for RL10 replacements is pretty small and more governed more by political virtues than economic ones.

>>14857427
hypergolic energia please

>>14857493
>I'm not convinced that making a 300kg FFSC hydrolox engine would actually be feasible because of it.
But the Soviets built a 153 kg ORSC engine (which should be heavier than a FFSC engine) in 1960.
Why would a lighter engine cycle built in an age where CNC machining can make 10% lighter parts and computer modelling can let you get much closer to strength margins somehow be unfeasible to achieve a sub-150 kg total mass?

>>14857496
I want them to do it in order to kill off aerojet rocketdyne and for no other purpose.

>>14857488
That's a tolerable tradeoff for an airless-body crew lander since you need total thrust more than crazy high TWR or Isp, and it keeps most of the plumbing complexity contained in a single proontable part which aids maintenance.

>>14857482
Actually a decent idea anon, if you can get enough cooling in the spike (3d printing?) you solve both. Catch is hydrolox have low thrust at sea level so now you have something that either crawls off the pad or pulls 10g near burnout.

14857450 (you)
the fuck is this gay shit lol

>>14857500
Because of the problems with miniaturization of staged combustion cycles, like I stated earlier, it's not linear. Making 100kN FFSC engine won't mean it has the possibility of having the same TWR as a 1000kN one, or even the same efficiency. For an upper stage that would only be used after it achieved orbit there the total mass and the efficiency of the engine is all that really matter in terms of performance (unless the thrust is absolutely ion engine tier awful) I'm not too sure FFSC will be better than an expander cycle engine.

>>14857501
The simplest way for SpaceX to do that is to kill off the viability of the rockets that use their engines. Failing that, a company like Ursa Major or Firelfy could come along with better engines. Both have an interest in commercially marketing engines and would love to get some big government launcher contracts.

>>14857482
You don't even need to use an aerospike. The LE-9 uses an expander-bleed cycle and it gets about 1200 kN of sea level thrust.

>>14857502
I doubt it!

>98kN
>470s (highest ISP ever achieved by a chemical engine)
>260kg

Why the fuck didn't Pratt & Whitney do anything with it? Now it's fated for the Angara yikes.

>>14857521
Yeah you keep saying that but REAL LIFE disagrees, dude. I was also hesitant to make the claim I'm making until I found the soviet shitbox ORSC engine that weighs less than half as much as an RL-10 and produces over half as much thrust. Scale up either figure to equal the RL-10 and you either get a more powerful engine for the same mass or a lighter engine for the same power.
The efficiency gains of FFSC come from the very high chamber pressure. This is independent of scale, and in fact for smaller overall turbomachinery the mass relative to power output should decrease as hoop stresses decrease with the smaller diameter pipes and components. In fact Elon once mentioned that Raptor is the size that it is because going to a larger size decreases TWR as the power output per unit mass of engine decreases, since the equal pressures components need to handle at larger scale result in greater stress on materials.

>>14857537
that's almost a high enough ISP to trick me into liking hydrologgs

After a thousand days in orbit, the CHEOPS space telescope shows almost no signs of wear. Under these conditions, it could continue to reveal details of some of the most fascinating exoplanets for quite some time. CHEOPS is a joint mission by the European Space Agency (ESA) and Switzerland

https://nccr-planets.ch/blog/2022/09/12/a-thousand-days-of-cheops/

>>14857522
>expander-bleed cycle
Interesting cycle, it's like diet combustion tap-off.
Speaking of cycles, does anyone else realize that the RS-25 is actually a hybrid expander-cycle and fuel rich staged combustion cycle engine?

>>14857537
I wonder what's going to happen with LM10-MIRA and Vega, it's derived from it but uses methane instead, similar thrust but 362Isp, could be dead on arrival

>>14857504
The LE-9 doesn't work yet specifically because of the challenge of scaling expander cycles with bell nozzles.

>>14857565
you can get similar performance with hypergolligs

>>14857554
>Yeah you keep saying that but REAL LIFE disagrees, dude. I was also hesitant to make the claim I'm making until I found the soviet shitbox ORSC engine that weighs less than half as much as an RL-10 and produces over half as much thrust. Scale up either figure to equal the RL-10 and you either get a more powerful engine for the same mass or a lighter engine for the same power.

Drop the thrust shit, it's of little relevancy here unless we're talking about abhorrently low thrust, which we aren't. Total mass and efficiency is what matters. The S1.5400 was built using very lightweight titanium alloys and its efficiency is pretty fucking shit for a kerolox engine used only in a vacuum. It's not a good argument for why a FFSC small hydrolox engine would have more mass saving and better efficiency than an expander cycle one.

> In fact Elon once mentioned that Raptor is the size that it is because going to a larger size decreases TWR as the power output per unit mass of engine decreases, since the equal pressures components need to handle at larger scale result in greater stress on materials
Yes, because there's a balance. Scale up the engine too much you will see a bunch of problems but if you scale it down enough you will see a set of different problems.

We're talking about a very niche application, which is a hydrolox engine used for a small upper stage that will only be fired in orbit. Of course a FFSC will be the better option in most case. You would be better off just strapping a ORSC RD-57 engine on the EUS than 4 RL-10s for an example and that engine was developed in the 60's.

>>14857574
wait wut i’ve been following this engine’s developments/problems for a while now and I’m just now realizing it’s expander cycle. LOL for a first stage?? Have any other rockets ever done this?

>>14857574
whoops meant for
>>14857522

>>14857504
I see it as working best either as a pure vacuum stage despite the aerospike or as a sustainer engine with kerosene boosters. I'd actually see it best as a tripropellant spaceplane: jet engines that breathe air up to Mach 6 (2km/s) on regular aviation fuel, and then the hydrolox aerospike all the way out to orbit.

>>14857577
>470 Isp with hypergolics is possible
Gonna need to see a phat fucking source for that claim, bucko

>>14857565
>>14857577
For me, it's LF2/LH2

>>14857598
Do you even LF2/NH3?

>>14857574
The LE-9 should be working now. Whatever problems they had have apparently been cleared up and they're aiming for a first launch on the H3 in the next six months.

>>14857589
>Total mass and efficiency is what matters
Uh huh, and what does having a high TWR engine with equal thrust imply? Lower mass, which equates directly to a lower total dry mass. Which obviously equates to better performance. I'm not dropping the thrust "shit" because it's the important part of my argument: even if you can only MATCH the efficiency of the RL-10 at an equal thrust scale, so long as you can do so with a lighter engine, you gain performance in real terms.
>efficiency was pretty fuckign shit for a kerolox engine
Yeah maybe because it was the first staged combustion engine ever flown and had a tiny expansion ratio due to it needing to fit in a tiny interstage volume. I shouldn't need to remind you that the Merlin 1D goes from a 305 Isp engine to a 340 Isp engine merely by changing the nozzle geometry, nor should I need to point out what that implies for the S1.5400. Also, the TWR would have increased with this larger expansion ratio too, because the nature of vacuum optimizing an engine is such that you add nozzle mass until the thrust gains due to increased Isp stop outpacing the mass gains due to having a bigger nozzle.

>>14857593
It's an expander tap-off cycle, not really an expander cycle proper (which is a closed cycle engine).
It's basically a gas generator engine except instead of the gas coming in the form of fuel rich combustion products, it's gas in the form of vaporized fuel from the nozzle cooling loop, and just like a gas generator engine the turbine output is dumped overboard.

>>14857594
>as a sustainer engine with kerosene boosters. I'd actually see it best as a tripropellant spaceplane: jet engines that breathe air up to Mach 6 (2km/s) on regular aviation fuel, and then the hydrolox aerospike all the way out to orbit.
>sustainer
>tripropellant
>spaceplane
>breathe air up to mach 6
>hydrolox
how many more meme technologies can you fit into this concept?

>>14857602
No, he means LF2 LH2.
I, however, want to bring up LB5H9/LF2. The thinking man's bipropellant.

>>14857605
>Uh huh, and what does having a high TWR engine with equal thrust imply? Lower mass, which equates directly to a lower total dry mass. Which obviously equates to better performance. I'm not dropping the thrust "shit" because it's the important part of my argument: even if you can only MATCH the efficiency of the RL-10 at an equal thrust scale, so long as you can do so with a lighter engine, you gain performance in real terms.

It's not since you simply ignore the problems of miniaturization and think a kerolox ORSC engine built with light weight titanium alloys with relatively poor efficiency is some argument for why it wouldn't be a problem for a FFSC hydrolox engine. The entire point I'm making is that it might not be feasible or even possible to make such a small FFSC hydrolox engine and have it have smaller mass and higher efficiency than expander cycle one. It's not as obvious and clear cut as you want it to be. Engines like the RL-10 and the RD-0146 are already pushing the absolute efficiency limit of hydrolox.

>Yeah maybe because it was the first staged combustion engine ever flown and had a tiny expansion ratio due to it needing to fit in a tiny interstage volume. I shouldn't need to remind you that the Merlin 1D goes from a 305 Isp engine to a 340 Isp engine merely by changing the nozzle geometry, nor should I need to point out what that implies for the S1.5400. Also, the TWR would have increased with this larger expansion ratio too, because the nature of vacuum optimizing an engine is such that you add nozzle mass until the thrust gains due to increased Isp stop outpacing the mass gains due to having a bigger nozzle.
Good, now do it with a FFSC hydrolox engine. Exactly the same thing as building a OSRC kerolox engine. It's simply a disingenuous argument.

>crying about twr or Isp when $ and reliability is what matters

>>14857619
>you simply ignore the problems of miniaturization
I'm not ignoring problems, I'm saying evidence suggests they don't exist. Very different situation.
>and think a kerolox ORSC engine
Which is inherently heavier than FFSC but lighter than hydrolox ORSC, making it a bit of a wash and why I don't prescribe exact figures
>built with light weight titanium alloys
Heavier than modern alloys (lest we forget stainless steel chilled to cryogenic fuel temperatures has better strength to mass ratio than titanium or aluminum alloys)
>with relatively poor efficiency
Due to having a nozzle expansion ratio of less than 40:1, compared to MVac's 165:1. Also, I need to amend my other post, the Isp of MVac is actually 348, not 340.
>is some argument for why it wouldn't be a problem for a FFSC hydrolox engine
Yes, everything I mentioned above does in fact point to the expectation that a 2020's FFSC 100 kN hydrolox engine would achieve equal thrust versus the best RL-10 variant for lower mass and higher Isp.

>>14857629
I'm not the one crying about it, I'm the one saying that a FFSC 100 kN engine would be better than the RL-10 and would also be cheaper due to the RL-10 having a massively inflated price tag.

Ken going ham on twitter rn fr

>>14857638
I don't care what the cunts on Twitter are saying, fr fr no cap.

>>14857612
metallic TPS and refueling in LEO

>>14857638
Ken ham?

>>14857644
>refueling in LEO
Suborbital refueling (oxidizer is carried internally)

is it a mini starship?

>>14857671
meant for >>14857438

>>14857671
Imagine a mini starship with the orbital maneuvering system capabilities of the space shuttle

>>14857671
No, it's basically a big capsule with TPS and an expendable insertion stage. Closer to halfway between Dragon and Starship.

>>>14857192
Why does apogee include Susie but not crew starship, considering crew starship will probably be a thing well over a decade before susie is?

sussy baka malaka

>>14857681
For coping reasons

Realistically speaking, when will the first human walk on Mars?

>>14857638
>Ken going ham on twitter rn fr
>about the ESA powerpoint rocket
couldnt care less

>>14857612
you forgot
>aerospike

>>14857689
Sussy Starship

>>14857688
October 2nd 2022

>>14857482
>Non-toroidal aerospike engines are not subject to the limitations from the square-cube law because the engine's linear shape does not scale isometrically: the fuel flow and nozzle area scale linearly with the engine's width.
Sounds like they're a few steps ahead of you

>>14857690
I was experiencing vaporware fatigue

>>14857673
Could it have thrusters on all sides or can there be a 360degree thruster cage that ships can enter,.get securely strapped to, and then act like an elevator between orbits.

>>14857574
>The LE-9 doesn't work yet

anon I...

>>14857698
LM9 is a power point presentation dude, last time we saw it they moved to a Starship clone design. It doesn't exist.

>>14857589
>Drop the thrust shit, it's of little relevancy here unless we're talking about abhorrently low thrust, which we aren't.

There is a reason why expander cycle engines are never first stage engines.

>>14857700
>Long March 9

Anon we are talking about the expander bleed cycle engine that is used on the first stage of Japan's H3 rocket.

>>14857708
Yeah I know

>>14857432
Because it’s gay like you.

>>14857425
For me it's Turbopumpe.

>>14857688
It all depends a lot on how the world is going.
>If we suddenly get another cold war, it could happen during the 2030's.
>If Starship or some other rocket like it has success, it could happen during the 2040's or 2050's.
>If we don't get a good rocket and/or there is no political pressure to pump resources into space exploration, it might only happen latter into this century.
I hope the second one becomes reality because the first is just Apollo all over again.

How well suited is a Vulcain engine for an upper stage?

I've been brainstorming a potential SpaceX - Ariane collaboration rocket. The first stage would have 13 Merlin 1D engines and propulsively land itself just like the smaller Falcon 9 booster. The second stage would use a single vacuum optimized Vulcain 2 engine.

https://www.youtube.com/watch?v=ZlQHF_yBkMQ
30 minutes for Starlink try.
How are the odds for good weather today?

>>14857776
40% chance of good weather

>>14857776
five

>>14857783
shit

>>14857688
mid 2030s

>>14857771

>SpaceX - Ariane collaboration

>>14857771
NASA considered the idea in some advanced trade studies back in the early 90s, mostly in the same roles that they thought about using modified RS-25s. You'd need to modify the ignition system a bit so it can be air started but it's not a completely unconsidered idea.

>>14857813
>just tweak it a bit to airlight bro
at that point just get some spare RD-0120s and modify them

>>14857820
Well, actually, about that...

>>14857826
OH SHIT LADS

>>14857826
how is the vulcain better? lighter weight engine?

This better be good.

>Ian McCollum
Gun Jesus narrating a SpaceX launch? Frankly excellent.

>>14857783
only 20% chance of violation. we gaan!

https://youtu.be/cMA7njOFqy8

Cloudy launches are so damn cool

kino

OH NO IT'S ON FIRE

MaxQute

>sunlight at apogee

>>14857834
It's only better politically. The RD-0120 was Energia's sustainer engine.

space rat spotted

>>14857870
It's over for SpaceX

>>14857671
Not really, because it can't do orbital refueling as far as we know; and is incapable of exceeding the boundaries of low earth orbit. Which Starship is designed to do and once it does, is technically designed to go anywhere in the solar system.

>>14857870
send a space cat after it

kino touchdown

it just werks

That landing amazes me every time.

>>14857850
First stage landing confirmed.
They got so much successful they made it boring.

Elon can't keep getting away with it

>>14857885
The next stage of landing excitement is catching it with the tower. It's as much genius in terms of mass saving as it is a spectacle. Catching a 175-200 foot tall building a 100+ feet in the air is absolutely bananas. If it actually succeeds, it will put SpaceX like 20 years further ahead the rest of the industry while simultaneously blowing up their livestreams. 42.7k people viewed the latest Starlink mission, that number would 10x at the lowest and like 25x at peak aka 1M people would show up to watch the videos just to see SpaceX catch the giant ass SuperHeavy booster with a tower and maybe do the same with the Starship.

>>14857834
The big advantage was that you could buy it from the French instead of the Russians.

It wasn’t really a question of ‘better.’ All of these designs planned around having a big upper stage engine, and since the only upper stage engines we had in service at the time were the RL10 and AJ10 they doodled out modifications of every engine they could conceivably develop, modify, or acquire; J-2S, RD-0120, Vulcain, RS-25 airstart edition, as well as something called the ‘low cost space shuttle main engine,’and versions of the space transportation main engine which were both probably pretty close to the RS-68.

>>14857891
What advantage has the catching tower over the Falcon 9 style landing?

>>14857898
No need to drag the booster back to the launchpad if it land in the thing that stacks it in the launchpad.

I've never caught a rocket explosion live. Falcon 9 mission in 9 minutes. This could be the one bros. I'll be watching clear's channel.

>>14857840
i knew i knew the new name new kname somewhere I knew

>>14857905
????

>>14857905
based mars poster

>>14857905
smartest clear viewer

>>14857438
t. seething spacex stan whose lunch about to be gobbled up

>>14857915
lol

>>14857464
always thought him and primaldino were elaborate trolls, esp cuz the latter prides himself as being a former spacex fanboy. jeesus i was way off. certified retards. at least entertaining

>>14857898
As this anon said: >>14857904, but detailing it further:

1. Don't need the drone ships, don't need the fairing catching ships and the overhead of that + maintenance + fuel costs + crew; which saves arguably double digit millions of dollars over a 12 month period

2. Booster lands back at tower ready to go for the next flight. In the time it takes for the tower to lower it back to OLM and for the booster to be refilled with cryogenics, then for the next Starship or Cargoship to be mounted onto the booster and it too filled with cryogenics and then crew, the engines will have sufficiently cooled for relight.

3. As mentioned, it's a spectacle, which generates major interest in the program, which is a positive feedback loop for interest in the company, its mission, and its larger long-term colonization goals. It makes people want to subscribe into it, potentially purchase options to migrate, and it empowers younger people to dream bigger knowing that his option now exists; this crazy engineering option made possible so more crazy engineering options as reality in the future also are, and they will go into fields where they'll be able to pursue them; making science and culture richer as a result.

4. You don't need landing legs on the SuperHeavy booster, which potentially can shave off anywhere from 10-25 tons off the mass of the vehicle. That's 10-25 tons more fuel you can load to launch the Starship/variant into a higher orbit or with more fuel onboard needing less fueling subsequent flights or that's 10-25 tons more mass you can put on the Starship when you launch it to LEO, at a lower orbit, but ultimately allowing that much more downmass to be achieved to Moon, Mars, or anywhere else in the solar system that the mission dictates it. Which is a massive massive win.

All of that is achieved by catching the SuperHeavy on the tower instead of landing it traditionally.

>>14857898
From my limited understanding, the weight of the booster and how strong the legs will have to be. With landing leg that strong, would add a lot of weight in addition to how long it would take to reset. When the booster lands, the arms will cushion the booster, because they can move up and down, so they don't need to bring it to an almost hover when it makes contact. I'd image if they tried landing like the falcon 9, they have to be much more precise with their landing velocity plus>>14857904

>>14857638
who tf is ken

>>14857930
King Ken IV if you don't stan him you aint my nigga

>>14857931
Link it faggot, don't gatekeep.

>>14857934
nah

>>14857931
Oh the apogee fag. I like him but his speculation can get full retard at times. and annoying

>>14857939
>is on /sfg/
>dislikes speculation

>>14857923
I like how F9 is "traditional" reuse now.

>>14857941
orion starship is one of the stupidest things i've ever heard. subscribe to my patreon

>>14857939
last video I saw was all about him desperately running defense for NASA's corruption

>>14857945
It's really the first one for a rocket.
What are the other current reusable rocket in use? I can only think of Electron and New Shepard.

>>14857951
>he doesn't stan NASA 100% 360 degrees both ways

yikes

>>14857951
yep he does that to appear objective even though he's a total spacex fanboy. it's an overcorrection to seem fair and balanced, and it makes him look like a goddamn idiot

>>14857939
>>14857951
>>14857956

Being objective would be to call out NASA's corruption and incompetence rather than trying to justify it by presenting a variety of ideas where SLS is relevant. The entire program exists to push jobs and facilitate grift. The fact that every launch attempts is scrubbed because something breaks in a way that should have been addressed prior to the launch process, all the while parts of the vehicle inches closer and closer to expiration is insanity. If SLS doesn't launch by mid October, the batteries on the fucking flight termination system expire. How the fuck can you conceivable design a system where one of the most important functions of a rocket, where if something goes wrong and you need to blow it up, may stop functioning cause the batteries are allowed to expire. That's insane. Same with the SRBs, that you can build them and then they're attached to the vehicle, but it has so many problems that they expire and then you're basically off the documented path where literally anything can happen between lighting them up, halfway up the flight, nearing MaxQ or up to booster separation.

He's got it in his head that he needs to put out long, detailed, and comprehensive videos and for that he's fishing for content. Which is trash. He should focus on what matters and be clear and simple on it. Who gives a shit if the video isn't 20+ minutes. Nobody gains anything from the rambling.

How can other rocket launchers survive an eventual success of Starship?
I want it to succeed, but I don't want other launchers (mainly Rocket Lab) to crash because of it.

>>14857956
So many SpaceX/Musk fanboys do that, specially on twitter and r*ddit, what's wrong with being a fanboy of the only space company/organization that's actually doing something?

>>14857956
>>14857968
when will people fucking learn
the only ones who would insist on defending garbage are people who do not watch their videos and never will
its the same shit everywhere, companies kneeling for zealots who don't not ever buy their products at the expense of people that do

>>14857975
>what's wrong with being a fanboy of the only space company/organization that's actually doing something?
Lest we face his ire

>>14857972
The success of Starship will mean that most rocket companies to survive will take their engines and flight hardware and move into the kickstage market, where the Cargoship for example, is the mothership of half a dozen or a dozen different payload where each has its own kickstage and they all live inside the hull. The Starship then basically runs along a mission profile and at every deployment marker, positions itself in the direction the mission payload needs to go and pushes out the satellite with an electromagnetic launcher (probably) to impart some extra few m/s deltaV. Then the kickstage activates at sufficient distance from the ship and off the payload goes, while the Starship keeps going then lights its engines and off to the next destination.

There's arguably a 10-50Bn dollar TAM for kickstages in the future. A lot of money on the table. Starship can get you anywhere within the solar system on the main highway that it builds, but to go out into the country side, you'll need something else to help you cross the divide.

>>14857986
The other area I can see growth potential with a 25-100Bn dollar TAM is where the rocket engine and flight hardware can be leveraged is for all the worker bees and point to point transport vessels that will need to exist across the moon, Mars, and any orbital facility that is designed over time. Taking Firefly's engines, or Rocketlab's engines, or Astra's engines, or Masten's engines. You can repurpose them for intermediate transport vessels across a low-gravity/low or no-atmosphere environment and tweak them for either deep throttle capabilities or keep them as is, but where these vessels would be used to move large mass cargo from mining/processing facility to launch facility, where they are offloaded for main shipment up to an orbital facility, back to Earth, out to Mars, the belt or elsewhere. These engines are small and simple compared to Raptor2 or whatever is on an SLS or NewGlen's BE-4s. Which means, their size and simplicity, relatively speaking, makes them prime candidates for mass production and mass volume use.

>>14857885
>They got so much successful they made it boring.
That's why there are level up challenges, like stacked starship, which hasn't flown yet, there was a lot of frustrating not boring with the starships that didn't land

>>14857986
impulse space

>>14857992
reminder that all those engines cost more than raptor 2

lunar tourism is the next big thing
whoever makes the first lunar hotel will be obscenely rich

what happened to the iss?

>>14858015
Obviously. But my point is that if Starship eats up the entire planetary launch market (hypothetically) of the democratic/republic nations of the world, then the opportunity of existing hardware moves offworld instead of just imploding and fading away.

>>14858023
At the bottom of the pacific. This picture would imply that this is at least 2030 earliest or later.

>>14858025
it just dies because they won't be able to pivot fast enough

>>14857992
The problem is that the RL10 spanks every vacuum engine smaller than it like a disobedient avocado if you have active refrigeration. The only way to be better at a full vehicle spacetug level is to use non-toxic storable propellants (like Impulse Space and Momentus) instead of cryogens.

>>14858034
>the RL10 spanks every vacuum engine smaller than it

Don't mind me just having triple the isp.

>>14858041
And such low thrust you need 2-3x as much delta-V to do an equivalent orbit change. SEP is only good for station keeping.

>>14858049
changing orbital inclination isn't fighting gravity losses to raise your orbit

>>14857868
>>14857894
thanks and I understand the politics behind it, I was more asking why the capacity of the vulcain rocket looks to be a bit better than the RD one, despite the russian engine being more powerful on paper. Again I’m assuming it has to do with the fact that the RD-0120 is heavier than a vulcain thus it eats into your capacity?

>>14857926
arms moving up and down have nothing to do with it, this goofy speculation stems from renderfags. SH will hover and lower itself onto the catching mechanism (more likely they will try to optimize for 0 velocity at the exact moment of contact but you get my point)
You are right about the landing legs and added mass; you worded that quite well

Sneed

>>14857939
I agree and I find his videos to be gay but he is actually pretty funny on twatter

>>14857926
The arms won't move vertically at all during a catch.

The probability of the booster hovering perfectly where the arms are going to be is low. I predict catches will be marked by loud echoing "CLANG"s when the raptors shut off and the booster falls six inches before capture by the chopsticks.

>>14858109
Someone tweeted this to Elon ages ago and he replied that this was essentially identical to what will happen.

>>14858128
It won't hover, it will just reach a slow descent velocity and the arm catch points will move into position correcting for errors until everything meets up and the hard points meet the catch points with a bonk (drowned out my engine noise) and the engines shut down. The booster will already be caught before the engines turn off.

>>14858101
The RD-0120 does weigh about 2.5 Vulcain-1s so it would have some impact but the differences in lifting performance are pretty incidental. This part of the study was supposed to be sketching out designs that could all lift about 50k lbs to a 220 NM orbit so they'd just shift the size of the F-1A/RD-0120 until it had around that much lifting capacity. Both of the designs are pretty close in size, so I'd guess that the extra weight is largely balanced out by the RD-0120 having +24s more specific impulse.

>>14858136
>essentially identical
yeah except the arms won’t move. This is coming straight from the horse’s mouth—musk said all of the people rendering a SH landing were doing the arms wrong

>>14858151
The arms AREN'T moving dipshit. Not up and down anyway.

>>14858136
How could the booster aim so well?
I know they got good with Falcon 9, but this seems like a huge step up.

>>14858157
Stevie Wonder, the arms in that webm are clearly at the top of the tower at the 0:05 mark and are almost halfway down the tower by the landing sequence. But either way if you are arguing the arms won’t move then we both agree

RS-25, 100 million bucks a pop, into the toilet after one use.
"Four for Artemis 1 lighting up the sky, five for the Congress and their halls of stone, three for the taxpayers asking why, two for NEO Surveyor cut to the bone. 14 flown engines doomed to die in the land of NASA where the rockets fly. One booster to bring them all, one booster to find them, one booster to fling them all, and in the darkness, blind them in the land of NASA where the rockets fly. "
Credit: Roger Goen, Planetary Radio podcast Sep. 7

>>14858136
>>14858151
>>14858157
>>14858167
You're both retarded. That webm was posted by Elon himself and was made by SpaceX people.
Also the arms aren't moving down in it, you're seeing things.

>>14858173
REDUNDANCY

>>14858128
>>14858139
How large and solid is the pad and the rocket has no leg kickstands, so it will be balencing standing on the rocker nozzles just as they touch the pad the chopsticks will strongly hold the ship? And the ship has to travel all the way back and aim and angle the right directions and timing, can't wait to see it and hope to see many successes, life is full of excitement,science and sci Fi escapes simple aspects of life and nature that are boring, making sci Fi, sci reality

>>14858173
seethe more, the first set of engines have already made their money back by virtue of flying on shuttle in a reuse configuration and the new set of engines will be cheaper

remember to not reply to obviously mentally challenged posters

>>14858183
>$146M per RS-25E
>"cheaper"

>>14858139
Is there a designated catch tower will there be, customized to make catching as easy and smooth as possible, using all kinds of techniques,

gah dang jupiter is bright as hell

>>14858206
-Galileo, 1610

>>14858218
kek

So I am too dumb to read a dV map despite how long I have been on /sfg/ so a) is it more intuitive than I think, and more importantly b) how much dV is required for a Venus flyby and could SLS do it? Starship? What’s the smallest / cheapest mission you could do with current/near rockets, like what is the limit? I assume you need a huge rocket but I’m still not sure what is meant by going “up the gravity well,” and why you still need big dV to leave mercury or venus orbit to return to earth (assuming you injected into orbit instead of doing a flyby)

>>14858136
You fucking dumb ass. This is an official internal simulation

>>14858237
Wondering about this too. People say you would need to replace Raptor2s with NTRs in order to get it into a Jupiter orbit. So how far can a Starship actually get you if you fully fuel it around Earth and full throttle. What about if you refueled one around Mars, which seems rather likely to happen in the future?

Where is the 4ASS booth at IAC? where are you guys? :(

>>14857767
there is no reason spacex doesn't reach mars by 2033 at the latest, and its very possible they could do so by 2029

>>14858237
Venus is fairly easy to get to due to how close and similar it and Earth's orbits are. A Venus rendezvous-return would have about the same propulsion difficulties you'd have with a Mars sample return, minus the landing-liftoff part. Mercury is ten bitches and then some. You have to kill off an absurd amount of solar orbital velocity to bend your periapsis that far in. I don't think I've heard of any serious proposals for a Mercury return mission.

Delta-v maps are somewhat useful, but if really want to be thinking about this sort of thing you're going to need to become closer friends with "Characteristic Energy" (C3, or, km2/s2). Fair warning: while this is a more useful and informative figure, it is also a great deal more confusing. It's also impossible to make maps of.

The good news is that you can just go over to NASA's trajectory browser (http://trajbrowser.arc.nasa.gov/traj_browser.php)) and tell it where you want to go and when you want to go there and it'll do its best to spit out all the trajectories that'll fit, complete with the C3 values. Then you go to NASA LSP Performance Web Site (http://elvperf.ksc.nasa.gov/Pages/Default.aspx)) or Silverbird Astronautic's Vehicle Performance Calculator (http://www.silverbirdastronautics.com/LVperform.html)) and plug the C3 figures in for various rockets.

The smallest and likely cheapest Venus flyby mission would be something launched on Electron. They're sending a deep space Photon to drop a 1kg atmosphere probe into Venus sometime next year. It's a private venture by Rocket Lab and MIT so it can't be super expensive and you can't get much smaller than a 1kg single instrument probe. The USSR's early Venera probes all weighed about 1,000 kg and they got flung by Molnyia launchers, which were just 1960s era Soyuz with an extra kick stage. SLS has enough giddyup to send an entire Salyut space station on a flyby of Venus, not that this should ever be seriously considered.

>>14858319
Over here

>>14858342
>between 2029 and 2033
this is probably it barring a major calamity

>>14858342
Are you talking about sending an uncrewed Starship to Mars for testing/probing, or a crewed Starship?
Remember they need to create all the life support tech for this, and that needs money, and the money has to come from someone willing to pay.

>>14858347
can u make me one?

>>14858319
I couldn't afford the trip this year, buying a house put my finances (temporary) shambles. How's Paris?
Think you'll go to Azerbaijan next fall?

>>14858379
Azerbaijan is currently in a shooting war with Armenia. Russia may or may not get involved.

>>14858400
That’s cool. War is based

Do you guys figure the universe is infinite or ultimately limited?

>>14858424
It's infinite, it was revealed to me in a dream.

>>14858422
take some estrogen for once

>>14858424
I think the universe wraps around because torus is cool and infinity is retarded.

>>14858432
That’d be very bizarre to actually witness the implications of; sounds like something you’d see in Futurama, but ultimately I think it’s more intuitive than infinity and much more intuitive than the universe having an edge.

>>14858400
lol yeah, Baku might not happen
Milan in 2024 should be cool if this winter doesn't cause the collapse of european society

>>14858431
Disgusting

>>14858049
>SEP is only good for station keeping.
Oh look, this baka again. If your point made any sense, it would go for the whole of low thrust propulsion, including nuclear electric and the direct fusion drive, all candidates for propulsion that could beat chemical to most interplanetary destinations, either in transit time/delta-v or in maximum payload. The increased payload ratio why SEP has become the defacto choice for satellites maneuvering from GTO to GEO. Every Starlink satellite uses SEP for raising orbit, station keeping, and subsequent deorbiting.
>And such low thrust you need 2-3x as much delta-V to do an equivalent orbit change.
Good thing a spacecraft with 10x the Isp has 10x the delta-v at the same dry mass to wet mass ratio, but a low thrust maneuver only approaches a 2x increase in delta-v if the radius of the final orbit is 100x that of the initial orbit, assuming escape velocity isn't reached first. For that to be true it's like injecting an interplanetary spacecraft into LEO instead of an orbit with high eccentricity, which would only happen if it was massive, even then it could be refueled and take on passengers just before spiraling out of Earth escape.


https://space.stackexchange.com/questions/34114/ratio-of-low-thrust-slow-spiral-to-hohmann-transfer-delta-v

>>14858436
European society collapsing would be based. That place hasn’t been cool since like 1300

Was looking at the moon last night. Was thinking maybe one of my /sfg/ lads was looking at the same time. Felt a kinship in my heart. Knowing that you guys are the only ones left that love me and understand me.

>>14858353
Crewed starship
>where will the money come from
Starlink retard we've been over this probably well over a hundred times at this point. also it'll be a spacex led operation, not a nasa one.

>>14858445
Perhaps we will meet in another life; on another planet or brane.

>>14858451
Thank you.

>>14858445
I was looking at the moon the other night thinking about how much I want to fuck it

>>14858319
Don't forget to go to the Advanced Space presentation

I NEED UPDATES

>>14858183
I can't wait to see have scrubs the new engines cause

>>14858477
Capstone is dead

>There are still no satellites in Venus's orbit

This confuses and enrages the chemfag. Imagine having such a paltry amount of delta-v that you can only do flyby missions to most of the solar system, instead of orbiting multiple bodies in one go, oh I'm laughing.

>>14858489
the expression in that picture is cracking me up
>he does this shit every time he loses
>why do I keep playing with this jackass

>>14858491
>we can change inclination somewhere with an escape velocity of ~350m/s
Not that impressive for real spaceflight but useful for exploring tiny bodies.

>>14858424
Doesn't matter If your fascist, history revising, "1984" intergalactic government is chasing you and your scrappy group of space libertarians on a quest to take your FTL spaceship to the end of the known universe because they don't want you looking through a telescope back at the universe, looking into the past to see what really happened and the dark secrets they're trying to cover up that if revealed to the public, would cause a revolt, ending their enslavement over the universe and forever ensuring that the truth could always be found when you can beat the speed of light.

>>14858567
Buddy, Dawn has the record for the greatest propulsive delta-v of any spacecraft, that mission couldn't have been done by chemical in any reasonable sense. Starship refueled in LEO is incapable of orbiting Vesta, let alone both Vesta and Ceres in the same mission.
>>14858308
Starship with LEO refueling, Earth-Moon L2 refueling, or Low Mars Orbit refueling would only be able to capture around Jupiter, it couldn't orbit any of its large moons. With a kick stage launched from the payload bay, capture could be achieved around some of the moons but the science payload would be next to nothing, thus another type of propulsion should be used like ion thrusters or a plasma magnet drive.

>>14858580
Would this actually work? Like they say on JWST that we're looking at stars years in the past because of how long it takes for the light to reach us, but say you had the ability to travel faster than light,
could you look back at earth and see the past? If this is possible what's the theoretical maximum resolution a telescope could have, given that you have unlimited resources? Could I go light years into
space, build a fuckhuge telescope and look at major events through history?

>>14858308
We will build a second stage you dock it into that is optimized for solar system exploration.

>>14858640
Improving the mass ratio and adding more staging only gets you so far. Ultimately the only way to get relatively high delta-v with chemical propulsion is through brute force via refueling and that borders on absurdity. Take for instance SpaceX 'plans' for Jovian exploration, read marketing material, which would probably require hundreds of launches for a single landing, refueling in LEO and then twice at Jupiter. It's not realistic to return the interplanetary tankers as they'd need to be full to come back, with aerobraking, which at that speed would be very spicy.

>>14858679
That's why we need NTR.

>>14858347
It's 4chan, not 4Chan.

>>14858695
How the fuck is cuckold porn going to get us farther out into the solar system?

>>14858349
>>14858342
No way they will do it by 2029. Even SpaceX isn't safe from constant delays. If they say 2030 that means 2040.

>>14858349
>>14858722
the thing the delays posters keep intentionally ignoring is that SpaceX isn't your bog standard jewish contractor
while they aren't flying, they haven't stopped
rockets are still being mass produced in the background
24 being delayed further just means that 25, 26, and 27 will launch closer together than they otherwise would
Once this shit starts flying it'll be a starship a month until they deplete their supply

>>14858679
We're never going interstellar with rockets. We'd need fundamentally new tech which is not guaranteed that it's even physically possible. No wonder that we haven't seen sign of alien life. The big filter is still in front of us. And it's called distance.

>>14857454
>That Falcon 9 booster looks too wide.
that's not Falcon 9

>>14858726
Haven't they stopped Falcon booster production though?

>>14857435
Kinda reminds me of BFR.

>>14857435
>>14858758
A mix of F9/BFR

>>14857435
riddle me this: why is it using F9 landing legs despite being designed from the ground up to land??? Falcon only uses those legs because it was an expendable rocket bootlegged to land propulsively. Are the euros incapable of doing ANYthing original?
Also they were scoffing at the idea of reusability not even 5 years ago

Rip Valeri Polyakov, he spent 438 fucking days in a row on MIR.

>>14858679
If you aren’t aerobraking at ball numbingly fast interplanetary speeds are you even living?

>>14858766
It's concept art you retard, it's just a place holder.

>>14858769
we shall see

>>14858772
They already stated it, it's literally just concept art of a "future reusable rocket" that the Susie hopefully will fly on in the future. The same concept art has been used since like 2018 for Ariane NEXT.

Try something else to whine over /pol/tranny mutt.

>>14858718
Japanese ingenuity can do anything.

>>14858757
No. Why do people keep thinking this?

If they “stopped F9 booster production” they’d be stopping flights of the Falcon 9 outright, since the first and second stages are built on the same production line.

>>14858779
Calm down I was referring to the final leg design not the rocket itself you self conscious woman

>>14858790
I'm just calling out the thread's tranny. I wasn't the one making a whining bitch post about some concept art.

>>14858695
Solid core nuclear thermal is still quite limited, even if you assume a 2x increase in delta-v over chemical despite the worse mass ratio. Let's say your hypothetical NTR has 15 km/s of dV, more than twice that of Starship, you still can't land on Mercury, Ganymede, Europa, IO, Titan, Enceladus, etc. For any mission that doesn't involve landing, electric propulsion would be better, it's far more efficient way to move propellant and chemical landers around, which would make for the most optimal near-term architecture, with the benefit that most missions wouldn't need ISRU refueling.

>>14858025
>>14858031
>>14857992
>>14857986

I think with starship, the cost ($ billions per year) and time (20 years of hard iteration, consuming thousands of the best engineers) to build your own competitive orbital launch vehicle will be so big no one will attempt it (except adversary governments like China). Thus the remaining space market is to build things that get to orbit via starship.
I think a company that makes standardized satellite busses for cheap (get a 10 year warrantied LEO satellite with instruments of your choice for $1m, bulk discount you get 10% off for up to 100 and 20% off for 1000!)
I think there will be standardized sun synchronous satellites, LiDAR, telecom, weather, etc.
another big market is orbital manufacturing. I think a company that can provide the expertise of space construction/maintenance can let the production experts do their work. For example, a modern semiconductor fab costs billions of dollars, so a foray into orbital manufacturing pathfinder for tens to hundreds of millions isn’t unreasonable. Orbital crystal manufacturing could allow bigger and more precise chips, but the semiconductor companies have no clue how rockets and satellite stuff works. So they’d contract with ‘space industries r us’ to help do that

>>14858434
>much more intuitive than the universe having an edge.
The universe may not have an edge, like being inside cardboard box you are surrounded by edges, but what is meant by edge is extent, like if you threw a bunch of bocce balls around you, the furthest one would represent the edge of their extent around you.

If things if the universe are spreading out, this edge could get further and further, and by that one might say, in-finite, but it is infinite of time and space (perhaps even space outside the universe (the universe grows there must be space for it to grow into).

>>14858869
the left can't meme

>>14858869
That post is extremely low quality

>>14858733
Which direction is the solar system traveling in bottom right pic, I'm curious what causes Sedna orbit to get so close, so far away, but still rushed back to being so close

>>14857688
>The South African native is a two-time winner of the dot.com Gold Rush
>dot.com
>dot dot com

>>14858888

>>14857688
Hopefully late 2020s, but realistically, probab 2030s.

>>14858766
folding legs are a good starting point
legs work perfectly fine even with >10m accuracy
landing without legs using catching arm on pad requires <1m accuracy and if you fail, you need to spend months and millions rebuilding the pad
once you determine you can in fact land accurately, you can remove the legs

also, see Fig.22 in >>14858739

>>14858893
>person of color smart catcher

>The health risks to astronauts associated with chronic exposure to radiation in space include carcinogenesis, cardiovascular damage, and degradation of the central nervous system. Since the Earth’s magnetic field is responsible for protecting us on Earth’s surface, a logical solution to the problem would be to have a spacecraft bring along its equivalent magnetic field. Here we propose CREW HaT, a new concept for a Halbach Torus (HaT), which consists of light, deployable, mechanically supported magnetic coils activated by a new generation of high-temperature superconducting tapes which have recently become available. This configuration produces an enhanced external magnetic field that diverts cosmic radiation particles, complemented by a suppressed magnetic field in the astronaut’s habitat. The HaT geometry has never been explored before in this context or studied in combination with modern superconductive tapes. It diverts over 50% of the biology-damaging cosmic rays (protons below 1 GeV) and higher energy high-Z ions. This is sufficient to reduce the radiation dose absorbed by astronauts to a level that is <5% of the lifetime excess risk of cancer mortality levels established by NASA.
https://www.nasa.gov/directorates/spacetech/niac/2022/CREW_HaT/

>>14858897
>we can catch so many persons of color with one of these

>>14858893
>without legs using catching arm on pad requires <1m accuracy
this is wrong. the arms close around wherever the booster is and have shock absorbers.
there is plenty of tolerance.

>>14858906
again, if you can get within that tolerance in the first place

>>14858893
Is the thread just retarded today? My complaint isn’t that ESA should be using catching arms. It’s that they are using (well, showing a render at least) shitty falcon 9 style legs. If you are building a rocket FROM SCRATCH to be reusable you should have a much more integrated leg design
My point is that all of these people going around showing “their” version of a propulsive landing first stage, from russia to ESA to china and previously rocket lab, have shown those fold-out bolt-on style legs because that’s what F9 has. But those were added to Falcon AFTER the fact. If you are making a rocket from scratch there is no need to design it with bootleg landing legs

>>14858930
what does a non bootleg landing system look like?

>>14858930
And for decades everyone was certain that a reusable launch vehicle had to have wings like the shuttle. Some people are just born to chase other people’s trends. Maybe if they linger in development long enough they can switch lanes to copying New Glenn.

>>14858943
Different anon, but it should fold flush with the outside diameter, at the bare minimum

>>14858884
It's called an elliptical orbit.

>>14858955
I think he thinks the Sun is in the center of that orbit in the final pic.

>>14858930
Anon, I think it's just a proposal that will most likely be changed. Currently if you mention a reusable booster, everyone sees Falcon 9. Neutron also used to look like Falcon 9, but the final version is completely different.

>>14858888
>>14858890
https://www.youtube.com/watch?v=_4qHcAESKbA

Booster testing

>>14858733
>We're never going interstellar with rockets
Fusion and antimatter could do it, and one or two funky fission designs.
>No wonder that we haven't seen sign of alien life.
Wrong. There’s plenty of signs of aliens.

>>14858960

>>14858963

>>14858158
It's not a huge step up. The Booster only needs to hit a point in space with ~3 meter side to side margin of error. The arm swing and the catch points on the arms can easily remove the rest of the error.

>>14858960
Overpressure notice or not?

>>14858963
>>14858964

>>14858967
Yes

>>14858167
>the arms in that webm are clearly at the top of the tower at the 0:05 mark
Wrong lmao, do you not understand foreshortening?

>>14858183
You don't make your money back on a reusable engine by spending $100 million on making it expendable, then throwing it away.

reminder not to engage with euroids and seething transsexuals
they will either see the light, move to Texas and ascend to the stars, or die surrounded by gibbering hordes of unwashed comeuppance.

>>14858308
>People say you would need to replace Raptor2s with NTRs in order to get it into a Jupiter orbit
Those people are wrong.

>>14858733
Planet Nine bros...

>ANOTHER spin prime test

>UNDERPRESSURE NOTICE

>>14858988
>LAUNCH TRAPPING SYSTEM

Propellent loading underway now

>>14858899
we need more of this and less hand-wringing. same with all the puling over zero-gravity-build a spacecraft that can spin and get the fuck over it.

>>14858679
>which would probably require hundreds of launches for a single landing
Dumb. Realistic plans using Starship at Jupiter would involve going to one of its distant irregular moons with very low gravity to set up propellant production, and then using that fingerhold as a point to refill in-situ and drop into the main Jovian moon system. This would likely be accomplished with SOME specializations in terms of Starship hardware, but no complete overhaul or move towards nuclear propulsion would be needed. At the absolute most, the fingerhold-to-Jupiter-proper leg of transportation would use dedicated hydrolox vehicles instead of Starship itself.

>>14858988
>GROUND FALL PART

>>14858794
"wouldn't need ISRU refueling" is only a true advantage as long as ISRU refueling is still an option. It's great to be able to do a round trip without needing to make fuel in situ, but being able to make fuel in situ still acts as a huge capability multiplier and allows more things to be done in that region of space. For example, efficient water or hydrogen propelled tugs coupled with a water ice mining setup on any of Jupiter or Saturn's moons would effectively open up the entire system of moons around those planets to direct exploration and surface activities, from inner moons to distant irregular moons.

>>14858997
>not hovering the starship over titans methane lake to hoover it up with a hose
Ngmi

>>14858976
>unwashed comeuppance
Is that what they're calling "migrants" these days?
>>14858988
Pressure... under pressure...
https://www.youtube.com/watch?v=a01QQZyl-_I

>>14859016
>Is that what they're calling "migrants" these days?
I prefer "unwelcomed invaders"

>>14858679
>>14858997
For the amount of effort it takes to develop a launch plan capable of going outside of the asteroid belt, you could just build a bespoke system with much higher specific impulse and then use Starship to launch it.

This is a setting where NTR or torch ships might actually be better than methalox.

>>14858794
Biggest limitation of any nuclear engine is the intense radiation it gives off during operation and for several days after shutdown. The Isp advantage needs to overcome both the dry mass increase and the headache of dealing with the dose rate environment.

>>14859024
>>>/lit/21011642

>>14858884
Nothing to do with the motion of the solar system.

>>14858899
>Since the Earth’s magnetic field is responsible for protecting us on Earth’s surface
Incorrect premise. I blame that movie The Core for spreading this misinformation. The atmosphere blocks radiation, not the magnetic field. Aurorae are literally caused by the magnetic field accelerating charged particles down to slam into the atmosphere, and you may have noticed that standing under aurorae doesn't result in deadly dose rates.

>>14858908
The tolerance is more like a 5 meter radius.

>>14858951
Wouldn't that mean taking away propellant volume from the tank and adding material to create the slot that the leg folds into?

>>14859046
If Earth were in orbit of Jupiter, would its surface be bathed in radiation?

>>14859030
I think the solution to this is just building one that fits inside of a starship second stage. That way, it's only ever emitting in deep space where environmental concerns don't really matter.

>>14859055
Starship uses almost all its fuel just reaching orbit.

>>14859030
>he fell for the anti-nuclear propaganda

>>14859058
Wow, that's really inconvenient. If only there was some way Starship could be in orbit but have MORE fuel. Too bad no one has ever considered trying to solve that problem before.

>>14859058
It has 100 tons of capacity to orbit.

If you have a 100 ton upper stage running some kind of exotic high ISP propulsion method, and then you just follow the normal procedure and gas up the Starship in orbit, you can get all of the Delta V from a normal starship system, combined with the delta v from some more exotic propulsion system.

That or just use multiple 100 ton trips to build something massive.

>>14859063

>>14859055
LH2 is very voluminous, it's not something you'd want inside Starship unless you want to defeat the purpose of NTP, job creation, sorry, I mean slightly higher dV.

>>14859073
I'm not married to NTR, I just suspect there is some kind of technology other than methalox that offers higher Delta V and is actually technologically feasible.

>>14859013
Free fuel and no free oxidizer is about as useful as free oxidizer and no free fuel. That is to say, it's not useful except for purposes unrelated to energy generation.

>>14859049
well then good thing the legs are simple bolt-on ones and can be simply deleted from the design if SpaceX proves catching is as easy as we hope for

Spin prime happened.

Possible another test later?

Another spin prime

>>14858869
Wait, wasn't Musk actually just a conman and a thief, and also the one who steals all the credit from his engineers? Wouldn't the engineers themselves be the ones responsible for the cobalt mines and child slaves?

>>14859024
>For the amount of effort it takes to develop a launch plan capable of going outside of the asteroid belt
Which is equal to refueling Starship completely in LEO, since Starship with full propellant tanks in LEO can go directly to Jupiter with over 100,000kg of payload.
>you could just build a bespoke system with much higher specific impulse and then use Starship to launch it.
The biggest possible hydrolox stage you could fit into a Starship payload envelope would, after deployment and a complete refill, deliver less mass to Jupiter than just refilling a Starship. Size and impulse density matter. IF you're going to build dedicated Jupiter-loop transportation vehicles, you're going to either assemble or fabricate them in space using modules or materials launched via Starship. If you're building a specialized Jupiter transporter you're probably picking hydrolox if you're using chemical propellants, simply because Jupiter's moons have hyperabundant water resources compared to carbon resources.
>torch ships
By definition better than anything we have today, and also happen to be firmly sci-fi level technology at this time. We would need to invent high efficiency gamma ray reflecting materials and aneutronic fusion with very very high net gain and fuel burnup rates to have something you could call a torch drive (if you don't consider the NSWR, which I'm choosing not to in this scenario as fueling this kind of propulsion system would be extremely expensive and difficult, plus using NSWR would be inherently risky. It's basically a nuclear monopropellant rocket).
That being said, high efficiency propulsion is on the table, in the form of a hybrid chemical + electric propulsion vehicle. Use your chemical engines to boost out of and capture into gravity wells, and use your electric propulsion to perform long term acceleration between destinations.

>>14859076
NTRs

>>14859053
No. Atmospheric stripping over geologic timescales would likely be more of an issue though, specifically for hydrogen loss.

>>14859053
Depends on where you’re orbiting.

>>14859055
>That way, it's only ever emitting in deep space where environmental concerns don't really matter.
No I'm talking about irradiating the ship the engine is bolted to. Neutron and gamma radiation are difficult to block and they also like to refract/reflect off of materials, meaning any part of your vehicle that isn't hidden by the shadow shield is going to "shine" radiation onto the rest of your vehicle. The edges of your shadow shield will also shine radiation onto things too, though less intensely.
In practical terms, this means there's a minimum distance you need to have between your nuclear engine and your habitation section, and since those engines remain extremely powerful gamma ray sources for days after their last burn at minimum, any nuclear thermal vehicle is going to be a pain to maneuver around and use in conjunction with other vehicles, at all times.
Again, this major disadvantage would not be so bad if the engine were some 3000 Isp monster, but for your basic 900 Isp NERVA-style propulsion system it's hard to see the appeal, especially after factoring in the 70 kg/m^3 density of liquid hydrogen.

>>14859059
Nah I work in the nuclear industry and I love nuclear more than anyone else in this thread. I'm also aware of when nuclear makes sense and when it doesn't.

>>14859013
thumbnail reminded me of this

>>14859076
>I just suspect there is some kind of technology other than methalox that offers higher Delta V and is actually technologically feasible
NTR but using methane instead of hydrogen and carbon-carbon structures instead of metal and ceramics

>>14859127
>Again, this major disadvantage would not be so bad if the engine were some 3000 Isp monster, but for your basic 900 Isp NERVA-style propulsion system it's hard to see the appeal, especially after factoring in the 70 kg/m^3 density of liquid hydrogen.
this is why pulsed NTR is the obvious solution

>>14859081
>the legs are simple bolt-on ones
It doesn't have any legs.
>>14859125
If Earth orbited directly inside of Jupiter's most intense radiation-belt regions, the radiation dose rates at Earth's surface would rise by zero percent, because all of that radiation would be blocked before it reached down to an altitude of 50 km above Earth's surface.

>>14859132
You would probably need to run a lot of tests to see if radiation embrittles CFRP

>>14859135
Aurora would be fucking wild, and a civilization that arose in such a location would probably take longer to leave.

I feel like a species that breaths water would be more comfortable operating in zero-g but I’m not entirely sure why. They’d be able to move around largely uninhibited, I think.

>>14859110
Laser thermal is another possibility, acting as a kick stage to put Starship on a Jupiter intercept before returning to be reused, or given enough resources, another laser can be setup so it can capture deep with the gravity well. It's like nuclear thermal without the dry mass penalty and the won't cost >20 billion per ship.

>>14859076
Laser thermal is capable of 3000s Isp with LH2 in current designs, and means you only need a small reactor for shipboard power in the outer system. Inner system works just fine with ROSAs. I strongly suspect this'll be how civilian interplanetary craft work, with solar or nuclear fed laser powersats orbiting the planets and a few major dwarfs like Ceres and Pluto. As with ocean ships, only a major government will maintain a fleet of nukes.

https://www.centauri-dreams.org/2022/02/17/laser-thermal-propulsion-for-rapid-transit-to-mars-part-1/
https://www.centauri-dreams.org/2022/02/18/laser-thermal-propulsion-for-rapid-transit-to-mars-part-2/

>>14859146
meds

>>14859151
>noooo there can’t be aliens I’m special

>>14859133
You're not entirely wrong.
We either need to go the ISRU approach of just using orbital refueling and making hydrolox (or maybe methalox) somewhere in the Jovian system, OR, we need to have a propulsion system with performance on the order of pulsed NTR. Anything in-between just gets you the worst of both worlds and is a shitty option.
I'm personally of the opinion of doing it the low Isp low tech way because it avoids the issues of trying to convince normies to let us build and launch multi-gigawatt scale nuclear reactors into space for those pulsed nuclear thermal systems.

>>14859138
The TIMBERWIND development project already verified carbon-carbon materials.

>>14859146
Rather than "breathes water" I think you mean "is aquatic". Anyway, humans adapt just fine to working on zero G. An aquatic species trying to build a space station would run into the issue of having to transport a thousand kilograms of water to fill each cubic meter of that habitat.

>>14859173
This cubic kilometer Watership will never lift off.

>>14858951
sometimes things are better kept outside. For example the propellant line on the outside of the orange tanks, it's easier than disrupting the nice symmetry of the tanks

>>14859133
>pulsed NTR
May as well take the argument to antimatter. You get solid core or you get nothing.

>>14858766
>why is it using F9 landing legs despite being designed from the ground up to land???
How else are you supposed to land them? >>14858893
>landing without legs using catching arm on pad requires <1m accuracy
the arms can move, it's not that easy determining their equivalent allowable accuracy

>>14859149
Laser thermal has some nice performance and no ionizing radiation complications but it's also not something we actually have and I'm not sure we would have it by the time we're doing Jupiter system missions. If we did decide to develop it though, then it would certainly make the Earth-Jupiter-Earth transport loop much more convenient. Transfers in both directions could go faster, as the laser arrays would assist both in departure and capture on arrival, and transfers in-system of Jupiter would be much more capable and high frequency (since laser-thermal using pure water propellant is higher Isp than hydrolox engines, water tanks have a much better mass fraction than hydrolox bipropellant tanks, and of course, it requires far less energy and time to produce 1000 tons of pure water than it takes to produce 1000 tons of hydrogen and oxygen bipropellant. Laser thermal tug infrastructure would be a great enabling technology for deep space transportation.

>>14859110
The other kind of electric-chemical hybrid is using ion-doped fuel and using an MHD accelerator to directly raise chemical Ve. That airship to orbit guy has actually been testing this with a potassium solution for seeding and tabletop sized engines. This might actually justify using HTP over LOX as your oxidizer depending on how you handle injecting the seeded ions.

>>14859173
Humans can’t move through the air except by jumping off of surfaces and feebly flapping if they get stuck; whereas swimming in zero-g would be just as maneuverable as swimming on a world.
>Rather than "breathes water" I think you mean "is aquatic"
Don’t be pedantic. Everyone uses “waterbreathing” to refer to organisms that extract oxygen from water via gills.
>An aquatic species trying to build a space station would run into the issue of having to transport a thousand kilograms of water to fill each cubic meter of that habitat.
Make bigger rockets.

>>14859150
>Laser thermal is capable of 3000s Isp with LH2 in current designs
>>14859187
>laser-thermal using pure water propellant is higher Isp than hydrolox engines
What's the expected Isp of laser thermal using water propellant?

spin prime is overpressure?

>>14859194
Still requires effectively magic power supply to be worth the effort. The advantage of laser thermal is that the power source is independent of the actual vehicle, so you can get away with saying stuff like "And here's where the 50 MW of laser light enters the heating chamber" without raising questions about power supply watts/kilogram ratios etc.

>>14859184
retard alert!!! https://en.wikipedia.org/wiki/Pulsed_nuclear_thermal_rocket

>>14859207
no

>>14859215
So you read a Wikipedia article, so what? It's laughable you think that will be built before you die of old age, or more likely some type of super Monkeypox preying on members of the homosexual community such as yourself.

>>14859196
>feebly flapping if they get stuck
You literally cannot get "stuck" because drag is so minimal at low speeds that in order to have time to come to an effective halt without first bumping into the other side of the habitat, your habitat would need to be hundreds of meters across. At that point, just rotate it at 0.1 rpm to produce a tiny centripetal force that still allows the entire volume of the habitat to be used effectively but also ensures any floating debris or objects or people will find a wall in several minutes.
>everyone uses waterbreathing
Uh huh, and not every aquatic animal uses gills dumbass. Dolphins, pinnipeds, penguins, mosasaurs, etc.
>make bigger rockets
Doesn't solve the problem. Have fun trying to build a 3D environment when every ten by ten by ten cubic meter habitat masses over 1000 tons.

>>14858779
>>14859231

>>14859231
>backpedaling
You thought pulsed NTR was something else, otherwise you wouldn't have mentioned solid core as that is what it is.

>>14859237
> otherwise you wouldn't have mentioned solid core as that is what it is.
Huh? I didn't imply that. Read my post again, realize you can't read, and never talk to me again

https://www.youtube.com/watch?v=7oFgGXlHi8Q

>>14859252
cope

all this reminds me of the best moon in the solar system

>>14859254
WWWWAAAAOOOOOWWW

>/sci/ is leaking in

>>14859254
I'm just glad they're doing something.

>>14859203
According to my naive calculations, as much as 1100 Isp, assuming pure water and a chamber temperature of 10,000K. In real life water is gonna dissociate long before reaching those temperatures so maybe something more like 700 Isp is realistic, which would still make water propelled laser-thermal a very attractive option compared to hydrolox tugs.
I guess the question becomes, do we have any materials which can realistically withstand exposure to extremely high temperature oxygen rich gasses? We're talking at least ten times the temperature of the inside of the Raptor oxygen rich preburner and turbine assembly. Are there any oxide ceramic materials that are also good thermal conductors with high melting points? Ideally this material would be a fully oxidized metal compound with a much stronger affinity to oxygen than oxygen has to hydrogen, such that the dissociated hydrogen radicals would not be capable of stripping the oxygen atoms away from the metal atoms in the ceramic. Maybe a nozzle throat made of a single piece of aluminum oxide with transpiration cooling pores to bleed water through would work.

>>14858976
Texas is famous for its lack of gibbering hordes of unwashed comeuppance

>>14859259
It really is the most interesting moon. Too bad it would be a shitty place to live.

https://twitter.com/elonmusk/status/1571910631971758081
its gonna explode, isn't it?

>>14859254
edgar kino gunnersman is salivating, cumming, investing in Ariane-x stock as we speak

>>14859315
now we're talking

>>14859315
>Seven Raptor 2 engines firing
That's over double the full thrust of a Falcon 9 booster by the way

>>14858017
Forget the hotels, think of the industry. Place a mass driver up there, and the rewards are unimaginable.

>>14859315
BRAAAPP SOOON

>>14859316
I will lol if he posts something tomorrow calling this rocket bizarre and effectively useless

>>14859315
SOMETHING IS ACTUALLY HAPPENING LET'S GOOO

>>14859315
>static fire #3745
>tiles still falling off
>static fire #3746 in two (2) weeks

>well before I have to be quiet I just have to shill

>>14859299
>laser pumped squirtgun made of solid sapphire
This is very 4ASS. I approve. You'd also need an external power source to drive the pumps. NASA's attempt to shoehorn water propellant into their classic expander cycle NTP design was a hilarious failure.

>>14859337
>tiles
>on a booster test
?

inb4 catastrophic error

Sign up here for a tier 1 /sfg/ premium membership, only $19.99 per month~!

>>14859350

>>14859349
it will shake SS, you see

>>14859343
>You'd also need an external power source to drive the pumps
Expander cycle, bro. Your cooling channels are gonna have supercritical water coming out, expand that shit over the turbopump.
>muh corrosive high temperature steam
You need to solve the corrosion problem to get this far anyway. Build the entire turbopump assembly out of corundum idk.

dammit I have to take a shit so bad

>>14859362
you should go sit on the toilette and time your shit with the static fire

>>14859362
b7 posts here confirmed

It's not happening, is it.

>>14859315
It's sad that spacex can barely fire any of these. remember the falcon 9 days? they used to do 9 of these but weve gone backward

>>14859363
But I'm watching it on my big TV

>>14859368
The bastard lied again

>spaceX booster team is watching the stream live in the control room
>they're trolling them by holding for longer than they need to

HOOOOOOOOOLD

the siren is wrong, you heard it bros

This guy's commentary is like a man who was stood up on a date by a girl he thought was very interested

>>14859362
Autism
https://www.youtube.com/watch?v=ri1MrA7cbNo

>it's one of the both

>>14858158
Counterintuitively, bigger rockets are easier to balance and land. Example- Try to balance a broomstick on your finger. Now try to balance a pencil.

>>14859380
i just fucking realized. NONE of the guys working at NSF have girlfriends

a depress is kinda a small static fire, we can find solace in that

>>14859387
I swear I'm going to give up and the moment a 1.5 cm wide rope of shit fires out of my ass the booster is going to fire

>>14859315
RIP too all the tiles that are about to die

>>14859394
do you not have a phone?

>>14859392
Damn, they're just like me

>>14859393
Static cold gas thruster test

>>14859394
just take your phone with you faggot

>>14859362
>>14859387
https://youtu.be/aCB-UO7p5RA

we're gonna gimbol and static at the same time aren't we

>>14859397
Yes it's about 1% the screen area of my tv

FUCK i missed it

Wait a minute, 7 engines is a weird number. The Booster has 3 in the middle and those three are surrounded by 10, which are further surrounded by the remaining 20. There's really no happy way to divide up the middle 13 engines into 7.

>>14859417
No you didn't, my colon is still locked and loaded.

>>14859419

happeningu tiiime

POOP

>it didnt blow up
boring

Surprisingly it's still in one piece

>NO HORN
WE ARE GOING

Roasted

>>14859437

>>14859440
Wtf spacexbros, I thought methalox wasn't supposed to produce any coking??

NO TILES FELL OFF, SPACEX STANS WE ARE WINNING

This proves a flame tranch and waterworks will be necessary......

I have a good feeling SHSS will work on the first launch

i love starship superheavy so much boys

>>14859444
>I-it's just burnt paint bro
Get ready for excuses out the ass

>>14859452
There's no way they can sugarcoat this

>>14859437
webm