/sci/ - Science & Math

Reminder that SLS will reach orbit before Starship

First for Blue Origin delaying New Glenn to 2022

>>12280589
The green run gets delayed a week every time you post this.

>>12280589
SLS was supposed to reach orbit before the Starship program even began

>>12280589
SLS, Vulcan, New Glenn, Ariane 6, Starship
IN THAT ORDER

SLS A SHIT! A SHIT!

>>12280589
>can't even do a green run

>>12280468
as a whole the new Glenn is very oldspace in its design, reusability aside. By that I mean that it's unambitious.

Note that this chart is a bit outdated. The raptor has reached a chamber pressure of 330 bar, specific impulse of 330/380, and thrust of 2.2MN.

>>12280617
and size comparison

SLS is a conspiracy intended to have NASA abolished on the basis of ineptitude.

>>12280603
Bros Skylon is catching up with Starship we cannot delay the inevitable!

>>12280617
This chart could use thrust/area

>>12280617
Holy fuck Be-4 is literally worse than a Kerolox engine ohnononono hahahahahahahahahahhaha.
Seriously though how the actual fuck do you fuck up so bad that 30 year old Soviet engines are better.
>>12280618
Honestly this is getting kind of sad, Blue Origin is really only being propped up by Bezos and this will continue until the end of this decade.

>>12280617
>>12280618
How the fuck is Raptor's thrust to weight so much better? Is that the power of full flow? I know next to nothing about Tom Mueller- is he like some sort of genius or something?

>>12280617
>all of those shit horrible inefficient engines
>SSME is still kind with the best ISP
Nothing will ever compete, the SSME is the best main stage engine ever made, and super efficient

>>12280637
Tom mueller only holds advisory role for Raptor afaik. He's mainly retired.

>>12280631
BO needs to be the second to hit full reusability. They should be considering the state of the competition, but until then they're going to be borderline irrelevant. NG is too late.

>>12280637
Extremely high chamber pressure. They're just forcing a huge amount of material through the engine for it's size.

>>12280578

What the shuttle should have been

>Fully Reusable SSTO Nuclear Ramjet Spaceplane

https://newatlas.com/space/nuclear-thermal-propulsion-ntp-nasa-unsc-tech-deep-space-travel/

>NTP
>American
>Mars in 3 months
Bros...

>>12280670
Nuclear rockets are a huge environmental hazard and should be banned from being launched until rockets are more reliable

>>12280617
What does open / closed cycle mean?

>>12280678
>open cycle
fuel is burned in a turbine to run pumps, the exhaust is dumped overboard (like Merlin or F1)
>closed cycle
fuel is burned in a turbine to run pumps, the resulting fuel rich hot gas is fed into the combustion chamber
>full flow closed cycle
as above, but with one pump running fuel rich and a second pump running oxygen rich, in a full flow engine ALL of the fuel is burned with a small amount of oxygen and vice versa, these fuel rich and oxygen rich exhausts are what's pumped into the chamber

>>12280670
It would be good if it refilled the gas tank with stray atoms from space vacuum

>>12280689
>positive thrust bussard ramjet
and other fairytales

>>12280670
pic looks like an apollo capsule docked to a large engine bell

>>12280678
It's a cope used by engineers to make more efficient engines, despite the fact that it makes the engine super complex and expensive, Open Cycle will always be king because a 5% improvement efficiency only matters in space outside of a gravity well, whereas a cheap, powerful, easy to build, reliable engine will always be better for a first stage (Like F9, or the F1)

>>12280689
Now you're talking.

>>12280689
Yes anon you just need 6020000000000000000 cubic metres of vacuum to maybe get 1 gram of Hydrogen.

>>12280699
Bussard ramjets fusing interstellar hydrogen may be a meme, but scooping up reaction mass from the interstellar medium and then heating it up using an on board fusion reactor is not.

>>12280705
Meanwhile Raptor is already around Merlin in dollars per thrust output and should come down. Admittedly, that is forbidden magic as far as the industry at large is concerned.

GUYS THE STARLINK ToS
>9. Governing Law.
>For Services provided to, on, or in orbit around the planet Earth or the Moon, these Terms and any disputes between us arising out of or related to these Terms, including disputes regarding arbitrability (“Disputes”) will be governed by and construed in accordance with the laws of the State of California in the United States. For Services provided on Mars, or in transit to Mars via Starship or other colonization spacecraft, the parties recognize Mars as a free planet and that no Earth-based government has authority or sovereignty over Martian activities. Accordingly, Disputes will be settled through self-governing principles, established in good faith, at the time of Martian settlement.
IT'S HAPPENING

>>12280713
Yes.

>>12280715
Just carry the fuel onboard until you get to a planet then scoop the atmosphere up.

>>12280676
I know you're trolling anon, but launching a uranium based reactor that hasn't been turned on yet is literally safer than the plutonium RTG powered probes that NASA has sent into space dozens of times. Uranium's radioactivity is pathetically negligible.

>>12280721
holy shit

>>12280721
BASED

>>12280721
>it's real
Feelin' like a glorious new dawn desu senpai

>>12280722
Based SpaceX. They larp only because they know they can make it happen

>>12280721
Praise the Omnissiah

>>12280738
Meant for >>12280721

>>12280721
MARTIAN FREE STATE

>>12280721
IT BEGINS

Theoretically speaking, shouldn't any material undergoing fission be able to create thrust proportional to the mass that is lost via gamma/alpha/beta decay?

>>12280713
Don't worry Boeing is on it

>>12280750
Good fucking luck aiming all the gamma rays to fly out the ass end of the rocket. Gammas net to zero thrust because they're not directional.

>>12280715
>heating it up using an on board fusion reactor
Isn't this just the same thing but worse? It's not like you can improve mass flow through since you're limited by the density of the interstellar medium, so you're left getting as much performance as possible out of each atom, which would be fusing it.

>>12280678
https://youtu.be/LbH1ZDImaI8

>>12280757
For you

>>12280759
Epic Win for team humanity!

>>12280757
>Gammas net to zero thrust because they're not directional
Nothing special metamaterials can't do

>>12280762
>>12280765
why is /sci/ obsessed with magic handwaves

>>12280721
This is unironically Mars' greatest asset and attraction: A fresh start. The established governing systems on earth are broken to the point of being unfixable. The only way to move things forwards is to start from scratch. People would gladly live in a radioactive hell for this opportunity.

>>12280759
I asked because I do not have patience to watch one of Tim's videos. I bet he's great person but his videos are fucking annoying.

>>12280764
I dont know about you fellas but I think I we should cut the rhetoric and all join #TeamSpace

>>12280589
>SLS will- AIIIIIIEEEEEEEEEE
ENTER CHADSHIP

>Thank gosh for Blue Origin, ULA, and Team Space for landing the first Starship on Mars :)
Epic win for Humanity

>>12280721
HERE WE GO

How about creating thrust with a cathode ray tube

>>12280776
You joke but there will unironically be people saying shit like this when SpaceX gets to Mars

>>12280771
Could always skim the article version then.

>>12280780
It would work like this:

>fire electrons away into the space
>ship is now positively charged
>negatively charged planet attracts ship with electrostatic

https://www.space.com/nasa-sls-megarocket-shortage-artemis-europa-mission-delays
>NASA SLS megarocket shortage causes tug-of-war between moon missions, Europa exploration
>NASA is choosing between human missions to the moon and a robotic mission to Jupiter's icy moon Europa as the agency manages its limited supply of megarockets in the coming years.
>"We have a requirement right now by law that says that we're going to launch this vehicle on an SLS rocket"
ABSOLUTE DOGS DINNER

>>12280758
Well it solves a few major problems. First is how the fuck you're supposed to fuse atomic hydrogen in the first place, as pretty much every realistic design for fusion reactors use deuterium or tritium. Secondly you no longer have to slow down the hydrogen as much in order to fuse it, you just need to heat it up relatively quickly and shoot it out the back with an increased velocity. This dramatically reduces the drag experienced by the ramjet, which is the main issue with Bussard ramjets. So your rocket now only needs to carry its own fuel, while the reaction mass is provided by the interstellar medium, which can dramatically improve the mass fraction of your vehicle. Sure, interstellar medium might be very low in our region of the galaxy, so I don't know if this is a viable solution for interstellar travel where we live. But it's going to much higher in other places, such as near the galactic core, so it could work there.

>>12280721
>SpaceX unilaterally declaring both Martian Independence and American sovereignty over Luna
Uh, BASED DEPARTMENT

>>12280812
How did the meme of launching Europa Clipper on an SLS even start? Did someone at NASA do some maths and figured out they could get there quicker assuming SLS was fully operational at the time of launch, and then lawmakers when seeing this put it into law?

>>12280721
Unimaginably based. God I love Elon.

>>12280812
>18m starship launches SLS, payload and all, just to technically solve the deadlock

>>12280827
I am 100% certain they got White House signoff on this.

>>12280832
Parasites in Congress mandated it

>>12280721
>the US government is a Starlink customer
>Elon just silicon valley'd the American government into preemptively recognizing Mars
lol

>>12280721
It's a tired cliche, but what a flex on oldspace

>>12280837
But why? Out of all purposed missions why Europa Clipper? Was it just because Europa was in the news cycle at the time so they decided to hitch its wagon to SLS?

>>12280721
The expanse was unironically meant to be a historic documentary.
https://www.youtube.com/watch?v=-yzuv3rqHfw

>>12280518
>That's why you bring it with you. Zubrin's original presentation goes into some degree of detail on how. Hell, even bring it as water and crack it on site if you're worried about boil off.
Think for a minute, anon. Why would you bring water? You want to bring hydrogen, I get it. Why choose water? it's a horrible hydrogen-storage compound, only two atomic mass units out of every 18 are hydrogen. Hydrogen itself is the best in terms of specific concentration of hydrogen atoms, but it's shitty to handle and store long term. You know what the next best thing is? Methane.
Seriously. If you are scared of not finding enough water on Mars to make your methane, just send the methane from Earth. You only need to send ~260 tons of it to completely fill a Starship, since the remaining ~940 tons of propellant is all liquid oxygen. Methane masses less than water per molecule, yet carries twice as much hydrogen per molecule, and of course is the actual fuel you want on Mars and can use the exact same storage system as the main propellant supply.
We're never gonna send water or liquid hydrogen to Mars, except for the small amount of water that humans use day-to-day. At most, we'll send enough methane to guarantee a return option as long as the crewmembers can operate a CO2 electrolysis machine to generate all the liquid oxygen necessary.

>>12280845
Meant for >>12280839

>>12280822
>so I don't know if this is a viable solution for interstellar travel where we live
What if the ship captured an asteroid or something like that and uset its atoms as reaction mass

>>12280809
>strip and fire electrons
>fire the now positively charged nuclei too
>???
>profit

>>12280721
We live in a society... NOT ANYMORE

WAIT FUCK CALIFORNIA STATE LAW NOW HAS JURISDICTION OVER LUNA FUCK FUCK FUCKITY ELON WHY

>>12280849
>If you are scared of not finding enough water on Mars...
...you're fucking retarded.

>>12280858
FUCK UPDATE IT TO SAY TEXAS HURRY HURRY HURRY HUUUUUUUURRRRRRRRRYYYYYYYYYYYYY

>>12280848
Lets nuke China, India, Pakistan, Bangladesh, and every city south of the Sahara right now. Can't have the Expanse future if the third world is dead.

>>12280848
The aurorae on Mars are a nice touch.

>>12280858
>it turns out to be 60s era Califonina law
We're bringing surfing to the Moon boys

>>12280721
>no space guns
>no space free speech
>no heinlein-esque libertarian moon colony
Fuck California.

>>12280849
>We're never gonna send water or liquid hydrogen to Mars
>send ship to jupiter
>steal some H2
>bring it back to mars
>burn it with O2 extracted from CO2
>free water

>>12280866
No, as the legal language is written now, any dispute between a user and Starlink will be governed by California law as it exists at the time of arbitration

This does NOT mean that California has legal authority over Luna, but it DOES mean they have legal authority over any contracts signed by Starlink in Earth's SOI.

>>12280858
Over Starlink because SpaceX is registered in cali. Something like that anyway, I assume they can transfer it to Texas when SpaceX finishes hauling its ass out of there.

>>12280853
Well it would be difficult to capture an asteroid with an electromagnetic field, then safely guide it into your fusion chamber without destroying your rocket while travelling at .2c, and then fully vaporize that asteroid in a matter of microseconds.

A note for all anons. When you say “Luna” instead of “The Moon” you don’t sound smart. You just sound like an asshole.

>>12280888
They will hate this anon because he spoke the truth

>>12280888
cope nanoraa

https://twitter.com/Philae2014/status/1321173213381099521
>Philae Lander
>There is something I would like to tell you… tomorrow at 17:00 CET.

>>12280888
When you say "Sol" instead of "The Sun" you don't sound smart. You just sound like RESTITUTOR ORBIS

>>12280888
But what if future Martian anthropologists are harvesting this thread for memes, I wouldn't want them to get confused

>>12280900
Turns out philae has been operational all this time and discovered comet spiders

>>12280904
the comet spiders have assumed control of the lander and fixed the antenna

>>12280873
>flying all the way out to jupiter
>climbing in and back out of jupiters gravity well
>flying all the way back
>just for some fucking water
what a terrible plan.

>>12280900
It's gonna say the N-word!
>BREAKING: Worlds first comet lander becomes sentient and is an absolute racist!!

Speaking of space spiders we need to have an /sfg/ watch of Apollo 18 for Haloween

>>12280888
>year 2300
>what planet are you from?
>oh I’m from the moon
>which moon?
>THE MOON
>Oh you mean Luna
>NO I MEAN THE MOON
Fucking space hippies

>>12280637
>Is that the power of full flow?
To an extent, yes. Putting all the propellant mass through the turbopumps means that temperatures stay manageably low so matter how much mass flow you're trying to get, and having all of the mass flowing across the turbines means there's a huge amount of work that can be extracted for pumping the propellants. A lot of Raptor's TWR advantage comes from smart design choices though, not just the combustion cycle. One example is having the oxygen turbopump in-line with the main combustion chamber, allowing the oxygen to basically go from low pressure liquid to high pressure turbine exhaust blasting into the main combustion chamber across a length of about half a meter.

>>12280888
Luna is literally the Moon's name you dumb fuck.

>>12280873
>go to Ceres
>get the ice
>back to Mars
>go to Ceres
>get the ice
>back to Mars
>go to Ceres
>get the ice
>stop at Deimos

>>12280650
>as if Isp even matters for a launch vehicle once it goes above 300
lol, RS-25 would work great if it cost ~$2 million and was only used as a high thrust vacuum engine in orbit. The fact that it's ~$200 million per engine and only used as part of the least-efficient launch vehicle architecture (a booster-sustainer) means it's actually a giant white elephant.

>>12280670
Why even bother going faster if it only shaves a month off of what chemical propulsion can do? Take advantage of the Isp and send more payload.

>>12280771
fair enough. Have a quick rundown, then.

First off, an oversimplified description of how chemical rocket engines work: you take massive amounts of oxidizer/propellant and throw it out the back while combusting it. But you're never going to get the flow rates you need by letting gravity empty the tanks, so you use turbopumps to shove everything out as quickly as possible.

The catch here is that in order to do this the turbopumps need considerable power themselves. The open/closed distinction comes from how you handle accomplishing this.
In an open engine some fuel/oxidizer is diverted to running them and the exhaust is dumped out the side. It's simple but some fuel ends up being wasted
In a closed engine some fuel/oxidizer is diverted to running them but instead of dumping the exhaust it's thrown into the combustion chamber where it can finish reacting. This is far more complex but more efficient because nothing is thrown away.

>>12280888
Luna is the default for romance languages (except portuguese, which uses Lua). Moon is the barbaric-tribe-ooga-booga name.

>>12280920
>F-1B lower with two SSME upper

>>12280578
> Raptor SN36 installed on SN8
has it been confirmed that it was SN36 that was installed? The installation happened near midnight so none of the reporters were near enough to see I don't think.

video of the installation: https://youtu.be/QeO8KtqEPYg?t=856

>>12280919
>go to Mars
>get ice

>>12280926
>the exhaust it's thrown into the combustion chamber where it can finish reacting
So it's like a rabbit eating its own poop

All in all just a regular engine but with extra piping to get bit more thrust per unit of fuel?

>>12280678
In open cycle, some of the propellant stream is diverted from the main combustion chamber.
In closed cycle, all of the propellant stream goes into the main combustion chamber.
Since propellant mass flow rate is what is used to determined engine efficiency, having mass that is flowing somewhere that it doesn't produce thrust means less thrust per unit propellant and less efficiency.

Side note, the RS-25 has a few little bleed lines that are constantly venting a small amount of propellants out right at the nozzle lip, which means technically despite using fuel rich staged combustion the RS-25 is actually an open cycle engine and thus complete shit.

>>12280622
that would be useful. I have this for spacex's engines but not for anything else

>>12280928

>>12280935
If they do that venting thing just for cooling, why don't they use a secondary turbine to use some of the exhaust energy to compress atmospheric air and then vent that air through holes on the outer part of the engine, kinda like an open-cycle refrigerator

>>12280699
Antimatter powered bussard ramjets would be viable, so would micro-blackhole powered ramjets. The latter would actually be ideal for intergalactic vehicles because you don't need to carry antimatter fuel mass with you, you just use the ergosphere of your one megaton black hole to superheat interstellar medium and let it blast out the ass of your vehicle, accelerate along the entire diameter of your home galaxy, coast to arrival at the target galaxy, then do the same thing but blasting in reverse. Your black hole also serves as a power generator that can run off of literally any matter you have available to feed it.

>>12280928

>>12280942
should I take the time to make a F-1B / SSME based alternative to SLS in RO?

>>12280713
Which would be harvested by a 1 million square kilometer magnetic scoop travelling at 10,000 km/s in about half a second.

>>12280956

>>12280720
Yes. This is because once you have the alloys that can handle the conditions, and you have a design that doesn't require autistic artistic handcrafting for 9000 hours per gram of engine on average, there's basically nothing stopping you from just mass producing those engine parts like any other part of any other machine on Earth.

>>12280934
>All in all just a regular engine but with extra piping to get bit more thrust per unit of fuel?
basically, yes.

I should have emphasized that the "exhaust" still has plenty of combustible material. Turbopumps are deliberately ran inefficiently- either by giving them too much oxidizer or too much fuel. Reason for this is that these things are sensitive and would melt if you went all-out combusting shit next to them. I mean you can't really regeneratively cool something like pic related. Too many small, sensitive parts.

This is why you bother going through all the pain to take what's left over after the preburner and throw it into the main combustion chamber. But it really is a pain in the ass so some designs just use open engines like the Merlin and F1. They seem to do great as 1st stage options. Not so hot as a 2nd stage engine. Really need efficiency there.

>>12280956
>F-1 first stage
>RS-25 upper stage
The most American rocket ever made

>>12280966
The vacuum Merlin still manages to get 348 ISP, which is fantastic for an open cycle kerolox engine.

>>12280978
yeah 348 is pretty fucking ridiculous. They optimized the shit out of that engine. Hope they can give the raptor the same tlc

>>12280860
Read it again. I'm saying, even if that other anon is afraid we won't be able to find enough water ice on Mars to refill a Starship, it's still stupid to send water from Earth, because it's better in literally every way to just send methane in that case. Personally I don't think anyone will have any trouble at all sourcing billions of tons of water ice on Mars, because the shit is everywhere.

>>12280966
>I should have emphasized that the "exhaust" still has plenty of combustible material
Can't they use like electronic fuel injection to decrease the amount of injected fuel or increase the amount of injected O2

>>12280984
If you're going to send methane itself, what are you going to do ISRU for

>>12280873
>go to Mars
>land somewhere north of the tropics
>dig one meter down
>unlimited permafrost, 20 tons of water per square meter to an accessible depth of 30 meters

>>12280888
Absolutely based

>>12280970
Or maybe something like 8x F-1B first stage, 2x RS-25 upper but with even larger drop-down expansion nozzles, like the RL-10. Neo-Nova.

>>12280993
>unlimited permafrost, 20 tons of water per square meter to an accessible depth of 30 meters
Ice will sublimate at martian pressure. There isn't useable water in Mars.

>>12280934
A gas generator is fundamentally limited by the fact that it has to trade Isp for combustion chamber pressure. More CC pressure, more pump power required. More pump power required, more mass flow through the pump turbine. In a gas generator, than turbine exhaust is dumped mass, which means it reduces Isp. Basically if you go beyond ~Merlin 1D chamber pressure, your engine just gets shittier and shittier.
With staged combustion your max effectiveness chamber pressure is much higher, and with FFSC it is effectively unlimited except by chemistry and materials properties.

>>12280914
>there's only one Moon, ma'am

>>12280986
No, it runs fuel rich on purpose, because if it ran stochiometric they'd melt it, and nobody wants to play with hot oxygen unless you have top tier metallurgy

>>12281007
>dig hole
>put dome over hole

>>12280943
>If they do that venting thing just for cooling
I don't think it's for cooling.
>why don't they use a secondary turbine to use some of the exhaust energy to compress atmospheric air
Because the engine would only be in the air for the first ~1:30 of the launch, and out in vacuum for the remaining ~8 minutes of the burn to orbit. It would only be in air dense enough for significant cooling capacity for the first ~50 seconds of flight, also.

>>12280663
>They're just forcing a huge amount of material through the engine for it's size.
sounds like an accident waiting to happen.

>>12281007
As long as it's cold enough (hence not along the equator for the most part) no, it won't. Damn near every significant atmosphere-less rocky body in our solar system has ice where it isn't subject to intense solar radiation.

>>12281026
That's why they keep eating turbopumps, but the SpaceX development cycle is to run things until they explode and fix the part that exploded. Raptor runs hardware-rich.

>>12280991
Oxygen, which makes up 78% of the propellant mass on Starship. If you read my comment again you'll find that I said we'd only send methane for the first few missions before we had water ISRU up and running. Learn to reading comprehension.

>>12281026
SpaceX will explode as many engines as possible to find a construction method and metal able to handle those pressures

>>12281026
This is generally a true statement regarding all rocket engines.

>>12280721
Confirming the inspiration for the Martian colonial flag to be El Matador on black velvet.

>>12281007
>Ice will sublimate at martian pressure
Yeah, it'll sublimate slowly, and it will cool off. Put it in a dark shed and it will stop sublimating. That doesn't matter anyway, because in any ISRU scenario we'd be loading up big hoppers with permafrost, sealing them, and then blowing hot compressed CO2 through the dirt to melt and boil the water, remove it from the dirt, and condense it elsewhere in big holding tanks.

>>12280928
Tried it in KSP with BDB. It's kinda shit.

>>12281026
nice FUD

why haven't I seen any sfg 4chan ads?
are we poor?

>>12281051
Had to substitute BDB's regenerative RS-68, which is actually a bit better than a real RS-25, but could only fit 1 in the interstage. Couldn't even loft 2 full 2.5m ore containers into a 100km orbit.

>>12281055
I don't even want half the people who are already here

>>12281055
The space agency has always been underfunded

>>12281058
wow rude?

>>12281056
ive always wondered by dont fairings have a petal opening configuration like pic shown.

>>12281056
>>12281051
Did you only use one of each engine?
You gotta optimize the stages dude, at least 3 F-1 engines on stage 1 and one RS-25 (or analog) on the second stage. If you are doing expendable launch vehicles you want ~5 km/s per stage as a good rule of thumb.

>>12281067
More moving parts increases cost I imagine

>>12281067
Mass inefficient and heavy.

>>12281067
On one of the early Apollo missions (7?) I think the fairing didn't quite open all the way and it raised concerns about a stuck petal leading to an inability to dock with the payload in the S-IVB, so later missions just dumped the fairing panels.

>>12281067
Also reliability is worse. Fairings are generally a clamshell design because that minimizes the number of seams and the chances that something will go wrong. Unlike with rocket engine clusters where having more engines increases reliability because you can lose one or two and still be fine, if you have an arbitrary number of fairing segments they still all need to work perfectly or the mission is ruined.

>>12281051
Make it bigger. 5xF-1B lower.

>>12280757
nigga just use a mirror lmaoooo

>>12281075
I assumed he meant a single F-1B lower with 2 SSMEs on the upper stage. I couldn't fit more than one RS-25-like engine inside a 3.75m diameter interstage without the nozzles clipping through each other. With 2 full ore containers onboard, the vehicle comes out to somewhere around 4km/s of dv in a vacuum, which is usually enough to get a minimum 70km orbit (3400km/s is the most commonly-stated threshold). I'm sure I could fly it a bit better, but the configuration is way less powerful than I thought it would be.

>>12281085
>where having more engines increases reliability because you can lose one or two and still be fine
how do you prevent a malfunctioning engine from taking out the one next to it? Unless I'm mistaken and engines tend to go out rather quietly

>>12281098
Dangerously based

>>12280765
it's not magic, we already have metamaterials that do this

>>12281086
Done it before. The TWR is a bit better, but an S-IC-style stage is so overpowered at the stock scale to begin with, it's hard to notice much of a difference.

>>12281102
Kevlar and armor plating around the main combustion chamber to keep shrapnel from reaching other engines and downstream you already have an opening to get rid off the gas in the engine.Worked for Falcon 9 1.0 that had engine failure up the hill

>>12281101
Yeah no, it would be 6/2, not 1/1. It would be a big rocket (for you).

>>12281098
If you can make gamma ray mirrors you can make an antimatter Orion drive and fly forever.

>>12281058
Based and isolationist pilled

>>12281102
>Unless I'm mistaken and engines tend to go out rather quietly
One they're running they're already containing the explosive power of the propellants, which means that when they do go it'll be because something burned through somewhere, leading it to piss out some fire and shut down. Solid motors can explode, but unless you accidentally start a metal-oxygen fire in your turbopump (Antares) the engine probably won't explode.

>>12281058
ok boomer

>>12281113
cool. I just watched that F9 engine failure and it seemed to handle it pretty well.

>>12281142
thanks, your explanation makes a lot of sense. A breach would depressurize the system and just shut it off instead of exploding. I now see where people who say that humans should never ride up on SRBs are coming from.

>metal-oxygen fire in your turbopump (Antares)
>https://www.youtube.com/watch?v=MZ0SgAU9LXI
impressive

https://mobile.twitter.com/elonmusk/status/1321275062998257665
>this tweet will be immortalized in the Martian Congressional Archives

>>12281155
>starts sobbing after the shockwave
>runs away saying "holy mackerel"
Why are journalists like this?

>>12281083
that was gemini. Angry alligator.

>>12281155
>holy mackerel
the most gay shit I've heard this week

>>12281163
goddammit elon..

>>12281165
unironically ruined a beautiful explosion

>>12281155
>thanks, your explanation makes a lot of sense
This is one of my favorite things about this general. Despite how shitpost-ery and heated it can get everyone here cares about spaceflight and is more than happy to impart any knowledge they may have to help a fellow anon

>>12281163
>Wow, this mayo sure is salty!
>Come here … no, come, here
I think he's found the ambien again.

>>12281101
>I assumed he meant a single F-1B lower with 2 SSMEs on the upper stage
Well that would be silly, the size ratio of the first stage to the second stage would be completely off base. For a decently performance optimized first-to-second-stage mass ratio look at the Falcon 9. The first stage has roughly 9x the thrust and roughly 3.5 times the mass of the second stage (the second stage gets away with a much lower thrust to weight ratio).
Following this rule of thumb, if your second stage has one RS-25 producing ~2300 kN of thrust, you should have a first stage producing ~20,000 kN of thrust, which is about 3 F-1 engines. You want the entire rocket to start off with a TWR of ~1.3 and you want the second stage to start off with a TWR of ~0.8. I'd do it but I don't have realism overhaul installed because I'm a poopy dum dum who can't computer.

>>12281194
>I don't have realism overhaul installed
I'm just waiting for Kerbal Scale RSS to update to the current version of KSP. Planning on doing a save with exclusively BDB vehicles at 2.5x stock scale and KOS for any flight controls beyond SAS. Apparently they're adding PBR shaders to the terrain, so that'll be pretty cool.

>>12281155
is that pussy actually crying???? WHAT THE FUCK

>>12281182
ok gay boy ;)

>>12281210
A """journalist""".

>>12281215
dont make fun they lead very stressful lives

>>12281163
lol what the fuck Elon
He's smoking the good stuff tonight

>>12280589
My bet is SLS flies twice and gets cancelled.

>>12281231
after the first one launches I wonder how many years it will take for them to finish constructing the 2nd

>>12281232
n+1

>>12280873
just mine en mass it from saturn's rings

>>12281163
>TFW Musk is trying to crash Tesla stock prices AGAIN
lmao based

>>12280686
Dont forget expander cycle and older engines like V2, Redstone and R7 that use peroxide-permanganate gas generators to run the turbopumps.

>>12281237
I wonder if anyone's done the math on whether it's energetically favorable to mine ice from Saturn's rings vs from Iapetus, since the latter is very far outside Saturn's gravity well. Sure it's nice that you can basically just grab ring material in zero G and leave, but having to get all the way down to a circular low Saturn orbit in order to get that material then fight your way back up is probably harder than just capturing and landing at Iapetus then launching again, especially since the gravity there is only 0.0228 gees.

>>12280827
>American sovereignty over Luna
Only until the wizards decide to take it. Luna belongs to nobody but itself, Terran scum.

>>12281244
With the Expanse setting's 12g+ fuck-you torch drives, convenience trumps the delta V penalty.

>>12281245
based. If earthers don't like it they can enjoy a few megatons of lunar sand dumped in their low and middle altitude orbits.

>want to work on spess stuff someday (currently working towards an ME degree)
>The seemingly only company doing anything innovative in space is SpaceX, but I don't want to work 80+ hours per week for the rest of my life
wat do

>>12281131
Still flying the R7 in 2020 is like an airline offering flight service on a DC-10.

>>12280888
Nobody's trying to sound smart, "Luna" is just a less clunky way to refer to it

>>12281249
>want to work
>dont want to work

>>12281247
Yeah but fuck the expanse, we are so far off from propulsion tech of that capability if it's even possible that there's no reason to even think about it yet.

>>12281237
space mining a huge industry when

>>12281251
The Moon will always be The Moon. Any other Moon that anyone works on will be either be referred to by name or as "Saturns third moon" etc.

>>12281245

>>12281249
By the time you're hireable, Starship will have probably brought on a boom of LEO-focused small space companies doing some cool shit.

It does seem suspicious...

>>12281257
And? It's still a clunky and ambiguous way to refer to it.

>>12281250
welcome to canada

>>12280721
Funny, but the Outer Space Treaty specifically states that things like SpaceX colony ships would be under governance of the US. Colony ships from other countries would be under the governance of their respective countries too. The FBI would instantly lock down SpaceX if they tried it.

>>12281270
Why? "The Moon" seems pretty definitive unless you know any other planets in the solar system with only one moon

>>12281279
The FBI is getting fucking disbanded if they don't stop their bullshit.

>>12281279
>Outer Space Treaty
Isn't that set to expire very soon or am I thinking of the Antartica Treaty

Has Musk talked about the weather conditions Starship is expected to launch in? It's obviously sturdier than Falcon 9 but I'd like to know how much

>>12281279
The Outer Space Treaty will be violated just about as soon as anyone is capable of violating it in a meaningful way, with the possible exception of the "no nukes in space" rule, which I can see governments actually being afraid to break only because of the thought of needing to deal with the consequences of a failed launch.

>>12281166
no, anon is right. apollo 7 had the sequel to angry alligator but fortunately they didn't actually need to dock with anything. if there had been an LM in there they would've been in trouble. they quit using petal fairings after that.

>>12281282
I'm talking about ambiguity of terminology, not ambiguity of the thing being referred to. And still, "The Moon" is clunky and awkward compared to it just having a singular name. I guess you could just call it "Moon" but that's also dumb.

>>12281314
spit the difference and call it The Luna

>>12281314
>And still, "The Moon" is clunky and awkward compared to it just having a singular name.
But why? Everyone immediately knows what you're talking about and it has been in use for hundreds of years. Calling the moon "The Moon" has literally never been an issue for anybody

>>12281321
You have to think big anon
In the future when humanity has colonized many planets and moons calling one celestial body "The Moon" won't cut it anymore

>>12281279
They'll have to get to Mars to lay a hand on them.

>>12281210
He has ptsd now

>>12281335
Nah, The Moon and The Earth will forever hold a ceremonial place in the collective conscious of humanity when she reaches across the cosmons

>>12281319
loona

>>12281336
Mars colonies won't be self-sustainable in our lifetime.

>>12281362
>t. Anonymous shitposter

The Lunar Moon

The Munar Lune

https://twitter.com/dfuji1/status/1320652980299788288?s=19

They are fast.

>>12281342
Nope because I will personally drop an RKV onto urf and turn it into a cloud of space dust.

>>12281394

>>12281373
Most countries on Earth are not self-sustainable and wouldn't last long without trade. Mars would be much more vulnerable in this regard because it's a giant desert with fewer resources.

If Martians wanted to say fuck you to Earth and face embargo they'd have to replicate most industries and be able to produce everything we produce now - which, as I said, not even normal countries on Earth can do. Technology, equipment, rare and super expensive resources, people... If they wanted to be truly independent they'd have to build Earth 2.0 on Mars which would easily cost trillions and be the equivalent of sending an entire country like China with all its industries and factories to the red planet.

>>12281400
Sigh....don't be lazy anon. Just pop it into gooooooooooog's translate feature.

The Starlink satellite (Starlink V1 L14), which passed at 17:26 on October 26, 2020, was photographed from his home in Hiratsuka with a telescope. It is playing at the actual speed without fast-forwarding. You can feel the speed of an artificial satellite that orbits the earth at a speed of 8 km / s.

>>12281412
Those countries have to sustain hundreds of millions. 10k or fewer could easily self sustain

>>12281412
Most of the industry on earth is focused on producing junk consumer goods, you could slash a massive amount of that with zero consequences other than employment and economic figures and people whinging about iphones.

>Mars (an entire planet) has fewer resources than a small country on earth

ogey

>>12280767
>This is unironically Mars' greatest asset and attraction: A fresh start. The established governing systems on earth are broken to the point of being unfixable. The only way to move things forwards is to start from scratch. People would gladly live in a radioactive hell for this opportunity.
Mars and space as a whole also creates a way for common people to feel like they're making an impact in ways they haven't been able to for over a century. On Earth the janitors and line cooks are a dime a dozen, can be replaced easily, and are generally forgotten, while on a Mars colony they're critical for keeping the colony from falling apart at the seams and will be in high demand for decades to come, so long as immigration continues.

>>12280664
Mine's prettier :^)

>>12281420
>you could slash a massive amount of that with zero consequences other than employment and economic figures and people whinging about iphones.
Oh to cut back all the excess of the modern world and return to a life where the average person's problems where related to how their farm was doing rather than how well they were doing on social media

Bros and sisters, to prepare myself for mars, thinking of joining an Antarctic scientific expedition. What say?

>>12281432
Needs more Minmatar.

>>12281439
Incredibly based if not meme-ing. South Pole exploration history is incredible and anyone with any fascination with space exploration should definitely look into it
Also
>sisters

>>12281432
>gallente trash

https://www.youtube.com/watch?v=Il4xDpx4rJk
Imagine an Orion stack horizontally stacked instead of vertically

>>12281455
Total waste. Just use a Falcon Heavy.

>>12281394
https://www.youtube.com/watch?v=SRbhLtjOiRc

>>12281455
But that would require little modification to existing space shuttle infrastructure. How would that benefit the American taxpayer?

>>12281459
Shuttle HLV was proposed as a replacement for the space shuttle, as a cheap alternative to Ares V, and most likely would have actually seen use over SLS
it was proposed before f9 ever flew

when?

>>12281420
>Ogey
It's about the variety, not volume. Mars doesn't have most of the stuff that Earth does.

>>12281284
Not that I know? The Artemis Accords even use the Outer Space Treaty as the foundation upon which the Accords are built.

>>12281473
>direct ascent lunar mission
Holy based

>>12281485
Luna 3 apparently did one giant continuous burn launching at 90 degrees inclination, straight over the pole to TLI.

>>12281439
that sounds awesome and I'm saving up for that myself

>>12281480
Such as?

>>12281412
You don't need need to import poor people to mars.

>>12281491
The whole Luna 3 mission was fucking crazy. Specifically thinking about the story behind it and how the data was processed

>>12280926
>But you're never going to get the flow rates you need by letting gravity empty the tanks, so you use turbopumps to shove everything out as quickly as possible.
You're never going to get ANY flow rate, gravity or not, because pressure in combustion chamber is higher than in tanks (unless it's a pressure-fed engine where the opposite is the case, but it only works for small and low-performance engines because tanks rated for high enough pressure become ridiculously heavy at orbital rocket scale). That's why you need pumps to shove fuel into the combustion chamber against the pressure inside.

Lmao some people really thought the SLS green run would happen before a Falcon Heavy ever flew. Just remember at one point these events were supposed to be happening at around the same time.......

>>12281511
SLS IS FUCKING OLD ENOUGH THERE IS CONCEPT ART SHOWING IT WITH A WHITE MAIN TANK, BEFORE THE SHUTTLE PROGRAM FIGURED OUT THEY DIDN'T NEED TO PAINT IT

THAT FUCKING OLD

>>12281511
Look here buster, SLS is released. You've seen it down in Michoud. Now Elon Musk says he wants to weld together an interplanetary rocket out of steel out in Texas. Its not that easy in Rocketry

>>12280721
Go SpaceX
Fuck UN

>>12281530
No matter how many times I read this it never fails to make me laugh hahah

>>12280721
ELON STOP YOU'RE BLOWING YOUR LOAD TOO EARLY

>>12281216
We’d be way better off as a species if people’s daily lives were a lot harder

>>12281432
Wait, is that a working SSTO in RO?

>>12280721
i can't believe SpaceX are Contolists

>>12280721
can you post a link to this

So Starship garbage disposal. How would you do it? Have it scoop satellites into its maw and land with them or have couple arms inside it that push the satellites into atmosphere or what?

>>12281576
Starlink-based satellites with a bigger focus on mobility and a universal grabber/pusher part on the front. They would latch on to the target satellite/debris, and deliver it to a rubble pile somewhere in an unused part of MEO.

>>12281563
There's a difference between effort required and stress. I hate to defend the judenpresse but there is a distinction. Sometimes there's actually an inverse correlation - I was more stressed working remote third shift on my ass than I ever was playing high school football.

>>12281581
If possible I'd rework the design so that the onboard ion engines could use nitrogen, which would be replenished by a small fleet of LEO atmosphere scoops.

>>12281576
>ave it scoop satellites into its maw and land with them
Yes, while broadcasting Pacman sound effects on wideband. WAKKA WAKKA WAKKA

>>12281581
Scoop up full fairing of satellites, include trash compactor to maximise density, eject on Tel Aviv intercept orbit, boost orbit and repeat.

>>12281412
>Most countries on Earth are not self-sustainable and wouldn't last long without trade. Mars would be much more vulnerable in this regard because it's a giant desert with fewer resources.
Most countries on Earth could become self sustainable in several years if forced to, and have enough bits and bobs and spare parts laying around in warehouses to last that long. If those videos of chinese outdoor primitive technology forges that use a bug hunk of scrap steel as a power hammer have taught me anything, it's that as long as a population can feed itself and already has access to machinery, it's not that hard to get decently capable basic manufacturing up and running really quickly.
With this in mind, I'd say Mars could theoretically sue for independence and survive alone once they had robust steel manufacturing, in-situ power capacity growth, and were capable of producing a surplus of food. Of course, the longer they delay this event means the more 'free' resources they get, and more importantly the greater a bank of genetic stock they can build up, in the form of thousands of species of plant seeds and animal embryos in cryo stasis. Everything non-biological can eventually be bootstrapped up to, but you can't bootstrap your way to farming mangos if you don't have any mango seeds (or mango DNA, assuming we can one day build viable plants starting with nothing but genetic sequences).

>>12281420
a billion niggers in mud huts in africa have fewer useful resources than a million Brits did, because the Brits knew how to make them resources rather than just another kind of rock in the ground.

>>12281455
Before I watched the video you posted I assumed you meant Orion nuclear pulse spacecraft, which goes to show how irrelevant I believe the actual Orion capsule to be.

>>12281627
>as long as a population can feed itself
Most countries are net food importers.

omaAga

>>12281508
I mean, you're not wrong, but you're kinda wrong.
Yeah, we use pumps to force propellants into a combustion chamber, but it's in order to get HIGHER chamber pressure, not to just get any chamber pressure. An engine could be designed to run off of the pressure generated by the weight of the propellant alone; it'd just be a really shitty engine. Just for fun I'm gonna imagine how you'd optimize for that.
Based on my 4:30 am thoughts, in order to make a rocket with an engine like this viable you'd want a dense propellant and a fuel tank no wider than the width of the combustion chamber. This is to make the propellant tank as tall and skinny as possible, and thus get the highest column of propellants generating the maximum hydrostatic pressure. This hydrostatic pressure is what will force fluids into the combustion chamber; if your rocket is 20 meters tall and uses a monopropellant with the same density as water the chamber pressure can be up to, but less than, ~20 bar. In reality the chamber pressure would equalize somewhere where the flow rate into the chamber was great enough to begin slowing down the inflowing propellant and reduce the chamber pressure again. If this thing has a TWR >1, which is doubtful, as it climbed and got lighter it would accelerate faster and thus maintain more of its thrust performance than you would expect if looking at the fluid height in a 1G field.
This entire post contributed nothing and I'm posting it anyway

>>12281640
>in order to make a rocket with an engine like this viable you'd want a dense propellant and a fuel tank no wider than the width of the combustion chamber
literally an SRB

>>12281526
Literally before Shuttle ever flew, they were already drawing up plans to build a shuttle-derived heavy lift stack.

>>12281576
>So Starship garbage disposal. How would you do it?
Ten-ton steel trash compactor. Robotic manipulator arm with electromagnets grabs target debris and dead sats and puts them into the open door of the compactor. Compactor closes and crushes the debris into a pancake. Pancake is not going to shift around in transit or during landing because it's held in place by a hydraulic ram. Once on the ground the compactor is dumped out.
>but high pressure tanks on dead satellites!
Robot arm has a small drill to vent those bottles
>but the drill will make tiny bits of space debris!
Yes

>>12281634
Yes because they are massively overpopulated, Mars will of necessity be producing all food on planet almost from the get go.

>>12280650
SSME is a fucking upper stage engine for vacuum use being trotted out as a first stage engine for the future.
That specific impulse means nothing.

>>12281627
Hard agree desu. Pretty much everything could be bootstrapped fairly quickly I think, but electronics will be a real cockblock, shits insanely hard, although that being said they could easily get by on chips a fraction of the power we have today. My man Elon just needs to make sure import a few kilotonnes of chips and such before dropping rocks on urf.

>>12281634
Yeah I know, which is why I gave that caveat. The problem of becoming self sustaining in terms of food if you aren't already gets worse as your population goes up, so Mars which will have between a few hundred thousand to a few million people at that point shouldn't have much issue with food production. Making pressurized steel tubes which are climate controlled and stuffed with extra CO2 and moisture to reliably grow all types of crops all year round is actually not that hard, not hard at all, it's just more expensive than putting seeds in dirt and letting the Sun get at it.
So yeah, if Mars can make steel beams and steel panels, they can build 60 meter diameter pressurized steel tubes 200 meters long with multiple decks that use purple LEDs to grow dense arrangements of food crops at maximum growth rate limited by biological factors instead of resource availability. It'll cost energy, but they won't be hurting for energy. It'll cost materials, but so will everything, so if they can't source materials they have bigger problems still. Once they have it they can produce thousands of tons of grains, root vegetables, fruits, nuts, and basically any other produce imaginable. They could have one tube cycling into 'autumn' to trigger orchards of apples and pears to ripen their fruits and go dormant for 'winter', which lasts one week before 'spring' starts to wake them back up, while in the next tube over the temperature's always about 32 celsius and the humidity is always ~80% to 100%, and groves of banana and papaya and mango trees are producing fruits continuously, while in another tube billions of krill are living in a perpetual north Atlantic summer, feeding off of algae growing from sunlight and fertilizer produced by agricultural and biological waste streams, and sea bass feed off of those krill. No real limits to what you can have going on when you have fingers on all the climate dials.

>>12281642
but liquid!

>>12281055
>seeing ads

>>12281668
MUH

DICK

I WANT TO FARM CRAZY MARTIAN BIOME TUBES BROS

>>12281664
Agreed, although I'm not convinced that it's REALLY that hard to grow silicon buoles, cut them into wafers, and then etch the circuitry into those wafers before wiring everything up. I really feel like they could have miniaturized transistors and microchips in general much faster than they have, I mean seriously what exactly needed to be improved in order to go from a 500 nanometer transistor to a 100 nanometer transistor? I can't think of any technology that was seriously a limiting factor that could only improve fast enough to make electronics get better at a suspiciously hampered rate, almost as if it were by design in order to sell more generations of tech products over time. I know it's a bit tinfoil-hat to say that, but come on, just look at the state of the launch vehicle industry and tell me that the electronics industry is totally honest and goodwilled.

>take take oxygen and methane propellant
>Freeze them
>Powderize them
>Mix them together in a metal tube
>Put hole in bottom of tube and ignite combustible materials
I just invented a Methalox rocket that doesn't need a fancy rocket engine, or tankage :^)

>>12281678
Congrats! You've made a bomb about as powerful as a chemical explosive can possibly be!

>>12281676
It is in fact that hard. Laser light wavelength is about 500 nanometers. Chip fabs are working on 5 nanometer production now.

>>12281672
The best part is once you break the sunlight dependence you can start replicating it all the way out to Neptune.

>>12281678
>not using frozen hydrogen powder

>>12281686
>Tropical farming on Triton

MUH

DICK

>>12281678
Based instant megatonne range explosion staging.

>>12281678
and then someone points a heat lamp at your tube, prematurely detonating it

>>12281648
Starship variant with whale like gills that scoops small debris.

>>12281682
Alright, however I wonder if whatever method we use today to draw those etch patterns were hard to develop because the machine is hard to build, or because there were some problems that we learned how to solve, which means starting from scratch an industry could jump 30 years ahead of the curve to 50 nanometer transistors immediately because they already know about the physics and engineering of how they solved the problem in the first place?
Think of it like the entire development history of rocket propulsion all the way from Goddard to the 2000's, vs SpaceX developing Raptor in ~ten years pretty much unassisted. They already knew what made sense, what could be done, what materials they could use, and building upon those things they have created arguably the best rocket engine ever. I don't see why in a couple years they couldn't go from a few lab-scale furnaces and equipment to a decently sized silicon wafer manufacturing industry and microchip production on Mars, as long as someone remembers to bring a flash drive with the required cheat sheets.

>>12281714
How about Starships that launch into retrograde high altitude sub orbital trajectories that coo out a bunch of expanding foam once they get above the atmosphere?
Debris strikes the foam and loses momentum, dropping the debris into the atmosphere where it burns up. The foam itself is never orbital, so it just falls down after ~30 minutes. Starship lands, gets refilled with foaming agents and propellants, and does another suborbital hop. Even if the entire future Starlink constellation with 40,000 satellites went full Kessler syndrome I don't see how we couldn't scrub LEO of all debris using this method in a few years or less.

>>12280721
Extremely good news!
Except for
>governed by and construed in accordance with the laws of the State of California
>>12281194
The timeline that really should've happened:
>F-1B first stages with RS-25 second stages
>mini version is that pic
>standard version is 6 F-1Bs with 2 RS-25s
>heavy lift version is 9 F-1Bs in Falcon 9 pattern with 3 RS-25s
How much could we do?
>>12281678
>not just riding the nuclear manhole cover

>RS-25 Restart engines (i.e. new builds) values each engine at $99,444,444. So for one SLS flight that equals $398M worth of RS-25 engines that get thrown away.

The absolute state of government programs.

>>12280721
>transit to Mars via Starship or other colonization spacecraft, the parties recognize Mars as a free planet and that no Earth-based government has authority or sovereignty over Martian activities.

This is never ever going to be accepted by any government on Earth and you have to be utterly insane to think otherwise. The Moon treaty will be extended and expanded for all celestial objects.

In the UN vote alone, who is going to support such nonsense? The US? Then what?

>>12281730
>In the UN vote alone, who is going to support such nonsense? The US? Then what

Sorry none of these entities matter because several multi gigatonne asteroids will be hitting urf at 1%c soon.

>>12281730
>UN

lol go cry to league of nations for all I care.

>>12281718
>coo out a bunch of expanding foam
coom*

>>12281725
>9 F-1Bs in Falcon 9 pattern with 3 RS-25s
Seems like you’d have to exclusively fly stupidly heavy payloads on that thing for the TWR to be in a reasonable range.

>>12281730
They can bitch and moan about it in Copenhagen, same as they always do

>>12281725
>How much could we do?
>>standard version is 6 F-1Bs with 2 RS-25s
About 160 tons
>>heavy lift version is 9 F-1Bs in Falcon 9 pattern with 3 RS-25s
About 240 tons
The heavy lift version could get away with using a third stage identical to the second stage of the 'mini' version, which would need to fire in order to achieve orbit but would be able to push a ~80 ton payload to trans lunar injection if my guesses are correct.

>>12281743
Nah, you size the tanks so that the TWR stays manageable. If your brain is telling you that you'll have crazy TWR at the end of a burn, it's because you aren't considering just how big your tanks are nor how but your payload is. Also, if stage thrust to weight ratio did become a problem, it's not like you could just shut down two or three of your nine F-1B engines during ascent, assuming you can't throttle.

>>12281748
I note that said three stage option features zero relights.

>>12281750
I guess. Still, I can’t imagine many payloads that’d make use of 2x RS-25s and enough fuel to weigh it down. It’s pretty stupidly powerful to be used as an upper stage engine to begin with.

>>12281730
>Muh UN

Lol. America can make its own treaties with other countries and never involve the retarded UN

>>12281735
>multi gigatonne asteroids will be hitting urf at 1%c soon.
Not if everyone were grounded before they can leave mother earth.

>>12281750
Wasn't F-1B throttleable down to like 30%? You could do a giant fucking F9 style flyback booster with 9 F-1Bs.

>>12281762
>Wasn't F-1B throttleable down to like 30%
I don’t think it was designed to be any more capable of throttling than the F-1 and F-1A (so basically 0% or 100%). The main goal of the F-1B was matching or exceeding the F-1A’s performance with much cheaper modern design and manufacturing techniques.

>>12281753
>It’s pretty stupidly powerful to be used as an upper stage engine to begin with.
Well, it's three RS-25s, same as what pushed the Shuttle once the solids farted away. It's not that much thrust; Starship will have about twice the thrust of a hypothetical 3x RS-25 engine stage, given that Raptor is almost the same thrust as an RS-25.
To humor you though, a stage with a total mass of 700 tons would have a TWR of ~1 when powered by three RS-25 engines. A more realistic 2nd stage TWR of 0.8 gets us a total stage mass of 880 tons, which means the unladen stage (wet but no payload) would have a mass of 640 tons. These numbers are definitely not huge, "only" 150% the mass of the Saturn V second stage (which conveniently also used hydrolox). This is 100% a doable engineering project.
Looking at the 240 ton to LEO 2 stage option, the first stage with its nine F-1B engines would produce a huge 72,000 kN of thrust, which means for the entire rocket to have a liftoff TWR of 1.4 the first stage would need a mass of 4368 tons. The first stage of this rocket alone would mass almost 1.5 times that of the entire Saturn V stack. The total vehicle mass with a 240 ton payload would be ~5250 tons, or five and a quarter million kilograms, outweighing the Starship Super Heavy by 250 tons.

>>12281762
>>12281768
I should also mention that I had been using the figures for the Saturn V era F-1, not the F-1B nor even the F-1A, until this post here >>12281772

>>12281640
Or you can just make it pull enough Gs for the liquid column in the tanks to generate high pressure to feed the engines. Still it's not a very good idea either way because you essentially get a pressure-fed engine with just the bottom half of the tank that must hold the pressure, and in my case alse become limited to payloads that can handle high acceleration. On the other hand though, high Gs lessen the gravity losses, so maybe there could be a tradeoff that would let it make some sense.

>>12281026
>sounds like an accident waiting to happen.
At 300 bar?
Yes, it's unreliable at chamber pressures that high.
At 270 bar?
Not realy a big deal.
But inowing SpaceX, that thing will soon do test runs beyond 300 bar to make it reliable at 300 bar.
>>12280721
Holy shit, it's happening!

SLS delayed again ahahahaha

>>12281784
Didn't Elon say that they've done sustained burns at 300 bar now without damage? I thought it was at 330 bar that they were getting the engine to turn 'a bit melty'.
Anyway, yeah, important to remember that 250 bar minimum is what is needed to make Raptor good enough to get Starship to Mars and back, 300 bar is their goal, and >300 bar is their stretch goal. If Raptor is already running for minutes at 300 bar, and can run basically forever at 270 bar, then Mars is basically a done deal at least in terms of propulsion. Every extra bit of pressure they get Raptor producing now is just bonus performance that helps their economics.

>>12281790
This is why we test.

https://twitter.com/NASASpaceflight/status/1321144847026343937
This is just getting pathetic.

>>12281804
With this the SLS first launch is NET 2022.

>>12281743
Or just a heavy lift LEO-capable Sprint missile?
>>12281748
>>12281772
>not even half of Sea Dragon
Fuck. There's only one solution.
Pictured: arrangements for a 21 engine first stage of F-1Bs for a Saturn V and Shuttle-derived ultra heavy lift rocket. From left- The Cyclone, The Diamond, The Flower, and The Fortress. This brings the total LEO lift capability up to 560 tons, just ten over Sea Dragon.

>>12281806
I would like to remind everyone that Boeing is not doing ANY integrated software testing between SLS and Orion, and that Artemis 1 will almost certainly fail spectacularly like Starliner because of it.

>>12281800
I swear Berger is beating his wife at this point

>>12281681
A frozen methane/oxygen bomb-pellet could be usefull in an orion-like engine.

>>12281791
Seems like my info wasn't up to date.
However I'm sure they will try to push Raptor even further...

>>12281812
If SLS ends up killing people what will the consequences be?

>>12281836
>space is hard mumble mumble our American heroes mumble investigation mumble assured access to space mumble mumble new project for boing.

>>12280928
SSME are not air startable you'll need a new engine for that.

>>12281847
>How were we supposed to know we can‘t launch in cold weather? It only happened once before and we added an entire third O ring since then. Are you suggesting we listen to every single of our engineers when they are yelling at us not to launch?

>>12281856
>sparkplug fired torch ignition
it would totally be airstartable you'd just need to hot stage it

When will we see sn8's f8 and s8 in action?

>>12281892
sneed?

>>12281908
Chuck

>>12281908
Sneed feed and seed, best machienes ever created by men.

>>12280958
Yes let's ruin our mass ratio and get insane amounts of drag for 0.0000001% of our propellant mass.

>>12281913
>SNeed feed & seed
that's the martian agricultural department

>>12281730
By the time ceres or the jovian moons are being colonized by SpaceX, mars will be self sufficient and UN treaties won't matter.

>>12281941
I really doubt mars could ever be self sufficient unless it has large enough ice/water deposits as it's theorized.
It would be great if it had then in abundance but so far we can only make guesses.

>>12281951
it has huge amounts of water even on the surface

>>12280721

>>12281951
Mars has plenty of fuckin' ice I swear to god you people and fucking ice. At least come up with something actually restrictive. There are a few metals we don't have good confirmed sources of on Mars, at least start there.

>>12281250

Nah, the DC-8 or Boeing 707 would be a better comparison. Also, you cannot compare the DC-10 with the R7 because unlike the DC-10, the R7 is actualy safe for people to fly in.

>>12281876
"Just" hot staging it suicidal as well as incredibly difficult. SSME is not upper stage engine and can't be used as such - the initial SLS design had it as upper stage engine. Guess why they dropped it.

>>12281856
They are air start able, just not zero G start able. as the other anon said, hot stage, or settle with ullage and rely on tank gas pressure.

>>12281916
Yes

>>12281973
>Guess why they dropped it.
Because old space is petrified of having to do anything new, because it would showcase just how shit they've become in an undeniable manner.

>>12280822
The only information about the Lawson Criterion for the proton-proton chain is that it's HUGE, considering Proton-Boron11 is 500, it's just not practical in the least. And if you'd figure it out you'd use it for thrust, 11,7%c exhaust velocity is insane.

>>12281973
>SSME is not upper stage engine and can't be used as such
So you're telling me a dramatically overpriced engine which prioritizes ISP over thrust to the point that no one's ever designed a vehicle around it with positive launch TWR is also incapable of being used in the one role it seems suitable for? God I hate hydrogen and the SSME.

>>12281973
Russians use it constantly though.

>>12281973
>hot staging it suicidal
Tell that to Soyuz

>>12281973
>suicidal as well as incredibly difficult.
Even the Americans have used hot staging, dude.

>>12281253
He wants to live his life.

Honestly, the Delta IV is the biggest fuck-up in the history of rocketry; It is:

-Horrifically inefficient, due to the first stage using hydrolox
-Incredibly expensive (350M $)
-Weak and anemic, only managing 28 370kg into LEO, 8 000 GTO
-The size of a Falcon Heavy, yet half the payload capability, more than double the cost (if FH is expended)
-Latest rocket has been standing on the pad for two months now, and will stand there for atleast two more weeks

What the hell were they thinking when they decided that a low density, low power, high ISP vacuum optimized propellant would be good for a first stage?

>>12282104
>What the hell were they thinking
That's volume 1, 2 & 3 in my 5 volume series about the SLS.
In all honesty, it's "Dat Mileage Doe", mixed with a bit of environmentally friendly bullshit that spread far and wide during the late 70s and 80s. I remember there being so much focus in the 80s about how good hydrogen was because it ONLY let out water as an exhaust gas and how this was a really really really really good thing.

>>12282104
>What the hell were they thinking when they decided that a low density, low power, high ISP vacuum optimized propellant would be good for a first stage?
Either "we want the most efficiency" or "how can we justify billing the government as much as possible".

>>12281973
>>12282072
The Titan rockets used hot staging.

>>12282168
>Either "we want the most efficiency"
Let me introduce you to my friend gravity losses

>>12282168
You want thrust, not efficiency, to get off the launch pad.

>>12282176
>>12282182
>"but dudes, high specific impulse. that means it must be good."

>>12280888
Retards, I have a compromise. We should call Earth's moon the Loon.

>>12280888
That's just
lunacy

Barron Trump will be made advisor to the President for spaceflight activities.

>>12282228
He's 15
but he might just be tall enough for the job regardless

>>12280654
Is there any one person in charge of Raptor or is it just the collective culmination of lots of spacex autists and all-nighters pulled by 20 year olds? It outperforms every other engine ever made in many different areas

>>12282194
I was actually curious so I checked launch mass/payload ratio to see what their actual efficiencies come out to. FH (expendable) is superior to LEO and loses out very slightly to GTO. In other words, in mass ratio terms the hydromeme first stage is so inefficient that even the hydrolox second stage is barely able to make up the difference vs. a <$1m open cycle kerolox shitbox.

>>12282273
Why do you think oldspace gets so much shit here?

>>12280888
People's use of synonyms makes you feel insecure because you're a vocabularylet.

>>12280917
>>12282307
Umm akchually

If Starship revolutionizes the launch market as SpaceX expects it, then will smallsat launch companies switch to smallsat landers? Starship is meant to be a universal landing vehicle, but it can't land everywhere and having a smaller lander might be better for smallsat payloads. The technology is already there, and it'll only become more accessible with time.

>>12282228
No brakes

>>12280721
>the parties recognize Mars as a free planet

The major powers of earth will never let this come to pass (at least in the near term). Once/if spacex demonstrates the ability to send a ship of 100s of people to mars or the moon, there’s a good chance that it will set off a new great power competition. It would have some similarities to the age of sail/European colonization - except that it would occur in space. Governments on earth will start coming to the realization that there’s an entire solar systems worth of wealth and resources that are now reachable. Countries and other companies will race to develop vehicles similar to starship. There will be a Chinese Sector and American sector on the moon and Mars.

>and that no Earth-based government has authority or sovereignty over Martian activities.

What are the Martian settlers going to do if the Chinese people’s liberation army or
the US space force sets up shop on Mars?

Martian independence only has a chance of becoming a thing once Mars has a population of tens of millions.

I miss the early 2000's. Forums were so fun and interesting. This is like a time capsule of days gone
https://web.archive.org/web/20080929092332/http://spacefellowship.com/Forum/about1216.html

>>12282395
These suits are kino

>>12281283
They should be disbanded no matter what, there's no fucking mob to go after anymore and they have outlived their original purpose by half a fucking century.

>>12282404
Yeah I know they are for protection against hypergolics, but would they protect you in a decompression event in a dragon capsule? I feel like they serve the same purpose. Pressurized with their own air supply... this is the 4ASStronaut suit.

>>12282301
Oh it's not new to me I just hadn't checked the direct numbers on those two rockets. I expected it to be a little more competitive since DH's first stage isn't SSME tier bad (or it wouldn't leave the pad at all) and hydrogen doesn't have to lose out on a sheer mass ratio factor to be worse overall.

>>12282395
You should not be sad that those times are past, you should be happy that you got to experience them.

>>12281715
They have the internet on mars too dude just higher latency

>>12282387
>governments
>plural
>muh china
No one but SpaceX has will have capability to put significant mass on Mars in the next couple of decades. They have all the leverage in the world.

>>12282417
Engine TWR is just as important as ISP when it comes to mass fractions, and Merlins have God-tier TWRs. Hydrolox density also hurts because you have a higher tankage-to-impulse ratio, all else equal.

Wait wait wait wait everyone please I have a question. The RS-25 is retarded. It was supposed to be a "cheap" engine for SLS, but now it costs $200 million because they had to remake more (i.e. restart the tooling process, retrain people, etc.)
Why the FUCK doesn't the SLS just use RS-68's. It is MORE powerful than the SSME and to add on to this it is already in production and would only cost $20 million per engine. You get 1277kN more thrust at sea level for 180 million less.

>>12282472
Ablative nozzles don't like being clustered and next to two blazing hot SRBs.

>>12282472
The SLS is a gibs program for old Shuttle contractors. The rocket is a side effect.

>>12282472
>successfully sell "muh spare parts bin" scam
>put force buy into law
>charge whatever the fuck you feel like
you may not like it but this is what peak statespace looks like

>>12282479
Ahh okay. I was gonna ask about that. It looks like it was made in the 70's with that weird fucking foamy ablative texture. Also it was probably in their interest to go with an expensive engine because contractors

>>12282395
>Has any thought been given to contacting the ARCA (Romainian) team about sharing information and technology...?
>2005
How long have these motherfuckers been grifting? holy shit

>>12282479
What fraction of 720 dollars do you think it would cost to make a thermal skirt?

>>12282497
720m* derp

>>12282497
Making a regeneratively cooled RS-68 wouldn't be hard either, if you had a competent operation going. We don't know how much it cost to switch Merlin from ablative to regenerative but there's no way it was more than $100m.

Together, we will destroy Armenia

>>12282513
Ottoman Empire 2 in Acidalia Planitia when?

>>12282479
Couldn't you just give it a non-ablative bell? Or just cluster them anyways? It's not like SLS is a reusable rocket- just fucking slap them on

>>12281975
You still run into the problem of a rube goldberg rig. And if memory serves me right its DOA (or dead in orbit) once you stop it because of ice buildup in some vital places meaning your first upper stage burn is also your last. SSME is a meme. It was made specifically for the shuttle and making it work in SLS-like rocket is about the best you can do with it.

>>12282556
space is hard :^)

>>12282472
>In 2008, it was reported that the RS-68 needs over 200 changes to receive a human-rating certification.
This probably was a big factor

>>12282472
>20million per engine
Why charge 20 when you can charge 200?

will any big rockets make orbit next year? got any inside info bros?

>>12282556
You could, but then you'd have to regeneratively cool it, or perhaps film cool it. The whole reason it's ablative and not just a solid metal ring is because they must have calculated it would melt. What I don't get is why those fucking exhaust gas dumps stick out SO far from the nozzle. Why can't the turbomachinery hug the sides of the combustion chamber like normal so the whole entire setup can articulate instead of splitting it into two distinct pieces which then requires the exhaust dumps to be separate and awkward?

Who designed this clusterfuck?

>>12282104
What's the website with these cool pixelart of almost all rockets?

>>12282585
Long March flies often enough

>>12282585
i asked my time traveler friend and he said the SLS core is gonna accidentally SSTO during a botched static fire

Is any work even being done on SN8 right now? It looks like the site is empty

>>12282585
Ariane 6, New Glenn, Vulcan, and SLS have been delayed to 2022 :^)

>>12282442
The TWR of an engine is exactly 0.

>>12282552
>not arcadia planitia
into the airlock it goes

question: why is helium so widely used in rocket engines? What purpose does it serve? Is it possible to do without it or replace it with something else?

I mean, I know the RS-25 uses it its hygrogen seal, but looking at this raptor diagram it looks like it uses it as well.

>>12282611
>Thrust-to-weight ratio is a dimensionless ratio of thrust to weight of a rocket, jet engine, propeller engine, or a vehicle propelled by such an engine that is an indicator of the performance of the engine or vehicle.

>>12282556
I just did the quick math and this is what I came up with. Though they are hard to cluster it isn't impossible. The money you save could go into making a new bell. Or something idk. Space is hard :^)

>>12282618
Its fully inert, and it expands greatly in volume with considerable force when it changes phase from liquid to gas. The chart is suspected to be inaccurate because helium will not be available in any quantity off of the Earth for a long time to come to spin-start the engines.

>>12282585
>>12282592

Falcon Heavy will fly a couple of times. New Glenn will also start testing.

Then you also got the usual lineup of Delta-IV heavies, Ariane-5's, Proton-M's and a couple of Angara-A5's.

All of this is besides the whole Starship stuff ofcourse.

>>12282628
You did your math on cost wrong. you would save SIX HUNDRED AND EIGHTY MILLION dollars... what the fuck