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/sci/ - Science & Math

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7425013 No.7425013 [Reply] [Original]

If you lashed lots of sounding rockets together dropping them in stages could you get into orbit? Seems like a cheap way to do it.

>> No.7425016

sure

>> No.7425022

>>7425013
>If you lashed lots of sounding rockets together dropping them in stages could you get into orbit?

yes

>Seems like a cheap way to do it.

no

>> No.7425023

>>7425013
>cubic packing
barf

>> No.7425024

Since you're using an OTRAG image, I assume you already know that it would work and are just shitposting.

>> No.7425030

>>7425013
In an orbital launch most of the energy is spent speeding the payload to orbital velocity. The orbital speed of the ISS is 17,150 mph. It probably is less efficient to lash a bunch of sounding rockets together, mostly through excess weight for all the redundant separate systems in each rocket.

>> No.7425104

>>7425024
What I really want to know is if it's is so cheap that an amateur could do it.
>>7425030
Don't care just want something that can get up there and is cheap. 1) Big dumb booster and 2) abandoning manned flight is the way forward. The money that those companies put into getting a dude into sub orbital flight they could have shot a tiny probe to the moon on a big ass cheap rocket with that money. We don't need space tourism we need more probes however small out there taking pictures and readings. New horizons opened my eyes, there is so much shit out there but we have to rely on the whims of politicians to see it. we need ideas that are so cheap that anyone could do it. I really can't see why a small company couldn't send up say a tiny phobos probe with the OTRAG concept. I'm desperate man I wanna know for sure if there's life on mars, europa etc within my lifetime.

>> No.7425129

#kerbalspaceprogram

>> No.7425137

>>7425104
Amateurs have done launches to space, but not to orbit. I think that to get approval to launch something to orbit will take the involvement of professionals. Certainly, the people who would have to approve it are getting paid a salary.

As for "so cheap", people and groups who could be considered "amateur" have a wide range of resources. Some are millionaires, some are aerospace engineers at their day jobs, some have friends in high places.

The amateur/professional distinction isn't a very meaningful or helpful one.

>> No.7425168
File: 366 KB, 998x381, copsub.png [View same] [iqdb] [saucenao] [google]
7425168

>>7425137

>> No.7425203

>>7425104
>we need ideas that are so cheap that anyone could do it

No, we need smart people to implement these ideas. Stupid shit like lashing sounding rockets together just makes rocket scientists roll their eyes. You can't contribute anything. The best you can do for humanity's space exploration is to refrain from going on a shooting spree.

>> No.7425242

>>7425203
>An idea that was successfully tested in the 70s
>Stupid shit
I can't stand faggots like you, Why don't you get your head out of your ass and realize that there are other ways of doing things. Worst part is you probably think you're some genius just because you may have a degree from a top school when you are this narrow minded and dogmatic. If all you are going to contribute to science is attacking anything that doesn't go by the book then you may as well have just joined the clergy.

>> No.7425393

>>7425104
OP it seems you want to launch a cubesat. Currently the best way to get cubesats into orbit is to hitch a ride. Because cubesats can hitch rides no one really cares about building dedicated cubesat launchers.

We also don't send cubesats further than earth orbit. This is because we haven't really figured out how yet. It is not impossible, but it is still an engineering problem. This is something that you might be able to do.

>> No.7425445
File: 43 KB, 413x307, IMG_2509.jpg [View same] [iqdb] [saucenao] [google]
7425445

>>7425013
Of course. Just strap enough Black Brants together and make sure they payload fits under the rocket equation and you should be set.

>> No.7425494

>>7425445
How much does each one cost?

>> No.7426086

>>7425129
this

OP there are a lot of people in the space industry trying desperately to make space launches more and more efficient. I'm sorry but you're not going to find some secret overlooked way to cheaply get into orbit.

also
>>7425242
you're getting mad at someone making a valid point for no reason
>>7425104
not sure what your beef with manned space flight is

lastly if I may make this point - OP you're not sending your own probe to space, I'm not being a defeatist or trying to oppress you or whatever, I'm just telling you the truth

>> No.7426399

>>7425129
Kek

>> No.7426465

>>7425013
why does it say orbit is at 100 nanometers in the pic?

>> No.7426568

>>7426465
It's a rocket to land on your dick.

>> No.7426598

>>7426465
nautical miles

>> No.7426605

>>7426598
>nautical miles
>in air
>not even an SI unit

>> No.7426609

>>7426605
A lot of American aerospace stuff is still in feet per second and thousandths of an inch.

>> No.7426650

>>7426086
>le if it could be done it's already been done argument
That's a real positive attitude you have there, you'll get far in engineering. Just don't bother trying to innovate, it's already all been done. And FYI no-one is trying to make it cheaper, if you read about OTRAG it got shut down precisely because it was too cheap. Cheap space rockets = cheap ballistic missiles.

>> No.7426668

>>7425013

How about asparagus staging? Seems quite efficient if rather expensive and complex. More room for error.

Fewer more powerful rockets is easier and more practical. Thats why NASA does it

>> No.7426707 [DELETED] 

>>7426668
Pumping fuel to rockets in series is retarded. the pressure will be nothing by the time you get to the last one. It's harder to mass produce though.

You have to make the big rocket to order because not everyone wants a big rocket. But with small rockets you can just have loads of them on a shelf and someone buys a number depending on whether they want to go to LEO or Jupiter. Smaller things are also easier to manufacture in a small workshop. You could even 3D print the rocket, cast it in steel then weld it together.

>> No.7426709

>>7426668
Pumping fuel to rockets in series is retarded. the pressure will be nothing by the time you get to the last one.

It's harder to mass produce though. You have to make the big rocket to order because not everyone wants a big rocket. But with small rockets you can just have loads of them on a shelf and someone buys a number depending on whether they want to go to LEO or Jupiter. Smaller things are also easier to manufacture in a small workshop. You could even 3D print the rocket, cast it in steel then weld it together.

>> No.7426715

>>7426668
>Fewer more powerful rockets is easier and more practical.
You're disregarding the advantages of small unit testing and mass production.

A big rocket stage is a construction project. A big rocket engine is going to end up being hand-built from custom-machined components. You're barely going to be able to do useful testing. You're not going to be able to test a hundred of each to destruction. It's going to take you months or years to get the first samples, and then further months to change anything that doesn't work and test the changes.

A modular rocket means you can build machines to produce the parts. Touch labor is kept to a minimum. You can throw together prototypes in days, test them on reasonably-sized rigs, go back and change what doesn't work to test again the same week.

Your components might not have the same potential to be efficient, due to scaling factors, but they can be made much closer to their potential, due to practical considerations.

>Thats why NASA does it
Oh, that's just hilarious. NASA being practical. What an idea.

>> No.7426740

>>7426715
Man if I had a CNC mill I could make rocket engines for pennies.

>> No.7426840

>>7426740
Remember that the combustion region in a rocket engine gets very hot. There are no materials which can simply withstand the heating during a prolonged burn (such as a trip to space), so there needs to be some cooling method, such as ablation, curtain cooling, regenerative cooling, etc.

You still need to get clever with a small engine, it's just that you can afford more tries on the same budget.

>> No.7426987

>>7425445
shit man, you could probably do it with one black brant and an upper stage.

>>7425494
a lot.

>> No.7427032

>>7426840
Can't you just line the CC in ceramic?

>> No.7427054

>>7426987
What about using the moving air to cool it?

>> No.7427079

Protip: if you make overly complicated rocket systems they will probably explode.

>> No.7427085

>>7426840
Ablation is easy.

>> No.7427087
File: 34 KB, 392x318, model_suborbital[1].png [View same] [iqdb] [saucenao] [google]
7427087

The xkcd guy wrote up an article where he did the calculations for the mass-thrust ratio of model rockets and some model of air drag. Orbit wasn't possible but getting to space was.

>> No.7427160

>>7427032
>>There are no materials which can simply withstand the heating during a prolonged burn
>Can't you just line the CC in ceramic?
There are no materials which can simply withstand the heating during a prolonged burn

>>7427085
>Ablation is easy.
Maybe, but there's no such thing as a tested and proven ablatively-cooled rocket engine. If you tested it, you only really tested the part of the ablative coat that you ablated.

SpaceX started out trying to do Merlin 1 with ablative cooling, but their pintle injector focused heat and pressure on a particular ring, and burned through the ablative coat faster than the rest.

They switched to regenerative cooling partly because of that, and because they were learning quickly that testing everything before using it made it less likely to blow up.

>> No.7427403

Why is it so hard to get off this fucking rock?

>> No.7427406

yeah

>> No.7427417

>>7425023
That concept was originally designed by a German design firm. It's no surprise.

>> No.7427717

>>7427403
Because we want to do it by going really fast instead of figuring out a way to slowly get up there.

>> No.7427751

>>7427717
We don't have the materials to build a space elevator. Isn't that the only practical way to go up slowly?

The future of space in the next decade or so looks a bit bleak, knowing that politicians hold control over NASA and that the public doesn't give a shit. Unless something big happens in terms of funding, Mars by 2040 looks like a pie in the sky.

>> No.7427774

>>7427717
I know i've seen the concept proposed somewhere or other. But i guess... balloons?

With a rocket stage to break orbit. Not too sure how feasible it actually is however.

>> No.7427781

>>7427774
See here:
en.wikipedia.org/wiki/Non-rocket_spacelaunch#Balloon
The answer is: somewhat feasible.

>> No.7427788

>>7427774
They sound like a good idea, but most of the capability of the rocket is used to speed up sideways. Balloons obviously don't offer that, but the Pegasus rocket (decommissioned) could launch from a plane. Sounds like the biggest problem with balloons is payload.

>> No.7427812

>>7427403
Gravity is a big pain in the ass, but atmosphere doesn't make things easier too.

>> No.7427815

>>7425104
>abandoning manned flight is the way forward
b&
>>7425393
We sure will though, on InSight.

>> No.7427951

>>7427815
For commercial enterprises yes. Commercial rail companies started out ferrying goods before they moved to humans. It's far less paperwork.
>>7427781
Can this thing get a sounding rocket into LEO though?

>> No.7428026

>>7427951
Balloons are alright for really small rockets, but generally, you're not going to be able to get your balloon back. You're dropping a lot of weight. How are you going to get it down after doing that?

So you don't want to build some huge airship to lift your rocket. These things aren't good at gaining much altitude anyway. The Hindenberg was this quarter-kilometer monster, and it could only carry 72 passengers up to about a kilometer above the surface.

Balloons don't have a lot of lifting power. A big balloon will lift a small rocket up high enough that the rocket only has to be about half the size to get to space. A large rocket just can't be lifted by a balloon high enough to help.

>> No.7428040

>>7427774
How about supersonic air launch to orbit? We've only done subsonic so far.

>> No.7428089

>>7427403
99% of the people are dullards like you who are unwilling to apply math and think that innovation is a matter of coming up with "one weird trick" that teams of professionals could never envision. They distract the legitimately intelligent people, draining society's resources and causing their efforts to be less effective.

>> No.7428134

>>7428040
Well, it's been done to space. There have been demonstrations of antisatellite weapons launched from fighter jets. This is practical.

The problem is that a supersonic aircraft is a good deal more expensive and size-limited than a rocket. Then there's the whole thing with carrying it at supersonic speeds, which subjects it to quite a lot of stress.

So your rocket has to be pretty small and sturdy. That's not good for taking payloads to orbit. Once you get to space, it's an ideal environment and there are hardly any stresses on the rocket, so you don't want it to be this overbuilt thing.

Bottom line, you're going to end up with a very expensive system and get quite a limited benefit from it.

>> No.7428141

>>7427951
Why are you so fixated on sounding rockets? I get that you want to feel special by coming up with zany new ideas, but sounding rockets are about as vanilla as you can get.

>> No.7428172
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7428172

>>7426709
>3D print the rocket
>cast it in steel

>> No.7428378

>>7428141
>"Stop trying to be special!"
Are you feeling threatened or something?

>> No.7428410

>>7428172
Like lost wax casting. It's really not a terrible idea, and there are steels that are fine for an ablatively-cooled rocket engine. I don't think this method would be suitable for something like regenerative cooling, though you can do that just by bending sheet steel and making something similar to corrugated cardboard with brazed joints.

An interesting idea is to use aluminum for a regeneratively-cooled engine. It needs an anticorrosion coating (and plating aluminum is a bit tricky), but aluminum's cheap and easy to work with, and has the thermal conductivity and strength-to-weight for it. XCOR has been working on this.

I think an aluminum aerospike engine would be a pretty good idea for an upper stage. Very light, inexpensive, and quite compact and convenient compared to the huge extended nozzles that are typical.

>> No.7428562

>>7428410
>Like lost wax casting
Yeah.
>aluminum for a regeneratively-cooled engine
But aluminium has a ridiculously low melting point? You would have to pull off some thermal wizardry to keep it from melting. Might work with an aerospike though because of the air layer. With aerospikes can you do the combustion on the spike or does it have to be done in a CC beforehand?

>> No.7428578

>>7428562
>But aluminium has a ridiculously low melting point? You would have to pull off some thermal wizardry to keep it from melting.
Regenerative cooling, with curtain cooling. You can't let most coolants get too hot either. Kerosene will coke, hydrogen peroxide or MMH will exothermically decompose and possibly detonate. Only hydrogen and ammonia really respond well to high temperatures.

>> No.7428581

>>7428141
>you want to feel special
different from you is not "special"

>> No.7428599
File: 45 KB, 733x660, idea.jpg [View same] [iqdb] [saucenao] [google]
7428599

>>7428410
Ok guys what about this idea? No solid parts actually touch the exhaust therefore you could make it out of plastic even. the supersonic flow into the intake might cause problems though.

>> No.7428600

>>7428562
>With aerospikes can you do the combustion on the spike or does it have to be done in a CC beforehand?
That's a question of scale, but for smaller engines, you certainly need a combustion chamber.

The larger your engine, the less you need a real combustion chamber. The F-1 of the Saturn V had a "thrust chamber" that didn't really neck down, like it's just a deep dent in the nozzle. An even bigger engine could just inject fuel directly into a parabolic nozzle.

It's a question of how far the mixture will travel before being reasonably completely combusted. The neck between nozzle and combustion chamber is there to slow the mixture's escape, to ensure that combustion happens in the engine. The smaller the engine, the deeper the combustion chamber and the tighter the neck needs to be, to keep the fuel from just squirting out and burning out where it contributes little to the thrust.

>> No.7428622
File: 354 KB, 1184x825, aluminium foam.jpg [View same] [iqdb] [saucenao] [google]
7428622

>>7428578
There's metal foam maybe that would be a good idea to use as a heat exchanger. It is notorious for being difficult to manufacture but seeing as we're lost wax casting aluminium from a 3D print it won't be hard in this case. Run the fuel through this and it'll cool like a motherfucker.

>> No.7428806

>>7427774
people have tried using balloons to get near the upper layers of the atmosphere. The problem is, the balloons have to pop due to diminishing air pressure. would it be possible to slowly "leak" helium out of the balloon at regular intervals to ensure that the pressure difference is relatively small and prevent rupture of balloon?

>> No.7428844

>>7428806
Even so once the atmosphere ends your balloon fun ends.

>> No.7428911

>>7428806
Sounds feasible, but it probably won't get you a whole lot of additional altitude. It will probably help the balloon stabilize near peak altitude though, and it could also allow you to add excess gas to the balloon for faster initial ascent without compromising burst altitude.
>>7428844
>Implying the atmosphere "ends"

>> No.7428920

>>7428844
https://www.youtube.com/watch?v=9h8IhrVP3iI

>> No.7428927

>>7427160
>Maybe, but there's no such thing as a tested and proven ablatively-cooled rocket engine.
Sure there is. Reloadable solid motors are a thing. Sure, you have to replace the lining and possibly the throat, but with enough trials and good QA you can establish good repeatability.
>SpaceX started out trying to do Merlin 1 with ablative cooling, but their pintle injector focused heat and pressure on a particular ring, and burned through the ablative coat faster than the rest.
So add more/thicker ablator in that area, problem solved.
>They switched to regenerative cooling partly because of that
Partly. Bear in mind, reusability has always been a big part of SpaceX's game plan.
>>7428562
>You would have to pull off some thermal wizardry to keep it from melting.
A B L A T I O N
Seriously. At the amateur level it's really the only way to go.

>> No.7429084

>>7428927
reeee i mentioned 2 cooling methods for amateurs (metal foam heat exchanger and air curtains) and nobody replied

>> No.7429183

>>7428927
>>Maybe, but there's no such thing as a tested and proven ablatively-cooled rocket engine.
>Sure there is. Reloadable solid motors are a thing. Sure, you have to replace the lining and possibly the throat
That's a tested and proven shell of a rocket engine. An essential functional part is new and hasn't been tested.

It's possible to get your process down so testing is unnecessary and you have near-perfect reliability without it, but that takes a LOT of testing and extremely disciplined process control.

>> No.7429191

>>7429084
What, do you want mom to put your crayon drawings on her fridge?

Why on Earth would a metal foam be good for a heat exchanger? That's exactly the opposite of what you want.

The "air curtains", in the first place, would only work in the air, and in the second place, would only work at speed, and in the third place, wouldn't work very well. You're suggesting a shittier ramjet, not a rocket. There are air-augmented rockets, but they don't depend on airflow (at least in principle, they're just enhanced when it's there.

>> No.7429735

>>7429191
>Why on Earth would a metal foam be good for a heat exchanger?
Please tell me your not serious.

>> No.7429756

>>7429735
>I don't have any answer to your objection, so I hope by being scornful, I can fool some people into thinking I haven't said something dumb.

>> No.7429768
File: 182 KB, 1735x688, fucking retard fucking off yourself.jpg [View same] [iqdb] [saucenao] [google]
7429768

>>7429756
If you don't know why what you said was unbelievably fucking retarded then frankly you need Jesus.

>> No.7429814

>>7429768
>Wikipedia says there's "great potential" and I have no idea why or what sort of heat exchanger it would apply to, and think that someone having an opinion that something has potential means it works.
We're talking about rocket engines here. This wouldn't help at all.