Some future update mod ideas/wishlist

[8BitCosmonaut]

This little project of mine is to find out the stuff I need to find an altitude compensated delta velocity value. Yes it may look ludicrous, but it may actually help us understand which launch vehicle of specific fuel types are the most efficient under specific conditions. For example a 100 ton to LEO heavy lift rocket using highly efficient but low density hydrogen fuel may be less efficient overall, compared to a heavy lift rocket with the same capability but burning less efficient but high density fossil/alkane/hypergolic fuel.

The Soviets were aware of this problem, which was why they implemented this phenomena into the design of the MAKS spaceplane. This is not just any spaceplane, the engine it uses is a tripropellant RD-701, where it exploits the higher thrust and mass ratio efficiency of the denser RP-1 fuel under atmospheric conditions, and switch to burning the higher efficiency LH2/LOX once it reaches space towards orbital velocity.

 

[8BitCosmonaut]

Not to say it's not worth doing, but you're going to need some computer action to help you out there especially if you're doing this in a real world setting.

I strongly agree that we have to use computer aided systems to achieve the greatest accuracy in such fields. There are just too many values to work with, and I am just digging them all up to show all the players the real deal of rocket engineering.

 

[Altaïr]

Yeah, mainly pressure. About the free stream pressure, it is most likely the air pressure of a specific altitude the rocket is in. The basic delta velocity equation in my opinion is only fully reliable under prefect vacuum conditions.

But what do you mean by "relevant to talk about delta-V when the launcher is still in the atmosphere"? The delta V budget is spent throughout the entire burn time, so that means from surface to orbit no matter the atmospheric conditions, its just that calculating for atmospheric conditions compensation for delta V gain are far more complicated.

Ok, thanks for the precision.
What I meant is that in atmospheric and suborbital flight, there are losses due to atmospheric drag and "gravity drag", so spending 100 m/s doesn't actually increases your speed by 100 m/s. I understand your reasoning in terms of delta-V losses, but in the end this becomes quite abstract in those conditions...
The performance of a launcher will depend a lot on the TWR in the beginning (gravity is still the biggest obstacle).

 

[8BitCosmonaut]

Ok, thanks for the precision.
What I meant is that in atmospheric and suborbital flight, there are losses due to atmospheric drag and "gravity drag", so spending 100 m/s doesn't actually increases your speed by 100 m/s. I understand your reasoning in terms of delta-V losses, but in the end this becomes quite abstract in those conditions...
The performance of a launcher will depend a lot on the TWR in the beginning (gravity is still the biggest obstacle).

At this stage for me, these are pretty obvious factors. Right now I am asking everyone about the exact gains and losses of delta V due to thrust and efficiency change over altitude but no one can give me a direct answer, so far the only answer I have from this site is the word "abstract", so I might as well find out myself.

Big boys like us already know that drag and gravity are the biggest contenders in delta V loss, efficiency/thrust gain on the other hand is still a mystery, and I am very close to getting my answer.

"if you won't let me buy a gun, I'll build one!"

 

[TtTOtW]

Finding the area under a pressure-altitude graph won't get us anything officially usable

That there is the difference between us and Einstein.

 

[BANDWITH]

We need cool animations before launching and after recovering.

 

[Danny Batten]

We need cool animations before launching and after recovering.

Definitely

 

[8BitCosmonaut]

At this stage for me, these are pretty obvious factors. Right now I am asking everyone about the exact gains and losses of delta V due to thrust and efficiency change over altitude but no one can give me a direct answer, so far the only answer I have from this site is the word "abstract", so I might as well find out myself.

Big boys like us already know that drag and gravity are the biggest contenders in delta V loss, efficiency/thrust gain on the other hand is still a mystery, and I am very close to getting my answer.

"if you won't let me buy a gun, I'll build one!"

Alright, I have attempted on making the graph, but I am still short on one thing, the acceleration with reducing mass and increasing thrust. I'll try to get that done by tomorrow, I need some sleep.

 

[8BitCosmonaut]

We need cool animations before launching and after recovering.

hey! I have an idea for this! Gimme a minute.

 

[TtTOtW]

hey! I have an idea for this! Gimme a minute.

Oh no...

 

[BANDWITH]

Ballons! You could put floating platforms in Venus' atmosphere, and never have to leave the comfort of the clouds.

 

[Horus Lupercal]

At this stage for me, these are pretty obvious factors. Right now I am asking everyone about the exact gains and losses of delta V due to thrust and efficiency change over altitude but no one can give me a direct answer, so far the only answer I have from this site is the word "abstract", so I might as well find out myself.

Big boys like us already know that drag and gravity are the biggest contenders in delta V loss, efficiency/thrust gain on the other hand is still a mystery, and I am very close to getting my answer.

"if you won't let me buy a gun, I'll build one!"

I think that if you're going to make a catch all Dv system you're going to need to map air pressure from sea level to vacuum so you can work that against the drag co-eff of your launch vehicle.
Factor in weather effects on air pressure and density.
Then work out how that decrease in air pressure is going to affect either your ISP or thrust. As long as you have one you can work out the other.
Then you can figure out your TWR based upon fuel consp/weight and updated thrust value over time. That allows you to work out your theoretical acceleration against your drag value to work out the actual acceleration.
Then maybe (Altair can hammer me for this) factor in the changes in gravity as you get further from Earth. I know Dv only uses gravity as a constant so I'm not on about that but surely as gravity gets lower, the craft becomes 'lighter' and thus accelerates faster?
Then you'll have a continuously updated ISP for the continuously being updated Dv working alongside a continuously updated TWR for your drag model to fight against throughout your flight profile.

Or you've already worked it all out and I can just shut my dirty whorish mouth...

 

[8BitCosmonaut]

I think that if you're going to make a catch all Dv system you're going to need to map air pressure from sea level to vacuum so you can work that against the drag co-eff of your launch vehicle.
Factor in weather effects on air pressure and density.
Then work out how that decrease in air pressure is going to affect either your ISP or thrust. As long as you have one you can work out the other.
Then you can figure out your TWR based upon fuel consp/weight and updated thrust value over time. That allows you to work out your theoretical acceleration against your drag value to work out the actual acceleration.
Then maybe (Altair can hammer me for this) factor in the changes in gravity as you get further from Earth. I know Dv only uses gravity as a constant so I'm not on about that but surely as gravity gets lower, the craft becomes 'lighter' and thus accelerates faster?
Then you'll have a continuously updated ISP for the continuously being updated Dv working alongside a continuously updated TWR for your drag model to fight against throughout your flight profile.

Or you've already worked it all out and I can just shut my dirty whorish mouth...

I know what to do for know, I just need to figure out the acceleration.

 

[8BitCosmonaut]

hey! I have an idea for this! Gimme a minute.

If the player chooses American launch sites, their rockets will be anchored against a procedural tower and will roll out a VAB via a crawler nose up. it will dock with the launch pad and the crawler will return back to the VAB.



If the player chooses Russian launch sites, their rockets will show up sideways on a procedural railcar and roll out to a launch pad, the railcar will tilt the rocket to the nose up position and return to the VAB once done.

of course the players can skip this animation by time warping.

 

[Altaïr]

If the player chooses American launch sites, their rockets will be anchored against a procedural tower and will roll out a VAB via a crawler nose up. it will dock with the launch pad and the crawler will return back to the VAB.
View attachment 14443
View attachment 14447

If the player chooses Russian launch sites, their rockets will show up sideways on a procedural railcar and roll out to a launch pad, the railcar will tilt the rocket to the nose up position and return to the VAB once done.
View attachment 14444
View attachment 14448
of course the players can skip this animation by time warping.

Nice idea, though it should not be Stef priority. But people would still ruin the realism by doing pad assembly

 

[Lt. Snakestrike]

Nice idea, though it should not be Stef priority. But people would still ruin the realism by doing pad assembly

Hehehe

 

[8BitCosmonaut]

Nice idea, though it should not be Stef priority. But people would still ruin the realism by doing pad assembly

Since when did any of these ideas claim to be of any priority? They are ideas, not a to-do list. Anyways there shouldn't be a limit to the build space in the first place, this was why players turned to pad assembly.

This was also a response to an idea I liked on this post.

 

[Horus Lupercal]

Anyways there shouldn't be a limit to the build space in the first place, this was why players turned to pad assembly.

I think a limited build screen is almost a requirement for sanity. It limits you to something a bit more realistic as without those limits, you'd never know when to stop.

And I say that as someone who would love a bigger build screen and habitually builds monsters on the pad and but I know no build screen will ever be big enough for my designs.

Absolutely need a crawler/building/rail system to transport launch vehicles to and from. Maybe a much, much bigger launch area to go with a larger build screen to make creating a crawler worth while

 

[Blazer Ayanami]

Since when did any of these ideas claim to be of any priority? They are ideas, not a to-do list. Anyways there shouldn't be a limit to the build space in the first place, this was why players turned to pad assembly.

This was also a response to an idea I liked on this post.

The limited build space is to make challenges harder.

 

[TtTOtW]

It also limits the amount of strain you can add to your CPU and RAM at any given time...

 

[8BitCosmonaut]

I think a limited build screen is almost a requirement for sanity. It limits you to something a bit more realistic as without those limits, you'd never know when to stop.

And I say that as someone who would love a bigger build screen and habitually builds monsters on the pad and but I know no build screen will ever be big enough for my designs.

Absolutely need a crawler/building/rail system to transport launch vehicles to and from. Maybe a much, much bigger launch area to go with a larger build screen to make creating a crawler worth while

RSS/RO players love to use the boundary breaker mod where the build width and height are removed, since IRL rockets are far larger than the vanilla build space can handle.

 

[TtTOtW]

DLC build space is 18m wide. That's no problem. But it is only 65.5m high. A whole 45m less than the tallest rocket to date.

 

[8BitCosmonaut]

The limited build space is to make challenges harder.

Nah, I find it a hindrance, there was a reason NASA built the Saturn V's personal VAB, to accommodate its larger than usual size. If they can do this IRL why can't we?

 

[8BitCosmonaut]

It also limits the amount of strain you can add to your CPU and RAM at any given time...

There is a way around this, I call this the Minecraft Chunk Loader method, whereby the game will only add build space when you need it and load only what you are looking at, they can also reduce the quality of the load when the load size increases to compensate for a balanced framerate.

Kinda like how gasoline generators increase the power of the engine by injecting more fuel whenever the output load increases, in order to maintain a balanced output frequency.

 

[TtTOtW]

Yes, but the build space is not the problem. It is the impact on your autosave file that is at stake here.