The Rocket Maths Spreadsheet

Horus Lupercal

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#1
I'd say it's a little spreadsheet, but I'd be lying. Essentially my attempt at rocket maths made easy(er).


Screenshot_2018-12-06-00-10-38.png

The bottom line up front, the main master sheet allows you to enter the constituent components of a build and it spits out the data you need. Dry, wet mass, TWR, Dv, burn times, combined ISP, thrust and consumption of engines (regardless of number and combination), electric data (how much you generate, store and consume). It is separated into groups allowing you to look at up to 3 separate stages, a payload and boosters and will total them up for you as well.

Screenshot_2018-12-06-00-12-21.png


There's a theory numbers page that allows you to plan the engine section of your builds without the big main sheet. You place the details in the green area, it gives you hard data.
There's a bit under it as well that allows you to see its mass, speed and distance from launch against time. Useless, but makes a cool graph or 2.

Screenshot_2018-12-06-00-12-31.png

Screenshot_2018-12-06-00-12-34.png

Screenshot_2018-12-06-00-12-39.png


These pages are for saving your builds so you can copy and paste them into the sheets, saves you re-entering them over and again.

Screenshot_2018-12-06-00-11-27.png


Lastly, there is an incomplete celestial body data page which I left in. It has all the extended Sol System bodies and some funnies as well I've seen in mods. The intent was a sort of nav system where you input your location (peri/apo in the relevant body SOI), input where you want to go and it would spit out the Dv requirements. Needs a lot more work on that side though.


I'm infantry, which means my legs have to be long otherwise my knuckle drag and thus the sheet is my work, however all the maths is from other sources so acknowledgements go out to google, Scott Manley for the calculations page and Altair for the celestial data maths stuff. All I've done is collate their brains for us mortals.
 

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Altaïr

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#2
Wow, amazing work!
Can't remember when I shared that kind of calculations, but thanks for the credits and your work anyway :)
 

Zeeray13

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#3
I'd say it's a little spreadsheet, but I'd be lying. Essentially my attempt at rocket maths made easy(er).


View attachment 10134
The bottom line up front, the main master sheet allows you to enter the constituent components of a build and it spits out the data you need. Dry, wet mass, TWR, Dv, burn times, combined ISP, thrust and consumption of engines (regardless of number and combination), electric data (how much you generate, store and consume). It is separated into groups allowing you to look at up to 3 separate stages, a payload and boosters and will total them up for you as well.

View attachment 10135

There's a theory numbers page that allows you to plan the engine section of your builds without the big main sheet. You place the details in the green area, it gives you hard data.
There's a bit under it as well that allows you to see its mass, speed and distance from launch against time. Useless, but makes a cool graph or 2.

View attachment 10136
View attachment 10137
View attachment 10138

These pages are for saving your builds so you can copy and paste them into the sheets, saves you re-entering them over and again.

View attachment 10139

Lastly, there is an incomplete celestial body data page which I left in. It has all the extended Sol System bodies and some funnies as well I've seen in mods. The intent was a sort of nav system where you input your location (peri/apo in the relevant body SOI), input where you want to go and it would spit out the Dv requirements. Needs a lot more work on that side though.


I'm infantry, which means my legs have to be long otherwise my knuckle drag and thus the sheet is my work, however all the maths is from other sources so acknowledgements go out to google, Scott Manley for the calculations page and Altair for the celestial data maths stuff. All I've done is collate their brains for us mortals.
Thats really good!
 

Horus Lupercal

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Altaïr

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#5

Horus Lupercal

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#6
Feel free to pick holes in it as well, there's a lot of cells going in weird directions and I know I've messed up somewhere or something is in the wrong place
 

Altaïr

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Feel free to pick holes in it as well, there's a lot of cells going in weird directions and I know I've messed up somewhere or something is in the wrong place
I'll have a look when I have time.
About your navigation system, the idea is interesting. I can imagine an algorithm to do that, but it will be hard to make it work under a spreadsheet. :rolleyes:
Personally I have a spreadsheet with all planet data, and a dedicated sheet to make all basic calculations. That way, I can calculate in a few steps the cost of a transfer from XXX to YYY.
Actually I even imagined a deltaV map that could give you all possible transfers cost, even including bi-elliptic transfers, but because there are so much possibilities, the map is very confusing in the end. I proposed such a map recently, but it didn't have a lot of success, so I finally did a more conventional map :)
 

Horus Lupercal

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I'll have a look when I have time.
About your navigation system, the idea is interesting. I can imagine an algorithm to do that, but it will be hard to make it work under a spreadsheet. :rolleyes:
Personally I have a spreadsheet with all planet data, and a dedicated sheet to make all basic calculations. That way, I can calculate in a few steps the cost of a transfer from XXX to YYY.
Actually I even imagined a deltaV map that could give you all possible transfers cost, even including bi-elliptic transfers, but because there are so much possibilities, the map is very confusing in the end. I proposed such a map recently, but it didn't have a lot of success, so I finally did a more conventional map :)
Yeah, that's what I'm going for. Something that will take your exact postion into account (rather than say just 'Earth SOI) and an end state at a specific orbit at a set distance from another body in very much the way how you explained in that link I sent last night but it does all the paper maths automatically in a list at the left of a page.

I've seen the 'basic' Delta v map you created as well. Ho-ly balls. On the plus side, at least this game is 2D, imagine planning this for a 3D system
 

Altaïr

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#9
Yeah, that's what I'm going for. Something that will take your exact postion into account (rather than say just 'Earth SOI) and an end state at a specific orbit at a set distance from another body in very much the way how you explained in that link I sent last night but it does all the paper maths automatically in a list at the left of a page.

I've seen the 'basic' Delta v map you created as well. Ho-ly balls. On the plus side, at least this game is 2D, imagine planning this for a 3D system
Haha, yes! And planet orbits are not even elliptical! This is so much more complicated in real life :p
 

Horus Lupercal

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#12
Im jealous that you have the time and effort todo something like this, good work man
Ha don't be. That sheet and dry drilling a new holster draw and grip represent 4 months working abroad with no supervision and no tasks bored out of my mind haha
 
#17
I'd say it's a little spreadsheet, but I'd be lying. Essentially my attempt at rocket maths made easy(er).


View attachment 10134
The bottom line up front, the main master sheet allows you to enter the constituent components of a build and it spits out the data you need. Dry, wet mass, TWR, Dv, burn times, combined ISP, thrust and consumption of engines (regardless of number and combination), electric data (how much you generate, store and consume). It is separated into groups allowing you to look at up to 3 separate stages, a payload and boosters and will total them up for you as well.

View attachment 10135

There's a theory numbers page that allows you to plan the engine section of your builds without the big main sheet. You place the details in the green area, it gives you hard data.
There's a bit under it as well that allows you to see its mass, speed and distance from launch against time. Useless, but makes a cool graph or 2.

View attachment 10136
View attachment 10137
View attachment 10138

These pages are for saving your builds so you can copy and paste them into the sheets, saves you re-entering them over and again.

View attachment 10139

Lastly, there is an incomplete celestial body data page which I left in. It has all the extended Sol System bodies and some funnies as well I've seen in mods. The intent was a sort of nav system where you input your location (peri/apo in the relevant body SOI), input where you want to go and it would spit out the Dv requirements. Needs a lot more work on that side though.


I'm infantry, which means my legs have to be long otherwise my knuckle drag and thus the sheet is my work, however all the maths is from other sources so acknowledgements go out to google, Scott Manley for the calculations page and Altair for the celestial data maths stuff. All I've done is collate their brains for us mortals.
This is really impressive, and I wish I had looked for it sooner. I ended up transcribing most of the celestial data from a screenshot you sent, and used that in some of my math. Well, I don't actually have excel on this computer, so I can't actually open this. May I suggest that you put the spreadsheet into a google doc, so that it is available for anyone to use and improve? A community spreadsheet may help collaboration.

I made a google doc with some of the planetary data in yours, and added a fun little Oberth calculator at the bottom. Here's the link:

https://docs.google.com/spreadsheets/d/1WSoudiHAexfhdcruKXq1czMNloii5gqBim_LYS-1oPc/edit?usp=sharing
 

Horus Lupercal

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#21
This is really impressive, and I wish I had looked for it sooner. I ended up transcribing most of the celestial data from a screenshot you sent, and used that in some of my math. Well, I don't actually have excel on this computer, so I can't actually open this. May I suggest that you put the spreadsheet into a google doc, so that it is available for anyone to use and improve? A community spreadsheet may help collaboration.

I made a google doc with some of the planetary data in yours, and added a fun little Oberth calculator at the bottom. Here's the link:

https://docs.google.com/spreadsheets/d/1WSoudiHAexfhdcruKXq1czMNloii5gqBim_LYS-1oPc/edit?usp=sharing
Did you manage to open it in docs?

That's why I posted it, I created it for the intention of making it open source to help people like me who aren't engineers or working on actual programs but still have an interest in the deeper side of throwing weight into orbit.

I may pick your brains on the Oberth and slingshot maths and add it to the spreadsheet. I'd already started something similar but need someone who actually understands it all to hold my hand...
 

Horus Lupercal

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#22
Right, update time for the old headache sheet.

It has all the usual refinements 007, but with some added shiney (spelling intentional) new bits.

Screenshot_2019-03-13-17-43-05.png


Firstly, all the engines data has been made more accurate than the in game help guide. The changes are minor and mostly a bit more ISP and thrust because of how things are worked out in-game

Screenshot_2019-03-13-17-41-46.png


The table has been tidied up loads. All the formulas work and point to the right places.
They are set up to account for changes in performance in flight as and when the rocket changes. So when the boosters drop or a stage drops, it works out when they'll go, how much fuel is left in the current burning stage, new thrust, ISP, dv, TWR etc.
I've got 3 different pages for 3 different styles of burn out, one for the classic 'booster drops first' configuration most rockets use, another for 'stage one goes before the boosters' set up, like my Ark or the Fireball series of rockets where the boosters burn pretty much throughout the flight and it's stage one that goes first. And also a bespoke one for the newer design of ultra-heavy lifters (Pandora/Komodo) with multiple build screens of identical engine sections stacked on top of each other to create each single stage.
As such, it comes with a multiply number at the top of each build section (highlighted green). If you have 2 large boosters, then apply the parts for one booster, change the multiplier to 2 and it will double everything for you on the output table. If you have 4 stage ones stacked onto each other burning simultaneously, again apply one stage build to the sheet, change the multiplier and it will account for them all for you.
That only really works if all the sections in that stage are identical. If you're using different sections in one stage (like my Komodo) then the bottom set of sections become the 'base' and the rest of that stage are the 'stage'. Make the base the thirstier/higher thrust part and it will account for that dropping off first.

Screenshot_2019-03-13-17-42-32.png


After all last night and this morning banging my head trying to understand google or reverse engineer some KSP orbit calculator, I went for the easy option and asked Grand Master g to unruin my life.
As such (in response to Zoddmarks question), I've put together a hideously easy to use resonance orbit calculator for anyone doing his sat network challenges.

Yes, I know there's a lot of Dividing By Zero going on, I'm not trying to break physics it just needs data to come alive.

Again, the whole sheet is made as Infantry proof as possible. You put your numbers in the green areas and leave the white bits alone.
So, when you want to work out your resonance orbit, you put your required orbit in the green Ra/Rp box, how many satellites you want to upload and how often you want to cross paths with the satellite orbit per rotation when you're delivering. It will spit out the orbit the bus needs to be in and the elliptical orbit speeds of the intended satellite orbit and the bus resonance orbit.

Again, big thanks to the Forums resident tame rocket scientist.
Some say that if you say Delta v in the mirror 3 times, he'll appear orbiting around you and that he came second in a competition to drive a Telsa to Mars.

All we know is, he's called @Altaïr...
 

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Altaïr

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#23
Nice, this will come in handy :)
Haha, that will be a huge task if I have to come and orbit around anybody that pronounces 3 times "delta-V" in front of his mirror. Please, just avoid to do it between 23:00 PM and 7:00 AM (french hour) :p
 
#24
That is so much prettier than my spreadsheet :p

Man, just saw this thread now and I'm impressed. I'm sure a lot of people here have dv spreadsheets but this takes it up a notch.

The isp accuracy is interesting. Probably wont drastically change current dv calculations but still really neat.
 

Horus Lupercal

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#25
The isp accuracy is interesting. Probably wont drastically change current dv calculations but still really neat.
Yeah, it came from Altairs experiments on delta v with drag and gravity off. He discovered what he was getting on paper and what was appearing in game were slight different. Turns out that even though Earth g is 9.8 when it comes to TWR, when the system works out thrust during launch it rounds up g to 10, making the ISP and thrust ever so slightly off against the stated tooltip. He checked the fuel consumption (which is correct) and worked out the ISP from there.

We talked about it (he talked, I pinned my ears back and listened) whilst I was re-designing the sheets to help with my re-design of the Ark II/III and make things more accurate rather than the in flight guess work with stages and boosters coming off all over the place.

That also meant stumbling on a much easier way to calculate combined ISP on multi engine builds, rather than using the hideously complex total engine Force / Every engines F/Isp added together I was using originally (and still using on the calculation page) to work out a potentially infinite variety of engine combinations, to a dumb simple overall force / (9.8 * overall fuel consumption) and getting the same answer.