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Newbie trying to learn

Noobton

By Noobton
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Noobton

Noobton

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Hi, I'm just rediscovering the game, I tried the demo a long while ago and didn't fully captured me but the adding of the campaign brought me back and I'm glad it did.

I played the vanilla campaign a little bit unlocking 7 tiers of tech, doing a few orbits and a landing on minmus, but really I was just slapping rockets until it gave me enough power to get there and add/remove parts until it worked, it is great fun but now I'm trying to understand what I'm doing.

I've read a lot but I still don't think I comprehend fully the mechanics of dV, TV, TWR and other basics; I installed deadly reentry an FAR, and with some modifications I can still do my old slap parts together to do what I want, but I'd like to be able to calculate with precision things like:

How much dV do I need to get to a circular 100k orbit, make a transfer to a higher 200k orbit and then come back?

What are good Rocket design principles? when should I use tailfins? what considerations should I keep in mind when building my stages (change of CoM with fuel depletion etc)? I've read in some post to keep my CoM away from CoL but others stating the contrary.

can anyone recommend any posts/websites/textbooks or videos? thanks for any help to all the forum community.

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austin4050

austin4050

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Well I am glad you found this game again! it is quite fun!! All of those question you have are really good (I do not even know most of them) although the use of tailfins should be used only on the lower stages that dont make it to the atmosphere after that you need RCS, so only use them on acent stages, nothing past that. I have never paid attention to my CoL and CoM when building rockets, only planes then you want the CoL as close to the CoM as possible someone correct me if I am wrong please. I would recommend the wiki for your dV maps this works wonders!!, any handy calcuation tools, and lastly scott manley helps a bunch too! I hope that helps you complete everything you are wanting too!!

Laugh a little it makes the 'splosions more awesome!

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Pecan

Pecan

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The Drawing Board: A library of tutorials and other useful information - Blogs - Kerbal Space Program Forum is the best place to start (and the link in my signature).

TWR (Thrust to Weight Ratio) is an easy concept and not really explained anywhere in particular - it's how much your Thrust can push you up compared to how much your Weight is pulling you down. It's just total-engine-thrust / total-vehicle-mass. If the figure is less than 1 gravity wins and you won't go to space today. At exactly 1 you can hover or maintain any upward velocity but can't accelerate upwards. Above 1 you can fly! Recommended launch TWR on Kerbin is usually 1.2+ so you can get through the dense lower atmosphere quickly. It's also below 2(ish) because otherwise you'll be wasting energy going too fast too soon.

deltaV is a tricky concept but comes down to something like (engine-efficiency * total-fuel) / total-mass. That is, quite sensibly, the more fuel you have and the more efficient your engines are the more energy you have but the heavier the whole ship is the harder it will be to move.

(The real equation is Tsiolkovsky's rocket equation)

EXACTLY calculating deltaV required to "get to a circular 100k orbit" is very difficult (read impossible in practice) because it depends so much on each individual rocket and precisely how you fly it through the atmosphere. It's fairly easy for vacuum-bodies, but not from Kerbin. Just accept the generally-accepted "about 4,500m/s" or look for numerous threads from people trying to work it out from first principles.

"TV" is not a phrase I recognise.

You should only use tailfins a) when you want to, B) when you need to.

Have a look at the tutorials section for everything else.

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Noobton

Noobton

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Thanks a lot for the answers, TV = Terminal Velocity (saw the Acronym somewhere in the forum)

I would recommend the wiki for your dV maps this works wonders!!, any handy calcuation tools, and lastly scott manley helps a bunch too! I hope that helps you complete everything you are wanting too!!

Do you know How much FAR affects these maps? it shouldn't affect the values outside the atmosphere. but to scape the different planets.

EXACTLY calculating deltaV required to "get to a circular 100k orbit" is very difficult (read impossible in practice) because it depends so much on each individual rocket and precisely how you fly it through the atmosphere. It's fairly easy for vacuum-bodies, but not from Kerbin. Just accept the generally-accepted "about 4,500m/s" or look for numerous threads from people trying to work it out from first principles.

I get this, but I'd like to have an expected consumption and then work out how efficient was the real maneuver, and part of my enjoyment comes from understanding how did people came up with this figure (yup, I'm a nerd).

I'll work with this number meanwhile.

I've been working my way slowly down the list on the drawing board so I might still have some answers in there.

You should only use tailfins a) when you want to, B) when you need to.

I've been doing that, but I'd like to be able to check my design and say ok if I add fins to this rocket it will help, not just the try and error approach I've been using ("let's add fins to this thing", "yup that helped", "nope let's see, what happen if I move it up a little bit, what if I use 2 instead of 4?"), it's still fun, I'd just like to understand why it works or doesn't

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SRV Ron

SRV Ron

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While using math, charts, Delta V calculations, and the mod flight aids are good learning tools, the best learning tool of them all is the Kerbal School of Hard Knocks. (Just slap something together and see what works or not. If it works, modify it to get it to work better. Learn how to do the orbital turn till you find a method that gives the best efficiently for orbit.)

Two early career Mun orbiters.

GO5zTmR.jpg

A very unconventional and very Kerbal lander.

MP3bFwS.jpg

Try one thing at a time and enjoy your success. (Or catastrophic failures.)

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Taki117

Taki117

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TV (terminal Velocity) is the point at which the drag of your rocket is equal to the acceleration due to gravity. This is a very good number to be at because it means that the effort put into fighting gravity is not wasted fighting air resistance. (at least in the Stock Game, if you hit TV with FAR you have issues)

FAR makes it easier to get into orbit from Kerbin by lowering the ammount of dV required to about 3200 m/s, if your rocket is well designed. Alos, if you are using FAR i reccomend getting Procedural Fairings (link not handy) as it will help a great deal. Another thing FAR does is allow you to liftoff with a lower TWR. Generally 1.4-1.6 (though you can go as low as 1.2 or as high as 2.4, neither are reccomended)

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qazsedcft

qazsedcft

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Hey, I'm new to KSP myself but I like to understand how stuff works too. I found this page http://www.braeunig.us/space/ to be useful for understanding orbital mechanics. But calculating the exact delta-v taking atmospheric effects into consideration is really complicated (in real life I would say extremely complicated but the KSP physics are quite simplified). Once you're out of the atmosphere it's much simpler so what I do is just take the empirical surface-to-orbit value and calculate how much extra I need to get where I want.

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