Flight Planning before launch

[Gravy]

Am i the only one that thinks that we should be able to set up maneuvers before the ship is in liftoff? It's too difficult to midflight decide your flight path and orbit the planet and things like that.

[HoloYolo]

Originally posted by Vladimir Put-it-in:

Am i the only one that thinks that we should be able to set up maneuvers before the ship is in liftoff? It's too difficult to midflight decide your flight path and orbit the planet and things like that.

Problem is, you haven't launched and therefore do not have a trajectory, which makes this impossible.

[Gravy]

It's impossible to plan out a flight before you're in the air? I don't see why that can't be a mechanic

[HoloYolo]

Originally posted by Vladimir Put-it-in:

It's impossible to plan out a flight before you're in the air? I don't see why that can't be a mechanic

Well, you would need an auto-planner and mechjeb does that, but you can't plan ahead.

[Syd Khaos]

Originally posted by Vladimir Put-it-in:

It's impossible to plan out a flight before you're in the air? I don't see why that can't be a mechanic

It can be a mechanic....so could true multiple body physics...so could real world aerodynamics....so could radiation, and heat.........and ALOT of other stuff......

But then youd need a super-computer on par with the rigs they use at NASA just to play KSP......

And you can PLAN a flight before hand as much as you want...you just cant EXECUTE that plan till your in flight. Not that many players complain about the time they have to adjust manuv nodes....and those that do have issues typicaly get a mod to assist with it.....like MechJeb2 or PerciseNode.

[BORDER OF PURGATORY]

Its not impossible.
You just need a really sophisticated auto pilot. You wouldn't be flying the vehicle because you wouldnt be able to do the manuvers as precise as the computer would, and as precise as you would need to be to get in the position for the next manuver.

[AlexMBrennan]

Thing is, I don't think the manoeuvre node system is entirely appropriate for the launch sequence - it works well enough for small changes changes in speed and relatively short burn times (afaik it assumes instanteneous changes in velocity) and doesn't take aerodynamics into account at all.

Of course all of that could be implemented, and you could add a plugin that switches between orbital manoeuvre mode, launch mode, atmospheric flight mode and julienne fries mode but I don't think this is realistically going to happen so I'd suggest to use existing tools (e.g. this http://alexmoon.github.io/ksp/) to plan the launch and put it in a circular orbit "by hand" instead of holding your breath for an all-in-one navigation solution.

[|8MM| Fatabi]

Originally posted by Khaos Gaming:

Originally posted by Vladimir Put-it-in:

It's impossible to plan out a flight before you're in the air? I don't see why that can't be a mechanic

It can be a mechanic....so could true multiple body physics...so could real world aerodynamics....so could radiation, and heat.........and ALOT of other stuff......

Funny thing is every single one you mentioned there has been implemented by mods:
True n-body physics: Principia
Real world aerodynamics: Ferram-Aerospace-Research
Radiation: Kerbalism
Heat: Real Heat
ALOT of other stuff: Realism Overhaul. LOL

Also Mechjeb 2 has ascent guidence/autopilot, but unfortunately no trajectory planning from ground. However you can specify quite a lot of stuff, like final eccentricity, AP, PE etc. so practically it is some sort of flight planning. If you are going for a parking orbit first it should work just fine, otherwise eyeballing is your best friend.

[AoD_lexandro]

Agreed. A pre-flight plan would be really great, and its not to tricky to implement in reality. All your doing is extending the node system to allow for a 0alt/0v starting point.

[Lystent]

Only problem I see a preflight plan from ksp encountering is atmospheric drag. But there is no atmospheric drag on either of Kerbin's moons, so it would make for a great system for a lander to to leave at exactly the right amount of burn at the right time.

[BORDER OF PURGATORY]

Originally posted by Lystent:

Only problem I see a preflight plan from ksp encountering is atmospheric drag. But there is no atmospheric drag on either of Kerbin's moons, so it would make for a great system for a lander to to leave at exactly the right amount of burn at the right time.

there is a mod that fixes this and calculates trajectory based on ship shape and size

[edorward]

Multiple node planning is pretty much dead from the get go because of how the game calculates dV in burns. The longer and more uneven the burn, the worse the error, no matter how accurately you fly. Compounding that issue over multiple burns and you'll end up getting nowhere fast.

[Lystent]

I like to plan ahead, so I use multiple nodes, but tweak the next one after each burn to repair it.

[Manwith Noname]

The main benefit I see of being able to plot something out before launch is to get an idea of the dV requirement.

While there is no in game dV reading for your craft, I suspect there will likely be no in game means to plot a journey before launch.

It's this kinda stuck in the middle thing KSP does. On one side it wants you to just wing it, on the other it wants you to play the game by numbers.

[RoofCat]

well, nodes only show theoretical delta v. And so does KER.
Without atmosphere drag math, burning off the perfect node spot by sin(some°) because it is never a single impulse burn, etc. That all is rather advanced math and putting that in game may scare off a lot of people.
Making the game itself to compute it all in detail in advance and also execute the plan (so no manual error is introduced!) basically turns the game into adjustable screensaver.

So kind of yes, but no. Life is complicated

[Manwith Noname]

Originally posted by RoofCat:

well, nodes only show theoretical delta v. And so does KER.

Totally. I personally wouldn't expect flight planning from ground to be exactly what was required. Like KER, manual math or simple rule of thumb approximations, I don't see the reason for wanting this as it being 100% accurate and depending on those numbers completely. They're more ball park so you have an idea of if you can reasonably expect to achieve those things or not. Same with dV maps available around the internet. You don't see a number on them and build to that exactly, you allow for error and a comfort zone.

Originally posted by RoofCat:

Making the game itself to compute it all in detail in advance and also execute the plan (so no manual error is introduced!) basically turns the game into adjustable screensaver.

I don't think the main point of wanting a system that allows you to plot out a mission is to automate it completely. It might be what some people want in some cases but I can certainly see a case for pre planning something so you know roughly what will be required from the craft you are going to build without multiple trial and error attempts or sources of information outside the game.

Trial and error is fine for missions close to home but it can become tiresome for certain more difficult voyages as the time between those potential errors increases. Note, that is "can". Some people might like failing repeatedly.