[1.0.5] GravityTurn version 1.3.1 - Automated Efficient Launches (1.1 pre-release available)

[mcirish3]

5 minutes ago, Thorbane said:

Why does the info window say I'm experiencing souposphere levels of drag?  I'm running FAR, and the drag calculation is off by over a factor of 4.

I could be wrong but I don't think this mod is configured to support FAR.

[langer]

One more thing. The mod seems doing a lot of calculation when not launching (e.g. staying on the surface), which causes a lot of CPU usage and some game lagging.

[Deimos Rast]

Been playing with this for a little bit now, and a couple of point:

- First, as someone who is rather new to KSP and doesn't really know which way is up or down, thank you for including basic explanations next to each number, big help, and a first I've seen in almost any mod.

- Second, I preface this by saying I know nothing about efficient ascent curves, but it seems I stay in the atmosphere too long. I'll be honest, I don't get the math behind it, but what I do understand is that the air friction from such sustain periods in the atmosphere causes my newbie solar panels (and attached parts, namely my Mk1 capsule) to reach 50-70% critical temperatures, according to KER and glow red hot. Granted, I do have both FAR and Deadly Reentry installed, neither of which you have stated are supported, so, I'll attribute it to that. Likewise, I was always under the impression it was best to escape the atmosphere as soon as possible, but I get the impression from this thread your mod is designed (and gravity turns in general) to let Kerbin's rotation and gravity do a lot of the heavy lifting for you. And also to minimize air drag, which I noticed from the readouts seems to stay near or at a constant zero.

- Third, this mod can stretch a tank of gas. Like, a lot.

- Fourth, not to mention the competition, but maybe something that tells you what the mod is doing every step of the way? At some points it just seems to be sitting there tooting my engine and I wonder if its hung up or coasting. Also, maybe a limited Time Acceleration to edge of atmosphere, because some of these shallow ascents take a while to get there.

Up till now I've been using Mech Jeb's Ascent Tool, but I'm always will to try new mods. Especially since your's has time to ApA...not that I know what that means (I think it's the rate/shallowness of your ascent profile?), but it's something new to play around with while I try not to blow up.

Anyway, enjoying the mod; does what it says on the tin, main issues so far are user error

Cheers.

[DStaal]

4 hours ago, Deimos Rast said:

Been playing with this for a little bit now, and a couple of point:

- First, as someone who is rather new to KSP and doesn't really know which way is up or down, thank you for including basic explanations next to each number, big help, and a first I've seen in almost any mod.

- Second, I preface this by saying I know nothing about efficient ascent curves, but it seems I stay in the atmosphere too long. I'll be honest, I don't get the math behind it, but what I do understand is that the air friction from such sustain periods in the atmosphere causes my newbie solar panels (and attached parts, namely my Mk1 capsule) to reach 50-70% critical temperatures, according to KER and glow red hot. Granted, I do have both FAR and Deadly Reentry installed, neither of which you have stated are supported, so, I'll attribute it to that. Likewise, I was always under the impression it was best to escape the atmosphere as soon as possible, but I get the impression from this thread your mod is designed (and gravity turns in general) to let Kerbin's rotation and gravity do a lot of the heavy lifting for you. And also to minimize air drag, which I noticed from the readouts seems to stay near or at a constant zero.

Air drag and heat are what fairings are for.    But yeah, in general escaping the atmosphere isn't the biggest problem with getting to orbit.  A straight-up launch to vacuum can be done for a lot less fuel than actually getting to orbit: It only takes a few hundred delta-v, really.  But you need around 2,500 m/s of sideways delta-v to convert that to an orbit, instead of just falling back down.  This mod attempts to get as much of that sideways delta-v as possible from gravity, without using fuel.  Despite the flames shooting from the front of your craft, once you're a few kilometers up the air is fairly thin, so air drag is minimal.  (Which you are seeing.)

Short version: instead of an 'L' shaped launch, (to the top of the atmosphere, and then over), this mod attempts a curve to the edge of the atmosphere.  Which means you stay in the atmosphere longer, but you're spending less fuel to get to where you're going.

4 hours ago, Deimos Rast said:

- Fourth, not to mention the competition, but maybe something that tells you what the mod is doing every step of the way? At some points it just seems to be sitting there tooting my engine and I wonder if its hung up or coasting. Also, maybe a limited Time Acceleration to edge of atmosphere, because some of these shallow ascents take a while to get there.

Up till now I've been using Mech Jeb's Ascent Tool, but I'm always will to try new mods. Especially since your's has time to ApA...not that I know what that means (I think it's the rate/shallowness of your ascent profile?), but it's something new to play around with while I try not to blow up.

Anyway, enjoying the mod; does what it says on the tin, main issues so far are user error

Cheers.

Time to apsis is how this mod works.  If you install a mod to let you see what your current apsis is, this mod will hold that number fairly steady during the entire ascent.  (Apsis/apoapsis being the 'highest' point of your current orbit - the point where you are furthest from the surface of the planet you are orbiting.  So with the normal settings using this mod, if during your launch you cut the engines and coasted, it would take about 40s before you actually started to fall down.  It basically continues to hold that until the highest point is your desired orbit altitude - though with most rockets there comes a point in the later stage of the launch where if you're keeping the engine on at all, it'll push the time to apsis out to later and later - that's what's happening during the coast: The apsis is already at your desired height, and the short bursts of thrust are just to keep it there because air drag is pulling it down.)

[Deimos Rast]

4 hours ago, DStaal said:

Air drag and heat are what fairings are for.    But yeah, in general escaping the atmosphere isn't the biggest problem with getting to orbit.  A straight-up launch to vacuum can be done for a lot less fuel than actually getting to orbit: It only takes a few hundred delta-v, really.  But you need around 2,500 m/s of sideways delta-v to convert that to an orbit, instead of just falling back down.  This mod attempts to get as much of that sideways delta-v as possible from gravity, without using fuel.  Despite the flames shooting from the front of your craft, once you're a few kilometers up the air is fairly thin, so air drag is minimal.  (Which you are seeing.)

 

2500m/s you say, I have work to do! The wiki states that it takes, under optimal situations, 4450–4700 m/s delta V to get into LKO. This mod just got my 3 seater tourist 'bus' (consisting of three Mk1 capsules bolted together) to a 80km LKO for 3,300 delta V (assuming I'm reading the 'total burn' right, and that number includes the follow up MJ circularization burn). Either way, in the editor, KER said the best I could hope for was 3,900 vacuum, so yeah.... This was with FAR and Deadly Re-Entry both installed.

I'm kind of impressed. Just a bit.

And thanks for the explanation. I'm getting the vague outline of an understanding, but all I know is that it works, and at the moment that's enough for me. Oh, and I had a fairing in an earlier ascent, but that kind of got melted (~70% critical, on normal).

Cheers.

[JAFO]

1 hour ago, Deimos Rast said:

2500m/s you say, I have work to do! The wiki states that it takes, under optimal situations, 4450–4700 m/s delta V to get into LKO. This mod just got my 3 seater tourist 'bus' (consisting of three Mk1 capsules bolted together) to a 80km LKO for 3,300 delta V (assuming I'm reading the 'total burn' right, and that number includes the follow up MJ circularization burn). Either way, in the editor, KER said the best I could hope for was 3,900 vacuum, so yeah.... This was with FAR and Deadly Re-Entry both installed.

I'm kind of impressed. Just a bit.

The wiki is way out of date. With 1.0.5, optimal ΔV to 80km LKO is 3400 m/s. The best I've seen GravityTurn achieve so far is 3106 m/s, including the final circularisation burn. So yes, I'm more than a little impressed myself.

 

(Oh yeah, the "total burn" figure supplied by GT does not include the MJ circularisation burn.. you'll need to add that to the figure supplied by GT to get the true total.)

Edited February 22, 2016 by JAFO

[Afterburner]

Hello Overengineer1

You made a great job with this invaluable mod which is really helpful! I just have a little suggestion: the orbit circularization should be optional when MechJeb is present, for two reasons:

1) you may want to set up your own maneuver node (not necessarily a circularization node) at apoapsis.

2) in career mode you can embark MechJeb on your vessel before its maneuver planer is enabled. In this case, Gravity Turn applies full throttle to your —totally uncontrollable— rocket!

[Deimos Rast]

15 hours ago, JAFO said:

The wiki is way out of date. With 1.0.5, optimal ΔV to 80km LKO is 3400 m/s. The best I've seen GravityTurn achieve so far is 3106 m/s, including the final circularisation burn. So yes, I'm more than a little impressed myself.

 

(Oh yeah, the "total burn" figure supplied by GT does not include the MJ circularisation burn.. you'll need to add that to the figure supplied by GT to get the true total.)

Ah, so my numbers are more in line with reality then. Still, considering what I would probably normally get, what I was flying, and the mods I had installed... And yeah, I know the total burn doesn't include circularization burn, which in the above example was only like 17 m/s iirc. And thanks for the link.

 

5 hours ago, Afterburner said:

Hello Overengineer1

You made a great job with this invaluable mod which is really helpful! I just have a little suggestion: the orbit circularization should be optional when MechJeb is present, for two reasons:

1) you may want to set up your own maneuver node (not necessarily a circularization node) at apoapsis.

2) in career mode you can embark MechJeb on your vessel before its maneuver planer is enabled. In this case, Gravity Turn applies full throttle to your —totally uncontrollable— rocket!

I know they talked about #2 in this thread already a few pages back and I'm pretty sure he added a check because to prevent that from happening (or maybe he never got around to it). Either way, it's been brought up before.

[DStaal]

That 2500 I gave was an estimate - and an estimate for what it would take for a ship somehow placed 80k up with no horizontal velocity versus an theoretical stationary Kerbin to achieve orbit.  As I said, it takes another few hundred m/s just to get it up there.    (And Kerbin is rotating, and you probably had some gravity effects, etc, all of which increase and decrease the amount of delta-v you get on the way, and how much you need to spend.)  So, yeah, that number's completely unrealistic for anything - it was just to give you some idea of what the scale of the different parts of the problem is.

[Miravlix]

[EXC 05:07:49.677] NullReferenceException: Object reference not set to an instance of an object
    GravityTurn.VesselState.ToggleRCSThrust (.Vessel vessel)
    GravityTurn.VesselState.Update (.Vessel vessel)
    GravityTurn.GravityTurner.FixedUpdate ()
[EXC 05:07:49.766] NullReferenceException: Object reference not set to an instance of an object
    GravityTurn.VesselState.ToggleRCSThrust (.Vessel vessel)
    GravityTurn.VesselState.Update (.Vessel vessel)
    GravityTurn.GravityTurner.FixedUpdate ()

This get spammed in the log like every 100th of a second?

 

It happends when GT is not active and I think when RCS is turned on, as already mentioned you really need to learn to code so GT is turned off when not actively controlling a ship.

[linuxgurugamer]

8 hours ago, Miravlix said:

It happends when GT is not active and I think when RCS is turned on, as already mentioned you really need to learn to code so GT is turned off when not actively controlling a ship.

No need to be insulting when you find a bug.  If you don't like the mod, don't use it.  Otherwise, report bug, and if you know how to fix, tell that also.  But don't insult anyone because it may be an obvious thing;  Not everyone is a professional coder, and for some people, modding is their first entry into coding

[Enceos]

@Overengineer1 Thank you for the mod I really love every bit of it. As it was mentioned above my Miravlix GravityTurn has a habbit of throwing an NRE spam when RCS is turned on. I noticed this bug cause I tend to play with the Exception Detector mod, but I didn't bother reporting it for quite a while, sorry for that. I'm not sure if it interacts with any mods to produce NREs. Would you please test the mod for NRE spam.

Screenshot:

Spoiler

P.S. A small feature request, I really love the Delta-V loss calculations done by the mod, it would be awesome if we could turn the calculations on while flying manually.

Edited March 1, 2016 by Enceos

[Guest]

I had been thinking about using a mod to reduce the workload when playing KSP. I used to use MechJeb, way back when I had no idea what I was doing, but after a while, the only thing I really wanted out of it was the ascent guidance. This mod automates all of the tedium out of launching tried and tested rockets. Now when I have to launch a few supply missions, or crew transfer missions, I can let Gravity Turn do the work for me.

Thank you for your hard work on this mod.

[JAFO]

On 10/01/2016 at 11:33 AM, Overengineer1 said:

The "Best Guess" button tries to find the best settings for a particular rocket. Here's the best I've seen it do so far, 80km orbit in 2987m/s: http://gfycat.com/WellmadeDefiantBlueshark

That record has now been broken. Here's my personal best seen using GravityTurn, 2924.8 m/s:

[fourfa]

This might be an odd bit of errata.  I landed a rocket in the water at Laythe, with plenty of dV to make orbit again.  I can launch to orbit manually, or with MechJeb.  However while sitting in the water, GravityTurn doesn't have any launch buttons; the whole window below "Time to match:40.00" is blank.  Don't know if that even within the scope of the project or what, but I thought I'd mention it...

[StickyScissors]

Is there any way to make GT just floor it once i am of the atmo? GTO/GSO transfers take FOREVER when a 0.7 TWR upper stage is throttled almost all the way down by GT, because it assumes that there is still atmosphere to be aware of.

Edited March 16, 2016 by StickyScissors

[komodo]

57 minutes ago, StickyScissors said:

Is there any way to make GT just floor it once i am of the atmo? GTO/GSO transfers take FOREVER when a 0.7 TWR upper stage is throttled almost all the way down by GT, because it assumes that there is still atmosphere to be aware of.

You probably want to set sensitivity to 1. It explains that it is the value to scale back to when the time gets ahead of the target. For doing a straight insertion, yeah, I imagine it's just a little confused. (The time! It does nothing but go up!! *flail*)

[fr33soul]

it will be good if we can save some custom presets!

[vardicd]

I use Kerbal Construction Time mod, and use its simulation mode to test next rockets, but when I do so, and have a bad launch with this mod, and try and use the improve best guess button, nothing changes. it uses the exact same presets as before, and the launch fails in exactly the same way. I'm wondering if this has something to do with the way KCT runs it's sims? by reverting the flight to a pre-sim save. could this be preventing this mod from saving the information from the previous failed launch, since the launch never really happens as far as the game is concerned? 

[linuxgurugamer]

Two things:  

1. KCT is going to depreciate it's sim mode in favor of KRASH.  Disclaimer, I'm the author of KRASH
2. Both KCT and KRASH work by saving the entire game, and then reverting it.  In order for GT to work with these, it is going to have to somehow save data external to the save file.

@Overengineer1Contact me if you would like to work on a way to have KRASH store persistent information for you (which will be available after the sim is completed).  I have a mechanism in place already which I use internally, will just need to write an API for you to access

 

LGG

[Guest]

7 hours ago, fr33soul said:

it will be good if we can save some custom presets!

I agree.

[Dman979]

Hi @Overengineer1! This looks like an awesome mod. Does it work with Realism Overhaul and Real Solar System? I think it might help the Real Space Program's first manned flight, but I would like to know if it will work before I install it and recommend it to the team.

 

[tmikesecrist3]

any one know of this works With RSS, RO, and FAR

 

[JAFO]

1 hour ago, tmikesecrist3 said:

any one know of this works With RSS, RO, and FAR

 

Have you considered finding out, by giving it a shot yourself?

[Deimos Rast]

6 hours ago, tmikesecrist3 said:

any one know of this works With RSS, RO, and FAR

 

Well if you read my posts a few up I talk about playing with it with FAR and DRE. To save you reading: aerodynamically, it flies fine with FAR. The issue is with Deadly Reentry (which I realize is outside the realm of your question), but because your turn is so gradual, the continual friction from the air ends up cooking your capsule, or at the very least burning off your solar panels.

I have heard of it having (or that it at one point had) an issue with the 64x kerbol expansion mod, since that mod moves where the boundary of space is as I understand it. This mod is programmed to basically putter along till 70km, at which point it thinks it's now in space (which in 64x it may not be) and proceeds to tell MJ to circularize. I don't know if that applies to RSS (if that mod changes the scale of the solar system, then it may). This issue may have been entirely fixed though, since it was brought up a while ago.