Modding Monday: Gravity Turn version 1.2.0!

[SQUAD]

Launch a craft into a low orbit with a few customizable settings. Performing a Gravity Turn is arguably the most efficient launch procedure.  The plugin will take care of the entire ascent for you by maintaining a strict hold to prograde and varying the throttle to keep the desired ascent curvature. #KSP

[Interplanetary Engineer]

Seems rather cheaty. [No,I'm not going to say "first reply"]

[StarManta]

16 minutes ago, Interplanetary Engineer said:

[No,I'm not going to say "first reply"]

....You still said it...

[legoclone09]

I used this and it doesn't like working with a craft that has next to no control authority. Add SAS/RCS onto ships for this to work good, it's important.

[linuxgurugamer]

4 hours ago, legoclone09 said:

I used this and it doesn't like working with a craft that has next to no control authority. Add SAS/RCS onto ships for this to work good, it's important.

Umm, I'm not sure I'd like working with a craft that has next to no control authority

[legoclone09]

1 hour ago, linuxgurugamer said:

Umm, I'm not sure I'd like working with a craft that has next to no control authority

I was just pointing it out, my ships fly perfectly with good control.

[maceemiller]

Not for me im afraid. I find launching manually important as depending on what I've built, no two craft fly the same so launching becomes part of the mission experience. 

I do see this working for more experienced players who can launch anything though.

[SSgt Baloo]

I have anxiety disorders. Manual launches could be a piece of cake, but more often they were stressful events. I like this mod.

 

[jedensuscg]

When using remote tech and putting a satellite constellation in the sky, mods like this are a blessing, and NOT cheating. Do not let anyone tell you that. Invariably the most important part of any mission is designing the craft to be functional, meet all the missions goals, be cheap, and reliable (I use entropy so redundancy also helps a lot).  If you have to fly by the seat of your pants during takeoff with barely controllable craft you have already made a mistake in the hangar.  If you built your craft right, which can be hard, then the launch stage, barring any failures (again, entropy mod is fun for this) is pretty much the easiest thing you can do, why not automate it and save your finger for the harder stuff that you only do a few times, never every time.

After launching dozens of identical craft, for say sat's, or rescues, or space station building, being able to minimize the tedious of repeating the same thing over and over is great.  Thank you for this.

 

[Warzouz]

Please don't start about "cheat" again !

Why not considering this type of mod can be a big help for :

• New players, as it shows what should be done to go to orbit efficiently.
• Players which have a dozen of similar rockets to launch (as I did in 0.9 Beta)
• Players that prefer to focus on navigation and landing rather than flying to LKO (which they already did hundreds of times).

[Lukaszenko]

12 minutes ago, Warzouz said:

Please don't start about "cheat" again !

Why not considering this type of mod can be a big help for :

• New players, as it shows what should be done to go to orbit efficiently.
• Players which have a dozen of similar rockets to launch (as I did in 0.9 Beta)
• Players that prefer to focus on navigation and landing rather than flying to LKO (which they already did hundreds of times).

....or players who would rather focus on design. I don't consider SpaceX, ULA, or whoever else to be "cheating".   

[Talavar]

 I play KSP as a coffee game. So Control mods are welcome as far as I'm concerned. However, Mechjeb pretty much handles this for me already. I just tweak the ascent for different vessels. Yeah, I can do it manually, but after a few 1000 hours of KSP, I'm more interested in what happens after I land, rather than the process of getting there.. lol

[Hotaru]

6 minutes ago, Talavar said:

 However, Mechjeb pretty much handles this for me already. I just tweak the ascent for different vessels.

This is what I do at the moment too, and at first my reaction to this was "what's the point, MJ already does this."

It occurs to me, however, that what MechJeb does is fly an approximate gravity turn, which is to say it steers the rocket (using fins, RCS, wheels, whatever) along a curved trajectory which resembles a gravity turn. What this mod does is fly a genuine gravity turn: it allows gravity to curve the rocket's trajectory and controls the steepness of the curve using the throttle, rather than steering. In addition to being a bit more efficient, this should have the advantage of keeping the angle of attack extremely low during most of the ascent, which should make it much easier to keep from flipping.

I'll definitely be giving this mod a try.

[Foxster]

GT v MJ:

It depends just how close to the edge of the envelope you are pushing it. If a few 10s or perhaps 100s of dV are mission critical then try GT. If you are used to building a little fat into your missions then unadjusted MJ is almost as good at getting a craft in orbit...and does another 100 things too. 

[Daveroski]

On take off I only use MJ for the circularisation burn. Which, by the way,  still seems to be getting it a couple of seconds late for me..

[mcirish3]

 [1.0.5] GravityTurn version 1.2.2 - Automated Efficient Launches  has MJ integration for the final circularization and is more efficient than MJ.

[Overengineer1]

To those that call this mod cheaty, that definitely can be true.  But it really depends on how you use it.

The first build of this was just for my own use.  The first release got a lot more attention than I was expecting, so now it's no longer just my personal tool.  Being able to repeatably send a rocket on an efficient launch path is the most scientific way to evaluate small or even large changes to your ship, settings. or habits.  How important is it to get higher, sooner?  GT tells us not only is it not important, it's actually a bad idea in a lot of cases.  How important is aerodynamics during a launch?  My readouts tell me it's not important enough to justify very much weight gain at all.  How bad is it if we see a little fire during ascent?  GT proved to me that not only is it not bad, but it's guaranteed to be my best launch profile for any but the most underpowered rockets.

If you're a beginner, it can teach you how you should be launching.  If you're an intermediate player, it can take the tedium out of resupply missions without sacrificing efficiency.  If you're an advanced designer, it can take human error out of design evaluation.  I think I'm a little bit of all three of those, so it helped me with all three.

[EatVacuum]

I don't see why this is could be considered cheaty. Just because you prefer to fly every launch manually doesn't make you a better player or more of a man. I could equally make the argument that those who do it that way are not playing realistically, everyone should be forced to preprogram a flight plan and live with the consequences. But how fun would that be?

I'll come out of the closet, yes I am a Mech-head and I'm proud of it! There, I said it. I use Mechjeb, I have an MM config to add it by default in all my capsules. And it's not that I couldn't WASD my way through every launch, but because I choose not to.

There is only one "right" way to play KSP. Everyone should play it the way they that they enjoy the most.

If this mod makes KSP more approachable or more fun for even one person then it is a good mod. So kudos to OverEngineer1.

Edited January 20, 2016 by EatVacuum

[mcirish3]

Got questions about cheating see here.

[Jim DiGriz]

I think my use of it is cheating.  I got a real book on rocket physics and started reading it and meant to finish researching how to do a real physics-based gravity turn in KSP, using math, and never quite got around to it.  But the way the mod gives back feedback on all the different kinds of delta-V losses on ascent has already taught me a ton, and I could still work on porting the ideas to MechJeb or kOS...  But then there's the day job to deal with, so cheating it is for now...

Also anyone who is wondering about how to launch SSTOs should probably use this first and observe.  I taught myself SSTOs back before 0.90 sometime and the way gravity turn launches rockets is much more similar to the way SSTOs need to be launched.  It may also actually improve my SSTO launching when I get around to playing with those again -- I usually pull back on the stick and nail the engines to get to orbit with SSTOs, but it looks like I should just keep gently pushing up the velocity and circularize at around 45km and not worry about air drag losses.  I'm thinking there's a lot of SSTO tutorials out there that may have the final-ascent-to-orbit completely wrong now after watching GT...

p.s. I find GT takes about 3600m/s vac delta-V to get to 80x80 vs 3800m/s for MJ launches

Edited January 21, 2016 by Jim DiGriz

[ExtremeSquared]

On 1/20/2016 at 6:39 PM, Overengineer1 said:

How important is it to get higher, sooner?  GT tells us not only is it not important, it's actually a bad idea in a lot of cases.  How important is aerodynamics during a launch?  My readouts tell me it's not important enough to justify very much weight gain at all.  How bad is it if we see a little fire during ascent?  GT proved to me that not only is it not bad, but it's guaranteed to be my best launch profile for any but the most underpowered rockets.

This goes out the window for any payload that doesn't fit in a 2.5m bay. It still is necessary to launch directly upwards past 10000m if your payload has wheels or other weird nonsense attached.

Edited January 21, 2016 by ExtremeSquared

[Green Baron]

On 21.1.2016 at 3:42 AM, Jim DiGriz said:

p.s. I find GT takes about 3600m/s vac delta-V to get to 80x80 vs 3800m/s for MJ launches

Really ? That would be 300-500 more than going manually (1.0.5 KER atmospheric readout, if i remember right, haven't played for some time cause waiting for 1.1) ...

 

Edited January 23, 2016 by kemde

[Jim DiGriz]

8 hours ago, kemde said:

Really ? That would be 300-500 more than going manually (1.0.5 KER atmospheric readout, if i remember right, haven't played for some time cause waiting for 1.1) ...

 

I measure using vac delta-V even though its climbing through an atmosphere, which adds (i think) 400m/s or so (as long as you don't burn inappropriate engines in the atmosphere).  GT actually has a readout that gives you how much delta-V you really burned, and also gives you how much dV you lost due to various kinds of drag (if you add up your orbital speed and all the drag losses it will equal the dV burned).  I don't find that too useful since what I care about is the vac dV number after I get to orbit, so I haven't been paying close attention to how large the dV difference is between what you really burned and how much lower vac dV is when you hit orbit.

So, you should read what I said as it beats decent manual launches or mechjeb and gives you 200m/s vac delta-V extra when you reach 80x80.

My launches are also not too silly and have rocket-looking rockets and keep the AoA fairly low and I do gravity turns to a fairly flat profile.  I'd be a bit surprised if anyone is substantially beating my numbers with manual launches, and be a little shocked if they could beat GT.

The KER readout might not be accurate as well, I have KER installed as well but haven't ever watched that one...  I'll try to pay a bit more attention on the next few launches and see what I find...

And I now play on a Mac (a hackintosh with 32GB of RAM), so I can't wait for 1.1 and 64-bit and being able to use parts mods again...

Edited January 23, 2016 by Jim DiGriz