[1.12.3+] RealChute Parachute Systems v1.4.9.5 | 20/10/24

[stupid_chris]

22 hours ago, Kublaj said:

Hi. please can someone explain me what are the last two cells in chute editor?

its pre-deployment speed and deployment speed. What confuses me is units in seconds and pre filled ammounts of 2 and 6.

I'm new to this mod. I started it using it due to remotetech mod, because I didn't wan to estimate landing time on Kerbin having no connection to my probe. This mod allows me to deploy chutes even without signal, but on the other hand I'm bit confused of all those possible settings of chutes Is there some tutorial or something explaining how theese chutes work and how to set them optimally? I of coure watched some YT videos, but those are not much deep in describing this mods functionality

As said by Kowgan, it is the time in seconds taken for the parachute to predeploy and deploy. Longer means smoother, but much more distance covered as it expands. Too quick snaps your cord, too slow makes you hit the ground before it deployed.

[Oromis]

Hi, I can't seem to find the "arm chute" option in the action groups... Is this intended? I'm on 1.0.5 and latest version of realchute.

[stupid_chris]

1 hour ago, Oromis said:

Hi, I can't seem to find the "arm chute" option in the action groups... Is this intended? I'm on 1.0.5 and latest version of realchute.

Because you've switched on "arm on deployment" in the settings window. That means deployment and arming is the same for you, so the action group you're looking for is deploy.

[TauPhraim]

Hi,

Is there an advanced doc somewhere ? The link "Explanation of some editor window fields" is broken on these forums, and I'm confused by some options:

Does "apply to all symmetry counterparts" apply to this part too, or just others ?

Is there a way to have touchdown speed estimations take into account non-symmetry linked parts ? For example if you stack 2 stack chutes, they won't be symmetry-linked, but it would be usefull to have calculations done with both. Is that what option "Parachutes used (parachutes)" is for ?

When applying and getting "the mass of the ship is too high", is it possible to see somewhere the touchdown speed obtained (greater than the wanted one) ?

 

[Oromis]

17 hours ago, stupid_chris said:

Because you've switched on "arm on deployment" in the settings window. That means deployment and arming is the same for you, so the action group you're looking for is deploy.

Thanks! That was it.

Let me ask you another question: if I manually input the craft's mass, should I consider the chute mass or not?
For example, if craft+chute=250kg, I input 250kg and the resulting chute is maybe 30kg more... so it's now 280kg, I enter that and the resulting chute again maybe 10kg more... endless loop. How is it supposed to work?

[Kowgan]

I don't think you're supposed to enter the the craft+chute mass, but instead, the craft mass without chute.

[stupid_chris]

13 hours ago, TauPhraim said:

Hi,

Is there an advanced doc somewhere ? The link "Explanation of some editor window fields" is broken on these forums, and I'm confused by some options:

Does "apply to all symmetry counterparts" apply to this part too, or just others ?

Is there a way to have touchdown speed estimations take into account non-symmetry linked parts ? For example if you stack 2 stack chutes, they won't be symmetry-linked, but it would be usefull to have calculations done with both. Is that what option "Parachutes used (parachutes)" is for ?

When applying and getting "the mass of the ship is too high", is it possible to see somewhere the touchdown speed obtained (greater than the wanted one) ?

 

I'll try to fix those links. In the meanwhile, "apply to all symmetry counterparts" applies to all the parts in this symmetry group, that means it includes the current one. For your second question, yes, it's exactly what this option does. Important to note that stack chutes have *two* parachutes on them. This is why this field does not say parts, it's the number of individual chutes that is important. Though the triple chute canopy is simply a visual effect, and acts as a single physical parachute. If you apply and it says the mass is too high, chances you forgot something, because that means you have *huge*parachutes. Make sure that your current craft is ONLY what will be landing. Temporarily detach any lancher, boosters, or extra weight that will be discarded before applying. If it still says that, then no, you can't figure out the actual landing speed. I'll see if I can slip that into RealChute 2. Though that probably means your payload is huge. Adding extra chutes or making used of a rocket assisted landing should fix it.

8 hours ago, Oromis said:

Thanks! That was it.

Let me ask you another question: if I manually input the craft's mass, should I consider the chute mass or not?
For example, if craft+chute=250kg, I input 250kg and the resulting chute is maybe 30kg more... so it's now 280kg, I enter that and the resulting chute again maybe 10kg more... endless loop. How is it supposed to work?

The difference that makes is negligible, you can ignore it.

[TauPhraim]

4 minutes ago, stupid_chris said:

If you apply and it says the mass is too high, chances you forgot something, because that means you have *huge*parachutes.

Thanks for the reply. I'm designing a 3-person Mars lander (with hopefully ascent capabilities), so I suppose I'll really need huge chutes.

I don't understand your distinction number of chutes vs number of parts: I was aware some parts contained several chutes, but I thought these were used in sequence, not simultaneously (like: one drogue, one regular).

[stupid_chris]

Landing on Duna solely on chutes is a terrible idea (worse if you actually meant Mars with RO). You're gonna need more chute mass than you would need fuel mass to slow you down. There are reasons why we don't land things with chutes on Mars IRL, it's very highly inefficient. I'd reccomend slowing yourself higher up with a drogue, then cutting it once your get a few hundred meters from the surface and switching to a rocket powered descent.

And most do, but not all. As I said, normal stack chutes have two parachutes in them, and both deploy at the same time, one on each side. That then counts for two parachutes.

[TauPhraim]

Yes I mean real Mars. Indeed in my previous attempt (barely successful but with a smaller craft), I noticed the chutes did not help much. That's why I'd be interested in knowing the terminal velocity obtained (to know how much powered help I need). Also the chutes got safe to deploy very late (I *had* to target a low altitude landing site). This was worsened by the lack of drogues, but I'm thinking some kind of readout of the safe deployment speed per altitude would be very helpful. Or maybe this is getting so complicated that doing actual landing simulations would be easier.

[stupid_chris]

4 hours ago, TauPhraim said:

Yes I mean real Mars. Indeed in my previous attempt (barely successful but with a smaller craft), I noticed the chutes did not help much. That's why I'd be interested in knowing the terminal velocity obtained (to know how much powered help I need). Also the chutes got safe to deploy very late (I *had* to target a low altitude landing site). This was worsened by the lack of drogues, but I'm thinking some kind of readout of the safe deployment speed per altitude would be very helpful. Or maybe this is getting so complicated that doing actual landing simulations would be easier.

That thing isn't there because it's never constant. It depends on the ambient temperature, the ambient atmospheric density, and the altitude. In the end, I propose you just stick with a very shallow descent, not coming from interplanetary space but from a LMO, a kevlar drogue when possible, and a rocket assisted landing.

[KocLobster]

Can I ask a few stupid questions? Both 'chute texture' and 'chute model' are only graphical in nature, and they have absolutely no bearing on the speed/performance/effectiveness/etc. of your parachute, right?

With this mod installed, what is the difference between stock chutes and RealChutes. For example, the Mk2-R radial chute and the RealChute radial chute basically seem identical, with very trivial differences. Am I missing anything; is there any important differences I don't know about?

What is the difference between 'arming' chutes, 'deploying' chutes, and just pressing the spacebar to stage them?

What difference exactly does the spare chutes input do? Is this solely for engineers that EVA to repack the chutes so they can be used again? Does this ever pertain to if you deploy a chute in too harsh an environment and they get destroyed, meaning the spares can automatically redeploy later (w/o an engineer I suppose)?

Why doesn't the price go up at all for more and more spare chutes? 0 chutes is the same cost as 5 or 10 spare chutes. Also, the mass stays the exact same.

How does the 'parachutes used (parachutes)' work? I can't make heads or tails of what this is supposed to do. It was talked about just a few posts above, but that didn't help my understanding of it in any way.

 

Thanks for putting up with my noob questions, I really like the mod so far.

[stupid_chris]

Alright, a lot of questions, so I'll go through them individually for clarity's sake.

3 hours ago, KocLobster said:

Can I ask a few stupid questions? Both 'chute texture' and 'chute model' are only graphical in nature, and they have absolutely no bearing on the speed/performance/effectiveness/etc. of your parachute, right?

I would say this is 99% right, as there is a very slight advantage to having a triple chute model: this allows for more chute area. Basically, the *fixed* maximum diameter for a single parachute for the RealChute part library is 70m wide. This is *large* to give you a sense of scale, I believe the Orion capsule's parachute are 60m wide each. 70m is a stretch, and larger than that is simply not realistic. So for a single chute, the maximum diameter is 70m. For triple chutes, it's around 121m if I recall correctly. This seems weird, but we have to take into account that since it's one physical object, it is being simulated as one big chute, and not three separate, and to simulate a cluster of three chutes as one, you need to merge their area, not their diameters. The area of a chute is pi*r^2, so A=pi*(70/2)², and then to get the diameter of the resulting chute, we want to do the inverse on 3*A, so we have d=2*sqrt(3*A/pi). And if my memory is correct, this is approximately equal to 121m. So using a triple chute allows you to compact the volume of three chutes into one part, which can be useful. Apart from that, it is entirely cosmetic, yes.

3 hours ago, KocLobster said:

With this mod installed, what is the difference between stock chutes and RealChutes. For example, the Mk2-R radial chute and the RealChute radial chute basically seem identical, with very trivial differences. Am I missing anything; is there any important differences I don't know about?

The stock module is, how to put this... lacking? The whole system relies entirely on the stock drag. It's much better now that stock drag is no longer mass dependant, but it's still a system that is not suited at all for parachutes. Parachutes are far better off handled manually by the actual viscous drag equation, and by manually inputting a force, which also means that the crafts realistically hang from the parachute's connecting rope. This allows you to have total control on exactly how much drag you want your parachute to apply, and at what speed you will land. The stock parachutes now offer an "approximate area" but, well, simply put I created the formula that calculates this approximate area for FARs implementation of RealChuteLite, then passed it up to NathanKell who added it in the game's code. Having written and tested it, I know that while it does the job, it's rather inaccurate and not very good at predicting landing speed. Area alone, is not a good mean to tell you just what happens with your chute.

Not only that, but stock deployment is very, VERY hard on your craft. This is a lot less of an issue now that part joints are much sturdier, and that the aero system has been overhauled, but during my recent testing with the stock chute while updating RealChute, I've still had deployment shocks of up to 34Gs. If you have any notion of what 10Gs can do to someone, it's easy to see that 34 is insane. The most I've ever had with RealChute is 6G, which is actually a number that makes sense on paper and in real life. The Soyuz capsule usually caps at 4-5G when deploying its main chutes.

RealChute also provides the whole in game parachute editor, which lets you completely configure procedurally your parachutes for your very specific job. No more "do I have enough chutes" wondering.

In the end, both do the same job. RealChute is simply a more polished and smoother version of it.

3 hours ago, KocLobster said:

What is the difference between 'arming' chutes, 'deploying' chutes, and just pressing the spacebar to stage them?

Arming is what you're used to with stock chutes. The parachute is in standby, waiting for the right conditions, and will deploy as soon as it can, or immediately if they already can. Deploying means instant deployment, if the conditions are right.

Difference happens when you can't deploy the chutes and try to do one or another. When arming, as mentioned, if the parachutes cannot deploy, they become in standby mode and wait for the right conditions. When 'deploying' if the conditions are not right, nothing happens and the parachute goes into inactive mode once more.

Pressing the spacebar, by default, will 'deploy' the chutes. This can be changed in the SpaceCenter settings window and the default can be set to 'arming'.

3 hours ago, KocLobster said:

What difference exactly does the spare chutes input do? Is this solely for engineers that EVA to repack the chutes so they can be used again? Does this ever pertain to if you deploy a chute in too harsh an environment and they get destroyed, meaning the spares can automatically redeploy later (w/o an engineer I suppose)?

In career mode, by default, you need a lvl 1 engineer to physically reach a chute part to repack it. This can also be changed in the SpaceCenter settings window, both the minimum level, and if it is restricted to an engineer at all. It is never done automatically, and the number in the input indicates the amount of times it can be done. Not putting anything removes this restriction and allows it to be repacked an infinite amount of time. For now.

3 hours ago, KocLobster said:

Why doesn't the price go up at all for more and more spare chutes? 0 chutes is the same cost as 5 or 10 spare chutes. Also, the mass stays the exact same.

Simply because it has not been implemented. This is one of the core features of RealChute2, along with EVA parachutes. Spares will add mass, cost, and will have to be transported by a kerbal to the part itself.

3 hours ago, KocLobster said:

How does the 'parachutes used (parachutes)' work? I can't make heads or tails of what this is supposed to do. It was talked about just a few posts above, but that didn't help my understanding of it in any way.

Simply put, this is used in the calculation for the diameter for the parachute.

The question this asks is "when this parachute is deployed, how many parachutes will be deployed at the same time on this craft, to achieve the same goal?". Basically, the more parachutes there are, the smaller each one of them can be, and the less load each one carries. This is far too complex to figure out automatically with staging and would be prone to crazy errors, so you have to just input this manually.For example, if you had four radial chutes working all at the same time to make your pod touch down, you'd want to input four. For stack chutes (not the grey combo chutes), the number is two by default, because as mentioned up there, this specific part has two distinct parachutes that act at the same time. So again, if you had three radial chutes and one stack chute on your craft, this number becomes five: two for the stack, one per radial. If you had one cone chute with a triple canopy model, however this is *one* chutes, because the triple canopy is simply a visual effect, it is treated as one big canopy, as mentioned earlier in this post.

It's simple when put in perspective, but weird to explain in a few words/a UI label. Tried my best to make it clear in game.

3 hours ago, KocLobster said:

Thanks for putting up with my noob questions, I really like the mod so far.

Don't worry about it, some things aren't quite clear

[KocLobster]

Thanks for taking the time to answer all my questions, I hadn't realized earlier when I asked them the large response they'd require.

Had a few follow up questions though.. I agree the stock chute is lacking, but with this mod installed and using your awesome code...is it still lacking? They'd seem identical at first glance.

To be honest (I'm not a genius here OK) the explanation of the difference between arming and deploying sounded exactly the same. They do the exact same things, no?

Lastly, parachutes used... I don't fullyunderstand. You input the number of chutes you're using? Why wouldn't the answer always be one? And each chute deploys it's own chute. Shouldn't I select a different chute and input how many chutes THAT chute should deploy, not pick one at random and input how many total chutes I have? Or is this just for symmetric chutes were you can select individuals and would need to input how many there are total? This is the only thing that makes sense to me.

Thanks so much for your help. Other than that I totally understood everything you said and clarified. I love the mod and look forward to RC2 (& more answers from you). Also, thanks for maintaining KSPX (I'm on my phone, cant easily check, hope I got that correct).

[Starwaster]

A word on g forces and the human body: Fighter pilots routinely are subjected to forces exceeding 9g's which is possible both through training and the use anti-G suits that they wear. Astronauts also were subjected to high g's in the Mercury-Apollo years.

And an army doctor by the name of John Stapp subjected himself to g's exceeding 40 g's one one occasion as part of high g testing involving rocket sleds. He didn't suffer any serious side effects though he was left with long term vision problems. (either because of the single 40g ride or cumulative effect of lesser rides)

[stupid_chris]

2 hours ago, KocLobster said:

Thanks for taking the time to answer all my questions, I hadn't realized earlier when I asked them the large response they'd require.

Had a few follow up questions though.. I agree the stock chute is lacking, but with this mod installed and using your awesome code...is it still lacking? They'd seem identical at first glance.

To be honest (I'm not a genius here OK) the explanation of the difference between arming and deploying sounded exactly the same. They do the exact same things, no?

Lastly, parachutes used... I don't fullyunderstand. You input the number of chutes you're using? Why wouldn't the answer always be one? And each chute deploys it's own chute. Shouldn't I select a different chute and input how many chutes THAT chute should deploy, not pick one at random and input how many total chutes I have? Or is this just for symmetric chutes were you can select individuals and would need to input how many there are total? This is the only thing that makes sense to me.

Thanks so much for your help. Other than that I totally understood everything you said and clarified. I love the mod and look forward to RC2 (& more answers from you). Also, thanks for maintaining KSPX (I'm on my phone, cant easily check, hope I got that correct).

Normal RealChute installation with the bundled MM patches replaces the stock parachutes with the RealChute parachute module.

Arming: if the parachute cant deploy, goes in a standby state and deploys as soon as possible.
Deploying: if can't deploy, returns to inactive and nothing ever happens.

The best example I can give you, is again, radial chutes. Let's say you have a lander and that you stuck three radial chutes on it. You want your lander to touch down at say, 10m/s. We agree that when landing, all three parachutes will be deployed, right? So you want to split the load of the lander across all three parachutes. So in the editor, in the parachutes used, you would put three. Because if you didnt, when applying the settings the mod will assume that this parachute will be supporting the whole craft alone, and will give it three times more area than it needs. By putting three in that field, you say "no need for a huge ass parachutes, there are two other different parachutes that will be helping to slow down, so just give this one a third of the area and when all three are deployed at the same time it will act the same as one big chute". For about 80% of normal usage, this number would be one. But in the case of radial chutes, stack chutes (because they are two parachutes in one part deployed at once), and special designs, you need to tell the mod how to split the load.

59 minutes ago, Starwaster said:

A word on g forces and the human body: Fighter pilots routinely are subjected to forces exceeding 9g's which is possible both through training and the use anti-G suits that they wear. Astronauts also were subjected to high g's in the Mercury-Apollo years.

And an army doctor by the name of John Stapp subjected himself to g's exceeding 40 g's one one occasion as part of high g testing involving rocket sleds. He didn't suffer any serious side effects though he was left with long term vision problems. (either because of the single 40g ride or cumulative effect of lesser rides)

I knew about fighter pilots being able to sustain 7-9G for a few seconds, but the last one is intense. Still makes no sense for parachutes to create forces encountered during rocket sled tests

[KocLobster]

@stupid_chris

That's weird, in my game I have both RealChutes and the stock chutes.

Got it, I get the difference now. I will want to change my space-bar to arm, not deploy then.

Ohhhhh, I understand now. Thank you for clarifying, this clicked for me now. The click was actually audible. This also explains why some chutes always were costing way more than it seemed they should have, and why I was receiving that error message about too much mass.

[stupid_chris]

12 minutes ago, KocLobster said:

@stupid_chris

That's weird, in my game I have both RealChutes and the stock chutes.

Got it, I get the difference now. I will want to change my space-bar to arm, not deploy then.

Ohhhhh, I understand now. Thank you for clarifying, this clicked for me now. The click was actually audible. This also explains why some chutes always were costing way more than it seemed they should have, and why I was receiving that error message about too much mass.

If you don't have RealChute on the stock parts, you don't have the latest MM installed correctly. Glad I could help for the rest

[KocLobster]

Oh I'm sorry I misunderstood.. I do have RC on the stock pieces, I just thought that those stock chutes would be removed...my misunderstanding.

[stupid_chris]

Removing them would break already existing crafts and craft files, no reason to do that.

[KocLobster]

Oh right duh...I can't believe I didn't realize that.

[Starwaster]

Some helpful tips to those using chutes over Duna (or worse, Mars) with heavy loads:

Try configuring the chute as a drogue. That fits their use case scenario better than as a main chute. 

Set a target altitude and target speed you want to be at when you hit that altitude. Set the auto-cut speed to your desired target speed or lower. (can't be higher than 100 m/s)

Let's say for example

• target altitude: 10000m
• desired speed 200 m/s
• autocut altitude 100 m/s (this assumes that you're descending the rest of the way on retropropulsion for landing)

Obviously, your deployment altitudes need to be at least equal to or higher than your target altitudes and you need to be able to decelerate to a safe deployment speed by the time you hit your deployment altitudes.

[Oromis]

I'm desperately trying to land on mars with a very small lander. It's just 300kg.
After getting to LMO (250km) and initiating the descent from 3500m/s orbital velocity, I get to 10km above the surface still going at about 2000m/s: drogues are destroyed by g-forces, then main chute is also destroyed around 1600m/s. And I finally hit the ground still going 1100 m/s....

edit: periapsis for the descent is 35-40km

So whose fault is it? the chutes? my approach?
I'm thinking maybe my lander is too small (a 0.625m heatshield manages to shield it) and doesn't produce enough drag to aerobrake decently?

also how is this guy able to deploy the chute going at 2000m/s video 

Edited March 29, 2016 by Oromis

[stupid_chris]

7 hours ago, Oromis said:

I'm desperately trying to land on mars with a very small lander. It's just 300kg.
After getting to LMO (250km) and initiating the descent from 3500m/s orbital velocity, I get to 10km above the surface still going at about 2000m/s: drogues are destroyed by g-forces, then main chute is also destroyed around 1600m/s. And I finally hit the ground still going 1100 m/s....

edit: periapsis for the descent is 35-40km

So whose fault is it? the chutes? my approach?
I'm thinking maybe my lander is too small (a 0.625m heatshield manages to shield it) and doesn't produce enough drag to aerobrake decently?

also how is this guy able to deploy the chute going at 2000m/s video 

That does indeed sound like your lander is so aerodynamic that it just punches through the atmosphere. First of, 10k is really really high to be deploying parachutes. Second, with such a small lander, get our original orbit much lower, and drop your periapsis higher. Try to slow yourself down through multiple dips into the atmosphere. Third, you are definitely going to need retropropulsion, probably even before deploying the chutes. Make sure you're using kevlar drogues.

[stupid_chris]

Letting you all know that a compatible version of RealChute for the 1.1 pre release should be available soon, just need to fix a few issues