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[1.12.1] JNSQ [0.10.0] [23 Sept 2021]


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7 hours ago, RyanRising said:

The commonly accepted figure for stock Eve ascent is ~8000 m/s, right? Course that’ll vary wildly depending on drag, but that’s the figure I’ve seen on Δv maps, and it’s worked alright for me. 
However, since I started playing JNSQ, I’ve had a look at that Δv map quite a few times, and its figure for Eve ascent is 6700 m/s. It does only have 1.4 g of surface gravity instead of 1.7 g, but is also 2050km in radius instead of 700 km and has 10 atm of pressure instead of stock Eve’s 5. 
With all that in mind, I certainly wasn’t expecting JNSQ’s Eve to require less of a rocket. Does that discrepancy come from different assumptions about vehicle aerodynamics, does that extra 0.3 g pack much more of a whallop than I think it does, or is there something else I’m not considering here? 

First, I actually think 8000 m/s for stock Eve is a bit high.  I've been able to do it for 7000-7500 m/s, but that involves some cheating by teleporting a very well designed are aerodynamic rocket there.  Designing something that can not only takeoff from Eve but also survive entry, descent and landing would likely require some compromises that could hurt efficiency.

As for why JNSQ Eve may actually be easier than stock Eve, I can suggest several reasons.  The first you've already mention, Eve's surface gravity in JNSQ is only 1.4 g rather than 1.7 g.  This means the gravity losses are going to be less.  The biggest reason, however, is that Eve's atmosphere in JNSQ is quite a bit different from the stock version.  Even though the atmospheric pressure at sea level is higher (10 atm vs. 5 stm), the JNSQ atmosphere thins out much more quickly.  The density of the JNSQ atmosphere is greater only for the first 7400 meters of altitude.  Above 7400 meters the JNSQ atmosphere is thinner than the stock version.  The fact that the stock atmosphere thins out so slowly is very unrealistic for a body with such high gravity.  The JNSQ atmosphere is much more realistic in how it changes with altitude.  So while JNSQ presents a greater challenge for those first 7 km, after that it becomes much easier.  This is the reason we increased the sea level pressure to 10 atm - to add back some difficulty that was lost by making a more realistic atmosphere.  So despite the higher sea level pressure, drag loses are much less in JNSQ than in stock.  Furthermore, because of stock EVE's unrealistically thick atmosphere at high altitude, it is necessary to maintain near vertical flight for quite some time before it's possible to pitch over and really start accelerating.  Because JNSQ's upper atmosphere is much thinner, it's possible to transition to horizontal flight sooner, which further decreases the gravity losses.  So while orbital velocity is much higher in JNSQ than it is in stock (about 5200 m/s vs. 3200 m/s), we save that difference or more in lower gravity and drag losses. 

The 10 atm sea level pressure is at first a real problem as far as engine efficiency goes (higher ambient pressure means lower thrust and specific impulse), but remember how quickly the atmosphere thins.  Engines may really struggle at first, but once above about 8500 meters (where the JNSQ and stock air pressure is equal) you're going to get better engine performance in JNSQ than in stock.  So while engine efficiency has no effect on the delta-v require to achieve orbit, it does effect how much delta-v a rocket can deliver for the same fuel mass.  So overall, Eve launch vehicles in JNSQ should require a lower fuel mass ratio than those in stock.
 

Edited by OhioBob
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36 minutes ago, OhioBob said:

First, I actually think 8000 m/s for stock Eve is a bit high.  I've been able to do it for 7000-7500 m/s, but that involves some cheating by teleporting a very well designed are aerodynamic rocket there.  Designing something that can not only takeoff from Eve but also survive entry, descent and landing would likely require some compromises that could hurt efficiency.

That may no longer be true in 1.12, as you could design it with the 10m inflatable heat shield at the bottom, ready to detach after reentry, lots of 'chutes, and an ISRU unit, then detach the chutes and ISRU with your engineer thanks to the new repair game mechanic. Maybe I'm missing something, though.

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3 hours ago, Space Nerd said:

You can get off Eve in JNSQ with explodium breathing engines or Eve optimized engines (10 atm config) or you can just launch from a plateau.

Also electric-powered propeller craft from Breaking Ground, and fuel cells.

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1 hour ago, panarchist said:

That may no longer be true in 1.12, as you could design it with the 10m inflatable heat shield at the bottom, ready to detach after reentry, lots of 'chutes, and an ISRU unit, then detach the chutes and ISRU with your engineer thanks to the new repair game mechanic. Maybe I'm missing something, though.

I haven't built a successfully Eve lander/launcher since v0.90.  Landing a probe is no problem, and launching is no problem if I use cheats to get there.  But every time I try building something capable of landing and launching, I can't get it to the surface without it becoming unstable and burning up during atmospheric entry.  I know many people recommend putting an inflatable heat shield on both the leading and trailing ends to stablize it, but I really don't like that solution.  I'm still searching for another way, though I really haven't put forth a concerted effort.

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13 hours ago, OhioBob said:

First, I actually think 8000 m/s for stock Eve is a bit high.  I've been able to do it for 7000-7500 m/s, but that involves some cheating by teleporting a very well designed are aerodynamic rocket there.  Designing something that can not only takeoff from Eve but also survive entry, descent and landing would likely require some compromises that could hurt efficiency.

As for why JNSQ Eve may actually be easier than stock Eve, I can suggest several reasons.  The first you've already mention, Eve's surface gravity in JNSQ is only 1.4 g rather than 1.7 g.  This means the gravity losses are going to be less.  The biggest reason, however, is that Eve's atmosphere in JNSQ is quite a bit different from the stock version.  Even though the atmospheric pressure at sea level is higher (10 atm vs. 5 stm), the JNSQ atmosphere thins out much more quickly.  The density of the JNSQ atmosphere is greater only for the first 7400 meters of altitude.  Above 7400 meters the JNSQ atmosphere is thinner than the stock version.  The fact that the stock atmosphere thins out so slowly is very unrealistic for a body with such high gravity.  The JNSQ atmosphere is much more realistic in how it changes with altitude.  So while JNSQ presents a greater challenge for those first 7 km, after that it becomes much easier.  This is the reason we increased the sea level pressure to 10 atm - to add back some difficulty that was lost by making a more realistic atmosphere.  So despite the higher sea level pressure, drag loses are much less in JNSQ than in stock.  Furthermore, because of stock EVE's unrealistically thick atmosphere at high altitude, it is necessary to maintain near vertical flight for quite some time before it's possible to pitch over and really start accelerating.  Because JNSQ's upper atmosphere is much thinner, it's possible to transition to horizontal flight sooner, which further decreases the gravity losses.  So while orbital velocity is much higher in JNSQ than it is in stock (about 5200 m/s vs. 3200 m/s), we save that difference or more in lower gravity and drag losses. 

The 10 atm sea level pressure is at first a real problem as far as engine efficiency goes (higher ambient pressure means lower thrust and specific impulse), but remember how quickly the atmosphere thins.  Engines may really struggle at first, but once above about 8500 meters (where the JNSQ and stock air pressure is equal) you're going to get better engine performance in JNSQ than in stock.  So while engine efficiency has no effect on the delta-v require to achieve orbit, it does effect how much delta-v a rocket can deliver for the same fuel mass.  So overall, Eve launch vehicles in JNSQ should require a lower fuel mass ratio than those in stock.
 

Thanks so much for the in-depth answer! It really is less about the atmospheric pressure and more how you distribute it.

While I’ve only sent probes to other planets so far in this new system, I’ll keep this in mind for when I do attempt a balled mission to Eve’s surface. EDL will be… interesting for sure.

10 hours ago, OhioBob said:

I haven't built a successfully Eve lander/launcher since v0.90.  Landing a probe is no problem, and launching is no problem if I use cheats to get there.  But every time I try building something capable of landing and launching, I can't get it to the surface without it becoming unstable and burning up during atmospheric entry.  I know many people recommend putting an inflatable heat shield on both the leading and trailing ends to stablize it, but I really don't like that solution.  I'm still searching for another way, though I really haven't put forth a concerted effort.

Also, it’s worth keeping in mind that while heat shields shield from heat, they don’t shield from aerodynamic effects. You could put detachable fins to the windward end of the lander to help stabilise it, though that makes even less sense from a “what should work” standpoint than the double heat shields. So if you’re searching for sensible solutions, this may not be it.

Edited by RyanRising
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On 6/28/2021 at 8:48 AM, OhioBob said:

I haven't built a successfully Eve lander/launcher since v0.90.  Landing a probe is no problem, and launching is no problem if I use cheats to get there.  But every time I try building something capable of landing and launching, I can't get it to the surface without it becoming unstable and burning up during atmospheric entry.  I know many people recommend putting an inflatable heat shield on both the leading and trailing ends to stablize it, but I really don't like that solution.  I'm still searching for another way, though I really haven't put forth a concerted effort.

Well to be fair, I could be completely talking out of my exhaust here - I took a quick look, and think the last time I actually tried landing on Eve was 0.24 or maaaaaybe 0.90. I thought it was later, but no. I'll defer to your more recent experience.

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Hello all,

Been a while since I've played JNSQ. I made a spreadsheet with all the bodies data around ~1 year ago. Have any of the bodies been modified (# of biomes, gravity, radius, etc.) in the last year or so? I'd like to not have to go through each body file and cross check with my spreadsheet if possible :)

Thanks!

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9 hours ago, Krydax said:

Hello all,

Been a while since I've played JNSQ. I made a spreadsheet with all the bodies data around ~1 year ago. Have any of the bodies been modified (# of biomes, gravity, radius, etc.) in the last year or so? I'd like to not have to go through each body file and cross check with my spreadsheet if possible :)

Thanks!

No changes.  We're still on v0.9.0 that was released in February 2020.

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1 hour ago, SpaceX_Boi said:

Hi

I know that this mod has 1.8.1 in it's title, but is it possible to work in 1.11.2? :P 

Has anyone else been playing in 1.11.2 with this mod with no major issues? :/ 

Please let me know, thanks. :) 

It should work fine as long as you use the correct version of Kopernicus.

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@OhioBob I was hoping you could help me out with relocating the KSC. I can't for the life of me remember how to do that via a ModuleManager patch as its been several years since I've fooled around with that. I was thinking of using @panarchist's Toast for an inclined JNSQ but would also want to reposition to the KSC to northern most point on its current continent to the northwest on a nice coastal position a la the real world Cape at 28.6 north.  Just need to reposition the KSC and flatten the area a little bit. at least I hope thats all. 

Edited by thunder175
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10 hours ago, thunder175 said:

@OhioBob I was hoping you could help me out with relocating the KSC. I can't for the life of me remember how to do that via a ModuleManager patch as its been several years since I've fooled around with that. I was thinking of using @panarchist's Toast for an inclined JNSQ but would also want to reposition to the KSC to northern most point on its current continent to the northwest on a nice coastal position a la the real world Cape at 28.6 north.  Just need to reposition the KSC and flatten the area a little bit. at least I hope thats all. 

If you want to relocate KSC, try the following patch.  The numbers given are for the current position, just change them to your new position.  The map decal is the flattened area around the space center.  You will need to relocate both the map decal and the space center.

Spoiler
@Kopernicus:AFTER[JNSQ]
{
    @Body[Kerbin]
    {
        @PQS
        {
            @Mods
            {
                @MapDecalTangent[KSC]
                {
                    @absoluteOffset = 300                           // elevation ASL of map decal, in meters
                    @angle = 0                                      // rotation of map decal, in degrees
                    @position = -0.0314107591,0,-0.9995065604       // position vector of map decal, with X,Y,Z coordinates as follows:
                                                                    // X = cos(latitude)*cos(longitude)
                                                                    // Y = sin(latitude)
                                                                    // Z = cos(latitude)*sin(longitude)
                    @radius = 8200                                  // radius of map decal, in meters
                }
            }
        }
        @SpaceCenter
        {
            @latitude = 0                                           // latitude of KSC center, in degrees
            @longitude = -91.8                                      // longitude of KSC center, in degrees
            @repositionRadiusOffset = 293                           // elevation ASL of KSC, in meters
            @reorientFinalAngle = 1.8                               // rotation of KSC, should be equal to 270-longitude
        }
    }
}

 

Edited by OhioBob
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58 minutes ago, OhioBob said:

If you want to relocate KSC, try the following patch.  The numbers given are for the current position, just change them to your new position.  The map decal is the flattened area around the space center.  You will need to relocate both the map decal and the space center.

EDIT: Alright, I rechecked the math and found I fatfingered the Z value. Looks to be working fine now.  Here are the values I used. I didn't touch the ASL values yet though.

Spoiler

@Kopernicus:AFTER[JNSQ]
{
    @Body[Kerbin]
    {
        @PQS
        {
            @Mods
            {
                @MapDecalTangent[KSC]
                {
                    @absoluteOffset = 300                                       // elevation ASL of map decal
                    @angle = 0                                                  // rotation of map decal
                    @position = -0.4404504557,0.47869185795,-0.759511344196     // position vector of map decal, with X,Y,Z coordinates as follows:
                                                                    // X = cos(latitude)*cos(longitude)
                                                                    // Y = sin(latitude)
                                                                    // Z = cos(latitude)*sin(longitude)
                    @radius = 8200                                  // radius of map decal
                }
            }
        }
        @SpaceCenter
        {
            @latitude = 28.6                                        // latitude of KSC center
            @longitude = -120.11                                    // longitude of KSC center
            @repositionRadiusOffset = 293                           // elevation ASL of KSC
            @reorientFinalAngle = 1.8                               // rotation of KSC, should be equal to 270-longitude
        }
    }
}

 

Edited by thunder175
MATH!!!!
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4 hours ago, thunder175 said:

EDIT: Alright, I rechecked the math and found I fatfingered the Z value. Looks to be working fine now.  Here are the values I used. I didn't touch the ASL values yet though.

You should change reorientFinalAngle to 30.11 degrees, or else the runway won't be aligned east-west.  The offsets should probably work as is, but the map decal may not blend in nicely with the surrounding terrain.  If you find you need to raise or lower it for aesthetic reasons, just try changing absoluteOffset and repositionRadiusOffset by the same amount.

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