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[Most 1.12.x] Near Future Technologies (August 26)


Nertea

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On 10/22/2018 at 11:36 AM, juanml82 said:

Are they useful in the stock sized solar systems, though? You'd be achieving orbital speeds pretty quickly with scramjets (and overheating too)

In stock scale? No. And there are a few reasons against even having one:

  • Kerbin is the largest stock planet providing Oxygen. Taking one to Laythe is pointless as it's easier to reach orbital velocity without involving a scramjet.
  • Scramjets are really inefficient. IRL ones are measured to have 1000 Isp which chips down as velocity further increases. To be player-friendly, the one in Mk2 Expansion has 2000 Isp.
  • Jet engines IRL can apparently run on Hydrogen and not just Kerosene-alike fuels. Their Isp will go up by an order of magnitude but outside of the Realism Overhaul realm, no one makes jet engines use anything other than abstract LiquidFuel.
  • A scramjet engine is dead mass for even more of the time than a rocket engine on an SSTO in atmosphere. You're really gambling your dV by involving any, and the extra fuel for it in your design.

That said, I made a few pretty viable craft that use scramjets (and I enjoy using these things) and they count on that engine's ability to far exceed Kerbin orbital velocity while still using air and still having higher Isp than any LFO engine.

  • Instead of depending on the Rapier's ClosedCycle, I can coast to over 300km Apoapsis on a scramjet, and be a little more liberal with nuke engines for vacuum.
  • I made a heavy SSTO that used just the Vector/SSME engine and scramjets. It may have been able to capture around Mun too. I used rockets where you normally use jet engines, and air-breathing (SCRAM) where you normally use upper-stage lifters. :cool:
On 10/22/2018 at 11:48 AM, BRAAAP_STUTUTU said:

depends, you could probably get enough speed to reach even the mun provided you don't burn up going that fast

it would definitely be even more useful on larger scale systems or larger oxygenenated planets (i.e. GPP's Tellumo)

still i see it being useful on stock sized oxygenated planets as a sort of high ISP SOI exit engine or even going interplanetary perhaps or making LF only SSTO's easier or heck, as a step inbetween the project eeloo engine

regardless it would create intresting design challenges and would probably still be quite balanced

In KSP 1.1, I made a very small test scramjet plane that could make escape velocity and clip the SMA of Duna or Eve. Now, in 2.5x, I'm very fond of this type of engine, especially in GPP where I have Gael itself to frolic in (Mach 11 at 2.5x is the nominal target velocity versus Mach 6 at 1x) and at some point, Tellumo, where roughly Mach 14 is the nominal target velocity at stock scale.... I've never been there in 2.5x to measure that. I'm anticipating that value is Mach 21/RSS level speeds. :o 

On 10/22/2018 at 1:41 PM, GrandProtectorDark said:

@BRAAAP_STUTUTU @juanml82 How I'm reading the technical data  about scramjets, It is estimated that the max speed for ramjets may be  somewhere from mach 10 to mach 17, to even orbital velocity, at mach 25(depending depending on the assumptions and input data). 
Kerbin Orbital velocity is somewhere at mach 6-7ish. For our stock size purposes, conventional ramjets are scramjets.

Btw
Mk2 expansion has a scramjet, which can get up to mach 10.
While testing, I got a cheat plane up to dres.

For stock size, Scramjets are too Powerfull to be reasonable.
But they would work well for RSS I could Imagine

Currently this engine peaks at Mach 10 and dies at Mach 13, and there's an optional patch now to make it start a little sooner and operate up to Mach 7, in accordance with your sentiment about stock scale. In earlier versions I do believe it could operate up to Mach 25.

I'm hoping @Nertea indeed eventually delivers some scramjet engines. 2.5x and higher scale games are indeed popular, and if I may say, there's quite a gap to fill.

There's another mod full of scramjets, but all their Isp are too high, their starting velocities may be too low, and the person who took it over, took down the mod, scared off by the Take-Two EULA thing.

Edited by JadeOfMaar
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2 hours ago, JadeOfMaar said:

In stock scale? No. And there are a few reasons against even having one:

  • Kerbin is the largest stock planet providing Oxygen. Taking one to Laythe is pointless as it's easier to reach orbital velocity without involving a scramjet.
  • Scramjets are really inefficient. IRL ones are measured to have 1000 Isp which chips down as velocity further increases. To be player-friendly, the one in Mk2 Expansion has 2000 Isp.
  • Jet engines IRL can apparently run on Hydrogen and not just Kerosene-alike fuels. Their Isp will go up by an order of magnitude but outside of the Realism Overhaul realm, no one makes jet engines use anything other than abstract LiquidFuel.
  • A scramjet engine is dead mass for even more of the time than a rocket engine on an SSTO in atmosphere. You're really gambling your dV by involving any, and the extra fuel for it in your design.

That said, I made a few pretty viable craft that use scramjets (and I enjoy using these things) and they count on that engine's ability to far exceed Kerbin orbital velocity while still using air and still having higher Isp than any LFO engine.

  • Instead of depending on the Rapier's ClosedCycle, I can coast to over 300km Apoapsis on a scramjet, and be a little more liberal with nuke engines for vacuum.
  • I made a heavy SSTO that used just the Vector/SSME engine and scramjets. It may have been able to capture around Mun too. I used rockets where you normally use jet engines, and air-breathing (SCRAM) where you normally use upper-stage lifters. :cool:

In KSP 1.1, I made a very small test scramjet plane that could make escape velocity and clip the SMA of Duna or Eve. Now, in 2.5x, I'm very fond of this type of engine, especially in GPP where I have Gael itself to frolic in (Mach 11 at 2.5x is the nominal target velocity versus Mach 6 at 1x) and at some point, Tellumo, where roughly Mach 14 is the nominal target velocity at stock scale.... I've never been there in 2.5x to measure that. I'm anticipating that value is Mach 21/RSS level speeds. :o 

Currently this engine peaks at Mach 10 and dies at Mach 13, and there's an optional patch now to make it start a little sooner and operate up to Mach 7, in accordance with your sentiment about stock scale. In earlier versions I do believe it could operate up to Mach 25.

I'm hoping @Nertea indeed eventually delivers some scramjet engines. 2.5x and higher scale games are indeed popular, and if I may say, there's quite a gap to fill.

There's another mod full of scramjets, but all their Isp are too high, their starting velocities may be too low, and the person who took it over, took down the mod, scared off by the Take-Two EULA thing.

i thought the ISP of that scramjet was about 1000?

 

on another note, project eeloo multimode nuclear engine is pretty gud:

FRYFX5l.jpg

yes that is indeed eve, i think i might even be able to get off of it!

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Is it at all Efficient, time or resource wise to attempt using the Near Future Propulsion electric/plasma engines for interplanetary travel?

 

I'm not much of a fan of the super-realistic hyper-delta V+ Long Burn Time engine types some mods use.

But I F'ing love the look of Electric Engines so much. Hnng.

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Depends on how you use them, and what you need. 

As the engines are more efficient, you can use less fuel to transfer more cargo (more resource efficient) or have more fuel and get there more quickly, as you have more delta-V from the same fuel volume. The second option also allows more trips to the target planet, as you can launch in less than optimal launch opportunities. 

There is also ISRU to consider, some planets have NFP fuels available to collect and refine (I believe that Eve has a lot of Argon in its atmosphere, as an example), so these engines are great if that's what you want to do. 

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20 hours ago, Nertea said:

There is a new 4-man pod in that render in the 2.5m scale. However there is also this:

Screen_Shot_2018-10-04_at_6.14.36_PM.png

 

Oh that's NICE. It looks like there's a hatch there below the crew hatch, is that an integrated docking port or some kind of cargo bay?

Edited by Kablob
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I've noticed that there's beautiful 1.25 and 2.5 meter Ion and Hall Effect engine models in the imgur gallery for NF Propulsion but I can't find any Ions or HEs bigger than the .625 size. Am I just crap at searching through my engines tab or am I missing something (like a partswitch model)?

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8 hours ago, ToastyOats said:

Is it at all Efficient, time or resource wise to attempt using the Near Future Propulsion electric/plasma engines for interplanetary travel?

 

I'm not much of a fan of the super-realistic hyper-delta V+ Long Burn Time engine types some mods use.

But I F'ing love the look of Electric Engines so much. Hnng.

It's very efficient resource wise. It's not necessarily best if you want really short burns. The high DV values achievable are great for speeding up interplanetary transfers though as was mentioned.

That being said, just like the stock ion engine, all these engines are tuned to be about 1000x more thrusty than they realistically should be. This helps with burn times.

6 hours ago, Sufficient Anonymity said:

Of course you've got to come out with an awesome release right when I'm moving house and starting a new job and have no time to play it :P

Seriously though, everything you've showed off over the past few pages looks beautiful - you're such a talented modeller.

Thanks! Weeeelll I still have to finish the IVAs for two of the pods so things are still a bit off. 

1 hour ago, Kablob said:

Oh that's NICE. It looks like there's a hatch there below the crew hatch, is that an integrated docking port or some kind of cargo bay?

It is an access door to a cargo area that you can use for adding a docking port or other things you like. 

30 minutes ago, Gibster said:

I've noticed that there's beautiful 1.25 and 2.5 meter Ion and Hall Effect engine models in the imgur gallery for NF Propulsion but I can't find any Ions or HEs bigger than the .625 size. Am I just crap at searching through my engines tab or am I missing something (like a partswitch model)?

Beautiful is subjective, they look like garbage to me! They were removed some time ago when I redid all the engines and made them more cluster friendly.

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Question.....I've been having issues with several craft loading and found out the part missing is the inlineCmdPod. I see the textures and stuff for it in the Parts folder, but the CFG file itself is missing. Is this due to the pod still being revamped or was it just accidentally left out of the build. I ask because the latest version seems to have a PPD-1 pod, but it is an upright vertical pod vs. the flatter PPD-1 from older versions.

Just wondering if I wait for a new version or have to go and manual tweak craft files to try and recover them.

Thanks!

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13 hours ago, jmbailey2000 said:

Question.....I've been having issues with several craft loading and found out the part missing is the inlineCmdPod. I see the textures and stuff for it in the Parts folder, but the CFG file itself is missing. Is this due to the pod still being revamped or was it just accidentally left out of the build. I ask because the latest version seems to have a PPD-1 pod, but it is an upright vertical pod vs. the flatter PPD-1 from older versions.

Just wondering if I wait for a new version or have to go and manual tweak craft files to try and recover them.

Thanks!

I haven't touched that config in a dozen releases. It kinda sounds like you're upgrading from a really archaic version. Perhaps 0.6.0 or thereabouts judging from the changelog. 

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On 10/25/2018 at 3:27 PM, Nertea said:

There is a new 4-man pod in that render in the 2.5m scale. However there is also this:

[Big command pod pic]

Is that an asymmetric biconic lifting body or a simple biconic?  Scott Manley just introduced me to the joys of editing CoM Offset in order to take advantage of Apollo-style re-entry lift, so I'm getting a kick out of realistic entry vehicle shaping.  All these new pods look  great.

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I'm having an interesting time experimenting with the different electric engines of NF Propulsion.

Ya'll probably all know this but from what I am gathering, Gridded Ions need large amounts of battery storage in order to sustain their long burns (greater Energy/Fuel ratio). That or a large amount of energy production. Hall effects have lower power requirements but need larger amounts of fuel than Ions (lesser Energy/Fuel ratio). 

Anyone have any tips on using these electric engines? Like whether energy storage or energy production should be the main concern for Ions? Also, tips for using them for interplanetary travel?

Edited by Gibster
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1 hour ago, Gibster said:

I'm having an interesting time experimenting with the different electric engines of NF Propulsion.

Ya'll probably all know this but from what I am gathering, Gridded Ions need large amounts of battery storage in order to sustain their long burns (greater Energy/Fuel ratio). That or a large amount of energy production. Hall effects have lower power requirements but need larger amounts of fuel than Ions (lesser Energy/Fuel ratio). 

Anyone have any tips on using these electric engines? Like whether energy storage or energy production should be the main concern for Ions? Also, tips for using them for interplanetary travel?

I found just pairing them with a nuclear reactor and scaling the power output to maximum burn works pretty well for a compact probe.  I'm not sure how well this scales up for manned ships though.  The issue I run into is that the larger gas tanks for these are pretty far up the tech tree, so I end up spamming the little ones to have enough dV to get anywhere good.

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1 hour ago, PolecatEZ said:

I found just pairing them with a nuclear reactor and scaling the power output to maximum burn works pretty well for a compact probe.  I'm not sure how well this scales up for manned ships though.  The issue I run into is that the larger gas tanks for these are pretty far up the tech tree, so I end up spamming the little ones to have enough dV to get anywhere good.

I haven't used the nuclear reactors yet. I am doing all my experiments with probes but I want to scale it up to large reusable interplanetary spaceships. I know some of the other engines are probably more conducive to being used on larger craft but at the moment I am kind of enthralled with the aesthetic of the Ions and Hall Effects. I am playing on Sandbox though (I've researched the entire tech tree far to many times for it to be much fun anymore) so I don't have to worry about tank size or whatnot. We'll see if my goal is even possible and it'll be a fine tuning process to figure out which engines are best and how best to use them.

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16 hours ago, KSPrynk said:

Is that an asymmetric biconic lifting body or a simple biconic?  Scott Manley just introduced me to the joys of editing CoM Offset in order to take advantage of Apollo-style re-entry lift, so I'm getting a kick out of realistic entry vehicle shaping.  All these new pods look  great.

I welcome testing of the development version, chances are this will need some tuning to get the profiles right for re-entry.

5 hours ago, Gibster said:

I'm having an interesting time experimenting with the different electric engines of NF Propulsion.

Ya'll probably all know this but from what I am gathering, Gridded Ions need large amounts of battery storage in order to sustain their long burns (greater Energy/Fuel ratio). That or a large amount of energy production. Hall effects have lower power requirements but need larger amounts of fuel than Ions (lesser Energy/Fuel ratio). 

Anyone have any tips on using these electric engines? Like whether energy storage or energy production should be the main concern for Ions? Also, tips for using them for interplanetary travel?

Generally in the mod, gridded thrusters provide more specific impulse at a lower thrust, and hall thrusters provide more thrust at a lower specific impulse. The power-to-performance should be fairly similar between them if you consider the same tech level (ie, entry level HET vs entry level electrostatic). Argon is also much cheaper and easier to find so HETs have another advantage. 

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May have found a bug with the 5m docking ports from the launch vehicle pack...

 

wmgqAKn.png

I tried redocking again at a different speed and with a more on-axis approach... same thing happened. As soon as it docked, it bent like that. :/ Kinda puts the kibosh on my plans to use this as a cargo transport ship if it leaves the cargo off the centerline.

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2 hours ago, MaverickSawyer said:

May have found a bug with the 5m docking ports from the launch vehicle pack...

 

wmgqAKn.png

I tried redocking again at a different speed and with a more on-axis approach... same thing happened. As soon as it docked, it bent like that. :/ Kinda puts the kibosh on my plans to use this as a cargo transport ship if it leaves the cargo off the centerline.

Are you using Autostruts? I've seen this exact thing happen when I used them. If you are, try turning them all off on both craft.

A second possibility is the clipped RCS thrusters. If you clip parts around a docking port the invisible colliders from clipped parts can cause problems.

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15 hours ago, Gibster said:

I'm having an interesting time experimenting with the different electric engines of NF Propulsion.

Ya'll probably all know this but from what I am gathering, Gridded Ions need large amounts of battery storage in order to sustain their long burns (greater Energy/Fuel ratio). That or a large amount of energy production. Hall effects have lower power requirements but need larger amounts of fuel than Ions (lesser Energy/Fuel ratio). 

Anyone have any tips on using these electric engines? Like whether energy storage or energy production should be the main concern for Ions? Also, tips for using them for interplanetary travel?

When designing a typical rocket, you pay attention to your mass ratio (wet mass to dry mass) and your thrust-weight ratio. With electric engines, there's a third thing you should consider: specific power. In other words, how many Ec/s you can generate for a given investment in dry mass.

This is important because electric engines give you this tradeoff in that they allow exceptional dV at the cost of having very bad TWR. But what if, in order to run them, you have to pack on a huge amount of dry mass just to produce power? Then you lose some of the dV advantage, while your TWR falls even lower. You want to avoid this. Therefore, you should examine your mission profile and decide on what kind of power solution you want to go with. On small expendable probes this is usually not such a big factor, but it definitely becomes one on larger ships that you want to be able to return home.

Here's a very rough rule of thumb guideline; the exact numbers and details may vary ingame (especially if you have other mods installed):

Solution Specific Power Advantages Disadvantages
Thermoelectric 10 to 20 Ec/s/ton Simply just works everywhere, no ifs or buts Worst performance
Somewhat pricey and late in tech tree
Might decay over time (with optional patch)
Fuel Cell Array up to 75 Ec/s/ton Works everywhere
Affordable
Fuel is limited and very heavy (reduces specific power)
Array is too large for small probes
Small single fuel cell performs massively worse than large array
Solar 65 to 120 Ec/s/ton No fuel usage
Specific power increases closer to the sun
Spacecraft must be able to align panels to sun during burns
Specific power decreases away from the sun
Might require a lot of area for high-end engines
Nuclear 100 to 250 Ec/s/ton

Compact and powerful
Works everywhere
Extremely low fuel use

Extremely expensive and late in tech tree
Needs dedicated radiators
Fuel is limited and very expensive
Might break if mishandled
Trickle charged capacitor buffer many hundreds of Ec/s/ton Best performance
Relatively cheap and accessible
Manual discharge control required during burns
Burn duration limited by size of buffer
Wait time between burns
Needs a different power source to go with it

Generally, the more you rely on storage - especially if that storage is capacitors - the higher your specific power becomes, but the lower your maximum full power burn time becomes. Since electric engines need long burn times, this needs to be carefully considered during spacecraft design.

However, if your storage solution becomes so large that it equals a large power production solution in mass, you might as well just go straight for that instead.

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9 hours ago, Tyko said:

Are you using Autostruts? I've seen this exact thing happen when I used them. If you are, try turning them all off on both craft.

A second possibility is the clipped RCS thrusters. If you clip parts around a docking port the invisible colliders from clipped parts can cause problems.

You know what... I did have an autostrut enabled to keep the truss section from wobbling atop the rocket. And I didn't know about the colliders...

 

Looks like I need to launch a new version of that truss section. Good thing it's in sandbox! lol.gif

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37 minutes ago, MaverickSawyer said:

You know what... I did have an autostrut enabled to keep the truss section from wobbling atop the rocket. And I didn't know about the colliders...

 

Looks like I need to launch a new version of that truss section. Good thing it's in sandbox! lol.gif

Cool, hope that helps. I made the same mistake many times and had lots of broken stations til someone finally told me about those issues.

 

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3 hours ago, Tyko said:

Cool, hope that helps. I made the same mistake many times and had lots of broken stations til someone finally told me about those issues.

 

Okay, ran the mission again with new RCS placement, no autostruts... and the issue remains. :/ Might have to do this as a monolithic launch, which sucks because the craft is so damned long.

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10 minutes ago, MaverickSawyer said:

Okay, ran the mission again with new RCS placement, no autostruts... and the issue remains. :/ Might have to do this as a monolithic launch, which sucks because the craft is so damned long.

You might want to try two very simple craft - just docking ports and bare minimum necessary to navigate and dock - see if those work okay. Then you'll at least know it's not your modded install that's causing the problems

You can use F12 to rendezvous them so you don't even need to build a launcher

Edited by Tyko
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