KSP Interstellar Extended Continued Development Thread

[FreeThinker]

Well took a bit of effort but I finally got some older shots onto imgur. Will do some more recent ones soon as mk2 versions are finished. (onto last tests now)

SOme of the shots are very dark, but there is detail on them if you turn up the brightness a bit and look at the full res versions.

Hope people find them interesting, very curious to see what others think of 'em. I tried to add enough explanation, but feel free to ask any questions.

http://imgur.com/a/6MFZs

impressive I realy liked your SSTO/Mothership/Lander Combo. That is the way you play it!

You mentioned you ran out of tritium. Why didn't you switch to D-D mode?

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I start to discover the mod and I have a question regarding the wasted heat.

Does it have a purpose? I mean the wasted heat accumulates in my solar panels (fine) and the game allows to stop the accumulation by deactivating the flow (right click/untoggle the green triangle like for fuel). But does the heat has a function with something? A generator or whatever?

THe Wasteheat is a balance realism feature. It forces you to deal with the effect of efficiencies. You cannot have electrical megawatts in space without radiators.

Edited July 30, 2015 by FreeThinker

[Flef]

THe Wasteheat is a balance realism feature. It forces you to deal with the effect of efficiencies. You cannot have electrical megawatts in space without radiators.

oh... yeah right. It can't release it into vacuum easily. Let's put radiators everywhere! Gonna be fun.

[Hazelnut]

impressive I realy liked your SSTO/Mothership/Lander Combo. That the way you play it!

You mentioned you ran out of tritium. Why didn't you switch to D-D mode?

EDIT: D-D mode is not listed for Dusty BTW. (I assume you added this since I built the JE, because it certainly didn't have this option at the time)

Because I also only have a tiny amount of Deuterium left on the Dusty based Jool Explorer, and there's an Endurance mk1-beta called Endeavour on it's way to replace it. To be honest I didn't realise that the stock rads and the KSPI rads were so different and the stock rads are pretty terrible for the KSPI reactors. I should have waited to unlock the KSPI rads before launching. Many times when switching to this craft all the rads explode because they clip into each other which was only way to get enough on for the Dusty to allow 2-3 mins of VISTA use before it throttles. It was a good experiment, but completely outclassed by the Endurance class ships.

Glad you liked em. I will finish the mk2 versions soon and post more detailed & labelled shots.

Edited July 30, 2015 by Hazelnut

[marc40k]

oh... yeah right. It can't release it into vacuum easily. Let's put radiators everywhere! Gonna be fun.

A tip: if you press "I" in the editor, it will show up the thermal manager, and there you can see the quantity of heat generated and radiated, so you don't place too much radiators (or not enough).

Usually, with only solar panels, you can place a couple of reduced radial radiators (using tweakscale) and you're good to go.

[pootis123]

So a thing happened:

I install KSPI-E by merging the GameData folder found in the .zip file with the GameData folder found in the KSP folder (the same for tweakscale) and boot up KSP. I load a save just fine, make a craft, save it, etc. But when I try to launch, all buttons become grayed out and I can't do anything. I restart KSP and try to load my craft. The Load button looks as if pressed, but nothing happens. Halp meh! (Note: on different computer than the one I have KSP on, no logs as a result) I really do want to play the game with this mod, but I can't, it seems. Hallelp ples

[Flef]

A tip: if you press "I" in the editor, it will show up the thermal manager, and there you can see the quantity of heat generated and radiated, so you don't place too much radiators (or not enough).

Usually, with only solar panels, you can place a couple of reduced radial radiators (using tweakscale) and you're good to go.

Ah! thank you!

I made a bit of archeology(I didn't dig much, it is in the OP) and found the initial Interstellar. There is a wiki. https://github.com/FractalUK/KSPInterstellar/wiki/Illustrated-Guide-Chapter-1%3A-Heat-and-Radiators

The illustrated guide covers only 2 chapters after the installation. Heat and Science.

[FreeThinker]

EDIT: D-D mode is not listed for Dusty BTW. (I assume you added this since I built the JE, because it certainly didn't have this option at the time)

Because I also only have a tiny amount of Deuterium left on the Dusty based Jool Explorer, and there's an Endurance mk1-beta called Endeavour on it's way to replace it. To be honest I didn't realise that the stock rads and the KSPI rads were so different and the stock rads are pretty terrible for the KSPI reactors. I should have waited to unlock the KSPI rads before launching. Many times when switching to this craft all the rads explode because they clip into each other which was only way to get enough on for the Dusty to allow 2-3 mins of VISTA use before it throttles. It was a good experiment, but completely outclassed by the Endurance class ships.

The Stock radiators are low tech radiators. They are white and not optimized for thermal rectors. They are only good for first generation Molten Salt reactors which temperature is relatively low. Anything more powerfully and you will suffer from the limited maximum radiator heat.

[raxo2222]

Hmmm AIM reactors are much better than antimatter reactors when it comes to longevity: One AIM reactor with single cryogenic tank of its fuel can last for one year under full load!

Antimatter reactors will burn trough its fuel in less than one day.

Here is makeshift AIM microwave network. I placed these with hyperedit - you could build them here with extraplanetary launchers anyway.

Javascript is disabled. View full album

Antimatter reactor produces as much energy as 6 AIM reactors, at least at 2.5m size.

[FreeThinker]

Hmmm AIM reactors are much better than antimatter reactors when it comes to longevity: One AIM reactor with single cryogenic tank of its fuel can last for one year under full load!

Antimatter reactors will burn trough its fuel in less than one day.

Correct, Antimatter allows you to generate very high amount of power, but due to the difficulty of storage it is not very good for long operation. AIM fuel on other hand is much more dense. Combined with the minimal power lever, it can last incredibly long. The combination is probably the most powerful single vessel solution, but also the most expansive as it requires both antimatter and Helium 3 and very expansive reactors.

[raxo2222]

Correct, Antimatter allows you to generate very high amount of power, but due to the difficulty of storage it is not very good for long operation. AIM fuel on other hand is much more dense. Combined with the minimal power lever, it can last incredibly long. The combination is probably the most powerful single vessel solution, but also the most expansive as it requires both antimatter and Helium 3 and very expansive reactors.

Is there anything denser? I have to test fusion reactors yet.

[Hazelnut]

Hmmm AIM reactors are much better than antimatter reactors when it comes to longevity: One AIM reactor with single cryogenic tank of its fuel can last for one year under full load!

Antimatter reactors will burn trough its fuel in less than one day.

That depends what you use them for. On my atmo plane (Intrepid) I used an AM reactor scaled down to 1.25m because it was the only one that could produce enough power for the thrust I wanted in such a small space. Also it hardly uses any AM when engines are not running so it will last for a long time with the 10g of AM it can store. Also it has some small 1.25 collectors to top up if necessary. For contsant high power applications a big fusion reactor is better.

[raxo2222]

What engine with what propellant has highest thrust per megawatt of power? Vista by default has 2.5 GW requirement which is nice for microwave network

[Hazelnut]

The Intrepid mk2 is complete! Managed to escape Eve legit (i.e. not switching off temp damage) although it took a few tries to get the ascent profile right. Love the fact that I completed a contract for an Eve base with it too. (That's why it has a crew cabin which was not in the original plans. Feedback welcome - will post mk2 of Endurance once it's done.

Here's an album of the Eve launch:

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Here's a labelled construction shot, feel free to ask any questions:

[FreeThinker]

Very cool looking SSTO, but where is the air pre-cooler located?

If you intent to use thermal turbojet at supersonic speed you need to pre cool the air or they will overheat

To solve the overheating at ascend, perhaps it would help try to install the Inline Radiator and connect it directly to the cockpit and move the mk2 reaction wheel to the back of the cargo bay.

Oh, for the ATILA thrusters, I would recommend Hydrazine as the ArcJet favors thermal propellant. It will effectively tripple the trust and only marginal Isp loss.

Optionally, I you could try replace all electric engines by 4 VASIMR and run them on all Hydrazine. Vasmir propulsion is also based on thermal expansion and there works great with hydrazine. It would offer about the same thrust during assent in upper atmosphere with the bonus ability to increase ISP to high value. On the other hand, Vasimr cannot work in Quantum Vacuum Mode like the plasma thrusters can when fully upgraded

Edited July 30, 2015 by FreeThinker

[Hazelnut]

Very cool looking SSTO, but where is the air pre-cooler located? If you intent to use thermal turbojet at supersonic speed you need to pre cool the air or they will overheat

Thanks, glad you like it. The precoolers have not moved, they're clipped into the fuel tanks between the intakes and the Turbojets since I didn't have any mk2 parts except the adapter for LH2. Couldn't figure out how to get enough fuel onboard without mucking up the look of it any other way, and I tried lots of variants. (this one was 5b) I know the engines overheat because I did the first third of the ascent with closed intakes so the precooler was not working and they overheated rather quick. (bit odd that they worked with closed intakes...)

Oh, to solve the overheating at ascend, perhaps it would help try to install the Inline Radiator and connect it directly to the cockpit and move the mk2 reaction wheel to the back of the cargo bay.

Hmm, didn't consider using a radiator - since the heating is from the superheated air flowing all around I figure it wouldn't help much TBH. WOuld be interested if anyone's tested that. Eve's atmo is quite the thing! :-) Taking off from Kerbin is a doddle by comparison.

Oh, for the ATILA thrusters, I would recommend Hydrazine as the ArcJet favors thermal propellant. It will effectively tripple the trust and only marginal Isp loss.

Optionally, I you could replace all electric engines by 4 VASIMR and run them on all Hydrazine. Vasmir propulsion is also base on thermal expansion and there works great with hydrazine. It would offer superior thrust during assent in upper atmosphere and the ability to increase ISP to high value

One of the design goals/constraints was the only fuel it would have is LqdHydrogen. (and Monoprop obv.) The reason for this is that's what the Endurance uses and has 340,000 units of, so it can re-fuel Intrepid. I didn't want to add different fuels basically, and the thrust while LH2 lasts is raised from 80kN to 235kN which is plenty. The other main constraint was that it had to have a 2.5m Sr docking port in middle at the back and not have a mass of more than 18t.

I'm very happy with how it turned out, and will only change it if I can replace the 1.25m fuel tanks with an inline mk2 tank to remove the clipping cheatyness. ;-)

I took a look at the VASIMR and I will use it at some point but I felt it was the wrong look for this spaceplane, so discarded it. I do love being able to maneuver using QV even after the LH2 is all used up. Used 20% slowing down to land and 75% to get up to orbit so I think I judged the amount of LH2 required pretty well.

Edited July 30, 2015 by Hazelnut

[FreeThinker]

One of the design goals/constraints was the only fuel it would have is LqdHydrogen. (and Monoprop obv.) The reason for this is that's what the Endurance uses and has 340,000 units of, so it can re-fuel Intrepid. I didn't want to add different fuels basically, and the thrust while LH2 lasts is raised from 80kN to 235kN which is plenty. The other main constraint was that it had to have a 2.5m Sr docking port in middle at the back and not have a mass of more than 18t.

I see. Notice, Instead of Hydrazine you could fit the SSTO with an Atmospheric scoop and IRSU refinery to create Ammonia in Eve atmosphere. It will give even more thrust at the expanse of a little ISP.

One concern I have with this design is that all fuel tanks are at the back which has consequences when they get empty as the plane will become top heavy, which will make it very hard to pull up. But I guess that's still better than the other way around

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Hmm, didn't consider using a radiator - since the heating is from the superheated air flowing all around I figure it wouldn't help much TBH. Would be interested if anyone's tested that. Eve's atmo is quite the thing! :-) Taking off from Kerbin is a doddle by comparison.

The inline radiator which is an efficient atmospheric Wasteheat radiator has a hidden feature. It also acts as a stock heat sink (it has 10 times the heat capacity for it's mass and high heat conductivity). This means it will effectively suck up a large amount of stock heat from parts around it, (including heat from superheated air) and tries to radiated it away as effective as possible.

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(bit odd that they worked with closed intakes...)

This sound like an exploit.

Edited July 31, 2015 by FreeThinker

[Sacnoth]

For me, mechjeb seems to have serious issues landing any craft with a thermal nozzle. The landing predictions start jumping around like crazy on the door it burns. I'm guessing it's getting confused by the variable thrust per reactor or something. The delta v and acceleration values seem to work ok.

Is anyone else experiencing this?

[FreeThinker]

It's a known issue

[Bishop149]

Excelent ideas. Note Hydrazine should already be possible to be made. check out the ISRU schematic. Note the 2.5m inline IRSU is actualy avialable earlier already (at 500 science). In the past you needed 1000 sci tech.

Ah yes, I see the peroxide process hes been fixed!

Didn't see that come up in a changelog, have been waiting for it!

[Kielm]

@sacnoth Mechjeb only seems to have a problem with the final descent, so you should be okay to use it up to there.

It can maintain the desired braking speed by oscillating around the desired thrust, but if you don't want to make any new craters you'll have to do the final part yourself (which is arguably the easiest part of landing anyway)

[nicholasd123]

I am having a issue with thermal rockets where I get no power unless i have a generator also attached to the reactor. If I just have Thermal Nozzle->Reactor->Fuel Tank I am unable to power my rocket, but if I go Thermal Nozzle->Reactor->Generator->Fuel Tank it works. Has anybody else experienced this issue?

[Cosmonauth]

For me, mechjeb seems to have serious issues landing any craft with a thermal nozzle. The landing predictions start jumping around like crazy on the door it burns. I'm guessing it's getting confused by the variable thrust per reactor or something. The delta v and acceleration values seem to work ok.

Is anyone else experiencing this?

You should try Translatron module of MJ for final descend. Hover at 500 meters, use Translatron "kill H/S" option with KEEP VERT button. Then enter desired speed in a field (-2 for example) and be patient.

Landing with Thermal Nozzle is a tricky thing, so good luck. Have a nice landing

[raxo2222]

It seems like atmospheric scoops doesn't work with RSS.

[Shad0wCatcher]

I can't remember if RSS changes Kerbin's name to Earth in the PQS stuff or not. If it does that's why (KSP-I is looking for specific body names that rely on the stock planets remaining their same name; if they're changed KSP-I won't recognize them and will crash and burn like you see).

[FreeThinker]

I am having a issue with thermal rockets where I get no power unless i have a generator also attached to the reactor. If I just have Thermal Nozzle->Reactor->Fuel Tank I am unable to power my rocket, but if I go Thermal Nozzle->Reactor->Generator->Fuel Tank it works. Has anybody else experienced this issue?

Make also sure you also have a thermal electric generator (+ radiators) connected with the reactor in order to allow the magnetic nozzle (which need megajoule power) to function. Also note the magnetic nozzle does not need to be connected directly to the reactor, you can put a generator in between them (or multiple pats), or even connect them radially

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I can't remember if RSS changes Kerbin's name to Earth in the PQS stuff or not. If it does that's why (KSP-I is looking for specific body names that rely on the stock planets remaining their same name; if they're changed KSP-I won't recognize them and will crash and burn like you see).

In that case, a simple solution would be to add the names of the RSS Planets to the Atmospheric definition files.

Edited August 1, 2015 by FreeThinker