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Project Indefatigability- another hard-mode Kerbalism Grand Tour attempt


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Indefatigability- it's pretty similar to intrepidity, but bigger. Much like this mission aims to be like Intrepidity, but this time I'll actually land on ALL the planets and moons rather than just most of them. Intrepidity missed Moho completely and yet I still didn't manage to visit either of Kerbin's moons. A combination of design issues and less than ideal trajectories is most likely to blame, so this time I'm cutting back on the dead weight and pushing the delta-V to new and exciting heights.

The best way to do both of those things is by using better fuel tanks. But wait, you say, there are no better fuel tanks in KSP! Well, not exactly...

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In the centre, a regular xenon tank with a mass ratio of just 4. On the right, a Kerbalism huge gas canister filled with xenon rather than the more typical oxygen or nitrogen, with a mass ratio of 50.87!

That sort of advantage is just too big to ignore. The only problem really is that ion thrusters are a) incredibly weak and b) very power-hungry; surely you can't make an interplanetary ship that can operate all the way out at Eeloo with ion thrusters?

Enter the mods: Near Future Propulsion with a plethora of bigger and more powerful xenon-fuelled engines; Near Future Electrical for the nuclear reactors needed to power those bigger and more power-hungry xenon-fuelled engines; Heat Control and System Heat to deal with the cooling for those nuclear reactors; and I added Near Future Launch Vehicles just to get a 5m cargo bay to store stuff in.

Xenon-fuelled Hall effect thrusters and a 1.25m reactor are enough to create a craft that can tow my entire Tylo lander stack and a year of supplies, with a delta-V of 13km/s and some of the best plumes out there:

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A bit of design work to adapt the Intrepidity has resulted in this, the Indefatigability:

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The top half is nearly identical to Intrepidity, but with a few key changes: the Eve lander now uses liquid-fuelled boosters rather than SRBs (maybe that'll make it easier to land where I want to?); one Hitchhiker has been removed to save weight, along with the 2.5m cargo module and most of the cargo parts that I ended up throwing away last time; and the life support and chemical modules have been tweaked to recycle waste resources into usable oxygen, water and even monopropellant.

The bottom half, on the other hand, is completely new: a 5m cargo bay (from NFLV) houses all the reaction wheels, radiation shields and RA-15 dishes along with four large nuclear reactors (NFE) to power the engines and three tiny reactors (also NFE) to power the rest of the ship; below that, a 5m probe core and a 5m engine adapter (both NFLV) are completely engulfed in xenon canisters, with the four VASIMR engines on the bottom. Radiators (Heat Control and System Heat) are positioned on the engine adapter, the 3.75m-5m tank and on the reactors themselves, while some capacitors (NFE) can provide a dribble of power while the reactors spool up. The ship is also outfitted with two independent RCS systems- a high-thrust system using NFLV monopropellant thrusters, and a low-thrust system using NFP xenon RCS thrusters. That xenon-fuelled space tug I showed earlier is also included on this design, however the Laythe plane is missing (it can't be docked in the VAB) and I plan to add a solar-powered xenon space tug to make the trip to Moho and back, which might replace the backup Tylo descent stage depending on how heavy it is.

Those VASIMR thrusters can vary their ISP and thrust- more thrust means less ISP and vice versa- and at maximum efficiency this ship in its current form has a delta-V of... 60km/s! Obviously this won't be the case in flight as the TWR in this mode is a pitiful 0.03, but with the engines set to 50% efficiency the TWR is broadly comparable to what I was getting when I tried using a dozen 5m NERV-powered boosters, yet the delta-V is more than triple what the nuclear version could manage at a tenth of the total ship mass.

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This isn't the final design- I might change the smaller nuclear reactors for a cluster of RTGs to avoid the risk of a failure and I've added some solar panels to the back of the cargo bay to power the ship's systems in the inner system, which can then be ditched when I head out beyond Duna.

At this point I've basically given up on the idea of doing this "as stock as possible"; I tried that, it didn't work very well, time for a different approach.

Full album: https://imgur.com/a/TFMD7Nv

Flag count so far: 0, because I haven't started yet :rolleyes:

Spoiler

When you're launching a large, high part count vessel using a large, high part count rocket and everything suddenly freezes for a whole minute, you know something bad is happening... And it was!

iDly2SS.png

Edited by jimmymcgoochie
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22 minutes ago, Spaceman.Spiff said:

ah yes... mods

I was trying not to go down the modded route, but when the options are a ten kiloton, thousand part ship using NERVs or a one kiloton, 600 part ship using mods there's only going to be one winner. Once I noticed the ludicrous mass ratios of those xenon tanks, there was no going back...

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I think I've tried at least eight times to launch Indefatigability into space over the last 24 hours, but every single time something has gone horribly wrong and the game did that "frozen for ages because everything is disintegrating" thing. At first I thought it was my hastily bodged together rocket that was to blame, but the same 2kt launcher I used for Intrepidity (with KSTS that time) also had issues. I'll come back to it later, but having repeated failures for no particular reason is annoying and I have to reboot the game each time it happens.

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I've spent a good while trying again and again to get this ship into space, but it just isn't happening- one way or another it explodes on the launchpad. I even tried just parking the ship itself on the pad, no autostruts and with the indestructibility cheats switched on, and parts were floating around all over the place. I don't know what's wrong with it, but it looks pretty terminal and I really don't have the patience to try and fix it when each launchpad explosion takes several minutes to happen and often requires a game reboot to recover from.

The one time it almost worked, I got all the way to booster burnout before everything spontaneously shattered:

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On closer inspection, it seems that Indefatigability has some weird structural issues when it sits on the ground in 1g:

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Floating parts that would wander around for no reason at all, horrlble instability and all that with the indestructibility cheats switched on- as soon as I turned those off, many explosions ensued. It seems Indefatigability can't handle gravity at all.

With no other option, I deployed KSTS again; first launching a payload of ore into orbit then re-using the launch profile to send Indefatigability up in one go, without the constant RUDs that happened when I tried to launch it using the very same rocket as in the recording.

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At last, Indefatigability is in Kerbin orbit, awaiting the Laythe plane (now upgraded with a heat shield on the nose) and its duo of plucky adventurers who will be making this voyage. And for the first time, I got a look at the Waterfall plumes for those VASIMR engines, which are suitably stunning:

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A test run showed that it would take about 90 minutes of continuous prograde burning to reach escape velocity, taking a whole orbit of Kerbin and a pretty long trip through both of its radiation belts in the process. Periapsis kicks might be an option, but with a TWR of 0.05 that would mean many doses of radiation which I'd rather avoid; plan B is to burn prograde until the apoapsis is half way to the Mun, circularise up there and then plot the course to Eve.

Speaking of Eve- the next transfer window is a whole year away, so there's plenty of time to get those flags planted on the Mun and Minmus and giving me a chance to test out the solar-powered ion probe that will eventually be taking a lander from Eve to Moho and back.

Full album: https://imgur.com/a/MWOQUoJ

Flag count so far: 0, I still haven't started yet!

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Indefatigability is finally complete and ready to go following the addition of the new and improved Laythe SSTO- improvements include a heat shield and an RTG. With that added, all that's left is the crew:

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I then noticed that a few important parts were missing, so sent up a little probe to deliver those:

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That crew pod will stay in LKO until Indefatigability returns to then take the crew (and science!) down to the surface; assuming all the parts don't fail following decades of drifting in space with no maintenance.

With the ship fully kitted out and a year to wait until the transfer window to Eve, there's plenty of time to get the easy flags planted on the Mun and Minmus, something I completely failed to do with Intrepidity.

To the Mun:

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Not the best landing ever, but nothing was damaged during landing or liftoff so it's fine.

And then to Minmus:

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This was the first real test of the solar-powered Ion Space Tug, which has passed with flying colours- admittedly the TWR of 0.07 with a fully loaded Vall lander is rather dismal, but with 25km/s of delta-V including that fully loaded Vall lander, there's more than enough range to get to Moho and back. It can even run four Dawn thrusters at full power around Kerbin so will be more than capable of working around Eve and Moho.

Completing these landings does mean that I'm no longer able to launch anything new to add to Indefatigability as the voyage has technically begun, even though it'll be parked in LKO for another year or so.

Full album: https://imgur.com/a/DNW4fp3

Flags planted so far: 2!

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There's some serious weirdness going on.

First, MechJeb keeps doing the stupidest transfer burns ever, including this absolute beauty:

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Yes, let's go SOLAR RETROGRADE to Eve...

And on top of that, the VASIMR engines aren't working properly- they're using far less power than expected (which is actually good, I only need to run one reactor instead of four) but are producing less than half their maximum thrust when using persistent thrust under time warp making all those long burns take even longer. In addition, the persistent heading part of it isn't working either which just makes things worse.

If I can't fix these issues, it might be the end of this Grand Tour; I'm not waiting for real life days to complete these incredibly long burns.

 

 

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1 hour ago, jimmymcgoochie said:

And on top of that, the VASIMR engines aren't working properly- they're using far less power than expected (which is actually good, I only need to run one reactor instead of four) but are producing less than half their maximum thrust when using persistent thrust under time warp making all those long burns take even longer. In addition, the persistent heading part of it isn't working either which just makes things worse.

If I can't fix these issues, it might be the end of this Grand Tour; I'm not waiting for real life days to complete these incredibly long burns.

yes, i had similar problems with ion-powered Nail. I had to turn it into nuclear-powered Bolt.

persistent thrust is seriously bugged when it comes to large ships. Still, with 0.07 twr it should not take days for burns, merely one or two hours. Unless you are actually trying to use that solar retrograde trajectory...

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These VASIMR engines are unusable with Persistent Thrust, I was doing the final burn to Eve and they were down to less than half thrust despite running all the reactors at full power. Maybe there's some kind of interference between PT and Kerbalism or between one of those and NFE, but the upshot is those burns are going to be prohibitively long especially when I have to do them at 1x speed- and that's considerably less than real time due to the fairly high part count.

The ship has the delta-V to complete the trip, definitely- up to 50km/s depending on the engine settings- but I just don't have the patience to leave the game running for hours just to make a single, horribly inaccurate transfer burn from Kerbin to Eve that's not even 1km/s, let alone the much larger burns to reach Moho or Jool, and then do course corrections after every burn and then course corrections for the course corrections...

As frustrating as it is, I'm pulling the plug on this mission.

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8 minutes ago, jimmymcgoochie said:

These VASIMR engines are unusable with Persistent Thrust, I was doing the final burn to Eve and they were down to less than half thrust despite running all the reactors at full power. Maybe there's some kind of interference between PT and Kerbalism or between one of those and NFE, but the upshot is those burns are going to be prohibitively long especially when I have to do them at 1x speed- and that's considerably less than real time due to the fairly high part count.

The ship has the delta-V to complete the trip, definitely- up to 50km/s depending on the engine settings- but I just don't have the patience to leave the game running for hours just to make a single, horribly inaccurate transfer burn from Kerbin to Eve that's not even 1km/s, let alone the much larger burns to reach Moho or Jool, and then do course corrections after every burn and then course corrections for the course corrections...

As frustrating as it is, I'm pulling the plug on this mission.

For the next attempt maybe try the Emancipator NTR from KA with the big round hydrogen CryoTanks. You can get a lot of delta-V with much more reasonable burn times. 

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1 hour ago, Spaceman.Spiff said:

For the next attempt maybe try the Emancipator NTR from KA with the big round hydrogen CryoTanks. You can get a lot of delta-V with much more reasonable burn times. 

I was trying to avoid using mods; I made the exception because of the stupidly high mass ratios of those Kerbalism gas tanks when filled with xenon.

I don't think there's necessarily going to be a next time, at least for the near future- back to Terranism Space Program for now.

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Don’t cancel, just add more engines and suck it up(sorry for bluntness) you can run 4x physics warp, which raises perceived twr to 0.28, more if u add 4x engines to use all the excess power, heavier and reduces dv, but a smidgen more fuel will do.

Remember, u have 50 km/s so moar engines won’t hurt.

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Indefatigability lives!

Goodbye buggy Persistent Thrust, hello Better Time Warp to crank the physics warp speed up well beyond stock. This obviously has detrimental effects on ship integrity (read: bending in half, bits snapping off and general wobbliness) but a few tactical autostruts will hold the shakiest components in place and prevent the ship from flexing too much. Long burns are guaranteed, but running at 8x physics warp and full engine thrust it's a lot more manageable than Persistent Thrust ever was.

It's goodbye to Kerbin...

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And hello Eve!

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It'll take 140m/s to capture into Eve's SOI, but 1400m/s to get to a low circular orbit due to the high gravity and correspondingly large SOI. A course correction between Kerbin and Eve fixed the poor accuracy of the final transfer burn and also provided an equatorial orbit around Eve, which is good for rendezvousing with the lander after landing but means I'll have to dodge the oceans again like with Intrepidity.

A few burns to drop the apoapsis and some of the first ring of xenon tanks are nearly empty. I've shuffled fuel between them to dump six empty tanks, but when I tried to do so I accidentally removed one of the tanks with fuel still in it; when I reattached it, many explosions ensued. Note to self- don't reattach those Kerbalism gas canisters, EVER!

Full album: https://imgur.com/a/68qcFU5

Flag count so far: 2

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58 minutes ago, jimmymcgoochie said:

It'll take 140m/s to capture into Eve's SOI, but 1400m/s to get to a low circular orbit

did...

did you really...

did you really CIRCULARIZE ON EVE?? :o:o:o:o:o:o

that's horrible. you never want to circularize a mothership around eve. it's a large fraction of your total fuel thrown away. I'd never have completed any of my missions if I tried circularizing around eve.

what you want to do is to send in the lander, possibly with aerobraking, and to circularize with a smaller ship, that's just large enough to grab the lander once it returns up from Eve.

Heck, I had to scrap my mission and start it again specifically because I lacked such a ship. your previous grand tour would have reached the end if you had saved those 2800 m/s.

 

the mothership wants to always stay in elliptic orbit. cheaper to get there because you don't need to circularize, cheaper to get away because you're already close to the edge of the SoI. The lander wants to start and stop from low orbit, because the lander must be light to have high thrust, you don't want to load extra fuel in it. And you use a support ship - one that's basically a glorified fuel tank - to ferry the lander from the mothership to low orbit. Your landers consume very little compared to the mothership. So you want to move the mothership as little as possible. it's cheaper to burn 1000 m/s on a shuttle than 50 m/s on the mothership.

 

then again, you have 50 km/s. You'll be fine.

 

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@king of nowhereI haven't gone all the way down yet, just ~400m/s of braking so far. My last attempt to land on Eve needed a lower orbit or the lander would cook itself, but I might be able to do something with one of my various Space Tugs to brake the lander down a bit more without wasting all that time bringing Indefatigability down with it.

The problem that then arises is getting back out of Eve's gravity well with a very elliptical orbit, if the destination is in another direction. I had to deal with that to some extent with Intrepidity but with the much lower TWR I have now it would be a lot worse.

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5 minutes ago, jimmymcgoochie said:

@king of nowhereI haven't gone all the way down yet, just ~400m/s of braking so far. My last attempt to land on Eve needed a lower orbit or the lander would cook itself, but I might be able to do something with one of my various Space Tugs to brake the lander down a bit more

can't you gradually aerobrake your lander? i found a 75 km periapsis is generally good for it

 

Quote

The problem that then arises is getting back out of Eve's gravity well with a very elliptical orbit, if the destination is in another direction. I had to deal with that to some extent with Intrepidity but with the much lower TWR I have now it would be a lot worse.

yes, but still worth it. With Bolt I solved it with gravity assists, I got cheap trajectories. with the Dream Big I solved the problem by a large correction burn in interplanetary space, it was more expensive but still much cheaper than trying to circularize around Eve and then getting away.

 

You also have the option of going around Gilly. From Gilly you can eject with the standard manuever of falling towards the planet first to get Oberth effect; it costs 500 m/s to reach Gilly and 400 to get away from it, but you can then leave Eve from an elliptic orbit pointed however you like.

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The hardest landing and ascent of the lot- Eve.

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Almost a hundred parts and a hundred tons is included in this mission just to get to Eve's surface and back. This is why I go to Eve first, to get rid of that big, heavy, high part count lump of stuff that hangs off the front of the ship.

The design here is nearly identical to that used by Intrepidity, so unsurprisingly it worked perfectly even when I tried some more aggressive aerobraking to avoid the oceans. The one thing I didn't change, though, was the ladder positioning; spoiler alert, I should have changed that.

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The landing and flag planting took place in the dark. As is right and proper.

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It took a few attempts to get a landing that wasn't in the water or at really low altitude; this one was at about 2km ASL in the peaks.

It was only after I sent Phoebe out to plant the flag and do some science that I realised the problem with the ladders- the lowest ladder is slightly too high for a Kerbal on the surface to jump up and grab. EVA construction solved that problem in a way that fortunately didn't cause any explosions and only one fall from a considerable height due to a misaligned ladder. That didn't stop Phoebe from climbing half of the ladders upside down, but I think that's just a minor bug with the way those ladders work.

With no way for the lander's upper stage to get all the way back to Indefatigability on its own, I sent one of the nuclear-powered Ion Space Tugs down into a 100km circular orbit of Eve to catch the lander and tow it back to Indefatigability, or Gilly if the opportunity arose. Sadly I completely forgot to add a docking adapter so they can't actually dock to each other, meaning I'll have to send that one back and deploy another; the good news is that the Ion Space Tug worked well, its four Hall effect thrusters hustling it along with a comparatively huge 32kN in total. Had I done the Eve ascent first and then sent the IST down I would just roll back to the last save and do it again with the adapter attached, but I sent IST down and then did the ascent so that's not an option- I'm not doing that Eve ascent again any time soon!

A few failed Eve ascents later and at last it all came together:

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There's enough fuel to do a bit of rendezvousing and docking, or quite possibly to do a landing on Gilly as the docking adapters now contain a small quantity of LF/Ox (a patch from Missing History turns the FL-A10 adapter into a fuel tank which I use regularly in other saves and have added here too) and the orbital velocity out there is ridiculously low- I could probably land the lander using RCS alone.

Full album: https://imgur.com/a/RAU7Okc

Flag count so far: 3.

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Following the minor debacle of the first Ion Space Tug being sent down to low Eve orbit without the docking adapter to actually dock to the Eve lander, the second IST was sent out- with adapter- and successfully docked.

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A short trip out to Gilly followed and the flag was duly planted.

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Returning to Indefatigability was a bit more challenging as the orbits didn't intersect very well. Approach speed was 1200m/s, requiring two braking burns to first enter into a 2:1 resonant orbit and then pull alongside and dock.

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Next up on the list is a trip to Moho. This may require some supply pod shenanigans to make sure that whoever goes over there is still alive when they get back...

Full album: https://imgur.com/a/TtrT4PL

Flag count so far: 4.

 

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Crunching the numbers for going to Moho and things are looking dicey...

On the one hand, it's not an issue of delta-V; I have oodles of that. The problems are threefold:

- Transfer windows are off. The window to Moho is open now, but it's less efficient than the next one which opens in about 120 days; but if I wait that long I'll miss the Eve to Jool window. I also have the problem of supplies, specifically that the food and oxygen supplies on the solar-powered Ion Space Tug, which I brought solely to go to Moho and back, aren't actually sufficient to get to Moho and back using the most efficient transfers. I could wait for the next Eve>Jool window in about a year's time and still have plenty of time to land on Jool's moons before heading to Eeloo, but if I went to Duna first I'd miss that Jool>Eeloo window and that would be that.

- Burn times with ion engines are ridiculously long, it'll take over an hour of continuous ion thrust to send a lander from Eve to Moho and nearly two hours to brake at the other end. Splitting up the departure burn is feasible, but the capture is an all or nothing event.

- I'll need to take the Vall lander with its full load of radiation shielding. I tried a run with the Tylo lander and poor Connor was at 75% radiation before I was even half way to Moho. The real issue is that there's no part shielding with this design, pointing away from the Sun doesn't reduce the radiation in the lander can at all. I could try to solve that by dragging along the normal, LF-powered Space Tug (drained of fuel to save weight) to act as a radiation shield, but that's a lot of excess weight and that makes the burn times even longer.

Going down to Moho with Indefatigability is a no-go, the burn times would be horrendous and I really don't want to waste the xenon on making that trip with the full ship; I may have to cannibalise some parts to make this trip feasible, maybe I can steal one of the radiation shields?

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Moho is a pain to get to- a very low, inclined and eccentric orbit means delta-V requirements are very high- and when you get there it's not even that interesting. Still, at least this time I actually got there!

The first time I tried, Connor hit 75% radiation exposure before getting half way to Moho; second time round I nicked one of the active shields from Indefatigability which made all the difference- he arrived at Moho with 0% exposure, but the delta-V for the Moho Space Tug tanked substantially due to the considerable extra weight.

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Burn times with ion engines are extremely long, good thing I can push physics warp up to 20x to make it happen a whole lot faster.

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Landing was uneventful and soon enough the flag was planted, sample taken and science gathered:

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And then it was time to go back again. Fortunately the Moho>Eve window was open as soon as Connor arrived, but unfortunately there was no way to make the ~4500m/s escape burn inside Moho's SOI without crashing into it. This required a very long course correction in solar orbit which used up most of the remaining xenon, but got an Eve intercept with mere days of oxygen left; the oxygen supply was the main limiting factor on this trip due to my not checking how long an Eve-Moho round trip would take.

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After arriving, the Moho Space Tug tried valiantly to get an intercept of Indefatigability but ran out of fuel. Connor swiped some useful parts- solar panels, capacitors and monopropellant tanks- before the Space Tug arrived to take him back to Indefatigability.

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92% stress from that trip, but amazingly not a single stress-related incident; 14% radiation exposure which can be healed away during the trip out to Jool. The shield is now attached to the front docking port of the ship since you can't attach parts if they clip into other parts in EVA construction mode, while the solar panels are still attached to the Tylo lander for now to get better exposure.

Full album: https://imgur.com/a/xcqG7op

Flag count so far: 5, and I made it to Moho this time unlike with Intrepidity.

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