king of nowhere
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Part 10: Spreading out
The various landers are launched towards their destinations. Some complexity was caused by having to make sure the long burns didn't overlap.
Day 226: The various landers each rushing to its destination
SpoilerNow comes the complex part. Of course, if I want to do a Jool 5 fast, I can't land on one moon at a time. My initial plan involved a lander for Bop and one for Pol, each with plenty of xenon. One for Tylo, with only enough xenon to get there. Laythe and Vall, being the closer moons, will both be serviced by La coscienza di xenon. It would have been complicated to add space for a fifth pilot inside the return pod; I'd have gone for 3 if I could have. So, La coscienza di xenon will go to Laythe, drop the lander, go to Vall, drop the lander, go to Tylo, pick up all the other crews that gathered there. I modified the plan a bit, but one thing at a time.
First thing, now that I'm in a 1-day orbit, is to determine the best times to drop the other landers. First let's see how hard it will be to get to Laythe.
Actually, I'm already in an intercept course for Laythe in less than 2 days
Ok, one problem solved - though I'd have liked to get there even faster, I have to be rational and conserve xenon for the return trip; it's likely to save a lot more time then.
So, before my current orbit intercepts Laythe, I can go for a sort-of-Hohmann transfer on Bop.
Indeed, the Bop lander trajectory
Handling Bop inclination from this low orbit is a real bother. But I can get there with 4 km/s in 4 and a half days, leaving 3.5 km/s and 5 days to return and keep the objective of finishing Jool in 10 days.
The plane change, also a good chance to get a good glimpse at this lander
Bop lander is performing its plane change while Pol lander is crossing Laythe's orbit
That plane change is finished only 8 minutes before the trajectory change for the Pol lander
Having so many landers with slow ion engines, I have to be careful to not overlap some burns. On the plus side, those small vehicles are so light that they manage to have a somewhat decent TWR despite an underpowered ion engine; their ignitons take a few minutes.
And here is a comparison between Bop lander and La coscienza di xenon. The latter's plane change is 25 minutes away from Bop lander's periapsis raising burn. Enough of a difference
La coscenza di xenon, on the other hand, has really low thrust. We're talking like 0.01 on Kerbin. Its injection burn on Laythe is going to take tens of minutes, 25 minutes of allowance would not be enough. Luckily, when it will need its capture burn in one day, all the other landers will be already on their way.
Meanwhile, I realize a fundamental construction mistake on the Vall lander. Two, actually. The first is that the Vall lander was attached to a truss on the Laythe lander. But I need to land on Laythe first. Easy enough, I have a few docking ports to move.
Moving the Vall lander to a different place
The second mistake is that it's got too little deltaV. I didn't factor in the mass of the pilot when calculating deltaV. It's fine, I can just finish orbiting with the jetpack; it's just another of those things I don't like doing, but no way I'm going to repeat that endless Jool capture burn to fix the lander if I can still make it work.
The Vall lander in its new place
With this first real good image of the Laythe lander, it's time to actually explain that thing with the trusses. See, while I have Bill on the Tylo lander to drop spent tanks (yes, I don't like doing it, but in this case I'm doing an exception), all the other landers will be crewed by pilots. And while I had everything working on the Laythe lander, I was missing the parachute.
Seems like an inconsequential issue, but where to strap it? I want to detach it before returning to orbit, but I won't have an engineer to do it by EVA construction. I considered putting it on a decoupler, but they leave some sort of half-trusses jutting out, and I'm not sure if they have mass or create drag. Plus, it's additional mass. The Laythe lander is only 3.5 tons, a parachute counts, every decoupler counts. So I devised that truss structure to hang the parachute on top of the lander while also being able to remove it. The other lateral trusses are simply landing legs, much lighter than the regular ones. And the trusses on top also give a good docking spot for the Tylo lander.
Speaking of which, it's its turn.
The Tylo lander detaches from La coscienza di xenon...
...And jettisons the connector
Maneuver to Tylo. The gravity assist from Laythe is purely coincidential: Laythe was on the way, and I had to incorporate it in the trajectory on way or another
This approach is fairly close to an Oberth transfer; Tylo is close enough that I can get there in a short time, and the Tylo lander doesn't have all that much fuel to spare. Especially since it will need over 800 m/s just to circularize. Once again, I made sure to not overlap maneuvers.
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Part 9: Gotta go even faster!
Going to Jool in 218 days.
Yes, it's a long time
, but the planetary alignment is unfavorable.
The last maneuver to Jool
SpoilerJool is behind Kerbin at the moment. Waiting for a better alignment is out of the question, using a solar retrograde orbit is a bit too much even for my purposes, so I have to go inward towards Kerbol, pivot around it and reach Jool at high speed. The first step, anyway, is to leave Kerbin. I have included chemical fuel to jumpstart the trip because leaving a gravity well with ions alone is not practical, it would cost me precious days.
This is where I will go with chemical fuel alone
The Kerbin ejection stage, in all its glory
I regret using cougars instead of rhinos for A'Twin. The cougars are better, but the rhinos just have a much cooler exhaust.
The Kerbin ejection stage is jettisoned. La coscienza di xenon is now on its own
The long piles of xenon tanks
And the trajectory
The first 3400 m/s is to reach peripapsis faster. The subsequent 10 km/s too. But that speed is not going to be wasted, because I'm pivoting around the sun and using that speed to reach Jool real fast. Is it appropriate to say I'm taking a gravity assist from Kerbol? You can't take a gravity assist from a body you're orbiting, but I'm actually in a hyperbolic trajectory.
I will make a modification to move some of that 10 km/s burn at perihelion; I get there a bit later, but I have a lot more Oberth effect, and I can better control my trajectory.
The 15 km/s intercept speed on Jool are underestimated; I won't be getting any Oberth effect with a long ion burn. But it's just to get a rough idea.
A quick calculation shows I nominally have 35 km/s - counting that some xenon is used by the landers - but I'm planning on shedding a lot of mass along the trip, so I will gain at least 10 km/s. And for the return trip I will only have a small ship.
Beautiful blue glow
Dumping some excess mass
I loathe using EVA construction in place of staging. Feels like an abuse. The original project actually included decouplers, actually. But you saw how the ship was 254/255 parts? Those decouplers alone were adding, like, 30 parts. They had to go. I also removed four solar panels, after realizing that only 2 are exposed to the sun anyway, and they are enough to feed the engines. Already 1200 km of dry mass saved!
Just the alignment bug. Some reloading fixed it
The burn at perihelion
I wanted to use the persistent thrust mod for this mission, since I have a lot of really long ion burns. But it turns out there was some malfunction, the ship had a lot less thrust than it should have during time warp. So, since my thrust is already low enough, I had to ditch the mod and perform every burn at 4x. I kept myself busy with other stuff, running kerbal in background.
After perihelion, another "staging"
I'm not talking about the empty tanks. This time I'm also ditching six engines. The thing is, I wanted to have "high" thrust for this part of the mission: I will stay close to perihelion only for a relatively short time, a burn time greater than one day would have incurred significant cosine losses and/or risked pulling me off trajectory. Hence the seven engines. But next burn will be at Jool, and the solar panels will be nearly useless. I can't power seven engines with the rtgs available, so I'm ditching them - and the solar panels - to save another couple tons. By now I'm left with 24 tons of xenon out of the original 44 - 23, counting that roughly one ton is reserved for the landers.
At first I kept two of the lateral engines, then I realized I could "borrow" those of the Bop/Pol landers.
Day 211: Starting Jool approach procedures. You can see Jool as a green dot just a few pixels wide on the left of the ship
After some approximated calculations, I determined that it will take some 13 days for La coscienza di xenon to brake. I then eyeballed 8 days before periapsis to start braking. Intuitively it feels right to use half the time to periapsis, because the ship will be slowing down, plus a bit more for safety. But I sit down to try and calculate it, and actually got that I have to start at 2/3 T. Which makes it 8 days 2 hours anyway. The ship losing mass and increasing acceleration compensates for the two hours missing.
For all the huge SoI of Jool, I'm still well outside of it by the time I start the burn. In fact, I'm, like, 8 million km from Jool. At this speed it would only take 10 days to cross the SoI and go out on the other side.
Day 214: inside Jool's SoI. 4500 m/s lost
Day 219: I've been braking for 8 Kerbin days. Since the ship has slowed down, I'm still 3 days from periapsis. 10 km/s lost so far. 10 tons of xenon used out of 23
Somewhere in there I realized I was braking faster than planned, and did a pause of one day or so.
Day 222: the speed was reduced to almost reasonable. Still A day and a half to periapsis
Day 224: Cilia leaves on the Pol lander
Pol lander trajectory
As you can see, by now Jool is curving my trajectory enough to pass near Pol. I detach the lander before braking further; this allows reaching the moonlet in less than 5 days. I have hopes of doing all the landings in 10 days and going back. The Pol lander (and its identical twin Bop lander) is a very lightweight ion probe with 8 km/s, it will land on ion power alone since the gravity is so low. Here I'm spending 3 km/s to reach Pol, leaving 4.5 km/s to return.
Bop is on the wrong side of Jool and I can't detachits lander yet. I have to take a turn around Jool first. As for Tylo, that lander does not have enough thrust or deltaV to get captured from a high energy trajectory like the one I'm using. So the other landers will have to wait until I get captured.
Losing 4 RTGs is impacting my already meager thrust, but La coscienza di xenon is almost captured.
Getting close
You can see I'm already in Jool orbit, but apoapsis is very high. I must make almost a full turn around Jool before I can release the Bop lander, so I need a fast orbit, can't waste time.
Day 225: In Jool orbit
I started with 43 tons of xenon (plus one for the landers) and I'm down to less than 6. I squeezed roughly 40 km/s out of it. I'm counting on my remaining xenon to give at least 20 km/s once the landers are dropped.
When I started the speedrun I wanted to go everywhere in 2 years, but now that I'm focusing everything in a single mission, maybe 1 year is feasible?
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Part 8: Up with challenges, down with burocracy!
The challenge is revamped, with a modified objective: instead of landing everywhere, a single Jool 5.
La coscienza di xenon, ready to launch
SpoilerEven as I abandoned this challenge, I felt some regret. What I really disliked about it was the hassle of having a dozen missions simultaneously, coupled with long burns on ion engines. However, if I could just make a single self-contained mission, then the speedrun would be more fun. Hence the Jool 5.
So, after finishing my other challenges elsewhere, I eventually returned here.
I reloaded to just before launching the Eeloo mission. There won't be one, and I need to save the money.
I still had a few missions returning from Mun with science, so I had to wait. And gather money. I waited for everything to return to Kerbin. First I needed to unlock a few additional pieces. Then I needed extra money. Then I had too many parts (VAB level 3 is too expensive) and I needed mammoth engines to save parts on the launcher.
I'm using my money and parts available to the utmost limit
This time, having a single mission to focus on, I tested more thoroughly. I also put more effort into weight reduction. I normally dislike external seats, I like to keep the appearance of a real spaceship. This time I used them. I still needed a crew pod with a thermal shield to survive a high speed reentry. Ok, maybe it would be more efficient to just load more xenon, but whatever; at least I can give the semblance of an actual cruise stage. I used a crew pod for Laythe because a seat in a fairing generated an incredible amount of drag. I asked about the workings of using a fairing as root part, and I got the impression that advanced aerodinamics is virtually indistinguishable from bug exploiting. Not for me.
With the landers and return vehicle ready, I only had to load as much xenon as possible, until I run out of money or parts - whichever comes first. Then a couple thousand m/s of chemical fuel to leave Kerbin's gravity, and a launcher.
The ship practically begs a name that's a pun on xenon. I picked La coscienza di xenon, from a famous book (La coscienza di Zeno). At least it's famous in italian literature classes, I'm not aware of anyone actually reading it.
The fairing is a big business, but still much smaller than the previous attempt at Jool
La coscienza di xenon, orbital stage. I went a bit overboard on the "safety margin" on the launcher
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18 hours ago, Kurld said:
If you play the game very long you will see it: decoupled boosters or other garbage in map view that dips well into kerbin's atmosphere only to emerge on the other side unscathed, and since they are on rails, their orbits never decay and they don't go away until you bother to go into the tracking station and remove them manually.
How low can you go and remain safe?
iirc, it should be 25 km, as long as you're not in physical range
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no idea, but i always used electric rotors. which consume a pittance and are basically endless with just a few rtgs
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if there is, i'm not aware of any.
still, having to press T or R doesn't seem like a big deal
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Part 11: Introducing Priax
Starting the circumnavigation of Priax, to the north pole.
SpoilerPriax is a small moon, but not diminutive. With a nominal radius of 74 km, it is slightly bigger than Bop, and it has slightly more surface gravity.
The most striking feature of Priax, though, is the extreme irregularity of its surface. Priax is the body with the highest difference between highest and lowest point - the highest being at a record 30 km, and the lowest at 8 km. By sheer coincidence, the highest point is the bump just to the northeast of my landing spot, but I didn't realize it at the time and didn't mark it with a flag. What's the point of having a lowest point at 8 km? Wouldn't it be simpler to just make the radius 82 km and reduce the altitude of everything by 8 km? Meh. Most of the surface is between 20 and 25 km of elevation, so the actual diameter of the moon is closer to 95-100 km, and the gravity is slightly lower than on Bop, seeing as how you are farther from the "sea level" where you'd get the nominal value. The craters are very deep, with steep walls, providing the lower altitudes. Priax is the most irregular body among those in hydrostatic equilibrium .
I landed just on the aforementioned steep edge of a deep crater. I have to be careful to not slip down
When I previously landed on Priax, I didn't like it at all, but the main reason was lack of visibility. Indeed, this dark rock doesn't give much perspective when it's poorly lit, and it doesn't work well with light amplification. Fortunately, right now the sun is high overhead, and Priax is actually quite interesting. I like mountains.
The terrain is much similar to the one I found in the Wal circumnavigation, but this time the gravity is low, and it makes a big difference. I can't really pick up speed, unless I'm falling down a cliff. At low speed, I'm at no risk of damage. And going uphill is not a problem. It's not particularly difficult.
The main limitation to picking up speed is the terrain texture: I just can't stay in contact with the ground long enough to accelerate. I am making extensive use of the rockets to pick up speed. But I learned to not go much faster than 10 m/s, or I risk damage to the wheels - even though on other planets I can go a lot faster safely.
Incidentally, rereading the conditions for the elcano challenge, I see what I'm doing here - using the rockets mid-flight - is technically irregular. But I'm not doing it in large scale, just a few nudges here and there. Occasionally using the rockets downward to cushion a fall down a cliff.
Planting the first flag. I didn't want to stop the rover, so I just left while Dancing Porcupine kept driving
It eventually hit a bump and capsized while I was planting the flag, so it stopped anyway
Here I jumped inside a crater without realizing. And on Priax, they are deep. Had to use the rockets to slow down and survive
Between the terrain and gravity, I'm spending a lot of time airborne
There is a rugged beauty to Priax. When the place is lit up enough to see, once you accepted that your rover can't go fast, it's actually a great landscape.
In this case I used the rockets to nudge the rover away from the crater. Else I'd still be falling down it
As I move northward away from the equator, the light is less direct and the visibility problem starts to be seen.
A landscape in natural light. I can't see what's underneath me
Same in amplified light. I see a uniform color, and can't really understand the topography
To make things worse, Dancing Porcupine had one light pointing downward, useful to see where I'm landing after a jump... except it's the one that got destroyed while circumnavigating Polta, and that I didn't want to reload. Now I regret it.
Going down a particularly large crater. It's over 7 km deep compared to its borders.
Up again on the other side
Over a crest, then down and up again
Looking back at the whole sequence of down a crater - up over a crest - down again - up diagonally over a slope
Wheels sinking into the ground, again
On Priax I had a lot of instances of the ground contact bug. A lot more than on Polta. Worse, sometimes the bug manifests in the rover exploding mid-air as soon as it touches the ground, like in the sequence below.
Just touching the ground with the struts at 2 m/s
Sometimes I can avoid it by speeding up and slowing down time. Other times I have to resort to more extreme measures. Once I was forced to reload an older save because there was literally nothing I could do - move forward, fly with the rockets, extend the struts, time warp - without the rover suddenly exploding. The previous save was 5 minutes older, not a huge loss. Another time I had to take an 8 km suborbital jump to skip an area that was extremely bug-riddled, where Dancing Porcupine kept exploding for no reasons. That suborbital jump would be big enough to qualify as rule-breaking, except it was only motivated by bug-skipping.
I'm getting nearer to the pole, where any OPM planet has the radial grooves ground glitch.
An appreciation of the grooves
Priax is no exception, and you can see them furrows if you zoom out. But the ground is so rough, on the ground you see no difference over the rest of the moon. There are advantages in a chaotic terrain.
Near the pole, you can see the full ring system above Priax
Getting really close. Left of the navisphere you can see the hole in the ground where the pole is
This close to the pole, now the ground finally looks different
But it's only for a few kilometers, and the low gravity makes it more bearable
The pole. If you zoom in you can see Bob having planted a flag
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what happened to @JacobJHC? he was always reviewing new entries in a few days, and now mine has been unanswered for one month
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2 hours ago, DennisB said:
I've finished the talc level. I made the necessary screenshots, I can post them, after someone tells me, how to do it.
you can use imgur.
go to https://imgur.com/upload and upload your pictures. then you can right-click copy the pictures there and paste them on the thread.
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2 minutes ago, Lt_Duckweed said:
The key here is that when a fairing is the root part, the fairing panels do not count for drag. This means that making it pointier does not help. What you have to do is occlude the fairing base via node attachment.
oh, I see.
when expressed like this it feels like bug exploiting though, just a step short of kraken engines. I will build something else. -
I completed the circumnavigation of Polta, my fifth OPM world.
Though technically I won't complete it until I return the crew on kerbin, which I won't do for a while because I'll be circumnavigating Priax and Tal first. So, besides being the first to circumnavigate a modded planet, I'll also be the first to complete a whole modded gas giant subsystem. whether @18Wattdecides to add this on the leaderboard now or later is up to him.
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Part 10: My rover will go on
Dancing Porcupine finishes the circumnavigation of Polta. I decide to also circumnavigate Priax.
SpoilerAfter the south pole, Dancing Porcupine press on for the first flag.
At first, near the pole, the terrain is very difficult, and traveling is slow. But the crew is comforted by the though that for every meter of road, it will become easier.
Soon, paths of relatively flat terrain start to appear amid the spikes
Perhaps the best view of Wal so far. Why do I get so excited for seeing Wal as a dot in the sky, after I spent months circumnavigating it? No idea
While I can't wait to get out of this hard polar terrain, I will miss the sky view
Another terrain bug like I encountered in the previous chapter. Just like then, at first it looked like I was getting out safely, and then the rover suddenly exploded
After the polar terrain ends, this emisphere of Polta looks more like the beginning of the trip, with highlands and lowlands intermixed and frequent changes of elevation when crossing a plateau.
Here descending into a "valley". I miss Slate's water-carved topography
I'm trying light amplification at 10%. Looks like an excellent compromise between seeing things and keeping a good atmosphere
After a few hundred kilometers, I start to see the first flag
A lowland region; they are more grey than the plateaus, but they aren't substantially different in terms of driving experience
Crossing the 30 km mark
Finally, the flag!
Dancing Porcupine returned where it landed, completing the circumnavigation.
Also, since it was going downhill, I could not brake and I had to capsize it to stop. I almost crashed onto the flag itself, it would have been hilarious.
It took almost 90 days between the first and the last flag, but there's no way to assess average speed, because I had to frequently stop to recharge the batteries, and unfrequently to make new fuel. The ground contact bug made this operation even slower; without kerbalism, when the bug strikes the drills authomatically stop, and I have to exit time warp and manually reactivate them every time.
At this point, I consider whether going home or pressing forward. I already circumnavigated Slate and Polta, I decide that I want to finish the moons of Urlum; I only miss Priax and Tal, both are small. Priax is in the same orbit as Polta, so I'm going there first.
Leaving Polta
I went back to read my mission diary on the OPM grand tour. I did drive several hours on Polta despite not needing to, I liked it so much. Well, now I've seen enough Polta for a lifetime. It's really nice, but it does get old after a while.
Conversely, I hated Priax. Really hated it. Even more than Dres. Do I really want to commit to driving there? Well, I'll land, then I'll decide. It's small anyway, how long can it take for a circumnavigation?
Exiting Polta in a slightly higher orbit, so that Priax will overtake me eventually
Priax and Wal
About to land on Priax
The ground is extremely irregular, though I did remember it even worse
I'm landing straight on the edge of a crater. But the low gravity will help me
This image is just the perfect presentation for Priax
This happened two days ago, and by now I crossed 30 degrees, so I'm committed. Turned out, I hated Priax because it was almost impossible to move a rover on it, but with proper care - and helped by the rockets - it's not halfway so bad. But more Priax on the next update.
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I was experimenting with a lightweight laythe rocket, but was twarted by an abnormal drag on the aerodinamic fairing.
I see people with aerodinamic fairings all the time, and I heard that if you make it the root part, it will have very little drag. well, I tried to do just that, here's the result.
drag is 4 times greater than gravity drag, and it's all on the fairing.
i tried by comparison with a mk1 pod, which is almost frictionless
only 0.08 kN, 250 times less drag than the fairing, despite having the same speed at lower altitude. there is still a significant drag, but it's mostly the flat bottom.
i experimented with a more pointy fairing, and with changing the root part, but got no improvement.
what's the issue with fairings and drag? I see people flying vehicles made of an external chair inside a fairing all the time, they wouldn't do that if there wasn't a way to reduce drag.
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3 hours ago, Empiro said:
I have OPM installed, and that might have modified with the maximum DSN range. I'm not 100% sure, however. I can look through my mod folders. Do you know what's the setting to look for that modifies the DSN?
I can confirm that OPM changes antenna settings
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11 hours ago, zerberr said:
Please forgive me if this topic been covered already, but here's my issue:
same with CO2, but nitrogen harvester works.
Was wondering if it's know issue or some incompatibility
update: so I looked through configs and found ResourceConfigs folder, with Nitrogen.cfg and Ammonia.cfg inside. I copied Nitrogen file and replaced contents with oxygen, and voila, oxygen now works.
Which puzzles me, no way that Kerbalism doesn't include these files by default? I installed it from CKAN, both Kerbalism and Kerbalism default config, version 3.17. Reinstalled to make sure with deletion of folders from gamedata, same thing, only 2 files.
Is there way to get full configs?
in the end I decided to go with Simplex config. I still didn't give up on the idea of self-sustainability and being able to refuel on planets, which seems hardly achievable with full configs.
Unexpected side effect is that my KSS now takes a second to load, as opposed to good 10 seconds prior to that.
well, it says there is no oxygen in the atmosphere, so the spectrovariometer is working exactly as it should.
the planetary resources, on the other hand, are not.
i see you have a bunch of other mods, it could be a compatibility issue
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On 3/3/2023 at 5:28 PM, mySynka said:
If I did, I wouldn’t be able to deploy the nosecone, and the fairing is not supposed to separate, instead I use it to protect the payload inside.
as i said, it's not protecting the payload inside. the game physics engine is limited like that.
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1 hour ago, Vanamonde said:
If you're still learning to make planes, why not make something smaller and more manageable?
a legit question, with a moltitude of answers.
because I don't like making planes. but I have an idea to try a fully reusable whirligig world grand tour, and that mod has 2 eve-like planets.
because I am already capable of making decent planes, and I seem to have hit a wall when it comes to improve there.
because I can easily value the performance of a spaceship and where it is lacking (too much dry mass, too few electricity, too few reaction wheels...), but I don't even know where to start in valuing the performance of a plane (wing angle? propeller power? center of mass? maybe the plane is fine but my flight profile is wrong?). and without being able to value performance, I can't improve.
because starting with something smaller and more manageable is boring.
But even accepting to make something smaller and going incremental? I already have several propeller planes that can ssto from kerbin with considerable payloads, despite sacrificing a lot of performance to luxuries like good iva view or fancy add-ons. the next logical step is eve. and I already had a model that could reach 13 km on propellers, then it could not orbit. I got the feeling that if only I could improve flight performance a little bit and gain a couple more km of elevation, ssto would be within my grasp.
also, because making planes in general doesn't seem to apply much to making something capable of eve ssto. stuff like angling the propellers or putting the CoM behind the CoL goes against the basics I knew of planes. and I am keeping the same mass/wing ratio that worked on smaller planes, but this time it's not working.
but perhaps more to the point, I am actually doing exactly that: something simpler and more manageable. So far, what I am trying to make is a plane that's 4 times heavier than my previous heavier model, that has similar wing and propeller ratios, and that flies. And I'm stumped, because I'm doing all the stuff that worked to make smaller planes, and it's not working anymore. I'm not even worrying about rocket flight so far, those rockets are only there to simulate the mass.
EDIT: I mean, this is Arrowhead, possibly my most successful spaceplane
it has a mass of 50 tons, its propellers generate 200 kN of thrust, it's got 4 wings, it flies easily on kerbin - though it's not very maneuverable. It reaches 7-8 km before needing the rockets, and it carries to orbit its dry mass of 20 tons, plus a bunch of spare fuel, so it's got almost 50% mass ratio to orbit. Despite using draggy Mk2 parts (I needed them for kerbalism reasons) and having that docking port on top and a similar one on the bottom interfering with a smooth flight.
As first step, I tried to make a plane that was 4-5 times heavier, I gave it 1000 kN of propeller thrust, 16 wings before I got talked into reducing them, and I streamlined everything to remove all the inefficiences arrowhead had. I fully expected to get something that would fly better. Instead I got something that can barely manage level flight at sea level, and I have no idea why.
I may have underestimated the task, but really, given that I've already taken all the steps before, what else could I do as practice?
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On 2/21/2023 at 8:16 PM, Lt_Duckweed said:
Adding rapiers to an Eve ssto for Kerbin takeoff is pointless dead mass and makes ssto'ing off Eve essentially impossible.
Wrong. Propellers can get a craft airborne on Kerbin and Eve just fine. All sea level Eve sstos using breaking ground take off using propellers.
Wrong. You need propellers to get up to the altitude where your engines will get good thrust and ISP. You don't even ignite your engines until past 15km.
@king of nowhere the main problems I am seeing with your craft are this:
1. Not enough prop blades. You have 16 total, 8 per rotor. At this mass you need to be using about 32 total. You can do that via 4 rotors with 8 blades each, or if you offset the prop blade base one tick past the axis of rotation (so that the base is on the other side of the axis from the rest of the rotor) you will need substantially less torque and thus can do 16 blades per rotor, but with this setup you have to be very careful as if the blades stall they will kraken. (This setup also makes the prop compact enough to shield in a 1.25m service bay, though it looks a bit clippy so you have to decide if that is something you are ok with).2. Too much engine mass. Margins on Eve sstos are very tight, for a craft of this size you should be looking at ~2 vectors, meaning you are carrying 7 tons of dead mass. Swapping to 2 vectors also means you can mid mount them, so that their dry mass is in line with the CoM and thus does not drag the CoM around as fuel drains.
3. Props too far forwards. Eve sstos, in order to not carry too much wing into the rocket phase of ascent (and therefore climb too rapidly) are under winged and therefore must adopt substantial angle of attack through the upper prop phase of Eve ascent or on Kerbin takeoff. This means the props are crabbing through the air at an angle, which causes all sorts of issues thanks to them being very far from the CoM. Move the props to mid mounted side pylons (or do one fore and one aft to cancel each other's stability effects). Additionally, I angle my props downwards 5 degrees on my Eve sstos, to better match the AoA in upper Eve ascent (this makes it even more important to mount them at the CoM, so the thrust axis points through the CoM)
4. CoL too far backwards. Your CoL being substantially behind the CoM means that you have to actively fight the craft to get the nose up AoA for upper Eve prop phase, and for Kerbin takeoff. You want your at rest CoL lightly ahead of your CoM, which you do by mounting your main wing slightly forward of your CoM. Doesn't have to be much, just a couple of ticks. Then to counter the resultant instability this would otherwise produce, you place your horizontal stabilizers as far aft as you can, and with 0 wing incidence. This means that when you pitch up, the horizontal stabilizers will gain lift proportionately faster than the main wing, since the main wing has angle of incidence already built in (wing lift is ~linear up to about 15-20 degrees AoA, so a pitch up from say 5 AoA to 10 AoA would have the main wing go from 5+5 AoA to 5+10 AoA for 50% more lift, but the horizontal stabilizer would go from 0+5 AoA to 0+10 AoA, for 100% more lift). This results in the CoL sliding backwards as you pitch up, providing stability, just at a non 0 pitch up AoA. This makes it much much easier to fly at a non 0 AoA as it won't fight you nearly as much, and it means the craft can adopt a substantially higher AoA on reentry since the passive stability will not be fighting nearly as hard to revert to 0 AoA.
Ok, it took me a long while to test with this stuff because my life got busy.
I tried your suggestions.
1) as already mentioned, I had 32 blades already. I moved them one at the front and one at the bottom.
2) I now have 2 vectors and 2 nervs; I am sure I'll have to add one or two more nervs, but that can wait; right now, it's important to just get this airborne.
3) I angled the propellers downward 5 degrees as you suggested. I removed a pair of wings, since you mentioned those planes are supposed to be underwinged.
4) I moved the CoL forward as you suggested. I forgot the horizontal stabilizers at first, but I tried them now, didn't help.
So, first model.
the first model at least can take off reliably at the end of the runway, without crashing in the ocean half the times, so I guess that's some progress.
but it starts to pitch up
and up. it flips and crashes.
so I moved the CoL back. one tick at a time, until I had a stable plane. here's what I got.
and it flies, but it stops there. It's barely air-worthy. it does not pick up speed. It does not climb, at least not significantly. and it was slowly losing speed.
in eve's greater gravity, this model wouldn't be able to get past 13 km, while it should reach 15 on propellers alone.
As I said, after reading again and realizing that I was missing the aft stabilizers, I tried to install them and move a single wing pair forward by two ticks. Plane tipped up again. I'm still stuck with something that doesn't fly well enough
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On 1/9/2017 at 12:02 AM, Carrot said:
I am trying to set up a Geostaionary orbit network with 4 satellites. I know the parking / deploying orbit is 4 hours if I want to set up a 3 satellites network. So I tried to do some maths myself for 6*2/4=3 hours. But I found it is wrong. So may I ask for the equation and the explanation of it please? Thanks
what kind of calculation is that? why are you doing *2/4, and what is 3 hours supposed to represent?
and what are you trying to achieve exactly?
if you want those satellites equally spaced, you have an easier time launching them at 2 hours interval, since that's how you equally divide in three a kerbin day. -
the problem is with the game modeling system. to you, it seems like you made a perfectly closed hatch. but the game does not model it that way; as far as the game is concerned, the nose cone is not closing the cargo bay. so your ship flies poorly because it has a giant hole on the front, making it super draggy. as for the hinge itself, it may be subject to vibrations and deformations. if you want to make a nose cone that opens, there's no convenient way to do it with stock parts; the physic engine of the game simply does not allow it. but there are nose cones that open in the near future mod, so I suggest you look there.
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Part 9: From north to south pole
Exactly as the title says. The land is mostly highlands of average difficulty, with some stretch at lower elevation.
SpoilerThe biome that I will cross through until close to the south pole is called nockmaar foothills, and crew reports often remark on how flat and featureless they are. Which is quite inaccurate, because they are the highest elevation on the planet. They are a relatively flat plateau, though. elevation is mostly above 6000 m, with peaks above 8000.
Crossing this region is relatively easy, as there are no big changes in elevation. Dancing Porcupine struggles with those; it can keep going uphill as long as it has fuel, and it can pick up dangerous speeds downhill - it doesn't brake very well.
As I progressed, I learned to control speed downhill better. Or, rather, to just steer all the way and provoke an accident while the rover is still going slow enough to survive it.
I picked this specific longitude for the view of Priax in the sky
Priax is at Polta's L5 lagrangian point. I don't know how stable such a configuration would actually be over astronomical times.
Using the rockets to get out of one of the rare sinkholes of lower elevation
I planted a flag here because it was the higher elevation I reached
But it was soon surpassed by others. This point ended up as the highest one I touched. The highest point on Polta is 8800 m
Priax is moving higher and higher in the sky, but I can still see it from the cupola when the rover is going uphill, like here
And here we have Wal too. Tal is not visible
Progress is not terribly fast, but at least it's steady. I try to accelerate, but I rarely make it past 20 m/s before sliding on the irregular terrain. Polta is more difficult than it looks like. On the plus side, I rarely have to reload for damage; the new armor is almost unbreakable, especially at those low speeds, but the plane wheels in front are not doing their job. Hitting a bump can still result in breaking them, it's the most common cause of having to reload. I am almost tempted to let them break, then I remember that the rover wheels are even more frail. I should perhaps have used the heavier, sturdier model of plane wheels - Leaping Mantis does, and it can ram headfirst into near-vertical walls and survive - but they would have added significant mass.
There's no telling what average speed I could keep in those conditions. In my previous circumnavigations I could track time by the flags, but here I had to take frequent stops to recharge the battery, which does not last forever going uphill. More rarely, I had to take longer stops - a few days - to make more fuel.
Here I was cutting through a cliffside when the rover tumbled down. The high arch gave me time to extend the lower struts, though, so now Dancing Porcupine is practically indestructible. It survived
I stopped to put a flag on that hillside because, for a few km, I crossed another biome
Here I found this strange terrain artifact. It doesn't seem related to any specific coordinate. No accidents happened, though
I realized there are few views encompassing the greater landscape, so I'm trying to compensate with some
The crater in the picture reminds me to mention: Polta has relatively few craters, at least compared to Mun. You do occasionally find one across your path.
The more I think of it, the more Polta - with its somewhat irregular terrain and few mid-sized craters - remind me of Dres. I had a much harder time driving Dancing Porcupine on Dres, but was it because the terrain here is better, or just because I am more skilled and the gravity is higher? I have no plan to drive Dacing Porcupine on Dres, so I'll never know. I do have plans to drive Leaping Mantis on Dres, but it's a very different rover, and on low gravity worlds the reaction wheels make all the difference.
Ooops! I lost a lamp!
I got distracted and crashed headfirst into a boulder. Luckily the illuminator made contact first, and the way the game models collisions, this protected the rest of the rover. After checking that the last save was over 10 minutes earlier, I decided to keep the rover like this.
Here surviving a particularly fast collision. When fully deployed, the porcupine armor 2TM is nigh-indestructible
I'm now close to the equator, so the rings make a vertical line in the sky
Priax is at my zenith, and difficult to include in a shot. The smaller bodies projecting dark spots on Urlum are flying boulders
A particularly steep passage
I am now closer to the south pole, the rings are extending behind me. The sun is providing less illumination, soon I'll ramp up light enahncement
And here we can appreciate the terrain artifacts as we're closing in on the south pole
I'm still at around 65° of latitude in the above picture, relatively far from the pole. The terrain artifacts become really bad around 10 degrees away, which translates to roughly 30 km on this planet. From the ground you barely notice them, unless you know what you're looking for. But seen from above, the terrain is already unmistakable.
Approaching 80° S, the grooves are getting deeper and more noticeable
And the terrain is getting more difficult, slowing my progress. But I only have to run 60 km like this
The bottom of the big crater seen a few pictures ago; it's incredibly flat, perhaps the flatter place on the whole planet, with only a few meters of difference in elevation between sides
Nice view of the polar crater
I take this chance to pick up some speed; but soon I have to slow down for the rim
Climbing up the rim. I had to extensively use the rockets, something I'm not too happy about because this biome has no ore
The polar terrain, in all its glory
And the actual south pole. This time there is no terrain glitch of any kind. I wonder why some poles have artifacts and some don't
Flag on the south pole
I don't know why the deltaV signal more than it did a few pics ago. I certainly did not refuel, ore concentration is too low for the small drills. Maybe that pic came from an aborted attempt where I crashed, and then when I reloaded I managed the climb at a lower cost. Or maybe it's just an irregularity because the rockets aren't perfectly lined up anymore; shortly after this I did some construction to fix them again.
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the ship turning around generally means aerodinamic problems, but your ship looks aerodinamic enough, so I'm a bit confused. I agree with superfluous, reducing thrust is probably your best bet.
another thing I see that I want to comment on, though: you have two radial decouplers for each booster, and that looks nice, but it doesn't actually work. the way the game models the rocket, you can't bind a booster on two points. you can use struts for that, if the boosters are unstable. that could be a reason for the issue
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5 hours ago, Robhar174 said:
Is there anyway I can uninstall kerbalism and the impacts it has on other components?
just delete the kerbalism folder.
if you want to keep different careers with and without kerbalism, you can copy the game folder to have a second install of ksp, and have one with and one without kerbalism. i myself have, like, 6 different versions of ksp
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42 minutes ago, Lt_Duckweed said:
ah, in that case, can you detail how you have the rotors and props setup in terms of torque, rpm and blade angle?
as you can see, i keep the aerodinamic window open while flying, and I check drag (resistenza totale in my italian interface). the kal controller sets blade angle, I just move it up and down until I find the value that gives me the most negative drag, and I keep adjusting during flight. people talk about angle of attack on the propellers, I guess they are using mods to show it, I don't so trying to calculate it according to air speed and blade speed would be too complicated.
max rpm is defaulted at maximum, though I had prepared a second kal controller to balance that too - I discovered that in dense atmospheres I can get better performance by reducing rpm, though maybe that just happens because the propeller itself is not powerful enough to reach it anyway, so lowering the value to something the propeller can sustain improves stability. anyway, this is just prelimitary testing and I wasn't yet using that. I also considered reducing maximum torque for parts of the ascent to conserve electricity, but again, preliminary testing, so far I just want to have a plane that flies reasonably at standard pressure and up to half an atmosphere. if it can do that on kerbin, it can generally reach 15 km on eve.
so, tl dr, I keep torque and rpm at maximum, and I regulate blade angle with the kal controller by experimentally picking the value that will give me the best negative drag
EDIT: when the plane is standing still, I get -1000 kN of drag, so that's about the power of the propellers. as speed goes up, that number goes down, and I have no way of knowing how much of that is due to reduced propeller power, and how much is due to actual drag rising. when I take off at about 100 m/s, total drag is around 0 to 200 kN depending on angle of ascent. I suppose the wings must generate a lot of drag to lift a 200-ton plane anyway
, but the planetary alignment is unfavorable.
Gotta go fast! Career speedrun
in KSP1 Mission Reports
Posted
Part 11: First landings, first hiccups
The Laythe lander succeeds despite some bugs, but La coscienza di xenon has too low thrust to get away from Laythe effectively, forcing some reevaluation. Meanwhile, Bop, Pol and Tylo landings proceed as planned.
La coscienza di xenon starts maneuvering several hours earlier to try and reduce its intercept speed on Laythe.
Here reducing Jool apoapsis to get a true Hohmann transfer
Meanwhile, status of the other landers on day 226
Approaching Laythe
I must stress how low the TWR of La coscienza di xenon is. 0.01 means that in a minute you gain 6 m/s. A full hour for a mild 360 m/s burn. Getting a capture in those conditions is not easy; on the first attempt I lowered periapsis too much and crashed on Laythe before I could fix it. And it's not good for a speedrun, because slow apoapsis lowering does not rhyme with "fast".
I could go for aerocapture, of course. It would be great, but I placed the heat-sensitive parts of the Vall lander exposed to the airflow. And I already sent away my only engineer. I can't even detach the lander alone, because La coscienza di xenon would then be without control, I need to park it in a safe orbit first. Still, after some rocket braking, I can use the atmosphere to slow down.
Day 227; entering Laythe atmosphere...
...And getting captured into a circular orbit
But I can't brake too hard, so I need a few consecutive passages to circularize.
Day 227:04, circularized on Laythe
Detaching lander
That truss structure has some bugs. Now that I freed it from the mothership, it explodes when exiting time warp. So I had to use 4x while looking for the landing spot. Would not be a big deal, except that I also had to try many times to land because I was aiming for a mountain.
Descent
Parachute
Landed
On top of a mountain, as I wanted. To make a lighter lander, I planned on getting at least 4 km of elevation. I'm not even sure this rocket could reach orbit from sea level.
Also, that decoupler on the side meant to detach the parachute arm does not work. It decouples, but the trusses stay in place. Fortunately, as I detached the landing platform the whole truss structure exploded. It didn't affect the ascent.
Ascent
After the boosters are spent
Day 227:05; Rejoined with La coscienza di xenon
Planning maneuver to Vall
So far I had a few glitches, here the real troubles begin. Because I have 3 days before Vall is aligned for a transfer, and I use this time to raise apoapsis...
Day 229; still stuck raising apoapsis
But it's not enough. The ship has just too little thrust. I will miss the transfer for Vall and have to wait 4 days. Ok, if I really wanted to push by using unfavorable maneuvers I could have done it, but it's not sensible to waste too much xenon for just four days. On the return trip that xenon will save a lot more time. And I have to wait the other landers on Vall anyway.
Indeed, I previously mentioned that I was planning to rejoing everything at Tylo, but I now realize it's a dumb idea. If I have so many problems just leaving Laythe, Tylo will be a lot worse. Instead, I'll pick up the rest of the crew on Vall, from where I can leave easily enough. Then I will take a gravity assist from Tylo or Laythe - whichever is more convenient - to get into a Jool escape trajectory. Once there, I can use the ion engine without worrying. Because otherwise, even a 10-day orbit would not be enough to efficiently leave on a high energy trajectory.
So, if La coscienza di xenon has to stop at Vall anyway, I can take a few more days to get there.
Meanwhile, between one apoapsis raising and another, the other landers are arriving.
Day 229; Pol lander
Descent
Here I discover another bug, this one working in my favor; even though I don't have enough electric charge to run the engine at 100%, I still can do it, and the engine does not lose thrust when it runs out of electricity. I decide to not abuse it, but to use it for faster burns, that I do.
Landed on Pol
Maneuver to get back to Vall
A fairly easy return trajectory, with no issues of time or deltaV. I keep reasonable margins of both. At this point I probably won't make it in exactly 10 days, but reuniting the crew in 11 days since arriving at Jool (that is, within day 236) is still feasible. I may lose a few more days to find a gravity assist, but looking at it in perspective, my target is one year, 428 days, and most of them are spent in interplanetary space. Five extra days at Jool won't make a huge difference.
Tylo lander starts injection burn
being heavier than the others, Tylo lander also has low thrust and must be maneuvered more accurately.
Day 230:03; Tylo orbit achieved
And with a low orbital period already, so I can lower apoapsis without losing too much time. Hours, but not days. But first I must take care of Bop.
Day 230:04; Approaching Bop
Descent
I was really worried about Bop because the lander had a nominal TWR around 4, but with the assumption of engine at full power. I did not calculate how limited power would affect it, and I wasn't sure I could get a TWR greater than 1. But as you can see, I get 1.3 (relative to Bop gravity) while keeping a positive net charge, so I could still land without exploiting the glitch of the engine not depowering for lack of electricity. Worst case scenario, I'd have had to land with the jetpack.
Day 230:05; landed on Bop
Return trajectory from Bop
A bit expensive. Vall was passing in the right place in the wrong time, so I had to either push for a higher energy trajectory, or wait 10 days. I will still have some 500 m/s left as margin, this is safe.
Day 231:02; Detaching cruise module. Commencing Tylo landing.
Here I am using Bill to make the ship lighter mid-flight. I feel dirty inside
Landed. Tylo landings are always hard, but this one went smoothly at the second or third try
Flag planted
Dropping some empty tanks, the lander gained 300 m/s. I can't drop the engines yet until I am in weightless condition
With so much thrust, leaving Tylo is a breeze
Nice view of Jool and Laythe on the horizon
Day 231:02; Return to the discarded cruise module
Now, there is an objection I did not raise when changing the plan from rendez-vous at Tylo to renzed-vous at Vall: that is, the Tylo lander discards its ion engine before landing and it's not meant to pick it up again. I did not raise the objection, because I have an engineer on board. I was hoping the decoupler would be the root part, which would allow me to salvage everything. Unfortunately, the ion engine is the root part, and I cannot move it. So I just have to transfer the command seat - and the probe core to keep orientation, and the battery - on the cruise module. A pity to abandon a bunch of still serviceable chemical fuel, it would have made leaving easier.
The refurbished Tylo lander. It's not visualizing, but it has 7500 m/s
A high thrust maneuver to Vall, but I have the deltaV for it, and I want to arrive early
I want to arrive early because I had another idea: use the refurbushed Tylo lander to rendez-vous and collect the other landers while waiting for La coscienza di xenon. This way I won't waste time with multiple rendez-vous and I will be able to leave immediately after landing.