Jump to content

king of nowhere

  • Posts

  • Joined

  • Last visited

Posts posted by king of nowhere

  1. question:

    Now that I'm done with Wal, I was considering going forward with Polta. However, I discovered that the roll cage of my rover doesn't work anymore as intended, because wheels are a lot more fragile and keep breaking.

    I considered adding 4-6 struts on the bottom of the rover, to be deployed quickly in an emergency to complete the roll cage on the bottom and protect the wheels. A minor change for a rover that's already very elaborate

    If I were to do such a change - using alt-f12 to bring the new rover in place and pretending it's always been like that - would it be legitimate? Or do I have to launch anew and repeat all the trip to Polta?

  2. Part 12: outward to the lopsided planet

    A'Twin moves outward to Uranus, sends a lander to the moons and refuels there.


    Refueling on Titania, admiring a passage of Ariel and Umbriel over Uranus

    12.1) Make sure you fill up your nitrogen stock before leaving Saturn


    I'm about to leave Iapetus base for good. Goodbye, best refueling spot in the whole solar system.

    But before I leave Saturn, I have to stop at Titan to stockpile on nitrogen - as there's no other practical source of it anywhere else.

    And this means I have to fix the Nitrogenie in a Bottle first.


    Sending out an engineer


    Tobono must first recover a spare docking port; those used to host the non-reusable landers, and are now redundant


    To reach the broken wheel, the engine must be removed. A Service Probe grabs it, and it is released from its docking port


    With the engine out of the way, Tobono can remove the docking port and finally the broken wheel. A new wheel was brough out of storage


    The new wheel is placed, the docking port is restored. The spare docking port was put on the engine, so that it can be docked back in its place


    The Service Probe proceeds with the docking. The cramped location and off-center push made this docking very difficult

    Overall it took over one hour - because I was subject to A'Twin's full lag during all the time. Definitely not something I want to do again.

    Meanwhile, I'm heading for Titan. Since Iapetus has a relatively large inclination, I'm arriving on a polar orbit. I have considered many ways to fix that, but they all cost fuel, which I want to spare. So my plan is to park A'Twin in a polar orbit, then use Fat Man to carry Nitrogenie in a Bottle up and down to Titan. Then, when it's time to leave, eject into a resonant orbit and get a gravity assist from Titan to get pointed in the right direction.


    Releasing Fat Man and Nitrogenie in a Bottle, around Titan


    For greater practicality, I'm using Nitrogenie's thrusters to help

    I already described the process of mining nitrogen from Titan and converting it into monopropellant in subchapter 7.3, and to a lesser extent in 8.5, so I won't make this already overly long report even longer by repetition. I'll just highlight the usual assortment of bugs.


    A manifestation of bug #2. Fortunately, it tends to revert on restarting the game


    The left wheel is also suffering from bug #2, but not too badly; I should still be able to land


    The propellers are twisted out of their way; that's a problem with the stock game that's not even in the list; anyway, they still work, and if the push is asymmetrical, it is not noticeable

    A'Twin is missing some 3000 units of monopropellant (12 tons), and Nitrogenie can make 1300 units on each trip. I would need three trips. However, after two trips I made some calculations. I only miss 400 units of monopropellant, what I have is enough for 220 years, I would only gain 12 years. And I have a pretty good estimate of how much time I'll need, and I can always return to Saturn in a pinch. So I skip the third trip and move immediately for Uranus.

    12.2) En route to where?


    Finding a trajectory to Uranus would be easy, except that I'm stuck in an eccentric polar orbit around Titan, and I have first to find a way to fix that without wasting too much fuel. Even that would not be too hard, except for all the lag. It took me a while, with a lot of trial and error, but that's what I managed.


    Trajectory to leave Saturn, zoomed in on Titan


    Trajectory to leave Saturn, zoomed out

    First I leave wih a 400 m/s burn at periapsis. This sends A'Twin into a higher Saturn orbit (green) with a 2:1 resonance, meeting Titan again. There, by carefully aligning the incoming trajectry, I can make a 1070 m/s burn, get a good Oberth effect from Titan, and exit equatorial and in the right direction. And I actually did a pretty good job: I simulated starting from an equatorial circular orbit around Titan, and (even accounting for 600 m/s of apoapsis raising for not starting elliptic) I couldn't find a cheaper trajectory.


    Trajectory for Uranus

    I'm put into a high energy trajectory leading to Uranus in 20 years. Yes, it's not a Hohmann transfer; I'm now too far from the Sun, and those are too slow. I am spending fuel to save time. I would spend even more, except that the moons of Uranus are inclined by nearly 90 degrees over the ecliptic, it will be extra expensive to reach them; and afterwards I have to land on Titania, the biggest of the lot. I miss Iapetus already.

    I am in a bit of a time crunch. Right now, Neptune is in a good position to reach from Uranus, and it will stay there for a few more decades. But there are no refueling opportunities on Neptune, so I will send Cylinder and it will also have to come back to Uranus. And all that will take at least 60 years. And after 60 years, Pluto will be properly aligned to reach from Uranus. It would be very convenient if I could catch such a transfer window.

    20 years for Uranus, 10 years for refueling, 20 years for Neptune, 20 years to return to Neptune, 10 more years for refueling, we're at 80 years already. And that's bad. I'm missing my transfer window opportunity; and Uranus has an orbital time of 80 years, it would take too long to wait for the next one. I'd have to return to Saturn and wait only 30 years for a transfer opportunity, and then Pluto would be farther away.

    So it looks like I'm losing this opportunity! I have to find a way to save time. Maybe I can skip the 10 years for refueling. I start concocting a crazy plan.

    If I approach Uranus, then I split A'Twin... Then I give all the water to Cylinder, which uses a gravity assist from Uranus to reach Neptune. While Trypophobia lands and refuels. But Trypophobia has low deltaV, and I didn't load much oxydizer for its chemical engines. But I can circumvent that! I load its fuel tanks with all the liquid fuel, then I use the nuclear engines on Fat Man for maneuvering Trypophobia. This way, I should stretch its fuel to 3 km/s, which probably are enough to land. Maybe. And meanwhile, there should be enough fuel for 5-6 km/s on Cylinder, and it will be already on its way to Neptune... I went as far as plotting this.


    Trajectory if I wanted to turn the Uranus approach into a gravity assist for Neptune

    Well, it probably wouldn't have worked. First, 3 km/s look like a lot when I'm already in an intercept trajectory; but there is the capture from a high energy transfer, and then the plane change because the moons have high inclinations, and finally Titania is relatively big. It probably wouldn't have sufficed. Then there is the matter of Cylinder; it would have to spend 1 km/s to capture around Neptune, and then to return to Uranus on a high energy trajectory, and then to capture and reach Titania. Hard to do when starting with half fuel.

    But what definitely closes the question is the water level A'Twin has got 100 tons right now, because I was planning a 20 years journey and I brought water for 50 years, it seemed safe. But now, by the time I'll reach Uranus I'll be down to 55 tons. I give all that to Cylinder, it will have 40 years worth of life support. By the time it will reach Neptune, it will have 7 years left. So, not a chance.

    It probably wouldn't have worked anyway.

    On the plus side, by plotting the calculated positions of Uranus and Pluto in 60 years, I see that I underestimated a bit the time it would take to enter the transfer window to Pluto. So, 80 years is still a good time to launch, that's my next target. Otherwise, I'd have probably skipped Neptune to reach the more difficult Pluto.

    Now that I decided to stay at Uranus, it's time to plot the course correction for the arrival.


    Trajectory for Uranus insertion. No puns, please


    Trajectory for Uranus insertion (no puns please) seen sideways

    Bad news here, I tried to get some way to minimize inclination, or at least to have a planar node at apoapsis to get a cheap plane change. There isn't any. As the second picture shows, I'm coming 90 degrees up from the plane of the moons, and there's no way around it. Even with all my effort, I still have a 45° inclination to pay for. So I first get captured around Uranus for 408 m/s, then I make a plane change for 1000 m/s.


    Trajectory to reach Titania

    From there, with a couple of minor corrections, I am already in an optimal trajectory for capture on Titania. It requires some more 850 m/s.

    Considering another 700 m/s to land on Titania, I'd have needed nearly 4 km/s from Uranus encounter to landing. So, an improvised nuclear-powered Trypophobia would likely not have worked. I could have tried getting gravity assists from the moons, but they are all too small to be effective.

    Twenty years of traveling passed without any major accident. Quite lucky here. I got three malfunctions on the nuclear reactors, plus a bunch of other unimportant parts, but none was critical. Furthermore, because of bug #15 (I am sooo happy I made a list for quick reference) most of the spaceship stopped aging almost completely. I long since gave up checking the main reaction wheels, the chemical plants, the mining drills, and none of them malfunctioned in over a century. There were only a few parts that were aging regularly, and now - except the main reactors - they all broke. I am not fixing them, so now I only have the reactors to check. This is actually a life saver, because at this point in the challenge, where I have to take very long trips with nothing to do but fix stuff under heavy lag, having to run full maintenance every time would be maddening. Having to run a dozen reactor maintenances before arriving anywhere is already annoying enough.


    The three reaction wheels on Nitrogenie in a Bottle are among the pieces that were aging regularly. Now they are all yellow; delightful!


    Arriving at Uranus. I really like the color

    12.3) Moons of a midsummer night


    Before arriving at Titania, I send out Clamp to land on the moons.

    By previous experience, those ice giants are really convenient environments to travel. They have enough Oberth effect to be good for gravity assists and cheap captures, but they are also small enough that moving between the moons is reasonably cheap. No more crazy desperate stunts like I had to pull for Io and Mimas. In fact, I'm planning to get all the three innermost moons in one go, despite the radiation belt. I'd go for the fourth too, but Clamp doesn't have enough fuel to land on all of them without refueling.


    Preparing Fat Man with Clamp. By the way, if you look closely you see a small speck on Uranus; that's Miranda, the innermost and smallest moon


    Separating Fat Man's trajectory from A'Twin, I use Titania for a gravity assist, and I use its Oberth effect to lower Uranus apoapsis. This saves 400 m/s


    Then first trajectory for Umbriel. 900 m/s total. Umbriel is just inside the radiation belt for half of the time

    That radiation belt is slightly more than one third as deadly as that of Jupiter, so a crew can spend several days inside in relative safety. From the picture above, it looks like Fat Man could try to syncronize to reach Umbriel when it's in a safe area, but the radiation belt actually rotates very fast, several times per day, I can't plan too much around it.

    By the way, all the moons of Uranus are named after literary characters from Shakespeare or Pope, hence the chapter title.




    Still Umbriel

    Unfortunately, at this point bug #17 manifested again: I can't get my crew out of Clamp. But I want to plant a flag and collect a sample, so...


    Somebody has to make the landings stuck on a ladder. This time it's Etdania


    Etdania still holding tightly to the ladder as Clamp brakes


    Flag on Umbriel

    Next is Ariel. Ariel is not properly aligned for a Hohmann transfer, but I am still inside a radiation belt, so I pick a high energy transfer to get there in 2 days. It's significantly more expensive, but still well within Fat Man capabilities.

    By the way, I'm starting with the external moons because they are bigger. This way I get to use up Clamp's fuel sooner, leaving more deltaV for a lighter Fat Man.


    Trajectory to Ariel


    Ariel. 34% radiation damage so far


    Ariel, and Uranus


    Once more, somebody has to travel in third class. More like fourth class. Tenth class?


    Planting flag... wait, where is the flag?


    Here it is, 300 meters above ground. And now the game crashed

    NEW BUG #34: on some moons of Uranus, planting a flag can result in the flag hundreds of meters above the ground. Selecting the flag may then crash the game. Reloading generally works at ensuring the flag gets planted correctly.

    Back to orbit, I was lucky to find Miranda in a perfect position for a transfer. As we're moving closer to Uranus, the costs of maneuvers are getting bigger and bigger, having to get to Miranda in a high energy trajectory would have been problematic.


    Trajectory to Miranda. Spending two days in the radiation belt netted 38% exposure, I should be safe


    Uranus is beautiful, isn't it? Not sure if the distant moon is Ariel or Miranda


    Miranda. It's got quite a peculiar shape


    Interesting terrain. Great sky. I don't miss Neidon


    Landing. This time it's Jeb staying outside. I left him on Iapetus for both the Jupiter and "comet" mission, so now I'm landing him on all the moons


    I picked a landing spot specifically to get this view of the sky


    I happened to land on a sort of plateau, just in front of a big ravine


    Mimas looks perfectly flat, with strange massifs jutting out of the plains. Probably the real one doesn't look like this


    Here I'm returning to orbit

    To be faster, I am chasing Fat Man on a high energy trajectory, something I can only do because the gravity is very low (orbital speed 100 m/s). Clamp is in hyperbolic trajectory, and occasionally burning downward to approximate a circular trajectory.

    Wait a minute, I made a bit of research and discovered that Miranda is renowned for having the biggest cliff of the solar sistem, Verona Rupes, over 10 km high. I missed the chance to land there, and with the radiations I'm not going to try, but I will sneak a peek with alt-f12.


    Bonus: a sight of Verona Rupes. I had to take it with Clamp in midair, because the bottom was below 0 altitude, which causes funny visual glitches


    Return trajectory to Titania

    To return I burn prograde until I'm level with Titania, then burn immediately to raise periapsis out of the radiations. It will take a few orbits to catch up with Titania, but it's safer this way. Irradiation will top at 73%. The 294 m/s maneuver is a plane change, Miranda has a different inclination from the other moons.

    Getting a rendez-vous with A'Twin in a polar orbit wasn't trivial, but Fat Man will still have 2 km/s, so I'm cutting the report short by skipping that part.


    Fat Man rejoins A'Twin for refueling. Docking in that position was quite complicated


    Now out to Oberon. It's very cheap. If I had enough fuel in the lander, I could have gone there directly

    To reach Oberon, I made a small push to exit Titania, and raised apoapsis from there. I was into a polar orbit misaligned with the plane of the moons, this was just easier. I got some slight complication when, along the way, I stumbled again on Titania. But I was moving very slowly compared to the moon, so I got a very small speed change from that encounter.


    Oberon! The north pole terrain glitch must be really impressive if it can be seen from this up high


    And this is Titania passing over Saturn, seen from the cupola on Fat Man


    Which reminds me, I've never shown internal visuals from Fat Man's cupola. That's why it's blocked by a water tank and docking port. I wish I could find a practical way to avoid blocking the view


    Flag on Oberon. Without bug, this time


    Once more I forgot to land on interesting terrain, and once more I fix with alt-f12. This is the north pole. The small speck in the middle is Clamp being swallowed. Impressive


    Going back to Titania

    12.4) SSllooww... rreeffuueelliinngg... oonn... TTiittaanniiaa...


    There are only two Uranus moons outside of the radiation belt: Titania and Oberon. Of them, only Titania has water (obligatory rant on how irrealistic that is), on a single biome - Messina Chasmata.


    Preparing to land


    The eponymous chasm

    I had to repeat the landing halfway because I realized too late I forgot to drain the oxidizer (bug #31), so I consumed extra fuel. It seems like half the times I make some major maneuver, I have to reload it because I forget goddamn bug #31. But in this case it saved me an engine, because the first time I landed I broke a nerv and the second time I didn't.


    Landing. Though I used chemical engines for a while, now I'm just using nuclear engines for finer control


    Bug #34 shows up again. At least it hasn't crashed the game

    Messina Chasmata is the only place with water, and nicely it also has uraninite. On the downside it has very low ore concentration, just 3%. So the drills are drilling slooooooowly, and refueling will take a looooooong time. Being down at 50% electrical power is not an issue here.


    A screen showing the speed of fuel mining. On Iapetus it was 664, at least before I started losing reactors


    Ariel passing in front of Uranus while Peretto is runnig maintenance on the reactors

    It took 11 years to refuel, even though I already had a 20% of fuel left upon landing. But I won't try to cut it short, because I've done some quick estimate of what it will take to get to Neptune and back, and I'll need all the fuel I can get.

    No accidents in those 11 years either. Two more reactors breaking reversibly, despite me being very regular with maintenance checks. Well, so far so good, 33 years spent without breaking anything.


    Status at the end of refueling

    Now I'm ready to send Cylinder to Neptune. Though I seriously doubt I'll be able to make the round trip in 40 years. And I need 10 more years for refueling anyway.  I would really, really like to leave for Pluto in 40 years, because I will be passing on the planar node, allowing to fix inclination as part of the ejection burn. I am seriously evaluating the pros and cons of waiting 40 years for a Pluto window, and the main con is "I'll go crazy if I spend 40 more years doing nothing".

    I'm confident I can tackle Neptune, but Pluto may yet turn out to be the greatest challenge in this mission.

    Bug compilation updated


    A numbered list is so convenient to refer to bugs quickly. This list keeps growing. Problem and Solution

    1) Launching most vessels will crash the game. Must send them to orbit with alt-f12

    2) Ship will randomly get twisted about. Hope it's not too bad, or that it reverts spontaneously. In some cases it is acceptable to alt-f12 in a new vessel to replace the mangled one

    3) Loading the mothership in physical range gets increasingly more difficult, to the point that it crashes the game. Quit and restart the game every time you load the mothership

    4) Propellers start twisting around. No worry, it fixes once you stop time warping

    5) Orbit will get changed upon entering time warp. First warp to 10x, in any case save before warping

    6) Crew transfer function may get stuck. Saving the game often reverts the bug. If all else fails, transfer the kerbal by EVA

    7) Drills won't find ground even though they are on the ground. It goes and passes spontaneously, just accept that mining will take longer

    8) Ship occasionally sinks into ground upon time warping. Just try until it works. Updated: It was limited to Phobos, probably related to microclipping and the extremely low gravity

    9) Pieces get spontaneously detached for no apparent reason. Always check that part count does not change; reload if it does

    10) I can't plan maneuvers or go EVA, the game thinks my buildings are level 1. On starting the game, load the last quicksave instead of going on tracking station. If the bug manifests, restart the game

    11) Chemical plants stop dumping resources they were told to dump. Reset the dump option; doing it once per process is enough for the whole vessel

    12) Occasionally, kerbals will die for lack of power during time warp, even though power is always abundant. Reload when it happens. Updated: save before exiting time warp

    13) Radiation cover glitches during time warp, becoming ineffective even when the sun is completely covered. Set shielding efficiency to 100%, it cancels radiation damage

    14) Docking ports do not undock. This nasty bug must be fixed by editing the save file. KML editor has the function incorporated, I recommend it to anyone with this bug

    15) Actual reliability time is different from what it should be. Just check more often the parts that get broken more often

    16) Intercept on a target disappears randomly. I know the intercept is still there, I can manage with some piloting skill

    17) Crew hatch registered as blocked even though it wasn't, preventing crew from leaving Clamp. Had to move the docking port to free up a different hatch

    18) Some fission reactors are not working, even though they are not broken. Next time I actually break a reactor, I will revert the malfunction with a reload, and drop one of the nonfunctional ones

    19) "Time warp to here" sends me to the next orbit. Always double check on the time, and if necessary time warp manually

    20) Upon starting the game, clicking on the VAB does not work. Clicking on the icon on the bottom left corner of the screen still works

    21) Sometimes elements of the HUD change size. It doesn't affect the game, and seem to revert spontaneously

    22) Sometimes, when the vessel is not in physical range, the nuclear reactors on Cylinder will stop for no reason. Load Cylinder into physical range and they restart

    23) Occasionally, Nitrogenie in a Bottle starts spinning, even though its aerodinamic is balanced. Reload when it happens, and it will get fixed

    24) The ground on Titan has all sort of glitches and malfunctions. Be extra careful during landing, cheat the vessel in orbit before leaving it, jump to start flying. See 7.3 for more details

    25) Negative aerodinamic drag displayed on the user interface. Drag is still behaving normally, it's only the display that's bugged

    26) The docking port on Clamp has all kinds of problems, does not allow fuel transfer, can't be removed. I stuck another docking port there, and I can grab Clamp with a claw if needed

    27) Sometimes there is no signal for probe control even though there should be. Switch to the vessel that's not being seen, then back to the probe

    28) Crew pod of Hartman rover has a broken life support and a functional wheel, but it instead appears to have a working life support and a broken wheel. Nothing I can do about it; but it still works

    29) The sun shines through Jupiter's body as if it was part of the sky. It's just an harmless visual glitch

    30) An object on the surface coming into physical range may be loaded tens of meters above it. Hope nothing explodes. Reload if necessary

    31) Cylinder's central tanks gets refilled on (useless) oxidizer upon reloading; see 10.2. Dump the dead weight again

    32) All mining drills suddenly manifested a new uranium drilling function. Can't revert it, but they still work normally; it seems harmless

    33) The game is not spawning comets. For the comet landing, pick a large asteroid in an inclined, eccentric orbit and pretend it's a comet

    34) Flags are planted hundreds of meters in the air. Sometimes this crashes the game (NEW). Just reload if it happens

  3. 16 hours ago, miklkit said:

    Ah, you both assume I know how to do orbital mechanics.  I do not.  I get into solar orbit and then let MechJeb do it.  Upon arrival I know enough to eventually get to where I want to go.  Jool is complicated and this was my first time exiting that system.

      As near as I can tell when I left Bop the game decided that I was in a retrograde orbit instead of a prograde orbit and it took forever to flip the orbit around before it would let the vessel actually leave the Jool system.  That is where most of the fuel went.  I need to learn more about that. 


    ok, I guess it makes sense.

    So, I already told you about oberth effect and why you want to make those burns in the planetary orbit. As for how to make the maneuver, I suggest a simple way that's relatively accurate.

    First, go to alexmoon.github.io/ksp. it's a very useful tool. So you want to go from kerbin to jool, tell the tool just that. In this case, it will tell you that the best time to start is in year 2:258, but you get a good transfer window also around 1:200. This will let you know the transfer windows.

    Then you scroll down, there are a bunch of additional informations. most of them I myself don't know how to use, because they don't have an easy ksp reference. but one you can use, the ejection deltaV. In this case it says 1987 m/s, so you know you should spend some 2 km/s to get there. you'll likely spend a bit more because you're not perfect, but try to stay within 10% of that.

    So now it's the transfer window, time to plan your maneuver. take your ship in kerbin orbit, and plot a prograde maneuver for 2 km/s. Any direction is good, you'll fix it later. So now your planned trajectory will exit kerbin and go in solar orbit, where it will produce an apoapsis (or periapsis if you're leaving on the wrong side. Highlight the apoapsis. You want to push apoapsis up as high as possible. So move your maneuver around kerbin's orbit, you'll see apoapsis increase, until you hit some point where you get maximum apoapsis and then it decreases. you found the optimal position for your ejection burn. Since this is the transfer window, chances are by now you'll also be seeing a close approach, because this is jool. now you can make small corrections to turn that into an encounter.

    for other, smaller planets you're unlikely to yet be seeing a close approach. In this case I suggest you also plot a second maneuver, on the planar nodes- they are marked as AN or DN, ascending or descending node, meaning that your ship is passing through the plane of the target orbit going up or down. if you maneuver on the descending node, make a burn upward (purple triangle). if you maneuvr on the ascending node, make a burn downward (purple triangle with lines coming out of it). once you match the target inclination, you'll see a close approach. again, you'll need small corrections, but they will be small.


  4. FInally finished my Wal equatorial circumnavigation, that I started 8 moths ago. I mostly let it drop for several months, until picking it up seriously again in september.

    I wanted to make the best mountain-climbing rover and test it on the most difficult terrain I knew, and nothing beats the equatorial mountain ring of Wal. Ok, kerbin has steeper mountains, but it's kind of a different environment. And I already climbed devil's tower (big mountains with near vertical cliffs and flat top to the west of ksc) on wheel power alone, but I wouldn't want to do that for a grand tour.


    anyway, mountains, mountains and even more mountains. This circumnavigation was more challenging, but less interesting than the one on Slate. Less variety

  5. Part 8: going home

    The circumnavigation is not complete without returning to Kerbin.



    Ascent was quite hard. I did move around the docking port to ensure a balanced push when Leaping Mantis was attached to the sky crane. Unfortunately, this meant that after the rover was detached, the sky crane had an asymmetric tank. Doesn't help that I'm using dart engines, lacking a gimbal.



    The second stage also has a low twr. I crashed a couple times into the mountains before I learned to compensate.

    Before I docked with the return module, I decided to take one last aereal survey on the path I undertook in the past 8 months. Seeing things from a different perspective, and all that.


    Top of the world terrace. Where I finally reached the top of the mountains, and felt I'm on top of the world. Literally.


    Football field plateau, the first strip of flattish terrain where I could pick up some speed


    Ladle cliff, so called because of the crater at its bottom. Looks as impressive as mount Thor, possibly more


    Mount Stegosaurus. Form here you can see a bit better the seesaw profile. Oh, well. It was only a mild resemblance, but it was a good name


    Mount cratertop, with its twin peaks. The tallest crater on the planet


    The Trench. In bad lighting, as usual


    The Caldera. I never mentioned this formation. Basically a giant hole in the middle of the path, had to turn around it on a very thin rock ledge.


    The 8-km hole, with its dramatic west wall


    The pass into Pandro mountains


    Mount Thor. Even from this high you can appreciate its especially steep ravine


    the last stretch of road, where I deviated out of the mountains. This area also marks the boundary between Pandro and Gault mountains, but looks like there is no major gap


    Finally reunited with the return pod, jettisoning the remains of the sky crane. The decoupler was mounted backwards, but nothing a quick eva constuction couldn't fix


    Finally, the return trajectory

    I'm keeping my tradition of high energy trajectories on ion engines for return. This time I didn't want any risk, so I may have gone a little bit overboard; I loaded 20 km/s worth of xenon. Totally overkill. There's food for 4 years (water is inaccurate because it doesn't account for water recycling, there's actually water for over 6 years) and I picked a high energy trajectory for 3 years.


    At first, I'm using what fuel is left in the old cruise module


    Then it's jettisoned and the return module proper is used

    5 km/s worth of xenon burn are slow. I don't trust the persistent thrust mod ever since it crashed my game and messed up my save, so I just made it with the game in background while doing something else.


    Reentering atmosphere at 6 km/s. Don't worry, I tested this kind of pods up to 9 km/s and they're fine


    Pulling 14 g of deceleration


    Floating down on the parachute

    And that's it for Wal.

    I'm not sure I'll ever do more circumnavigations. I'm one who always looks for new challenges, and I don't really see much I can do with a rover after this. I started a new circumnavigation with the idea of using my dear old first rover, the Dancing Porcupine, on Polta. However, once I arrived on the place I discovered that the later update changed wheels and made them a lot more frail. The Dancing Purcupine main selling point - besides combining rover and middle-range isru-capable spaceship in a single vehicle - was its highly elaborated roll cage, making it nearly indestructible and very fun to drive as a result. Well, now it's no more; it keeps breaking wheels. I tried to start that circumnavigation, and I've run the first 10 km already a half dozen times; not once I managed to do it without breaking something. So, I may very well give up on that attempt. I'm not eve sure I want to actually take the time to circumnavigate Polta.

    I may very well leave ksp in a few months. I'm nearly done with my latest grand tour (by "nearly done" I mean it would take at least another month or two, but since I started in early march, it still counts as nearly done). And I don't really know of any interesting challenge to pick up afterwards.

    Perhaps it's early to make eulogies. But I want to say already that if I end up leaving this game after doing all I cared to do, then it's been a fine two years and I regret nothing.

  6. Part 7: full circumnavigation

    After 8 months and 2800 km, Leaping Mantis makes it back to its sky crane



    I wish I could find more descriptive text to put in this report, but really; it was 2800 km of going up and down mountains. It gets monotonous after a while.


    The sky still making a good show



    Date is now 22:338 as I spent another night in place waiting for the sun to get to a better spot. The rover has oxigen for 70 days



    The mantis claws show their worth hitting a wall at high speed and turning the crash into a climb without damage


    A big crater on top of a big mountain. At 19 km on the top, I wondered if this was the tallest crater on the planet; I forgot about mount Cratertop by this time


    Going down said crater. Steep wall, must drive carefully


    I see the end within the 100 km range!

    Finally I arrived to the point where I can see the first flag.

    Now I faced a conundrum. Should I go for that flag directly? Or should I stick to the mountain tops until I reach the point where I first climbed up, so that I can say I circumnavigated the whole mountain chain? The sky crane landed slightly to the south of the mountains, if I deviate for it I will miss 100 km of them.

    Well, who cares, 2700 km of mountains are enough for anyone. Plus, have you seen the terrain down there? It's not like it's much easier than this. Wal is really the hardest place I ever saw for driving a rover. Strongly recommended to any rover driver who likes a challenge. Strongly recommended to anyone else to stay the hell away from here.


    I start gradually going down



    Look down there the terrain on the "plains". Would it have been any easier to drive down there?


    Climbing down, cutting through this patch, there's quite some hard terrain



    Finally down in the "plains". There's even a canyon to cross


    The canyon. After the Trench and the 8-km hole, this is nothing


    Yes, I have to conclude that driving down there is indeed a lot easier than driving up on the mountains. It's still quite a hard drive, at least as hard as one of the hard parts of Slate. But Leaping Mantis is a very good rover, and I just got an extensive training on ground much harder than this.


    5 km from the target, I break a wheel. Nothing uncommon here, but those are the very last of the repair kits I started with. It gives a nice sense of closure


    Back to the sky crane


    Actually, the ladder wasn't all that functional. The bulge caused by the thermal shield interferes with it. I could eventually reach the crew pod, but it took a lot of trying, as the kerbal kept trying to make a 180° turn every time it came near the top. It was easier to reach the pod by jumping with the jetpack; the gravity on Wal is too high to fly with the jetpack, but low enough that you can jump really high and float for a while.

  7. Part 6: moar mountaineering!

    It's all this mission is about, after all


    I made it to halfway!


    Halfway point was only a few tens of kilometers after the 8-km hole, so this section starts here. I planted a flag every 20 km, often very precisely, and while I occasionally broke the pattern for a significant landmark, there weren't many of those. So it's safe to say that I made at least 1300 km. Considering that the distance between flags is determined as the bird flies, while Leaping Mantis keeps on going up and down, it's probably safe to estimate even as high as 1500 km. It should have been 1200 km on a perfectly linear equatorial navigation.

    Took me 19 hours of game time to travel that much, which is a very good time - an average of 75-80 km/h, in that kind of terrain, is amazing.

    Of course, real life time was a lot longer, with all the times I had to reload.

    Once there, I decided to take a long stop and wait for a new day. Visibility is very bad, I'd like to have shadows again. Due to Wal's slow rotation, I had to wait over 10 days.



    Like this, much better!


    And this, some 400 km later, is the divide between the Boreth mountains and the Pandro mountains, the last biome. The pass goes down to 10900 m. I called that mountain with the nice round crater on top Crater peak; not very original, no. I mostly stopped naming features because I run out of such names.


    Higher than some lower elevation points I reached, but stll low enough to have boulders





    This was a particularly good stretch of road because it's on the right place to have Urlum low on the horizon. The sky is just better.

    My rythm has picked up now that I feel the end coming close, and I'm making some progress on this mission most days - even though with the end of the summer I have less free time.




    This was a particularly harsh stretch of road, where I had to cut through a very steep ravine




    All the celestial bodies visible from Wal: Urlum and Tal are obvious; Polta is just under Urlum. Priax is a lot smaller, can be seen from up close nearly halfway between Urlum and Tal


    No Priax here, but a much better view on the others


    Another low pass, this one falling below 9900 m




    Mount Thor!

    Thus named after the real world mount Thor, look it up on google maps (Mount Thor, Nunavut, Canada) it's quite impressive. This one has a similar shape, with a huge cliff on a side. Here I decided to stop and try to go down the cliff. After saving, of course.


    Down mount Thor, it's got 70° inclines. They are the steepest of the whole planet

    I tried a few times, don't remember if I ever successfully made it to the bottom without exploding. Either way, I then reloaded and went on with the circumnavigation.




    By now I'm only missing a few hundred km. Next it will be the arrival.

  8. 11 hours ago, miklkit said:

    Full disclosure.  The spaceplane took off and went to Minmus, refueled, took off and got into a solar orbit, then went to Jool for a cost of 2800m/s.  It had plenty of fuel left as it didn't take much to get to Bop after arrival.  It then refueled on Bop.

    It took off from Bop, circled around and burned for a solar orbit and just sat there.  Once it eventually did reach a solar orbit it then set course for Kerbin but didn't have much fuel left.  I hope this doesn't happen again as it was nerve wracking

    ah, that's it. you are not making use of oberth effect.

    Oberth effect means that making a prograde burn close to a planet is cheaper. making such a burn in solar orbit is a lot more expensive.

    you spent 2800 m/s to go from kerbin orbit to jool in solar orbit. that's already a lot more than it should be. from low kerbin orbit, you can spend 2000 m/s and reach jool. it's much cheaper, even though you have to spend 900 m/s just to get out of kerbin's gravity. from minmus you are already almost out of it, and you can spend less than 1300 m/s; the best way is from minmus to fall down on kerbin and make the ejection burn close to it, as shown in this picture


    160 m/s to go from minmus to low kerbin orbit, then it's only 1150 m/s to jool.


    and the same applies to jool, except you are potentially losing eve more there. I already showed you a pic where you could have returned from pol with 1 km/s, because jool is very big and has a lot of oberth effect. making the burn around bop would also add a tiny bit of oberth from the moon. by getting out of jool, then lowering periapsis in solar orbit, you spent a fortune leaving the gas giant and you also lost your oberth effect.

    frankly, i am surprised that you got to the point where you can make a spaceplane that can ssto from kerbin with enough fuel left to reach minmus (while carrying a lot of payload in the form of heavy passenger cabin and mining equipment) but you don't know about oberth effect and efficient interplanetary transfers. it's like finding a civilization that has discovered electricity but never invented the wheel.

  9. 1 hour ago, miklkit said:

    I have established a base on Bop and sent a spaceplane there to transfer crew for the first round trip there.  The spaceplane made it there just fine with plenty of fuel left over, refueled and took off.  It then took so much fuel just getting out of the Jool system that when it got to Kerbin it had to aerobrake to slow down enough to then get an orbit, then more aerobraking was needed to slow down enough to finally land.  I would think that it would take less fuel to return than to get there.  Is this how it is or did I do it wrong?

    Also, I just installed restock and it seems to be working well, but this fiery arc on the craft is new.  is this normal?


    From a purely energy perspective, it takes the same energy to get from kerbin to jool than it takes to make the reverse trip. that's because of energy conservation.

    however, there are many differences in the ways you can save energy.

    one is gravity assist. to get to jool, you don't have to pay for an insertion burn because you can use a gravity assist from tylo or laythe. another is oberth effect; haing a massive body helps you in prograde burns. Jool is very massive, but at bop you are also pretty far from it. another is aerobraking; on kerbin, if you have a plane with enough heat resistance, you don't have to pay for insertion either.


    that said, your experience is very surprising. because if you sent a spaceplane from kerbin to jool you had to spend 2 km/s to get to jool from kerbin orbit, plus whatever you had to spend to reach kerbin orbit in the first place, plus whatever you have to spend to orbit and land on bop from jool orbit - which is generally at least another km/s.

    while from bop you can get a kerbin intercept for 1 km/s. plus 200 m/s to orbit the small moon. you can easily reach kerbin with less than half the deltaV it took you to get there. and without even counting what you spent to reach kerbin orbit. are you sure it took more fuel to return? in that case, you must surely have made some major mistake, but without knowing your trajectory i can't guess it.

    actually, i can't even imagine what you could have done to spend more than 3 km/s getting a kerbin intercept from bop. so I'm more likely to put it down to you misreading or misremembering fuel cost.

  10. I used the deltaV map when i was less experienced, but now i find it of little use. for anything further away than mars or venus i'd use gravity assists, and the injection values are often not meaningful. for example, if I wanted to visit europa i wouldn't inject into a low jupiter orbit, circularize, and then go to europa. I'd inject directly into europa, or else I'd find some compromise between haviing enough oberth effect from jupiter but reducing intercept speed.

    even for a normal mission, what you actually have to pay for inclination can be very different.

  11. 52 minutes ago, sevenperforce said:

    All of this info can be found online if you know what to search for, but I can also answer these questions (mostly) off the top of my head.

    well, clearly I don't know what to look for.


    The Shuttle's OMS system contained about 300 m/s of total dV depending on the amount of payload it carried, but the overall launch profile dropped it off in a slightly-suborbital trajectory in order to allow the external tank to re-enter passively. It used about a third of this to raise its orbit after jettisoning the external tank and about third of this to lower its orbit back into the atmosphere at the end of the mission. The remaining third was used for on-orbit maneuvering and for attitude control during the first phases of re-entry. 

    My doubt about that is that the shuttle put hubble into orbit, and hubble is a lot higher than the iss. 300 m/s are not enough to raise its orbit to 500x500, especially not if you also have to pay for reentry.

    unless that the external tank had enough of an extra fuel to support the shuttle entering a 500x50 orbit before being dropped? so it means in regular missions it was dropped with some fuel still in it?


    The inclination of Mars is less than 2° off from the inclination of Earth. The two orbital planes intersect along a line, and any transfer trajectory between the two bodies will cross this line at one point or node. So typically in a Mars mission, the vehicle perform a very small mid-course correction at whatever place along the transfer orbit crosses that line. It's not the most efficient way to change inclination, but since it is such a small correction it's not that big of a deal and is typically performed with the basic RCS system on the vehicle.

    Every now and then, the orbital planes and the optimal transfer trajectory will line up such that the node is either at Mars or at Earth. If it's at Mars, then you can just use your atmospheric capture and you never need to correct; if it's at Earth, you perform that correction along with your transfer burn to take advantage of Uncle Oberth. 

    in my own rss experience, that small inclination still costed nearly 1000 m/s to correct. it's not a small amount by any mean. I myself used a slower trajectory, launching from earth when earth was passing through a planar node; then I waited a couple orbits in that parking orbit until I intersected Mars. This way I saved those 1000 m/s - I needed a few hundred m/s to syncronize my orbit for a Mars encounter, but still a large saving. But this two-times trajectory is never used in reality.

    what sparked my interest was exactly that I was surprised by how expensive that plane change was. And that none of the Mars missions ever mentioned that some transfer windows are cheaper than others, even though I know that if the window happens on a planar node you don't need the plane change and you can save a lot of deltaV. Generally speaking, in all my interplanetary transfers I went through great hassles to avoid paying for plane changes, because the cost was measured in km/s. and none of the planets are nicely aligned. I even named a subchapter in my mission report "there is no such thing as a simple hohmann transfer in rss" because of that.

    Speaking of atmospheric capture, even though the game is a lot more forgiving than reality in regard to thermal control, I found Mars too fast for aerocapture. Ok, I could perform the injection burn in the high atmosphere and save perhaps 100 m/s, but that's it. I could then slowly lower apoapsis with multiple passages, but I had to pay the cost of injection with rockets. A mars lander has a thermal shield to protect it, but I don't expect a mars satellyte to be able to aerocapture.

    On the other hand, Titan was extremely convenient for aerocapture. being much smaller, I got much slower at periapsis and I could aerobrake without burning. But then, I was coming in from Jupiter, or at most Ceres, so my intercept speed was a lot smaller than it would have been coming from earth; so I don't expect our real probes to be able to aerobrake at titan.


    It took about 780 m/s of dV, spread over 10 different burns as it got closer and closer.

    so little? Once more, this is a lot less than my own rss experience. When going to any target in solar orbit, even with the best hohmann transfers, intercept speed is going to be high. ok, its perihelion is close to earth, so with the right gravity assist you can eject into a very similar orbit, with the same aphelion, you only have to slightly raise periapsis. and I suppose they picked the comet specifically because it was in the right orbit. but still, it's impressively low.


    I don't know what your approach is to approach Mercury, but all missions to Mercury -- Mariner 10, MESSENGER, and the ongoing BepiColombo -- have used at least one planet flyby to reduce the propellant needed to reach the innermost planet. Mariner 10 used a single Venus flyby but it never entered Mercurian orbit, instead doing all of its observation during three Mercury flybys. MESSENGER used one Earth flyby, two Venus flybys, and three Mercury flybys before finally performing its Mercurian orbital insertion burn. BepiColombo has already done one Earth flyby, two Venus flybys, and two Mercury flybys, and will do four more Mercury flybys before finally entering a polar orbit around Mercury with minimal propellant use.

    starting from phobos because my mothership was refueling there, I took an earth flyby (1500 m/s) to get into a venus intercept. From venus I took a couple more flybys to lower my orbit. there I faced a conundrum; the cheapest mercury injection is by meeting mercury at perihelion, so that you have less of an aphelion lowering to pay for. But on the other hand, the cheapest injection is also on a planar node, because you can use venus gravity to pay the plane change. But the planar nodes are shifted by almost 90° from the aphelion-perihelion axis, so I had to pick one. In the end I decided to meet the innermost planet at perihelion, and I had to pay almost 3 km/s for a plane change in solar orbit. and there were still over 2 km/s of intercept speed, for a total cost of roughly 7 km/s from phobos to mercury orbit.

    Keeping the mothership in solar orbit and using one of its subships as an impromptu additonal stage I managed to land on mercury and return to phobos, but I was left with the feeling that I could have been more efficient in the approach. that's why I was specifically interested in that part. real mercury orbiters used ion engines, so it's going to have a different profile, but they still save as much as they can by gravity assists, and there I wanted to see if they could do it better than I did.

  12. ever since I started playing this game and I got some skills at navigation, I started wondering about exact trajectories of actual space missions.

    How much remaining deltaV did the space shuttle have once in orbit? how do they deal with inclination on a mars mission? did the cassini mission use a gravity assist from titan for capture around saturn? and if not, why not? how much did it cost for the rosetta mission to rendez-vous with its target? do they use an approach more efficient than mine to approach mercury?

    and all those things are never, ever discussed anywhere. too technical, i guess. but even sites where they do give quite technical details on the machinery and instruments are not technical on the issue of maneuvers. if you're lucky you can see a trajectory, but you never see any kind of discussion like "here we made a burn 450 m/s prograde, 30 m/s antinormal".

    anyone knows if/where I can find sources on the topic?

  13. 34 minutes ago, Scarecrow71 said:

    That's a bit confusing.  At least to me, anyhow.  How do I know which was is down so that I move the way I want to?  Pressing space to orient the Kerbal to my current camera angle will do...what, exactly?  Will that insure that towards the Kerbal's feet is down?  Or does that simply rotate the camera angle to center the Kerbal and keep "down" in the same direction?

    See, this is my major issue with the controls.  I don't know which way is down, I have no way of identifying which was is down, and I can't seem to get patient zero down oriented so the controls function the way I expect them to.  I'm quite sure they are working as designed, but not how I expect them to.  How does what you posted above solve the issue?

    And perhaps I just don't understand what you are saying, which is on me.  Some things I pick up really quickly.  Others...dinosaurs have been extinct for far less time than it takes me to learn.

    Down is always the same direction when you are eva*. you can turn right and left, but not up and down.

    go ahead and try. take your kerbal eva, press space, see how it orients. move around the camera, press space again, see how it reorients. you can rotate him left and right, but UP AND DOWN WILL ALWAYS BE THE SAME DIRECTION FOR HIM.

    i suggest you always use space and let your kerbal reorient before giving other commands. I also suggest moving your camera so you're looking at your kerbal's back. this way you will share your kerbal's frame of reference, and it may be more intuitive for you to control. but in any case, i suggest first you make some experiments until you understand the up/down thing



    * exception/problem: when you are in orbit, your head point northward. when you are on the ground, your head points up. when you are transitioning from orbital to suborbital, the kerbal may rearrange himself spontaneously to change orientation. this only happens at a very specific speed, though, and you'd have to be very unlucky to stumble onto that problem.

  14. On 10/22/2022 at 3:01 PM, farmerben said:

    The mission is to add a part to a rover and move it to a waypoint on Ike.  I'm having trouble navigating close to the rover and finding the waypoint.  The map view on maximum zoom is my best navigation tool but it;s not accurate enough.  I remember on an older version of the game I had yellow rectangles highlighting my target in camera mode, but that doesn't happen now.  


    What do you do to make these missions easier?

    go on map view. you should see the waypoint on ike. you can select it as target. now you will always see the waypoint on your navball, showing its direction.

    you may face additoonal problems if you don't have your rover driving properly set. if you are normally standing on the ground and you see the navisphere is pointing up, then it's not properly set up; click on the probe core and you should find an option for control pointing forward. so that when you move, navisphere is pointing prograde. then just point towards your target

  15. maybe your problem is one of perspective?

    eva kerbals are always standing straight from ground or orbital perspective. also, they will always default to your camera orientation. you can press space to align the kerbal to your actual orientation, which I suggest you do. at this point you shouldn't have any problem using the wasd commands

  16. Part 5: two giant holes

    Leaping Mantis encounters the very most difficult passages of the whole voyage, in the form of two huge holes in the ground with very sheer sides.


    It's hard to appreciate with the game perspective, luckily I managed to get some orbital pictures of the location



    After mount Stegosaurus there is this thin rock ledge I dubbed the knife edge

    This section has been the slowest progress, taking three months to advance maybe 10% of the way. The problem is, on one hand I already did one fourth of the circumnavigation, which is plenty of time to get tired. On the other hand, I'm nowhere near close to the end, so I can't summon the "just one last bit of effort and then I'm done" motivation. Furthermore, I was beginning my rss kerbalism grand tour, my biggest grand tour so far - which, given that I already have a tendency for extremely ambitious missions, is quite the achievement - and I was super excited about it. I resumed steady progress somewhere along the summer.


    mount Cratertop, a mountain with a crater on top. It has two twin peaks at almost the same altitude. It probably would have been the tallest mountain on Wal, if an asteroid hadn't intervened


    here the ravine is steep enough that you can see all the way down to the plains 15 km below

    In fact, the ravine is so steep that a bit of carelessness when planting the flag led to Bill slipping and falling down to his doom. That ravine was so steep, he could not stop. Dead for planting a flag. What an undignified way to go.



    Here the mountain crest followed a sort of S shape. I followed it. Maybe going straight would have been even more challenging?



    I much prefer those narrow ridges with steep walls. For large stretches of the road, the top of the chain was large enough that you wouldn't really appreciate being on top of a mountain. Here you can get a good view. Or at least you could get a good view, if Wal wasn't ugly.

    It was amid one such stretches of large, flattish mountain tops that I found the first big hole - which I dubbed the Trench.


    The Trench, seen from the ledge. Between perspective and poor light, you don't really appreciate that there is a 4 km deep hole in front of you

    The bottom of the Trench is at 13 km altitude. The ledge descends from a 19.8 km tall mountain, but it's already dropped to somewhere short of 17 before the final cliff. So we can call it a 4 km deep hole, keeping in mind that measuring holes is not an exact science.

    It's been an interesting stretch; mount Cratertop, the thin curving ledge and the Trench are all within 100 km of each other. Afterwards, there isn't much worth noting, and nearly 400 km pass by with barely any screenshot taken.

    I could have avoided the Trench, going around it. It certainly would have been faster and easier. But then, I could have avoided this whole mission if I was just looking for fast and easy.


    Moving down the ravine into the Trench. The slope is 60° steep. Those slopes are very dangerous; a small bounce would mean falling tens of meters before touching land again. And then upon landing you'd bounce again, falling more, and gaining more speed every time. Until no amount of roll cages can protect the rover. Easy, you may think; just avoid bouncing. Except the brakes themselves make the rover bump. I learned to always save before descending somewhere like that.

    By contrast, going uphill is easy.


    Going out of the Trench, it's significantly less steep. The cosmic alignment is also right for a nice view of Tal


    Well past the Trench, just another random location with a steep slope


    Leaping Mantis braving a 60° slope upwards


    And finally, in front of me opened the 8-km hole. Yes, that's its name. If that's not impressive enough, I don't know what is. It's a nearly cylindrical hole 8 km deep.


    Though as always, you can't really appreciate the scale


    Carefully inching down the steep walls of the 8-km hole


    The hole is so deep, it's got rocks at the bottom! Seems quite a stupid thing to say, but check the previous chapter for the significance of rocks in this voyage



    Going up, I did something I haven't done anywhere else on this planet: switchbacking!

    The most impressive feature of the 8-km hole is its eastern cliff, though (which I named the western wall because it looks west, or maybe just because I got confused). It's not strictly the steepest inclination on the planet, as a few ravines are roughly as steep (most impressively mount Thor, which will be shown in a later chapter). But it is the most steep east-west ravine, and the longest, with over 7 km of near vertical climb. To the point that despite Leaping Mantis extreme climbing skills, I actually had to stop going forward in some points, and start switchbacking. Even when I could go forward, the ravine is long enough that I run out of battery many times, and had to stop and recharge. Something else I never needed anywhere else.

    It took nearly one hour of game time to cross this handful of kilometers.



    Those two pics show the highest limit of vertical climb Leaping Mantis achieved. The slope is seen on the navisphere as 62 or 63°. The time on the top right shows the second image was taken 3 seconds after the first, and the speed gauge shows increased speed, showing that the rover could accelerate while going upwards a 62° slope. That's its utter limit; accurate use of SAS is necessary to get grip. And those 3.8 m/s are pretty much its top speed in this condition. Battery will lasts maybe two minutes.

    It's also quite complicated to rest and recharge the battery; even with brakes, the rover tend to slip.

    I keep complaining that you can't appreciate perspective, so I reloaded back and took some better pictures from the eastern ledge, after climbing the worst part of the west wall (yeah, it's really a confusing name, but it does sound cool)



    The rover is the white dot in the center of the image

    The 8-km hole is less than 100 km before the halfway point of the circumnavigation. Biome is still the Boreth mountains, this range encompasses half of the planet while the other two are shorter.

  17. Part 4: Mountaineering galore, part 2

    Yes, more traveling across the mountain range. Leaping Mantis changes biome, but the mountains are the same. I miss the variety of Slate.


    yeah, though I walk in the valley of really bumpy terrain, I will fear no wheel breakage: for the mantis claws are with me


    Actually, even the mantis claws can't always protect my wheels. I still need to reload quite often, even though after the first hundred kilometers or so I learned to drive better. To counteract that, I brough as many repair kits as I could (do notice the additional storage space for repair kits on the wheels trusses). To avoid depleting them too fast, I only repair a wheel if it's been more than 5 km since the last time I saved - else I reload the game. I plant a flag every 20 km, and I always save there; plus, I generally save a couple of times between flags. So, there's really a short time interval where breaking a wheel would result in using a repair kit. Even then, at the time of this writing I miss 150 km and I'm down to the last kit.




    Here I'm slamming against a wall at 46 m/s. I don't know what happened next. That's a borderline speed, in that at that speed sometimes Leaping Mantis hits the ground and survives (yeah, it's really sturdy), but it's far from guaranteed.


    This lump of terrain doesn't look like much, but it's the tallest elevation on Wal. I called it mount Lump


    The sky is also very pretty, at least from the part of Wal where Urlum is visible

    Speaking of sky and visibility, I'm using pretty strong light amplification here. Unfortunatly, the color of Wal is really bad for contrast, and it's very hard to understad the terrain in natural light. Even with artificial light enhancement, during the night visibility is poor. At two distinct points during the trip I stopped the rover and waited for the new day.


    A section where a crater chipped away a major chunk of mountan, resulting in a pass with much lower elevation. The mountain profile forms almost a perfect arc, only broken by the reverse uvula - so called because the profile of this mountain section looks like a troath with an uvula, only flipped vertically.

    Wal is a place of extreme elevations. In a few kilometers the altitude dropped from 18 km to 13, up to 15 again at the reverse uvula, down to 11 in the lowest point of the pass, and up again to 16. 11 km altitude has been a record low in the last 500 km, though it's going to get lower at the biome change.


    The biome change, aerial view

    This is the place where the Gault mountains end and the Boreth mountains begin. The Boreth mountains are on average one km lower than the Gault - I don't remember ever crossing 20 km again - but aside from that they are identical. This goal marks roughly one quarter of the voyage; Leaping Mantis landed at 150° W, and it's now at 55° W. Leaping Mantis has run around 700 km; it probably becomes a higher number if we account for all the ups and downs.



    I went down, really far. You may notice something unique here: rocks! Yeah, they are just normal rocks, authomatically generated by terrain scatter, what's so special with them? Well, do you see any in the previous images? Nope! They stop appearing somewhere between 10 and 11 km altitude. You can say that Wal mountains are so high, not even rocks grow on them!


    I should have stayed over the crest, but I took a slight detour to collect a sample from another biome



    A few km later, I'm again high enough that rocks disappeared


    Climbing a 55° slope. Leaping Mantis has a vey hard time, but it's actually making it


    I tried to turn the lights blue to see if it looked better. I eventually swapped them back to white


    This last place I named mount Stegosaurus, because from the profile it looks like a stegosaurus back - something that cannot be fully appreciated from this image. But it does give a stunning view of the plains 15 km below.

    That's close to one third across the planet. Time for another stop.

  18. 2 hours ago, intelliCom said:

    I'm referring to really damn advanced though. Fission fragments, fusion, NTR, ones that don't exist in reality. All the standard rocket engines have seemingly normal values for burn duration.

    Literally all of the advanced engines carry the same burn durations, as mentioned before. This doesn't seem right to me, and I wanted to know if the numbers are provable or just placeholders.

    so you are talking about far future engines. as far as i'm aware, kerbalism is not made with those in mind. as i said, there is a formula, and as far as I am aware (note, I am not in the dev team or anything, just a long time user) the equation is used for engines that the mod doesn't recognize. kerbalism is not even supposed to be strictly compatible with the far future stuff (while it is supposed to be compatible with near future)

  19. 3 hours ago, intelliCom said:

    Just started using Kerbalism for the first time; I've noticed that a lot of the higher-tier engines (mainly the Near Future and Far Future stuff from Nertea) have the exact same burn durations: 10 minutes standard, 40 minutes high quality. Why is this?

    Apparently the author is no longer developing it, which is a shame. Perhaps it would be worth someone figuring out what the burn durations should be?

    i think there is a formula for allowed duration and ignitions that takes into account thrust, Isp(vacuum) and Isp(sea level). basically, the more powerful an engine is, the more it is atmospheric-optimized, the less burn time and ignitions it has. until it hits a minimum, and can't go lower

  20. Part 3: mountaineering galore, part 1

    Leaping Mantis travels across the mountain range.



    Leaping Mantis landed at the base of the mountans. Now it has to climb some 10 km to reach the summit.



    Leaping Mantis path is crossed by those wave-shaped formations


    Up to a 50 degrees slope, Leaping Mantis keeps pushing forward



    Finally, the summit

    Actually, now that I'm on top, it looks even a bit flatter than the rest of the planet. Not that it is a high bar to clear.

    From this, Leaping Mantis starts its real voyage.

    Unfortunately, as I said, Wal is a lot less fun that Slate. Slate had an interesting geography; it had valleys and canyons, and it had different biomes with different characteristics. Here on Wal, there is no such variety. The mountains are not dug by ancient water, they are just a jumbled mess of chaotic terrain. The big equatorial mountain range is split into three different biomes, but they all look similar.

    So, instead of providing a narrative like I did in the previous circumnavigation, I'll just post a photo gallery. Mostly without much comments, unless there is something specific to comment on.



    Here I was desperately trying to save a rover capsized at high speed by landing on the rooftop wheels and going backwards. As I started in march, I don't remember if I was successful or not


    Here I found a bit of flattish terrain, and I took the chance to run faster for a while


    I named that place the football field plateau


    Here the mountain range is interrupted by a crater, only a thin crest remains



    Navigating the aforementioned crest


    Because driving on Wal was a lot more boring than on Slate - and still very dangerous, despite all of Leaping Mantis safety measures - this mission went slowly. Some days I'd drive 100 km, some days I'd drive 20, and sometimes I would go full weeks without even touching it. As a result, I started in march and today 20 october I still miss a couple hundred kilometers.



    The most difficult features to cross are ravines to be cut diagonally. Here the smallest mistake may lead to the rover jumping laterally and falling for hundreds of meters before rejoining the ground the hard way



    This is why, while a low baricenter helps stability, you still want the main body of the rover to be high above the ground



    And that's it for part 1. In retrospect, I should have snapped pictures with more references on progress made, because I'm not sure how much road I've done to that point.

    Anyway, I'll keep updating later.

  21. Part 2: launch and cruise

    Leaping Mantis was delivered on Wal by a relatively minimalistic sky crane.


    Leaping Mantis ready on the launchpad


    Leaping Mantis has a large area, presenting exceptional aerodinamic challenges.

    For Tamarromobile, I used a huge aerodinamic fairing, which was more massive than the rover itself. In this case, it would have been way too heavy to justify its mass. So I launched the rover unprotected, trusting in extra thrust and deltaV to compensate. I put the rover at the bottom of the stack so it won't cause aerodinamic instability.


    Jettisoning the boosters


    Once the atmosphere is cleared, the rhinos are used


    In space, the nose cones are removed for mass reduction

    Urlum is far, I'll use a Jool gravity assist to get there.


    Leaping Mantis plans a Jool gravity assist


    Jettisoning the last stage of the launcher

    Now that the launcher is removed, the cruise stage is a couple of large tanks with nuclear engines. There are a couple of relay satellites embedded in the stack. For return, I will use a small ion-powered pod like I did for Tamarromobile.

    I decided to simplify a bit the architecture from the previous mission by not having a dedicated vehicle to leave Wal; instead, the sky crane has some extra fuel and will double as Wal ascent vehicle.

    I am still using a version with kerbalism installed; I deactivated some of the harshest realities of kerbalism, but I still have to provide food; I loaded enough for 30 years, which makes quite a large pile of snacks.


    The cruise stage leaves on nuclear engines


    The cheapest path to Urlum


    The fast path to Urlum

    From the Jool flyby, I could find - with the help of a couple correction maneuvers - a path with a very clean injection at Urlum. However, it would leave me only three years worth of food. Since I have some extra fuel, I opted for a faster trajectory, spending a bit more on deltaV to shorten the trip by several years.


    Planned arrival at Urlum

    For arrival at Urlum, I use direct intercept at Wal; this way I can use the large moon's Oberth effect and orbital speed to reduce the injection cost, resulting in a cheap capture despite a less than ideal trajectory.


    Arrival at Urlum with 10 years left of food. Water estimate is wrong because it's not accounting for water recycler


    Capture burn. And first glimpse of Wal


    Releasing the two relays in high orbit


    Jettisoning some empty tanks


    The second stage of the cruise stage takes care of circularizing


    Sky crane separation



    Landing is potentially difficult, because of the terrain. I'm trying to aim for a large flattish area next to the mountain range, as a place that's less likely to have 45 degrees slopes.


    After a bit of trial and error, I managed to find a bit of flat ground to land safely

    And now the real challenge begins.

  • Create New...