FinalFan

Third Mun Mission, or, Jeb Gets Some New Toys (part 5/x, now with more Minmus)

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TL;DR:  TODAY I LEARNED THAT "CHECK YO' STAGIN'" APPLIES TO DOCKING PORTS.  

I am new to Kerbal Space Program and going through career mode.  After the crew of my second Mun landing returned to Kerbin with 1,859.6 science on board, I decided to get ... ambitious greedy.  

I started by unlocking Very Heavy Rocketry, its associated fueling needs, the long-awaited NERV, and Composites.  Initially I just wanted to use the NERV as any upper stage, since it was so efficient.  But there was a contract for mining ore, and I already wanted to land, so why not try to make a refueling lander?  It turned out to be a lot heavier than expected, so I went with 3x engine symmetry (2 would have been enough power but 3 made better symmetry and I was used to high munar TWR from my first two landings), and packed a bunch of the baby airplane fuel cylinders next to the engines since they have the best fuel-to-weight ratio of all the liquid tanks—which also gave me a place to mount landing gear that could actually reach the ground, and a better place to mount drills than some very sneaky girders.  Then, since I had the power, I upgraded the converter since the small one's ore-to-fuel ratio is garbage.  I didn't have the Gigantor solar panels unlocked yet, but looking at the energy requirements I decided to use the last of my science to do so.  

I wanted to do a bunch of contracts.  I had several around the Mun, for which I needed a rover and a satellite, and I wanted to mount them both on the nose.  Hmm.  I decided to put clamp-o-trons on the rover and nose, then put the satellite in the middle.  I added RCS to the rover so I could, in theory, detach in spaceflight, launch the satellite, and then reattach to the lander.  I've never docked anything before, but how hard can it be?  (Backup plan: carry the satellite down, drop the rover, launch satellite after takeoff.)  

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Speaking of docking, on this mission I plan to try it for the first time again—ship to ship this time.  My middle stage should make Mun orbit, and if the lander refinery works as well as hoped, I can potentially come back up, dock, donate a little fuel (I put modest L+O tankage on the nuke with this hope—contents donated to the middle stage, of course—plus I could refine more ore after docking), then transfer crews, land again, collect science and fuel again, and did I mention both crews still need a Mun landing under their belt?  

Now all I had to do was figure out how the heck to lift all this junk.  Fortunately I had just unlocked the Mammoth.  Even so, I still needed to attach some Kickbacks to give me what I consider decent launchpad thrust.  For the middle stage, a Skipper might be adequate to the task, but I thought, "Hey, the Rhino gets better ISP anyway, right?  And it will keep my burns short.  Let's try this sucker out."  Plus it let me keep my rocket fatter; this thing is much taller than any rocket I've made before.  

Looking at what I'd done in the VAB—what I'd done to the VAB?—I named it the Abomination.  The fairing covered 45% of the rocket.  It's over 100 tons heavier than my previously biggest rocket, which was almost 100 tons heavier than my previously biggest rocket.  And it's not too far shy of double the cost, though a lot of this is tied up in stuff meant to be recovered.  

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I had just accepted a contract to test the aerospace decoupler at 51-55km while going 1110-1890m/s, which put some constraints on my flight profile, but it actually worked pretty well with a reasonable gravity turn.  It took me a couple of tries to get it right, but I don't feel too guilty about reverting for that sort of thing.  They aren't terrible fins—or at least they looked the part.  

The Rhino performed beautifully, too.  It started up well in the upper atmosphere, so I'm sure it was at least as efficient as any other upper stage could have been, and the extra power let me carry more fuel that the main lifter would have otherwise been using (at less effiency).  The downside is that if the Mammoth was allowed to use that fuel I was confident of recovery; this way, I didn't even try for this mission, though I may if I find myself with a similar lower stage in the future.  

On the last Mun landing, I caught a Minmus intercept completely by accident while planning the trip home, but didn't have the fuel to do it.  Not this time, my crew thinks.  Not this time.  

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As it turns out, the main difficulty of reattaching the rover—other than that I'm terrible at docking—was that it really wasn't designed with docking in mind.  First, the lines of sight were very bad, and second, I didn't realize I'd offset the docking port so that a little bit of it was blocked by a girder.  The magnetism seems to be holding it in place for now, so hopefully that will hold up until I land.  If it falls off upon landing that will just save me the trouble.  

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The satellite was then on its merry way after reaching the correct altitude to turn on its engine to fulfill a contract.  I was careful of where the main ship was, after having read many horror stories about inattentive launch collisions!  It has tons of delta-V, which is good because it needs to fulfill two orbital requirements; it may have enough to spare to do something useful.  Even if it doesn't, three contracts on one small satellite that at worst will be a half-decent Mun relay antenna isn't bad.  

The orbiter (the Rhino) is another story.  By my calculations at the time, it did have enough to get into my preferred capture orbit but it's tighter than I thought back in the VAB when I was doing gross estimation instead of precise engineering.  I hoped I would be able to get into my subsequent planned lower orbit.  (To make a rendezvous with the mining ship easier—the refueling might be more than a novelty now.)  Alternatively I could have just bailed out and tried for Kerbin immediately after the capture, but I wanted to stick to the mission plan.  
 

Apparently, magnetism gets weaker during time warp.  
 

I wanted to orient my vessel in a certain direction to ensure the orbiter didn't get in the way of the lander's maneuver.  I knew that the maneuver node could sometimes move around a bit on you, but I was totally unprepared for one that meandered across a 45° swath of the navball!  I can't help but imagine the loosely attached rover had something to do with it, but even so, that was ridiculous.  Every time I thought I was close, it dashed back in the direction I came from, sort of like the way SAS autocorrects.  

Speaking of misbehaving maneuver nodes, apparently the satellite was small enough, and the antenna big enough, that the engine was significantly offset from the center of mass.  At least, that was the hypothesis I formed as the thing bucked like a bronco for the nearly two minute burn despite the fact that I was only packing a Spark.  Or perhaps too much of the weight was in the back?  I will keep this in mind for more important future missions.  

The rover, in the meantime, had gotten loose again.  Fortunately I cought it before it had gone more than a couple meters.  I was becoming concerned.  I wondered how it would behave under deceleration.  At least, I reasoned, it would be only compressive forces, not pulling the clamps apart, but it's off center—that's the whole problem.  But although the clamps are off center, the center of mass (as I eyeballed it) looked like it should be right over the center of the rocket, so maybe it would be fine.  I had plenty of monopropellant, even without being able to transfer any from the ship.  As long as it waits until landing—or perhaps even the final approach—to wobble off the ship, I'm golden.  

But, a pessimistic voice whispered, if it's not docked then you can't undock it.  what if it sticks through the landing and doesn't want to go?  Will the monopropellant be enough to push it loose?  Almost certainly yes, I thought.  I was glad I thought of the possibility, but I was sure it was not a true concern.  

After another repetition of the rover escape and a couple more times it seemed to be threatening to, I think I've figured out the behavior.  Whenever "normal activity" is suspended, either from time warp or from leaving the area (to adjust my satellite's orbit) the half-on, half-off docking port starts to freak out.  Possibly the game is trying to make it fit correctly, but running into a conflict with the girder that's in the way.  It wasn't a problem when it was built that way but it looks like detaching it was a one-way trip, at least for this particular rover.  

There seem to be one of two "resting states": one where the clamps are together but offset as in the picture above, and one where the clamps are perfectly aligned but being held apart by the girder.  If I leave the area when it's in the first position the rover wants to go to the second position, but if I leave the area when it's in the second position then it wants to lose the connection and drift away. 

Anyway, I lined up the target on the ground, giving it a little lead for rotation and overshooting a bit on purpose because I usually end up short of the planned line.  In this case I had to stick to the plan more than usual once I got close to the finish line because if I turned the ship too fast the rover would definitely lose its connection, and I didn't want to do that too far from the actual landing zone.  

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After what is by far the most fuel-wasteful deorbit I have ever done (possibly partially because of the unusually steep orbit I'm coming down from), I was slowly decelerating into the landing zone, and I noticed I was drifting a little bit.  As said before, any sudden course corrections would cause the rover to get squirrely, which is a complication I didn't need, so I quickly switched to it at a couple dozen meters up, mashed the RCS, and just let it fall to the ground, where it bounced very nicely without exploding even a little.  

I eased myself down in the most cowardly possible way, RCS blasting, secure in the knowledge that as long as I made it to the ground intact I would be taking off with full tanks.  

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The eagle-eyed may have spotted earlier that in addition to the Gigantor solar panels there were a bunch of smaller ones.  Did I simply forget to remove them after upgrading?  Yes.  But everybody pretended that the Gigantors were far too important to be deployed for measly in-transit operations. 

I'd like to say Jebediah had a fine old time roaming around the countryside on the rover, but it turns out Bill neglected to install any seats.  Not that that little detail would stop Jeb, but unfortunately his crewmates managed it.  OKTO sighed a little sigh and dutifully went off alone in search of temperature readings, and maybe love.  

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Well, like many would-be lovers, OKTO forgot which way was forward and went 20 kilometers in the wrong direction.  But the detour didn't cost much more time than it took for the mining and refining to finish completely.  Then I just burned for orbit, trying to get one that was easy to match to the orbiter (I went polar because of the landing zone, so rotation was a factor.)  Getting into AN obit wasn't so bad; getting into a MATCHING orbit was a little more of a chore.  But that, I think, is a mission report for another day. 

TO BE CONTINUED...

 

Edited by FinalFan
Upated report number
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Jeb managed to put the mining ship into a polar orbit without too much trouble, and the longitudinal inclination (if that's even a thing) was reasonably close.  But the other ship was a third of an orbit away, and the crew decided to take their time with the rendezvous to conserve on fuel, especially since the longer they lingered the more contract survey locations they were likely to pass through.  

Several orbits and surveys later—and in the meantime a more traditional munar tour bus had arrived—the time for rendezvous had finally come.  I'd accidentally let the orbiter get ahead on the last pass, so I lowered my orbit and scored a closest approach of 0.1 km, which in fact turned out to be twenty-five meters.  Nice!  

It turns out that I am terrible at both docking and RCS thruster placement on oddly shaped ships, so it's hard to tell which one was the bigger problem.  When I tried to finesse the docking attempt I met with abject failure, so I just lined up the noses, turned on SAS, and went in harder, braking as I got close.  That worked, and I was still able to fill the orbiting ship's mono with some left over.  

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Once the crew transfer was completed (Jeb called dibs on EVA) it was time to hit up another site for the other flag.  

The crew decided that since polar orbits were less likely to be done in the future, they might as well hit up a polar landing zone while they were at it.  They picked out a cliffside for the excellent view...

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Since we're in a refueling vessel, there's no shame in "stop and drop" to kill lateral velocity for an easy touchdown.  I don't think I'd quite call myself terrible at powered landings, but I'm certainly no expert.  This is only my fourth one, after all, not counting using the engine to supplement parachutes for soft touchdowns on Kerbin.  And not counting crashes.  

Meanwhile, the tourism orbiter bus had come and gone, but not before disgorging a lander carrying two more tourists and two scientists, landing in a more equatorial location with my shiny new very first science lab.  Free science is nice and all but it seems awfully slow.  I guess it would be great if I spent more time timewarping but I like to keep my kerbals occupied.  I suppose it really shines on interplanetary expeditions:  you don't have to wait for the full round trip to get your science income.  I overkilled on the electricity this time; it was easier than researching how much the lab would actually use.  

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Valentina allowed the scientists out just long enough to reset the goo and material bay experiments a bunch of times, and after a quick snack on the surface they were back in orbit, snapping up a couple more contract locations.  Hey, what's that?  A contract for docking two ships on or around the Mun?  Yeah, that doesn't seem too far out of the way.  Easy money.  Now let's go earn it while the remaining tourists head home.  

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This time I avoided the problem of being bad with RCS by docking on the main engine alone.  I shared the pilots' sentiments exactly.  

But the contract didn't complete.  Huh.  The contract doesn't say anything about the ships needing to be made after the contract was accepted, so maybe the problem is that they started as parts of the same launch.  Oh, well.  

A little calculation of my delta-V later, and it's off to Minmus!  (This will be my first trip there aside from the "wandering satellite" that picked up the career contract only a few hours ago.)  

TO BE CONTINUED ... AT MINMUS! 

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20 hours ago, FinalFan said:

maybe the problem is that they started as parts of the same launch.  Oh, well.  

Yes, I haven't experienced this issue myself, but @Snark has, and his conclusion was that they came from the same launch, thus causing the contact to say that it was not a "docking". You can ask @Snark for more info. Looking forward to seeing more! Also, very creative problem solving there!

23 hours ago, FinalFan said:

 

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This time I avoided the problem of being bad with RCS by docking on the main engine alone.  I shared the pilots' sentiments exactly. 

I do main engine docking 50% of the time!

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On 4/26/2018 at 6:37 PM, FinalFan said:

But the contract didn't complete.  Huh.  The contract doesn't say anything about the ships needing to be made after the contract was accepted, so maybe the problem is that they started as parts of the same launch.

Ding ding ding.  Yeah, it's frustrating, I know.

I assume they did this so that someone can't exploit it by launching a ship that just separates and immediately re-docks.  Forcing them to be from different launches certainly prevents that exploit.  However... seems to me that if you go to orbit, send a vehicle down to land, then bring it back up to orbit to re-dock, then that feels like it should count, gosh darn it.  And in any case, as a player, the part I found the most frustrating is that the contract didn't actually explicitly say "they have to be from two separate launches"-- it just says "two vessels".

Oh well.  I consider that to be a shortcoming in the game, so when I'm playing, I've got a house rule that it "counts" if one of the two vessels landed and re-orbited in the time since they were last docked.  If I've satisfied the contract otherwise, and I've done that, and the only reason it's not completing is the (IMHO) silly limitation about "has to have been from two launches", then I just go ahead and use the Alt+F12 cheat menu to complete the contract.  And I do so with a clear conscience.  :sticktongue:

Anyway, yeah, that's what's going on here.

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Interim report:  the tourist lander touched down in the desert and I tried for a nice landing.  Didn't quite make it, but found out something interesting ... cargo bay doors are really strong. 

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Interim report 2

 

On 4/27/2018 at 9:02 PM, Snark said:

Ding ding ding.  Yeah, it's frustrating, I know.

I assume they did this so that someone can't exploit it by launching a ship that just separates and immediately re-docks.  Forcing them to be from different launches certainly prevents that exploit.  However... seems to me that if you go to orbit, send a vehicle down to land, then bring it back up to orbit to re-dock, then that feels like it should count, gosh darn it.  And in any case, as a player, the part I found the most frustrating is that the contract didn't actually explicitly say "they have to be from two separate launches"-- it just says "two vessels".

Oh well.  I consider that to be a shortcoming in the game, so when I'm playing, I've got a house rule that it "counts" if one of the two vessels landed and re-orbited in the time since they were last docked.  If I've satisfied the contract otherwise, and I've done that, and the only reason it's not completing is the (IMHO) silly limitation about "has to have been from two launches", then I just go ahead and use the Alt+F12 cheat menu to complete the contract.  And I do so with a clear conscience.  :sticktongue:

Anyway, yeah, that's what's going on here.

I've done some additional research, and it turns out: 
1.  It is OK if the vessels have previously docked. 
2.  If they have previously docked, they must dock again within the Mun's SOI
3.  In my specific case, there was a PPD-10 in the middle that originally launched on one of the parts.  Its presence messed up the first re-dock attempt because I left it on the other part.  I don't know if having a piece of one part on the other part would prevent contract completion if it wasn't located at the junction, but either way separating them fully and then re-docking will work. 

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Interim Report 3: 
As the ship drew closer to its Minmus encounter, headquarters back home got a strange request:  FLOOYD Dynamics wanted me to "expand the station Abomination orbiter + Miner Mk.I" from six kerbals to eleven kerbals.  For this I would get the princely sum of 119 kilocredits. 

I've never turned down a contract yet, but this one is very tempting. 

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Final Interim Mission Report

I believe I have discovered an undocumented feature of "put a new station into orbit" contracts:  if the station in question is actually a ship with a Klaw, it cannot qualify while holding a piece of junk that another contract has put into space, even if that junk was created after the "new" requirement date. In my case I rendezvoused with one of my pilots (an onboard pilot being a requirement) after picking up two retrieval contract objects (one manned), but after he came on board the station did not qualify until I let go of both of the objects (the rescued kerbal was allowed to stay). 

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Posted (edited)

Extended Mission Report:  to Minmus and beyond?  Part 1

Many days later, our intrepid heroes were finally approaching Minmus.  They observed that the only thing to precede them, a satellite redirected from another mission after its extra delta-v was noticed, was still happily in polar orbit.  Perhaps something could be gained from a visit?  (I had a contract for "rendezvous" as opposed to dock at Minmus.)  

The Mun was desolate, but the landscape of Minmus seems even more alien despite its cheerful coloration.  

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Meanwhile, plenty of science was to be had.  Can't transmit?  Whoops, time to unpack that antenna and dust off the dish.  We almost missed a maneuver node because the ship had just begun passing over the Great Flats a minute ago.  

Well, after the sciencing had died down a bit, the crew picked out a landing spot.  And not just any landing spot!  Inspired by the low gravity, Jeb had decided to avoid the trouble of ferrying fuel to the Rhino ship by bringing the Rhino ship right to the surface—still attached to the nose of the lander!  For this to have even a chance of working, Bill knew he had to find the most absolutely perfectly level spot he possibly could.  Fortunately, Minmus is full of them.  

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On the approach, the crew aimed right for the middle of the cute little pond they'd found, but forgot that, unlike the Mun, Minmus rotates more than once a month.  They came down near the edge and had to spend a ridiculous amount of time (due to errors) repositioning and zeroing out sideways velocity again.  The only consolation was the hilarious wiggling of the Rhino in tune with the course corrections. 

Once this was achieved, it became obvious that as nice as the lake beds were for landing zones, there was one drawback, namely that aside from the ship's shadow the place was totally featureless.  I'd hate to do a night landing here!  

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Everyone but Jeb had been concerned about how much weight the legs could handle, but they needn't have:  they were not only strong enough to hold up the weight of the ship, they were strong enough to catapult it right back off the ground!  Fortunately, the ship's pitiful* stockpile of RCS was full, because at least half of it was gone by the time the ship stopped doing jumping jacks.  Everyone breathed a sigh of relief and let the RCS keep burning to make aboslutely sure it had settled down.  

(*This ship was launched before I started packing larger reserves of monopropellant, so there was only the 30 in each command pod for 60 total.)

Without further ado, the mining rigs started pumping delicious mint-flavored ore.  The onboard scientist went out to manage the experiments much more carefully than usual.  Don't rock the boat!

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Edited by FinalFan
wiggle jiggle
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8 hours ago, FinalFan said:

I'd hate to do a night landing here!  

 

Yeah, night landings on the flats are bad, the only helpful thing is that the flats are at 0 meters ASL.

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Extended Mission Report Part 2: 

When the sun set on my landing zone the Rhino's tanks were only half full, and the ship was unable to balance without SAS motors running (not that I could mine at night anyway, lacking fuel cells).  So the crew took off and tried to fulfill a storyline contract of rendezvousing with another vessel in Minmus orbit.  However, once again the contract failed to complete, only this time I'm pretty sure it's not my fault.  Oh, well.  We'll see if it fixes itself upon return to the KSC

After that, the crew decided to see if they could land a half-full monster attached to the lander's nose as well as a mostly-empty one.  Even Jeb was only 90% sure it would work, but everyone agreed that at worst the landing legs would explode and they could probably manage an emergency takeoff. 

In actuality, the landing was even smoother than the first one, probably due to the extra weight.  For added difficulty, the crew chose one of the two smallest ponds on Minmus, which interestingly enough were Flats and not Lesser Flats.  (Actually, I would have had to wait half a rotation for more flats to come into daylight if I missed this one.) 

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