Long-term Laythe Mission - Part 9

First of all, for all you DogFish fans out there (you know who you are), I continued the DogFish's voyage out into the ocean. The best travel mode I could find for running it managed to get it up to 7.6 m/s at under half-throttle, plowing through the water.

It used up half of its fuel and it came to a halt at the spot shown by the rover icon out in the ocean on the map below (about 21 km beyond OceanProbe 1). I was hoping (but not expecting) that the DogFish might be able to make it across to the next island, but that is not possible.

I'll leave the DogFish on duty for now monitoring conditions in the ocean. In the future, I could send it further out, or I could decide to bring it back to Dansen Island.

Next up: Another set of transfer windows for Kerbin->Jool and Jool->Kerbin was coming up, and I wanted to send at least one ship out in each transfer window...but there's still no mining and resource detection equipment available. So I decided to send a another base module and a slightly-more-compact Fido rover. These will be landed on some other island on Laythe in the future where they can be useful, although I haven't decided where yet.

In order to send that payload off to Jool, I first needed to refurbish one of the Nuclear Tugs that had previously returned from the Laythe. Originally, the payload for refueling the Tugs was going to be the one shown below (and it still will be for the more recent-version Tugs). The two standard X200-32 fuel tanks, plus RCS fuel, etc., just about maxes out the lifting capacity of my Reusable Rocket.

But I like the extra command pod torque that the new version of the Tugs have because of all the probe bodies they have, so I decided to upgrade the older Tugs by adding extra probe bodies. The Refurbisher payload to do this is shown below being launched on a Reusable Rocket.

The Reusable Rocket barely had enough fuel to put the Refurbisher payload into a 115 km orbit, so I had to give the R.R.'s sustainer stage a little extra fuel from the Refurbisher's tanks, and then the sustainer went back for a parachute landing at KSC (the R.R. sustainer needs about 100 units of fuel to deorbit and target the KSC for a parachute landing). The Refurbisher was left in orbit (see below). The front part of the Refurbisher (regular docking port, 18 OKTO2 probe cores, an X200-8 tank, and a Senior docking port) will become permanent parts of Laythe Tug 5. The X200-16 and X200-8 tanks behind it will be dropped when empty (in interplanetary space). The rest of the Refurbisher has fuel to refill the Tug's main tank and RCS tanks, and then it will return to KSC to be reused for refurbishing Laythe Tugs 1, 3, and 4 eventually. There are two 24-77 engines for orbital maneuvering so the Refurbisher can rendezvous and dock with Tug 5.

But here's where I ran into a problem: The Refurbisher had four small solar panels and small battery packs for power, and that would have been fine in the original design... but with the addition of 18 more probe bodies to the payload, it no longer had sufficient power to keep 19 probe bodies alive through the dark part of its orbit... and the maneuvers I needed to do for rendezvous with Tug 5 always happened deep into the dark part of the orbit, so I was making long burns with the 24-77 engines that were barely finishing before the batteries died during that nighttime pass. Too bad there's no way to selectively turn off some of the probe bodies on a ship. But, in the end, I made rendezvous, docked the Refurbisher to Tug 5, refueled most of the main tank and all of the RCS, then separated the rear section of the Refurbisher (below). I was not worried that the main tank was not quite full (the side pod tanks were also nearly empty) because there will be plenty of extra fuel sent up with the base/rover payload.

I now have MechJeb 2 installed, and I don't know where anything is. But I found enough of what I needed to target the Refueler back to KSC for a parachute landing. Oddly, MechJeb 2's landing guidance readouts no longer seem to give me the distance off from the target point in the north/south and east/est directions...only an overall estimated distance from the landing target point, with no direction specified. Maybe I have some settings wrong. There was no fuel/oxidizer left on the Refurbisher, so I did the reentry using RCS only, watching the MJ readouts to target the landing point.

Below we see the new base/rover payload boosting on a Reusable Rocket just after the recoverable boosters have separated and just before the gravity turn starts at 18.5 km. The slightly more compact Fido rover is just a little shorter that the previous Fido KE design so that it makes a bit more compact payload.

I docked the Tug to the base/rover payload, then fully fueled the Tug from the Refueler Top (the base/rover payload is easy for the Reusable Rocket to lift, so it can carry the extra Refueler Top as well...and the Reusable Rocket's sustainer had plenty of fuel left (452 units) for a rocket-powered landing at KSC (and even had 208 units of fuel leftover after landing). Note that there are also two ComSats snugged in under the front and rear of the Fido, above the heat shield. These will be added to the two ComSats already in Laythe orbit to give more-continuous coverage (which will be important as I spread more kerbals around Laythe).

Pop goes the refueler top, and the ship is now ready for transfer to Jool (but must wait in orbit a while for the transfer window). When I did an "engineering simulation test" of the base/rover payload over the KSC (to be sure that everything was sequenced properly), I noticed that if you use the probe body on the Reusable Rocket during launch (since it's oriented properly, this is wise...having one of the horizontally-facing rover command pods in control makes it difficult to fly the rocket), then when you separate the payload from the rocket in space, various engines and parachutes on the payload will be activated. This clears up the mystery of why the drogue chutes on the original Laythe Base got activated early (which caused them to pop open as soon as possible over Laythe)... so Kurt Kerman was NOT a squirmy chute-popper after all. The solution is to make sure that I have switched control to one of the probe bodies on the base/rover payload before separating the sustainer stage. Also you may notice that I now have the Crew Manifest mod installed... this is because KSP version 0.20 insists on populating a command pod when I damn well do not want a kerbal in it... and I can easily remove the kerbal with that mod.

Meanwhile in Laythe orbit, Nuclear Tugs L6, L7, and L8 were being prepared for return to Kerbin. The Tugs left their rear tanks and most of their fuel with Laythe Space Station, but they have some additional fuel in their main tanks as well as the full side pod tanks so that they will hopefully return to Kerbin with a bit more fuel for orbital maneuvers there (and also because these tugs are a little heavier than the previous tugs because of their extra probe bodies). Below, the three tugs pop off of Laythe Station.

The Tugs were sent away from Laythe and off into Jool orbit to await the transfer window.

With the previous batch of Tugs I sent away from Laythe, a couple of them had problems with Laythe trying to grab them back after they had escaped its SOI (since they were in larger, slower orbits about Jool, so Laythe could sneak up on them), which required some extra burns. So this time I sent the tugs out on escape trajectories that gave them Jool apoapses of 32,000 km (closer to Vall than Laythe, but still away from Vall's SOI). It took about 580 m/s of delta-V to leave Laythe on these trajectories, then another 160 m/s later to raise the periapses of the parking orbits awayf from Laythe's SOI.

Then the Tugs waited in the parking orbits for the Kerbin transfer window to open. But here I also ran into problems. Kerbal alarm clock was telling me one thing with regard to when the transfer window occurred, and Protractor was telling me another thing. And when I tried to plot trajectories to Kerbin, I was not getting any encounters showing up (because the orbital inclinations were aligned at their most extreme at the moment, so the tugs would be missing Kerbin's SOI until the plane shift maneuvers were accounted for later). But my main distraction was that Laythe Tug 9 was coming in toward the Jool system carrying BirdDog2 and GasStation3, and I needed to pay attention to that (since incoming payloads are more important than Tugs that can wait in parking orbits). Oh...AND, back at Kerbin, it was time to boost Tug 5 with the new base/rover payload off to Jool.

Below, Laythe Tug 5 and its payload burn for Jool. As usual, this burn was done in two parts. I was worried that the refurbished tug might be excessively wobbly because (unlike freshly launched tugs) its rear tank is not strutted in place. It did wobble somewhat at the standard docking port back there, so I couldn't use phys-warp, but it behaved fine at normal time speed. I used a Senior docking port to connect the rear drop tanks to the added section of the Tug to reduce wobbling (future tanks for these tugs will now need Senior docking ports on them), and I didn't notice that connection wobbling at all.

Below, we see Tug L5 and its payload leaving Kerbin and the Mün off in the distance, after having dropped the empty rear tanks (I ended their flights to avoid clutter).

The transfer trajectory for Laythe Tug 5 was such that it would not reach its descending node (where the plane shift to match Jool's orbital inclination will need to be done) until shortly before it gets to Jool. This is actually a good thing because the plane shift will require less delta-V when it is done far from Kerbol. But I ran into another problem: the Kerbal Alark Clock was telling me that the descending node would be reached AFTER the Jool encounter, but KSP's marker for the descending node was clearly BEFORE the ship enters Jool's SOI (if only by a day). I don't know why. But I padded out the Alarm Clock alarm with some extra days so that it will remind me before I get to Jool.

The Kerbal Alarm Clock display in the previous image shows that the incoming Laythe Tug 9 is 8 days out from Jool's SOI, so it was time to fine tune its incoming trajectory. In the diagram below you can see why I love the Improved Maneuver Node mod's ability to easily changed to Conics Mode 0 so that I can see the incoming trajectory with respect to Jool (once I focus on Jool), but can still tweak the maneuver node out by Tug L9 (or by tweaking the numbers in the Maneuver Node mod's window). And if the maneuver node collapses shut (which it always does at the worst times), I can press the "o" key to pop it back open. Here the incoming trajectory is being set for an inclination of zero and a periapsis of 114 km for aerocapture.

AND.... back to the Tugs in Jool orbit. OK... rather than mess with all of them (since I wasn't confident of getting a good Kerbin encounter), I decided to send off only Tug L6 and leave the other two Tugs sit in Jool orbit to be sent off during a later transfer window. I had incoming toys for the boys... I didn't want to mess with lots of tugs. So, below: The trajectory plot... and Laythe Tug 6 burning for Kerbin. Again, when I got the Tug out there on its way home and tried to set up an alarm for its ascending node, Kerbal Alarm Clock was giving me an incorrect date (this time wildly inaccurate)...so I manually plopped a node down at that ascending node point, and then added THAT node to Kerbal Alarm Clock's list of nag-me reminders.

And here comes Tug L9 with BirdDog2. At Laythe Base, the crew is having an all-hands meeting:

Thompbles: "We have a new jet plane coming in, and another GasStation, so this is going to give us more choices for long-range exploring and rescue options. So we need to decide who will be doing what.
Nelemy: "I want to fly the jet."
Kurt: "My grandmama wants to fly jets."
Nelemy: "No, really. I want to fly the jet. It would be awesome!"
Thompbles: "Let's not argue, You're all officers and gentlemen here."
Kurt: "It's fine. I'm cool with continuing the detailed geological exploration of Dansen Island using Fido 2."
Nelemy: "Dude! Won't you miss having me around?"
Kurt: "I think I'll survive."

Tug L9 and its payload survive the flaming passage through Jool's atmosphere. Thank goodness for ablative coatings and heat shields.

Happily, as Tug L9 rounded Jool in its new elliptical orbit, it required only a small burn to get an immediate encounter with Laythe. Below is the trajectory plot. Because I'm using conics mode 0, you can see at a glance (look at Laythe) that the encounter is going to be in a counterclockwise direction around Laythe, just as desired. The ship is targeted in at 26 km above Laythe for an aerocapture there. Well.... That was easy!

The aerocapture at Laythe had almost no flames (boring), and a further aerobraking pass and engine burn placed the ship into an equatorial 90 km orbit. Below we see it passing over the Fido Bay base area.

The next day it was time to bring BirdDog2 down to Laythe Base. Aldner flew BirdDog1 down from orbit after the crew arrived at Laythe, but Nelemy would be remotely controlling the entry and landing of the new jet. First, the BirdDog2 is separated from the GasStation3/Tug L9 combo. This looks hairy as the plane goes tumbling away, but it's safely clear of the rest of the ship... and it wouldn't be anywhere near as hairy if the SAS had been turned on.

Then comes the retro burn. The ship is controlled from the OKTO2 probe core located on the end of the fuel tank stack of the retro pack for this burn (since it's oriented properly for this). Then the retro pack is separated and the plane is put pointy end first.

Entry flames! The thermal protection of the BirdDog2 only needs to protect the plane during the Jool aerocapture and the entry over Laythe. The rover wheels always look so vulnerable to me, hanging out in the slipstream, so there are heat shield plates positioned to protect the tires during entry, and then the heat shields get jettisoned.

The plane comes in high, so Nelemy has to turn it around and fire up the jet engine a little to bring it back toward to base. Below we see the BirdDog2 coming around in a hard bank.

Kurt: "Easy... Eeeeasy."
Nelemy: "I got. I got it. Whoa!" (The BirdDog2 pitches up violently.)
Aldner: "Nose down."
Nelemy: "I got it. Recovered fine. I got it."

Nelemy brings the plane in from south to north and sets it down, bumping over a few low ridges before it finally settles onto the ground to stay.

Nelemy: "Alright! Down safe!"
Thompbles: "You know, it's less bumpy if you come in from east or west parallel to those little ridges."
Nelemy: "Hey, you know what they say: any landing you can remotely drive your plane away from is fine!"
Aldner: "But seriously, Nelemy, you need to watch your pitch with this plane. If you are going fast enough in thick air, you can quickly recover from those pitch-ups, especially if the avionics package is helping. But if you are in thin air at high altitude, it's a lot harder. During a test flight back over Kerbin at 20k, I flipped and ended up in an uncontrolled spin that I didn't get out of until I reached 500 meters. And if you get a violent pitch-up a low airspeed during a landing, you won't have time to recover, and you'll spread your pretty plane all over the landscape. Be especially careful when coming in for upslope landings here on Laythe... those require a lot of pitching up, so you need to come in hotter than you would for a normal landing in order to have the necessary speed. Corfrey and I smashed up a bunch of BirdDog prototypes in the hills near the KSC testing these beasties."
Thompbles: "Aldner, can you write up a set of checklists and notes for Nelemy?"
Aldner: "Sure thing, Cappy."
Nelemy: "Checklists? Jebediah don't use no checklists."
Thompbles: "Don't forget notes about how the ship handles in rover mode."
Nelemy: "Dude, I have loads of experience driving rovers."
Aldner: "Sure, but the BirdDog handles differently than the Fido. Especially when its heavy with fuel. Those innocent looking V-notch valleys that the Fido will shoot through with ease can smash the BirdDog. Corfrey hit one of those doing 40 and there was nothing left of his plane but the cockpit. And don't drive along straddling the top of a sharp ridge line... the wide set of the landing gear can allow the jet engine to bottom out. I left a turbojet sitting on top of a ridge during our testing, and that would be a lot more embarassing here on Laythe with no ride home... although the shorter jet engine we have on the BirdDog now should make this less likely to happen."
Nelemy: "OK, Dude, I'll be careful."
Aldner: "Oh...and you know that feeling you get when you've been driving along so long that you start to zone out, and seems like time is slipping by at 2, 3, or even 4 times normal speed?"
Nelemy: "Yeah! It's so awesome! My brain feels like it's fizzing and it's like time is warping. Almost the feeling you get when you go into a hibernation trance."
Aldner: "Right. Well, none of that fizz-warping while driving rough terrain. You must stay alert. Otherwise the BirdDog will just slide out from under you down a slope, and you can smash the thing up before you realize it."
Nelemy: "OK. I'll remember. And that's for caring, Aldner."
Aldner: "Sure thing, little buddy. Besides...I don't want to have to fly my plane back from halfway around the world just so we can send it out to rescue you."

Nelemy retracts the nose gear of the plane to place the rover wheels on the ground, then remotely drives it over to the base area.

Nelemy: "I'll park it nose-to-nose with your BirdDog, Aldner."
Aldner: "Don't bump my plane."
Nelemy: "No sweat, Dude. I'm good at driving rovers."
Aldner: "Don't bump my plane."
Nelemy: "I'll just get it close enough for a good picture."
Aldner: "You bump my plane, I'll thump your head."
Nelemy: "Yeah, I think it's close enough already."

Next came the landing of GasStation3. Rather than bring it down to Laythe Base, mission planners wanted to position it as a forward base to allow BirdDogs to explore far afield from the Laythe Base area. Specifically, the geologists were very interested in studying the huge impact feature that dominates the trailing hemisphere of Laythe (the giant ring of islands in the hemisphere 180 degrees around from Dansen Island). GasStation3 will be landed on island +6-68 (Mission planners aren't real imaginative about names), which is part of a big crater on the rim of the gigantic crater. Below, GasStation3 separates from Tug L9. Tug L9 will eventually be docked to the Laythe Space Station.

Below: Retro burn of the six 24-77 engines, and GasStation3 drops in toward island +6-68.

Entry flames (finally...you wait a long time on Laythe for entry affects to appear) as the ship nears the eastern part of the island. The landing location was chosen based on orbital surveys, so hopefully the site is a good one.

Parachutes set the GasStation3 down on mostly level terrain about 5 degrees north of the equator. Antennas were deployed and telemetry data indicated that all systems were functional, and the station appeared to be level enough for use.

Soon after landing, there was an alignment of Vall and Tylo visible from the GasStation3 landing site.

But the acid test wouldn't come until Aldner flew the BirdDog over to GasStation3 to see if it was at the correct height and angle that would allow for refueling the plane. If not, Aldner could be stuck far from home without enough fuel to fly back. Calculations indicated that he SHOULD be able to fly there and back on one fuel load, if no mistakes were made in flying and navigating the plane, but this wasn't certain. However, there is the SSTUBBY single-kerbal SSTO rocket in orbit attached to the Laythe Space Station that could be used to rescue Aldner if he does get stuck with insufficient fuel. So the next morning, Aldner (who has had the BirdDog prepped for this trip for weeks now), took off toward the east.

Aldner: "Aldner to Laythe Base."
Thompbles: "What's up Aldner?"
Aldner: "I've flown over that small island east of Dansen. The terrain looks fairly mild. You said you wanted a place for Nelemy to do a shakedown mission with BirdDog2. It looks like a good spot."
Thompbles: "Sounds good. You take care now."
Aldner: "You know me, Bossman. I always follow orders."

Aldner took the BirdDog up to 9,600 meters to minimize fuel consumption while still staying at an altitude where the plane was plenty stable in pitch. It wasn't long before Dansen Island dropped below the horizon and Aldner had nothing to look at from horizon to horizon but flat, boring water.

There was a tiny bit of excitement about halfway through the flight when the detectors indicated that Aldner was passing within 30 kilometers of Ocean Probe 5...but there was nothing to see but blue flatness. He eventually had some company as Tylo and Vall rose above the horizon.

Finally, the target island rose into view. To save fuel, Aldner decided to land the BirdDog on the western end of the island and drive the rest of the way to GasStation3. There was a high plateau area between the two mountain peaks closest to the western end of the island, so he set the BirdDog down on mostly level ground at an elevation of 2540 meters, about 96 km from GasStation3.

Aldner: "BirdDog to Laythe Base. Do you copy?"
Thompbles: "I read you load a clear through comsat 2. What's up, Aldner."
Aldner: "I have safely landed on the west end of the island. I used 129 units of fuel out of 300, so I can make it back to Dansen, at least from this point. I'm pumping fuel to the forward tank now to adjust the CoM, but I think I'll drive the rest of the way if the terrain is good. Also, I would like to name this fine island after Manley Kerman, the famous astrophycist. Some astronomical objects kept me company, so I'm felling good about astronomy right now."
Thompbles: "Noted. Are you going to camp now?"
Aldner: "Negative, kemosabe. I made good time, so there's still some light left. I'll grab some samples, then get some driving in before it gets dark."
Thompbles: "Roger. Laythe base out. What? Wait. Oh...Nelemy says to say "Hey, Dude" from him. Laythe base out."

Below: Aldner's landing place on Manley Island. Although Aldner left in the early morning, it's already nearly sunset on Manley island. All those assorted probes and station icons on that map are on the other side of the world...there's only BirdDog and GasStation3 'round these parts.

A view of the west end of Manley Island looking east-southeast. The land is fairly steep along the coastlines, so Aldner sticks to the highland route as he heads eastward.

Aldner drives not to close to the steep drop off to the ocean on his right. When Kerbol gets too low in the sky to keep the rover's batteries charged, Aldner stops for more sampling and to set up camp at 2,709 meters.

The next day, Aldner continued his drive. Below is the oblique view from above of the eastern end of Manley Island. The terrain is a bit rugged, but nothing hard to handle as long as you remember to not let your speed get away from you on the downslopes.

Thompbles: "Laythe Base to BirdDog. How are you doing today, Aldner?"
Aldner: "Hmm. I thought I was fine. But now I'm hearing voices when nobody else is around. Could be a bad sign."
Thompbles: "We'll have the KSC docs talk to you about that. How's the drive."
Aldner: "Good so far. Except there's this giant green planet hanging in the sky right above me. Huge. I forget about it after a while, but then I glance up and it's still hanging there. Disconcerting. Like a big-ass Sword of Kamocles."
Thompbles: "It's not very sharp."
Aldner: "Like a big-ass Blunt Instrument of Kamocles. Disconcerting. I liked it much better when it was a pretty decoration on the horizon."
Thompbles: "I'm sure you'll get used to it."

By now Aldner was heading downward at a fairly good rate as he approached the lower elevation where GasStation3 was located. He picked up some speed and caught some 'air' as he went over small ridges. Nothing he couldn't handle. But then he made one of the classic blunders, which was to allow the guy directing the movie to try lining up a shot to get a good picture from the side of the BirdDog going over some ridges... just when he came up to a really big drop off going about 40 m/s. And the BirdDog was airborne and flying free. Now this might have been disastrous for a regular rover... but BirdDog is, of course, an airplane, and Aldner is a pilot with sufficiently fast reactions, and he pulled up slowly after the nose suddenly dropped when the rover went over the ridge... and glided it down just fine.

...Well, not enTIREly fine, since the airplane isn't designed to land at fast speeds on its rover wheels, so he did blow a tire. So Aldner jumped out and did a little patch job, and did a little soil sampling while he was at it.

When the GasStation finally came into sight clearly, it was silhouetted against the sky as if it was on the top of a ridge, but as he got closer, Aldner could see that it was sitting on a more or less level area beyond which the elevation sloped down a bit, hence the apearence from a distance of it sitting on a ridge.

The first thing Aldner tried, of course, was see if any of the refueling arms would fit properly to the BirdDog's docking port. And the first one he tried.....clicked in place like a charm. OK! The mission is on!

Aldner: "Aldner to Base. You there, Thompbles?"
Nelemy: "I'm monitoring the radio, Dude. What's up?"
Aldner: "Let Thompbles know I here, and baby is drinking from momma just fine."
Nelemy: "Here? Here where?"
Aldner: "Here. Here where GasStation3 landed."
Nelemy: "You're naming your base 'Here'?"
Aldner: "Did you just wake up, Nelemy? Just tell Thompbles I'm here and the refueling works. I'm going to unpack the supplies."

Similarly to GasStation2, I dictated that part of GasStation3's internal space was a cargo container. This time only half of a tank (since I figured one guy alone wouldn't need so many supplies), so instead of three quarters of a ton of supplies, this tank held three eighths of a ton of supplies. I have removed the displaced 75 units of fuel by editing the save file. Aldner unpacks stuff like food, a tent, and other equipment, and sets up camp. And plants a flag, of course.

Aldner's journey to Manley:

Part 10 will be posted very soon. Just doing the final editing.