Long-term Laythe - Part 32

New Crew Now Cruising

Last time we got the ship for the new crew constructed, so it's time to send them on their way toward Jool. The boys have moved out of the Base modules mounted in the center (since we want to save the resources in there for use on Laythe...not that I actually have any life support mods installed, but I like to take such things into consideration occasionally).

Rodmy, Merfred, and Commander Nedmy (who spent a long time together on Minmus moonbase, so they get along well) are in one of the interplanetary transfer modules along with chief pilot Corfrey. The SCIENCE guys, Tomster, Henrey, Lembart, and Dansen are inhabiting the other interplanetary transfer module. Lembart and Dansen, who are also experienced astronauts, will make sure the SCIENCE nerds don't do anything silly like opening external hatches unexpectedly.

The burn to Jool was the typical 20-minute affair of around 1900 m/s delta-V.

The burn was done in two parts, so we got to enjoy the beauty of Kerbin with its clouds during the first loop outward nearly to the Mün's orbit.

The cloud mod was acting strangely during the second pass burn (see below) with blocky areas that looked fine, and other areas that were dark. This is the first time that the clouds and city lights mod (which apparently now goes by the name of Environmental Visual Enhancements) has acted up on me.

The descending node of the trajectory with Jool's orbit is out about 80% of the way to Jool, so the plane-shift and fine-targeting maneuvers will need to be done later. But the Jool insertion burns already expended the propellants in the rear tanks, so those were jettisoned. This is earlier than normal, but that's because these interplanetary transfer modules have quite a bit of propellant mass in the rings of tanks that surround their lower hitchhiker modules as interplanetary radiation protection...so the ship has plenty of fuel.

Leaving Laythe

Back on Laythe, Thompbles has called a meeting of the full crew at Base 2.

Thompbles: "The replacement crew is on its way, and Mission Control has lifted the moratorium on off-world activities, so you all can get started on our exploration missions away from Laythe. Emilynn, did you want to head out first?"
Emilynn: "I'm ready to get flying, but Hellou wants to let Aldner and Nelemy go first."
Hellou: "Umm...yes. Thinking about Aldner and Nelemy trying that dangerous landing on Tylo is going to be distracting. I don't want to be working in vacuo while I'm worrying about them...so I asked Emi if we could wait on our return to Vall until the boys are settled in place."
Aldner: "Aw...such a touching sentiment."
Hellou: "And I'd like to hear about their initial surface sampling to give them some immediate guidance on what to look for, because you can't trust either of them to know an important rock from a piece of leaverite."
Kurt: "Aw...such an accurate assessment."

So the crew had a celebratory dinner that couldn't be beat as a send-off party for Aldner and Nelemy.

Thompbles: "One of the things the Tylo payloads did not include was new communication satellites. So I'd like to move one of the Vall comsats over to Tylo, if you don't mind, Emilynn."
Emilynn: "Sure, no problem. We have four there, which is more than we need. And they have boatloads of propellant. The boys at KSC really over-engineered those comsats."

Below, the trajectory to send a comsat from Vall to Tylo took about 166 m/s of delta-V. The inset shows the ejection path.

The capture maneuver at Tylo took another 122 m/s of delta-V, and then the circularization at 5000 km took 395 m/s of delta-V. After the maneuvering, the stack of five Oscar-B propellant tanks were still over half full.

Below, the newly-renamed "Tylo ComSat" in place in its 5000 km high orbit, ready to support the mission.

In addition to the ComSat, there is also the old Tylo Refueling Station in a 2000-km-apoapsis elliptical orbit that has comsat capabilities. This ship is left over from the mission that landed Jeb on Tylo for a brief stay 14 years ago. The ship was for contingency refueling, and was also an emergency Kerbin-return ship for that expedition. Its resources are therefore available to Aldner and Nelemy should they need them. But the ship is in a retrograde orbit, so it would take a considerable amount of fuel to shift it to prograde if needed.

When everything was packed and ready, Aldner and Nelemy said goodbye to Thompbles and Kurt at Laythe Base 2, and then took the original Laythe Fido rover over to the Raptor SSTO spaceplane where Emilynn and Hellou were waiting to see them off.

Emilynn: "You boys be careful. But if you blow up trying to land on Tylo, be sure to make a pretty crater."
Hellou: "Emi! Don't talk that way! Nobody's going to blow up."
Emilynn: "Aw, Chickadee. That's just the way test pilots talk to each other."
Aldner: "Yeah, don't worry, Hellou. Tylo shouldn't be a problem for the two hottest pilots in the astronaut corps."
Emilynn: "The two hottest pudknockers. Anyway, be sure to leave one of those landers in orbit so that I can give it a try after you blow up."
Hellou: "Emi!"
Aldner: "We'll do that, Hawk. But I think Nelemy there wants a hug before we leave."
Nelemy: "I'm gonna miss you dude-girls!!"
Emilynn: "Aww...come to momma for a big squeeze."
Hellou: "Don't worry, Nelemy. We'll meet up at Bop just like we planned. Here, Aldner...you can have a hug, too."
Nelemy: "Kurt didn't want a goodbye hug from me."
Kurt: (over the radio) "I told you that you could give my goodbye hug to Hellou, and I'll get it from her later."

While Nelemy was having another round of hugs from Emilynn and Hellou, Aldner sauntered over to the Raptor and grabbed the cockpit seat...leaving Nelemy the seat in the rear cabin.

Aldner: "Preflight check is done. Everything fine back there, Little Buddy?"
Nelemy: "Roger, Dude."
Aldner: "Hawk, are you and Hellou back in your Base?"
Emilynn: "Roger, Buzz. Have a good flight."
Aldner: "Captain Thompbles, sir! The Raptor is ready to fly."
Thompbles: "OK, Aldner. You boys be careful out there. Keep in touch."
Aldner: "Will do, Cappy. Brakes off. RAPIER in air-breathing mode. And we're off."

Aldner piloted the Raptor toward the southeast away from Fido Bay and up into the pretty new volumetric clouds.

Another view of the volumetric clouds after the Raptor had turned toward the east over Joysina lake and began to climb in earnest.

Below, the Raptor cruising along at about 23 kilometers altitude, continuing to gain speed, passing south of the Manley Crater islands.

Aldner: "Man, I'm sure going to miss flying around in air. But vacuum has its own kinds of fun."
Nelemy: "It sure does, Dude. 1850 meters per second. How soon until you switchover to rocket mode?"
Aldner: "Somewhere over 1950 meters per second, and once the apoapsis gets up over 50 klicks."

The boost to orbit went well. But consulting MechJeb's Delta-V Stats after circularization showed zero delta-V left in the ship...that wasn't right. But a quick check found an updated version of MJ, and after installation the Delta-V Stats were working again.

Aldner: "Delta-V remaining: 1097 meters per second."
Nelemy: "Ha! Still not as good as my 1467 flight, Dude! These RAPIERs aren't like turbojets on an SSTO. You need to barrel along lower and switch over sooner."

Below, the orbital maneuvers to rendezvous with the Tylo ship went well...but the docking was a bit of a problem. The emergency escape capsules were sticking up a bit too high, stopping the Raptor from reaching the docking port. When this ship was originally designed (it's a modification of the Vall expedition ship), there was no thought given to docking with spaceplanes.

After yawing the Raptor around a little, a position was found where the docking ports could mate.

Nelemy and Aldner transferred over to the Tylo ship via EVA. There wasn't a lot of equipment to haul over, since most of what they would need was in the Tylo ship.

Aldner: "Aldner to Laythe Base. We haved moved over to the Tylo Express and are ready to undock the Raptor."
Emilynn: "Roger, Buzz. I'll be handling the transfer of the Raptor via remote control so you boys can get settled in."
Aldner: "Roger, Hawk. The Raptor is yours. Undock when ready."

Emilynn moved the Raptor away from the Tylo ship, then performed some maneuvers to rendezvous the ship to Laythe Space Station. The docking camera no doubt comes in very handy during remote piloting operations.

At Laythe Station, the Raptor was fully refueled and then powered down. A couple of the replacement crew could later use it to fly down to the surface of Laythe.

In the meantime, Thompbles was remotely maneuvering one of the spare Tugs stored in Laythe orbit to rendezvous with the Tylo ship to transfer some fuel.

The Tug was docked to the bottom of the Tylo ship, then fuel was transferred to top off the tanks of the Tylo ship, and then the Tug was undocked. The Tug still contains more fuel than it requires to return to Kerbin, so it will continue to wait in Laythe's orbit for now. I'll probably rendezvous it with Laythe Station at some point to offload the remaining excess fuel before sending it back to Kerbin for re-use.

Aldner: "Yo, Thompbles."
Thompbles: "Yes, Aldner?"
Aldner: "Do you want us to leave these emergency escape capsules here in Laythe orbit? They might be useful in case some future-Nelemy needs to return from orbit and doesn't feel like trusting ancient equipment. And they aren't going to be any use around airless Tylo."
Thompbles: "No, Aldner. Keep them with you in case you need to make a fast run back from Tylo if another giant Kerbol flare happens."
Aldner: "Ah, you worry too much. Besides...what if Hawk and Hellou need to run back from Vall again? Having capsules in orbit could be useful to them."
Thompbles: "No, Aldner. The spaceplanes will be in orbit, and they can rendezvous and use one of those. You guys would be more pressed for time. But thanks for offering."

The Tylo Transfer Trajectory was a simple Hohmann transfer that required 597 m/s of delta-V.

The Tylo transfer burn took a little over four minutes. Aldner and Nelemy certainly looked happy about starting their new adventure to the deadly moon of dangerous landing-ness.

Nelemy: "Dude! Look at Laythe! I'm going to miss that place."
Aldner: "It surely is a beautiful little planet. But space is big, and there's still lots of places I haven't been."

Below: the Tylo encounter trajectory. The Tylo ship gets whipped around nearly 180 degrees toward the direction of Tylo's motion, which means the massive moon is providing a nice gravitational assist in speeding up the Tylo ship to the moon's orbital speed. A retro burn of 99 m/s w as needed at the periapsis of 51 km to capture the ship into orbit.

Aldner and Nelemy got their first good look at Tylo as they approached. The capture burn was in darkness, so no pretty picture of that.

Below, Aldner and Nelemy safely in a 51 km by 5000 km orbit around Tylo, the moon of doom.

Tackling Tylo

So let's check out the neighborhood. The new Tylo ComSat is in a circular orbit at 5000 km (all of the orbits shown are equatorial). Aldner and Nelemy are in an elliptical orbit going out to 5000 km. In a similar orbit is the old ascent stage of the Sacagawea lander that Jebediah used to return from the surface of Tylo. In a lower elliptical orbit is the old Tylo Fuel Station (moving retrograde). Also in lower elliptical orbits are the two Triple Tugs with all the Tylo landing craft.

The first order of business was for Aldner and Nelemy to get all their mission hardware down into 90-km circular orbits from which all the landing would be made. For the Triple Tugs, this required retro burns of about 595 m/s at periapsis. Below, the Triple Tug carrying one Hab lander and the two crew landers does its retro burn.

The other Triple Tug carrying another Hab lander and the two Tylo Fido landers did its retro burn in darkness, but below we see it doing a small orbital adjustment afterwards.

Rather than take their whole Tylo ship way down into Tylo's gravity well (only to have to haul it all back up later, assuming a successful mission), Aldner and Nelemy split their ship to take only one of the Tugs down to low orbit. Then they did a small burn to raise the periapsis of their ship to 90 km.

The retro burn for the Tylo ship was scheduled to take 678 m/s of delta-V (the picture below is from a little ways into that 5-minute burn). But the burn was cut short when the ship's apoapsis was down to about 200 kilometers to leave the ship in a phasing orbit so that it could circle a few times and get lined up for a rendezvous with the Triple Tug carrying the crew landers.

Once the orbit phasing was correct, the Tylo ship was dropped the rest of the way to its 90-km orbit to rendezvous with the Triple Tug. The lander payloads don't have docking ports on top (to minimize weight), so Aldner and Nelemy docked their ship temporarily to the rear of the Triple Tug.

Nelemy: "Yo, Dude... the Vanallen sensor mounted on the hull is ticking away madly. Is Tylo that much more radioactive than Laythe?"
Aldner: "No. What its reading is radiation from the LV-N nuclear motors on the Triple Tugs. The way they are facing now, they aren't behind their shadow shields. And they've just been running, so they're still 'hot.' They'll cool down soon. But aren't you glad we have all those propellant tanks wrapped around our hab module to protect us?"
Nelemy: "Dude! You bet!"
Aldner: "Just don't go outside for a walk anytime soon."

While Aldner and Nelemy are running remote checks on all the landing hardware, let's take a look at the lay of the land in their target landing area (map below). The lines mark the equator and the meridian that faces Jool. Jebediah Kerman's landing location was on the east rim of the large crater at the sub-Jool point. Aldner and Nelemy will be targeting the basin to the west that KerbalMaps shows as having a flat, smooth surface with an elevation of 1 meter.

Aldner was going to land his landers using the method where you lower the periapsis of the orbit to very low over the landing target, and then do a two-phase landing: Phase one involves thrusting mostly horizontally to slow down from orbital speed, while thrusting a little upward as needed to keep the ship from dropping. Then, when the horizontal motion is mostly slowed, phase two involves the mostly vertical drop for the short distance to the surface. The problem here is that there is a ridge line to the west of the target basin, so the periapsis can't be lowered below 4 km there, or the ship will smash. Aldner has named this "Flyswatter Ridge" and will try to skim his landers in at orbital velocity a couple hundred meters over this ridge.

Nelemy will be using a more traditional landing technique: Retro burn to drop the ship in near the target area, then a 'suicide burn' to slow the ship down both vertically and horizontally close to the surface...then a hopefully gentle vertical descent from there. He has named a feature "Retro Crater" to mark the longitude in his orbit where he has to do the initial retro burn.

[The fun of Tylo is all about the danger of landing on such a large, airless body. So I practiced many times with multiple techniques before I decided to risk the actual landings for this mission. I also decided to do the landings using my Logitech Extreme 3D Pro joystick, a relatively new toy. This took some getting used to...but the rapid response of the throttle lever-thingie is certainly handy. Plus, I mapped the "hide the UI" and "take screenshot" functions to handy keys on the joystick to hopefully make taking pictures during the hectic landings easier. I found that the standard setup up of pitch, roll, and yaw as forward/backward, left/right, and twist on the joystick (which works fine for flying planes) did not work well for me when trying to land vertical-descent landers...so I swapped around roll and yaw...and this made me happier.]

Aldner: "Tylo Station to Laythe Base. Are you there, Fearless Leader?"
Kurt: "I'm on radio watch, Aldner. What can we do for you?"
Aldner: "We are ready to start landing ships, but we need to decide who goes first. Nelemy suggested we flip a coin, but that's hard to do in zero-G. Can you flip for us?"
Kurt: "You think I brought a coin to Laythe? OK...each of you pick a number between one and one million. Closest guess wins."
Nelemy: "I'll guess 500,000 Dude!"
Aldner: "I'll guess 499,999."
Kurt: "The magic number was 292,202. Aldner wins. Be careful with those toys...the boys at KSC spent a lot of money shipping them out here."

Below, Aldner remotely separates the Tylo Fido A lander from the other Triple Tug ship and prepares to guide it down via remote control. This lander was originally designed to be able to land on Tylo with just its eight internal and side tanks...but I later added the Rockomax X200-8 Fuel Tank to the bottom for more loiter time. But it's surprising how adding all that fuel only resulted in a little extra fuel available at landing -- a lot of the fuel gets used up just slowing down all the fuel for landing. Landing on Tylo is a situation where MOAR FUEL is often NOT as helpful as one might think.

Below, a top view of the Tylo Fido shows that it has four FL-T100 tanks built into its structure -- these tanks are there so that the rover can be used to transfer fuel between ships on the surface of Tylo. The FL-T400 tanks on the sides are the main descent fuel, and can be separated after landing. There are 12 Rockomax 48-7S engines clustered beneath the side tanks to give the ship a very impressive thrust-to-weight ratio, which is very helpful when landing on Tylo. The docking port on top of the Fido is used as the "control-from" point during landing.

The first step in the landing technique Aldner was to wait until the lander was directly 180 degrees opposite from a point on the west edge of the target basin. Then a retro burn was performed to lower the periapsis to a little under 4,000 meters just beyond Flyswatter Ridge, which has an elevation of 3,785 meters (so the lander will be skimming a couple hundred meters over this ridge). There are also mountains further to the west (near the Ap marker in this image) that the landing trajectory misses by a kilometer or so.

Below, the unmanned lander has passed the mountains and is headed toward Flyswatter Ridge.

The animated GIF does not quite relate the thrill of passing within 113 meters of the surface while zipping along at over 2,200 meters per second orbital velocity. Maybe Aldner needs to make sure the periapsis is a little OVER 4,000 meters next time.

After passing Flyswatter Ridge, Phase one of the landing sequence began, with Aldner slamming the throttle to 100% and adjusting the pitch angle of the lander so that it did not gain much vertical drop speed. The first panel below shows monitoring the fuel level in the big tank on the bottom. When that tank was empty (after having slowed down the ship to under 1,200 m/s) it was jettisoned (second panel). The full-power, mostly sideways blasting was continued until the horizontal speed dropped below 150 m/s.

Aldner: "Alright, phase two. Horizontal speed is slowing down."
Nelemy: "Dude! Radar altimeter shows a 400 meter discrepancy from the inertial guidance unit's altitude."
Aldner: "What the hell? Did I overshoot the basin?"
Nelemy: "No...longitude is correct. Ground elevation appears to be 407 meters. Dude, you're dropping fast!"
Aldner: "Suicide burn is the best way to deliver the most fuel to the surface. Braking now..."

[OK, I was a bit distracted and forgot to take a picture at landing. The ground came up faster than I thought it would. I had almost forgotten to deploy the landing legs, so I was doing that when I should have been flying. And there was the exciting BOOM at the end. Note that landing legs are VERY important when landing unmanned rovers: If you want them to be able to drive after landing, you need to protect those wheels.]

Aldner: "Annnd STOP."
Nelemy: "Dude! Explosions!"
Aldner: "Telemetry?"
Nelemy: "Still have it. Landing legs showing red. Almost all of the engines are reading red."
Aldner: "OK. One of the legs shows red...the others are orange or green. All the wheels are showing green. Fuel tank pressure is steady."
Nelemy: "Elevation shows 416 meters, but position is right in the center of the basin. Dude, what happened to our flat, smooth plain?"
Aldner: "Well...that data is from the radar mapping that Jeb did long ago. Maybe there have been changes. Or more likely Jeb was not the most careful mapper in history."

[Indeed, the elevations displayed on KerbalMaps.com do not appear to reflect the current situation on Tylo. I guess there has been a geographical update since that map data was gathered. I guess it's just lucky that the elevations of Flyswatter Ridge and the mountains further west had not changed much.]

But despite the exciting, if unwelcome, explosions upon landing, the situation was a lot better than first feared. The Fido rover itself was completely intact. On the side tanks, one landing leg was gone, two were broken, and the third was OK. Most of the engines on the bottoms of the side tanks were gone (and apparently were the main source of the explosions). And the lander was right near the middle of the basin.

Nelemy: "Dude, look at the fuel levels!"
Aldner: "Pressure dropping?"
Nelemy: "No, that's fine. But you got it down with over 47 units of fuel in each tank!"
Aldner: "Well, there you go. We wanted to be sure we had lots of fuel, so I delivered lots of fuel."

Indeed. The plan was that any leftover fuel from the side tanks would be transferred to the small tanks built into the rover's frame (the fuel in those tanks got used up during descent)... but Aldner had landed the ship with even more fuel in the side tanks than the inboard tanks could hold. Riches galore.

After the propellants were transferred to the inboard tanks, the side tanks (with engines and landing legs) were supposed to be jettisoned in an unexciting procedure. Instead, there were explosions.

Nelemy: "More explosions, Dude!"
Aldner: "What the hell? Have the Fido computer run another complete self check."
Nelemy: "I've been running it continuously. Everything still looks good, Dude."
Aldner: "OK. I'll trying backing it up."
Nelemy: "Looks fine, Dude. The tanks a visible now on the CockpitCam. They're spread out further than they should be, but they look intact."
Aldner: "OK. I guess that wasn't as elegant a landing as it could have been, but the payload is down and operating 100%, so I guess we'll call it a success."
Nelemy: "Cool, Dude. Now it's my turn!"

Nelemy prepared to remotely guide the remaining Tylo Fido B lander to the surface by first separating it from its Triple Tug.

A bottom view of the Tylo Fido lander with its dozen Rockomax 48-7S engines and assorted fuel lines.

In the hope to avoiding the unexpectedly high terrain, Nelemy did a small plane-shift burn a quarter of the way around Tylo to put the Fido's orbital path a little less than half a degree south over the landing zone. The he waited until the lander got to the proper longitude (as indicated by lining up north of Retro Crater), and did the big retro burn.

The retro burn more than depleted the bottom tank, but it didn't get jettisoned until later because it was necessary to watch the map view to see when the landing path was targeted...a little bit east of the lansing site was desired.

Below is the landing sequence. The bottom tank was discarded, and a small burst of thrust allowed the lander to move slowly away from it. Nelemy waited until the lander fell to about 30,000 meters, then blasted the engines. This managed to bring the lander to a near-stop at about 10,000 meters... so as suicide burns go, it was rather premature. Then Nelemy let the lander drop vertically...slowing it up every time it got up over 200 m/s descent rate. Not the most fuel-efficient ending, but he landed the Fido softly without any explosions. But whereas Aldner's Fido had over 196 units of fuel upon landing, Nelemy's had about 44 units of fuel.

Nelemy placed the Tylo Fido B lander down 5.8 km south-southwest of the Tylo Fido A, which is pretty fine shootin', Tex, considering that most of that distance is due to the plane shift south (which didn't get the lander to flat smoothness anyway).

Once the remaining fuel was pumped into the inboard tanks, the landing legs were folded up (wheel brakes applied), and the side tank assemblies were jettisoned in the expected peaceful manner.

The next order of business was to land the surface habitat base landers. Spending months living in nothing but a rover and small lander would not be very confortable, so a roomier base would be nice. There was one surface hab lander attached to each Triple Tug, so the boys used this opportunity to rearrange their ship.

First, the hab lander was separated and the ship backed away from it. The hab lander would be sent down shortly. But right now, the boys separated their orbital habitat module from the ship, and then they flipped the Tugs around and docked the orbital hab module to the port recently vacated by the surface hab lander. This put the orbital hab on the correct side of the ship relative to the Triple Tug's nuclear engines and radiation shadow shields.

And just for good measure, they undocked their original single Tug and flipped it so that its nuclear engines were properly shielded.

Aldner prepared to remotely control Tylo Hab A down to the surface. First, he opened the landing legs. He wasn't going to be caught distracted by THAT this time. Then, when the lander was 180 degrees away from Flyswatter Ridge, he performed the retro burn that lowered it periapsis to just over 4,000 meters.

Below we see Tylo Hab A skimming along a conveniently-placed pass in the mountains to the west of Flyswatter Ridge. I'm not sure how tall that mountain is at the top of the image, but the lander cleared that one off in the distance by about 1.5 kilometers. Later, the ship cleared Flyswatter Ridge with a margin of about 150 meters.

The habitat landers have 12 Rockomax 48-7S engines. There is a Rockomax X200-8 Fuel Tank underneath (which gets expended and jettisoned when the speed is about 2000 m/s), and six FL-T400 Fuel Tanks around its perimeter, two of which get used up a jettisoned slowing the ship down to about 1250 m/s. The four remaining FL-T400 Fuel Tanks remain with the ship to provide fuel for the rest of the landing.

Phase two of the landing was like a traditional landing profile from 3 km up, but Aldner waited a tad too long again at the end to do his final slow down [read: I was taking pictures].

Nelemy: "Explosions, Dude! But we still have telemetry. Looks like all the landing legs are intact, but broken...and most of the 48-7S engines blew up."
Aldner: "Screw the engines...those are just crumple zones once the ship touches down. How is the Hab pressure?"
Nelemy: "One atmosphere...holding steady. Propellant tank pressure also steady. And you got it down with almost 160 units of fuel, Dude!"
Aldner: "We should set up a gas station to service the tourist trade."

Tylo Hab A came to rest 6.1 km from one of the Fido rovers, and 8.2 km from the other one.

If the Tylo Hab A landing had gone perfectly, the other Hab might have been left in orbit so that it could potentially be landed at some other location later...but since there was some question about the condition of Hab A (despite positive telemetry), Nelemy was charged with landing the second Tylo Hab. This was the last lander on the Hab/Rovers Triple Tug.

As before with the landing profile Nelemy was using, there was a small plane shift to bring the Hab about a half degree south, then the big retro burn north of Retro Crater. The depleted bottom tank was dropped after the retro burn (instead of when it ran dry...because it was necessary to watch the map...so this could be more efficiently done). The too-chicken-to-be-really-called-suicidal burn was started at 30 km. The side drop tanks were discarded at about 20 km. And the touchdown was nominal.

Tylo Hab B landed 3 km from Tylo Fido B (nice grouping, partner) and 4.9 and 5 km from the two landers that Aldner landed. The lander had about 119 units of fuel after landing, since Nelemy didn't bobble it around as much at the end this time.

The Main Event

Finally, we get to the death-defying main event, where Aldner and Nelemy descend in one of the Crew Landers. Being that Nelemy had managed two landings with zero explosions, he won the right to pilot the lander. Below, we see the boys transferring over to Tylo Crew Lander A.

The Crew Lander has two single-kerbal cabins stacked vertically, surrounded by six FL-T400 Fuel Tanks (two of which are dropped during descent, and two of which will be left behind on the surface when the ascent stage hopefully returns to space). There is also an X200-8 tank on the bottom for extra fuel, and there are 12 Rockomax 48-7S engines to give the lander a hellacious TWR.

The descent followed the tried-and-true profile Nelemy used for landing his two unmanned ships. A small plane shift, followed by a big burn north of Retro Crater. A mistake was made after separating the undertank: bumping the throttle lever caused a short but unplanned retro blast. As a result, the ship was coming down a bit short of the target point.

Below, you can see that the side drop tanks are actually quite a bit depleted during the big retro burn (which continues after the undertank is empty). The boys seemed to be enjoying the drop from orbit, but got more serious when Nelemy started is big deceleration burn at 30,000 meters. They again seemed happier when Nelemy brought the ship to a near stand-still at 10,000 meters. Nelemy then did the vertical descent somewhat sloppily, slowing up too much too often, thereby wasting fuel.

Aldner: "Three thousand meters. You've stopped again."
Nelemy: "Dude, I'm just being careful. It's US in this ship, you know."
Aldner: "Bingo fuel. Abort To Orbit is not an option. ATS mode."
Nelemy: "OK. OK."
Aldner: "700 meters. Picking up horizontal. Four to the left. Six left. You're going up."
Nelemy: "I'm on it. I'm on it."
Aldner: "Bring 'er down. One ninety. Drifting right. One right. Going up again."
Nelemy: "OK. OK. Going DOWN!"
Aldner: "Annnnd...contact!"
Nelemy: "Engines off! Dude, we are landed. Take that, Jebediah! I, too, will get free drinks for the rest of my life!"

Nelemy: "Dude, how's the fuel level?"
Aldner: "Looks like 238 total."
Nelemy: "Damn. We need 250 to get back to the station right?"
Aldner: "That's what the manual says. But you know engineers. Anyway, we have a couple good rovers and habs with fuel onboard...we just need to transfer it over."
Nelemy: "Yeah. Well, assuming the surface docking equipment works, Dude."

Kurt: "Laythe Base to Tylo Lander. We copy you down, guys. Good thing, too...I thought Hellou was about to turn blue from holding her breath."
Aldner: "Roger, Laythe. Get her breathing again."
Hellou: *Gasp!* "Good job, Nelemy! I'm so happy you guys are down safe!"
Nelemy: "Thanks, Hellou-dude."
Aldner: "Kurt, tell Thompbles that I'm naming this place Nelemy Basin. It's not as flat as we expected, but it looks interesting."
Hellou: "Yeah! Go get me some nice rocks!"
Aldner: "Well, she sounds like she's recovered just fine. First we check out and button down the lander. Then maybe we'll find you some pretty rocks."

After the remaining fuel was shifted to the two ascent tanks, they were indeed a little short of the recommended load for returning to orbit. But the lander had worked well. And if the pilot hadn't been so overly concerned about the safety of the crew, and hadn't wasted so much fuel during the vertical descent, it would have worked much better.

[This Crew Lander is, in fact, overbuilt. I thought it was svelte compared to the portly ship I used to land Jebediah on Tylo long ago (which I thought at the time was svelte compared to the beastie Scott Manley used to land on Tylo)...but after sending these ships off to Jool, I continued to play around which variations while practicing my Tylo landing skills. I've been able to land a similar ship without the undertank, and with only eight engines, on Tylo, with enough fuel to return to orbit.]

You can see in the picture above that the lander came down to the west of all the other landers, which were between 5.2 and 12.2 kilometers away.

Tramping on Tylo

Aldner: "So, do you want to go outside and look around...maybe kick a few rocks?"
Nelemy: "Yeah, Dude. Who goes first?"
Aldner: "You landed the ship, so you get the honor."

So Nelemy was the first out of the ship, followed by "Buzz" Aldner, who remembered to bring a flag.

After having a little more fun, taking a few holiday snapshots, and grabbing some likely looking contingency surface samples, the boys returned to the lander cabins.

While Nelemy was having his first snacks on Tylo, Aldner connected to the Tylo Fido A rover and started driving it remotely toward their landing site 7.2 km away.

The rover is based on my tried-and-true eight-wheeled Fido design that has worked well on Kerbin, Mün, Duna, Eve, and Laythe. As expected, the rover handles great in the 0.8 g environment. It got up to 50 m/s on the drive over (and it wanted to go even faster down slope...but that would get too close to the speed where the tires would blow).

Once the Fido arrived at the Crew Lander, it was time to try out the surface docking equipment in actual Tylo conditions. Aldner and Nelemy NEEDED some of the fuel the Fido was carrying to be sure they could safely return to orbit. So the rover was lined up carefully, and slid into position...

...and no docking. Damn. Well, back away, try again. And again. And again. It was soooo close, but no cigar. The docking ports are arranged such that the Fido can easily slip its port underneath the lander's port...and then the landing legs on that side would be switched from "lock suspension" to "unlock suspension"...which is supposed to allow that side of the lander to sag a little, and dock. But after repeated attempts, no joy

So the Fido was rotated around to try its other docking port. No joy. Then the Fido was moved to the port on the other side of the lander (which is at a slightly different height). Fail again. Then the technique of raising one of the lander's legs was tried out. This lowered the port a lot, but shifted it a little sideways in the process...so the Fido was repositioned over and over again to get its port in the right spot for the other port to mash down on it. Fail. Fail. And more fail.

OK, I was frustrated and gave up for that night. I assume Aldner and Nelemy did too...worried that there might be no way to get the ship up from the surface of Tylo. Well, there were still options: I hadn't tried the other Fido yet. And there was the option of bringing down the other Crew Lander and hoping it landed with enough fuel to return to orbit. And, there was also the option of just trying to reach orbit with the less-than-recommended amount of fuel. The ship could probably reach a low orbit, from which a Tug could drop down to rescue it. But, Arrrgh, my kingdom for a fuel hose in the stock game. I guess I should have waited for the Claw to be released before I designed these ships and sent them off to Jool.

But on to the next day...

Kurt: "Laythe Base to Tylo Lander. Laythe Base to Tylo Lander. Show some awakeness, guys."
Aldner: "Yeah, we are here, Kurt. What's up?"
Kurt: "The Big Brains at KSC have a suggestion. Check your docking port state switch on the SFS panel." Aldner: "OK. It's set to 'Ready' like it's supposed to be."
Kurt: "OK...but the boys at KSC say your SFS telemetry is showing that the port is in 'Acquire' state. They recommend cycling the switch a couple times and then putting it back to 'Ready' setting."
Aldner: "Roger. Cycling the switch now." *click* *click* *click* *click*
[That's the sound of me editing the game's sfs file file to change "state = Acquire" to "state = Ready" for the docking port in question.]
Aldner: "Done."
Kurt: "OK. Go try the docking again."

Another attempt...the Fido was still lined up from yesterday...so just slide the Fido's port in under the Crew Lander's port........and immediate docking. Well, that was easy. So Aldner had the fuel transferred to completely fill the Crew Lander's ascent tanks before Nelemy was even finished with breakfast.

Aldner also used the new TAC Fuel Balancer software installed in the Fido to quickly and easily balance out the remaining fuel load in the rover's tanks.

The next order of business for our intrepid explorers, after getting the Crew Lander all set for return to orbit and buttoned down to sleep, was: Road Trip!

Aldner: "Nelemy, hop inside the Fido and let's go check out all the other equipment."
Nelemy: "Dude, I want to drive."
Aldner: "No. My rover. Get in back."
Nelemy: "Oooo...can I ride on top in the Granny Klampett chair?"
Aldner: "You know that Thompbles said we shouldn't use that until we did extensive tests to determine whether or not the Fido handled well on Tylo."
Nelemy: "So that's a yes?"
Aldner: "Sure. Climb on top."

First stop was the landing site of Tylo Fido B. The Fido B was fine, so Nelemy climbed into its cockpit.

Nelemy: "Dude! Now I have my own ride!"
Aldner: "OK, now follow me to the Hab B landing site."
Nelemy: "Ten-four, good buddy. Looks like we got us a CONVOY."
Aldner: "Umm...sure."
Nelemy: "See any smokies? I'm about to put the hammer down. Any bears in the air?"
Aldner: "There is no air on Tylo."
Nelemy: "Oh, that's a big ten four, good buddy."
Aldner: "You can stop that now."
Nelemy: "That's a negatory, good buddy dude."
Kurt: "Breaker one nine."
Nelemy: "Kurt, good buddy! You want to play?"
Kurt: "No, Nelemy. I meant that you should set circuit breaker 19 to off."
Nelemy: "Ten four! Breaker one nine to off!" *click*
Aldner: "How long do you think it will be before he realizes breaker 19 controls his transmitter?"
Kurt: "I'm thinking it might be a while. He never was one for studying circuit diagrams."

So after some convoying, a little radio repair, and some general racing around (sorry, I meant "Fido surface mobility testing") the boys reached Habitat Lander B.

They parked their hot rods and went about checking over the Hab, which all looked good.

The Habitat consists of a Hitchhiker module for living quarters, and a single-kerbal lander-can as an operations center. Aldner checked out the equipment in the cabin, as well as the view from the window.

Aldner: "Nelemy, I'm going to activate the materials exposure bay. Climb up and see if it looks like it's working OK."
Nelemy: "OK, Dude. I'm on top of the ladder."
Aldner: "Opening now. How's it look."
Nelemy: "Looks fine, Dude. All panels open. All readouts are on. The little plastic bubble things that go 'pop' in a vacuum went 'pop'. Business as normal, Dude. Now open up the Goo canisters so I can say hi to the Goos."

Nelemy: "Hey, little Goo-Dudes! Wake up! Welcome to Tylo, your new home!"
Aldner: "Ummm...They didn't answer back, did they?"
Nelemy: "Not in words, Dude. But Left Goo seems to be vibrating up and down more than Right Goo. Maybe its happier because it has a better sun angle."

So after Nelemy conversed with the Goo a while and Aldner finished checking out the Habitat systems, the boys piled into Fido B and headed off to check out the rest of the equipment. Nelemy was driving, and Aldner was having a nap in the single-kerbal hab module in the back of the rover.

Nelemy first drove to the Fido A landing site, even though Fido A was no longer there, to check out the destruction of the side tanks.

Nelemy: "Dude, you really did a number on these side-tank units. You blew up all but four of the Rockomak 48-7S engines."
Aldner: "You mean the 'Rockomax High-Pressure Impact Absorbers.' Crumple zone, Little Buddy."
Nelemy: "Dude, you even broke some of the cubic octagonal struts. Those things are hard to break."
Aldner: "'Cubic Octagonal Crumple Zone Units.' They protected the Fido perfectly on landing. And the side tanks themselves came through it just fine with all that sweet, sweet propellant. Remember that when we're riding back to orbit using that fuel."

Upon arriving at Habitat A, the boys found that all four of the landing legs were broken, but still attached.

Nelemy: "All four legs, Dude."
Aldner: "A convenience feature for you, Little Buddy. You don't even have to extend the ladder to get on board."
Nelemy: "And you exploded all but two of the..."
Aldner: "Uh! Uhhh..."
Nelemy: "...all but two of the Rockomax shock absorbers."
Aldner: "You're learning. Check out the hab pressure. I'll activate the experiments."
Nelemy: "I need to talk to the Goo, Dude."
Aldner: "You'll have days and days to talk to the goo later."

Aldner: "Nelemy, strap in."
Nelemy: "Mmmph?"
Aldner: "I said, 'Close up the snacks locker and strap into a seat. I'm going to try repairing a landing leg. The ship might buck a bit."
Nelemy: "OK, Dude. Strapped in."
Aldner: "Yeah, that kicked hard. But it held."
Nelemy: "Dude! Do it again!"
Aldner: "Hold on. I'll repair the next leg."
Nelemy: "That one wasn't as fun, Dude."

After completing the landing leg repairs, and a second round of checking the whole ship, Aldner declared the Habitat A to be 100% operational. Of course, without it's engines it would never fly again...but it was never meant to fly again anyway. And without those pesky engines, it was easier to walk under the lander without bumping your head. It pays to think positive.

So Aldner and Nelemy set up the habitat for comfy living mode and had a fine dinner while discussing the news of the day with the crew back on Laythe.

Late that night, Aldner went outside the admire the view. Jool was much smaller than it is as seen from Laythe, so even though it was high overhead, it didn't give him the foreboding 'Blunt object of Damocles' feeling that he got on Manley Island.

For the picture below, I parked the rover a distance away to light up the habitat to a not-glaring brightness. I still had to stitch two images together to get the habitat and Jool comfortably together in the same shot.

And that's all for today's episode. Aldner and Nelemy have enough supplies that they could spend over a year exploring Tylo...but I expect they'll get tired of it before then. We'll see what they find. And next time we'll probably get Emilynn and Hellou back to Vall to finish their mission there.