Long-term Laythe Mission - Part 14

Vall Venture - Part 1

Vall Venture? Yes, yes... people have been telling me I should explore Vall since I started this series. And I fully expected to be doing so by now since I thought that when Resources were released (which seemed to be imminent back then) I'd probably have to go to Vall to find places to drill for fuel...since the bulk of such resources on Laythe could be under the oceans. But since resources don't look like they'll appear any time soon, I'll just go explore Vall for fun.

But first let's check on the boys on Laythe to see how they're enjoying life in version 0.21.1. We join them as Aldner is preparing to explore some additional islands.

Aldner: "Hey, Thompbles!"
Thompbles: "Yes, Aldner. Is something wrong?"
Aldner: "What the hell is up with the BirdDog's avionics system?? It's acting strange."
Thompbles: "Ah. That's the new SAS software install that KSC uploaded last night. It's supposed to be great."
Aldner: "Well, when I drive around in rover mode, the avionics keeps trying to point me back to my previous heading."
Thompbles: "Hmmm. Yes. It says that the SAS will automatically adjust the heading when you give control stick inputs."
Aldner: "And what about rover direction control inputs? Are those supposed to reset the heading?"
Thompbles: "Umm... Apparently they forgot to allow for that. We can submit a software fix request."
Aldner: "How about we submit a request to downgrade back to the old avionics system?"
Thompbles: "No, they specifically said that's not an option. All computers in the system have been upgraded to the new software and that's what we have to use."
Aldner: "Did they warn us this change was coming and I just missed the memo?"
Thompbles: "Now, now. You know the software boys never announce the actual dates of upgrades ahead of time."

So Aldner took off and flew around a little...

Aldner: "Yo, Thompbles."
Thompbles: "I read you, Aldner."
Aldner: "The BirdDog is acting weird in the air as well. I'm going to have to scrub this mission and do some practicing with the new control system."
Thompbles: "Is it that bad?"
Aldner: "Well, I wouldn't say, 'bad,' ...but you know I've got to be able to put this bird down and take off again in some very limited spaces. I don't think the time to try out a new control system for the first time is when I'm landing on a far off island."
Thompbles: "OK, Aldner. I agree."
Aldner: "You're going to have to approve the extra fuel usage."
Thompbles: "That should be OK. The boys at KSC are just about finished with the next ship they'll be sending to us, and it will include TWO new BirdDogs with GasStations, plus and extra double-capacity GasStation."
Aldner: "Nice to hear, Cap'n. OK, I'm going to fly some touch-and-go's around the island. Aldner out."

Indeed. Let's see the ships that the crew at KSC have been putting together for the next Jool launch window. I really wasn't looking forward to juggling half a dozen ships on the way to Jool again, so I had the brilliant idea to lump the ships together into just two large ships. Much easier to handle, right? What could possibly go wrong?

Below is the first launch in the big construction project. The payload consists of two triple tug adapters. One will be used for the Laythe resupply vehicle. The other will be used for the Vall Expedition vehicle. The launch vehicle is, of course, my standard Reusable Rocket...undoubtedly using boosters and sustainer stage recycled from previous missions. There have been a few minor changes to the Reusable Rocket for version 0.21.1: The RCS system has been removed from the sustainer stage and an SAS unit has been installed to handle torquing the rocket around. This seems to work great. I did leave the RCS quads down at the bottom of the rocket just in case I decide to use RCS (and assuming the payload has RCS fuel to provide). The payload for this flight carries a reusable Refueler Topper, and it needed to provide some extra fuel to the sustainer stage so that the sustainer had enough fuel to deorbit and land on its rocket engine.

Next up is the new, improved Nuclear Tug. I keep upgrading this design in each version of KSP. You may recall that the previous upgraded design featured lots and lots of probe cores to provide extra control torque. But now that Squad has given us SAS units that provide torque, the new tug design just uses one of those. It also uses the Senior docking port for extra structural strength when pushing big payloads...but there is a standard docking port underneath the Senior just in case the tug is needed to haul around something with a standard port (in which case the Senior port must be discarded).

Because the mass of the tug exceeds the usual payload capacity of the Reusable Rocket, the nuclear engines of the tug must assist the sustainer in reaching orbit (because the sustainer has to get into orbit as well, so it can come around and land back at KSC). Don't be overly concerned about the nuclear exhaust washing down the side of the sustainer...these are two fresh nuclear engines that have not yet built up any neutron-activated radioisotopes in the fuel pipes that run through the reactor, so what little radioactivity that comes out of a Nerva-style engine is at its minimum at this point. And we'll have Jeb hose the sustainer down after landing.

The Tug gets left in orbit with its rear drop tank over 64% full, and it uses a little of that fuel to rendezvous and dock with the triple adapters.

In fact, this tug will be the core of the drive section for the Vall Expedition ship, so it grabs one of the two triple adapters (the one with the slightly longer arms) and backs away with it. It then shifts to a slightly different orbit so the two big ships can be assembled outside of each others' lag range.

The next launch is the core tug for the drive section of the ship that will bring more BirdDogs to Laythe. You can never have too many BirdDogs on Laythe. Sorry...night launch...

Once in orbit, the tug docks with the triple adapter to form the core of the drive section of the BirdDog transporter. The tug gets some fuel and monopropellant from the Topper to replace what was used in getting to orbit, so it will have full tanks for the trip to Jool.

And we do it again. Launch a tug. Return the sustainer to KSC. Rendezvous with the BirdDog Drive section. Dock the tug. A little bit crooked? Eh...close enough for kerbal government work.

Lather, rinse, repeat. Another tug launch. This was also a night launch, but the rocket soon reached a altitude where the sunlight could make a nice picture. Dock the tug onto the triple adapter, and the drive section is complete, all built with standard parts.

The refueler Topper gives up all the monopropellant and fuel it can to the tugs, then departs to return to KSC. The Topper was also there to keep the triple adapters steady for docking with the first two tugs. Ah... I keep forgetting to add a MecJeb unit to these Toppers (which I just grab from my collection using subassembly manager), so I targeted this one to KSC manually using only RCS power (it was empty of regular fuel). I dropped it a couple hundred meters offshore...oops.

Next up, boys and girls, is an early morning launch of the Double GasStation. This GasStation has twice the fuel capacity of the standard ones. It does, however, only have two refueling arms instead of the usual three, but I haven't been having difficulty in getting the BirdDogs to dock with at least two ports on the standard station, so I'm hoping two will be sufficient. The station does have double the number of 24-77 engines, so it will be able to "hop" if needed to shift the positions of the refueling arms if there is a problem. The main reason there are only two arms is because I couldn't get three to fit in the limited space the payload will fill on the big ship.

Because the drive section is rather large, the Refueler Topper acts as the tug for getting the Double GasStation into place on the drive section. I gave the Topper an SAS unit to help wrestle around the payload. I performed the rendezvous in the dark, but I waited for sunlight to do the docking (I didn't want to add docking-assist lights to the payloads to keep down the part count of this big ship).

Next comes a standard BirdDog payload with standard GasStation. I'll be able to drop these GasStations in a few select spots on Laythe, making exploration much easier. This new BirdDog is slightly modified...it no longer has an avionics package, since those are useless parts now, and I've shifted the position of the air intakes down a bit to decrease the tendency of the plane to pitch up. But the basic framework was left untouched to make sure all BirdDogs will fit all GasStations. There is no room for a reusable Refueler Topper on a BirdDog payload, so I added three fuel/RCS pods on the refueler arms. The orbital maneuvers were done using the GasStation's six 24-77 engines, which draw fuel/oxidizer from its torroidal gold tanks...and that fuel had to be replaced a couple times with fuel from the three fuel/RCS pods during and after the maneuvers. But the BirdDog was slid very carefully into place, only slightly crooked. But OH NOOOO, the lag. Arrrrgh. OK...so maybe building a big ship is not the way to go. But I didn't think a triple-tug/payload ship would tax my system as badly as it did. Maybe 0.21.1 is laggier than previous versions.

After the docking, all the remaining fuel in the three pods was transferred to the still hungry Tugs in the drive section, and then the pods were popped off. The RCS quads of the pods were used to deorbit them into handy oceans (they are not recovered for re-use, alas).

Once more unto the breach, my friends! A late evening launch of a standard BirdDog payload.

After the last BirdDog was docked in an agonizingly slow ballet, the Tugs were topped off, and then the three pods were jettisoned to head to their watery graves. And the BirdDog carrier was ready to be sent to Laythe.

OK...Now for the Vall ship. Two more tugs are needed for its drive section. With the first one, the sustainer came back and nearly hit the VAB. With the last Tug, the sustainer landed on the raised part of crawlway and almost tipped over.

With those two Tugs docked on, mostly straight, the drive section for the Vall ship is done. The connections between the Tugs may not look strong, but all three payloads that will go on top have nearly the same mass, so its like three Tugs/payloads that happen to be flying along in the same direction, so there is not a lot of stress on the connection.

Now for the Vall payloads. First: Two Fido rovers. These rovers are based upon my Fido KE design, and they each use eight of the older-style medium wheels. I know there are a lot of people who say the ruggedized medium wheels are better than the older ones in every way...but I disagree. I did a lot of "simulation" testing of rovers under Vall conditions with older wheels, newer wheels, and aircraft landing gear in various combinations. It's true that the ruggedized wheels can run up hills like champs, but they also are prone to mysteriously 'snagging' the ground and causing the rover to flip at high speeds. The older wheels do slip and slide more, and take longer to accelerate and slow up, but I did not experience the flipping out problem with them. So, old wheels it is, for me!

Arrgh! Already, with just the center payload, the lag was getting terrible with this ship. I guess it's all those struts and girders and whatnot for two complete rovers and their skycranes. After docking the Fidos in place, the Topper gave some fuel and monopropellant to the Tugs, then headed back to KSC.

The next piece of the puzzle is the Vall Expedition Lander. This lander basically serves as a base for the crew of two on Vall, so it has a two-kerbal lander cabin AND a Hitchhiker module to serve as living quarters and laboratory. I've wrapped the living quarters with six fuel tanks to serve as radiation protection. Unlike our happy campers on Laythe who have a substantial atmosphere to protect them from Jool's radiation belts (however strong they may be), the Vall crew will be spending their time on an airless moon with no such protection. Those four long stacks of Oscar tanks are the four communications satellites that will be placed into high Vall orbit before the lander descends to the surface. They have waaay more fuel than they need, but that was to get the mass of this payload up to the same mass as the main habitat module which will be on the opposite Tug.

And last to go up is the Vall ex. main habitat module that the crew rides in to get to Jool and for the return trip to Kerbin. I figured a 2-kerbal lander pod for the command pod, plus a Hitchhiker module for extra living space would be plenty of room for the two-kerbal crew. And wrapping the habitat module with fuel tanks for shielding against cosmic rays during the trip also seemed like a good idea. And...hey...this is almost exactly like the Lander. So, what the heck... I added some legs and engines and made it into another lander that could be used for some emergency, but which will not be used for that if all goes according to plan. Plus, I added a couple one-kerbal capsules with retro engines in case mission directors decide to send the Vall crew to visit our boys on Laythe after their Vall mission is done (they would need to use the Laythe SSTUBBY SSTO to return to orbit in that situation). It always helps to have contingency plans.

Alas, the perfect record of returning the sustainer stage from all twelve Reusable Rockets used for this project came to an end when the sustainer of this rocket returned to KSC. It landed on the crawlerway tracks and tipped over, exploding its two orange tanks. But the Mainsail and the complete bottom structure, plus most of the top parts such as the probe core and RTG and stage separator survived for re-use.

Oh. So far everything that has been launched has been un-kerballed. The crew will come up later via SSTO rocket when the launch window to Jool approaches. But every time I launched one of the rockets for this construction project that included a capsule, Jebediah tried to sneak on board. Every. damn. time. Annoying as hell. Look, if I wanted a crew on the rocket, I would have ASKED for it. Grrr.

So with the removal of the last Refueler Topper, this amazing lag-fest, the Vall Expedition ship, is fully assembled, fully fueled, and just needs its crew and a launch window to Jool.

Meanwhile, back on Laythe, the boys are having a discussion over supper...

Thompbles: "Hey, did you hear that they finally chose the crew for the Vall expedition?"
Kurt: "Who did they choose?"
Thompbles: "The Mission Scientist is going to be Hellou Kerman."
Aldner: "Really? That's great. It's about time we had a real geologist in the Jool system. All these rocks look the same to me."
Kurt: "Who's going to pilot the mission?"
Thompbles: "They're sending the Hawk."
Aldner: "What? Do you mean Emilynn "Hawk" Kermann??"
Kurt: "Hooo boy!"
Nelemy: "Wait, dudes. Who is this Hawk?"
Kurt: "Nelemy, do you never pay attention? She's been the flight instructor at KSC for years."
Nelemy: "Dude, I already knew how to fly. I'm not one of those Mission Scientists."
Kurt: "Obviously. "
Nelemy: "Is she any good?"
Kurt: "Well, she waxed Aldner's tail in a mock dogfight using the KSC K-38s."
Nelemy: "Dude! No, really?"
Thompbles: "You're not supposed to be using the K-38 planes for dogfights."
Aldner: "Yes, mother. Anyway, I'd just spent a month testing BirdDogs, and was in the habit of not pulling up hard."
Kurt: "Yeah, I'm sure that was it."

Back at KSC, the final rocket of this launch project is on the pad: An SSTO Crew Carrier. On board is...well, Jebediah again, of course, since he always sneaks on board. OK, Jeb, you can pilot the damn SSTO mission. Sheesh. Along with Jeb are the Vall expedition crew members, Hellou "Chickadee" Kerman, Ph.D, and Emilynn "Hawk" Kerman. Also on board are the backup crew members for the Vall mission, Tomster Kerman, Ph.D., and Corfrey Kerman (also acting as Jeb's co-pilot in the capsule). The backup crew members are along to help with final ship checkout and equipment transfer.

Below: Jeb spools up the jet engines, then blasts the Crew Carrier off with a brief burst of rocket thrust. The SSTO climbs on jet engines to 20,000 meters, then switches over to rocket engines for the press to orbit.

Below, Jebediah brings the Crew Carrier in very slowly for docking (well...I assume it was fast for him, but it was an annoying lag fest for me... OK, OK, I'll quit complaining about the lag now. It's my own fault.).

After docking, the crew transferred over to the habitat ship...first Emilynn and Jeb to the control cabin to run the ship system checks, and then Hellou to the crew habitat module.

Emilynn: "How are you doing, Hellou? You're floating along kinda slow."
Hellou: "I'm fine, Emi. I'm just doing this carefully."
Jeb: "Is she going to be all right, Hawk?"
Emilynn: "Oh, sure, Jeb. It took me forever to teach my Chickadee how to fly, but she gets there in the end."
Hellou: "At least I don't drive a rover like I'm a maniac. And it's not polite to talk about people when they are on EVA. Over an open circuit, anyway."
Emilynn: "Roger. You're cleared for landing at Hatch 01."
Hellou: "Don't rush me."
Jeb: "I wish I was heading out with you. I haven't had a deep space mission in years."
Emilynn: "Well, if you quit trying to muscle your way onto every ship that gets put on the launch pad, maybe the boys in mission control would be happier with you."
Jeb: "Hey, somebody has to do the system checks. If they forget to tell me to get out, that's their problem."
Hellou: "OK. I'm at the hatch. Boarding now."

After the system checks and the transfer of equipment, supplies, snacks, hair-care products, and snacks, Jeb, Corfrey, and Tomster transfer back to the SSTO, and Jeb takes them in for a landing at KSC.

To plan the transfer to Jool, I consulted the new Launch Window Planner (http://alexmoon.github.io/ksp/). It gave me a cool plot and lots of data...and a transfer date that agreed with Kerbal Alarm Clock's date within one day.

I sent off the Laythe ship first. As usual, I did the transfer burn in two parts for better efficiency. Below is the initial trajectory plot. Delta-V required was 1904.6 m/s, and after firing up the engines, the burn time showed up as 20 minutes. The ship was stable a 2x physical time acceleration, but too wobbly at 3x. And with the lag rate, the two-part burn took me over 30 minutes. Maybe there is something to be said for sending out multiple smaller ships. All those other trajectories on the plot (from right-to-left) are for a Tug returning from Jool, the new larger mobile base (soon to arrive at Jool), and a second Base/rover pair that I sent out when I had nothing better to send.

I started the burn about 6 minutes from the node, then cut it off after 10 minutes. This put the BirdDog ship in an elliptical orbit going most of the way out to the Mün.

I let the BirdDogs get most of the way out to the Mün, then I sent the Vall ship off on a similar trajectory. Oh. so. painful. Wait...I wasn't going to complain about lag anymore.

After the first halves of the burns, the orbits were as shown below:

When the BirdDog ship came back around toward perigee, I replotted the trajectory to Jool and sent it on its way into deep space with the second half of the burn. When the Hawk and her Chickadee came around, I sent them off as well. The orbits of the ships had started at 110 km, but the periapses got as low as 87 km during the second part of the burn. If you try to do a long burn like this in one go, you might end up with your periapsis dropping down into the atmosphere...and you'd certainly be doing a lot of your burn far from Kerbin where you lose the advantage of the Oberth effect. So two burns is a good method. Below, the second halves of the burns in artsy silhouette.

Below is are the final trajectories for Jool. As you see, they won't reach the descending node until out beyond Dres, so the plane change burns will be small (those are best done far from the sun).

Next episode: Stuff Arrives At Jool: A new bigger mobile base for the boys on Laythe; a secondary base/rover combo that I'm not sure yet where I'll use on Laythe; a Tug returning to Kerbin in a less-than-optimal trajectory, hopefully with enough fuel; and the Vall expedition arrives at Vall. I'm not going to bother with the "send something out in all available launch windows" thing anymore... Sure, it's more realistic, but it's a pain to have all this stuff going back and forth that I have to keep track of. And we've all seen the pretty plot of the coming and going trajectories now... so I'll just be more inefficient and buzz through time like it's going out of style. I'm sure the kerbals sitting on other planets or moons won't mind if I ignore them.