My first interplanetary mission, heading to Jool

[UH60guy]

Hi there. I thought I’d start a thread documenting my first interplanetary trip in KSP, not to mention give me a place to ask for advice along the way from the more seasoned KSP veterans out there.

Well, my industrious little Kerbals just built their first space station and have already landed on Mun and Minmus. It’s time to head out there and see what other worlds we can make it to. I was planning on going to Duna first, but the first planetary alignment is actually with Jool.

With a few modifications to my planned multipart craft, I’ll see if I can send it that far out. I’ll modify the planned Duna surface base as a floating habitat. I’ll also ferry more fuel to the space station, but I’m hoping that otherwise my intended spacecraft design might be robust enough to accomplish this. I don’t plan on using any mods with the exception of MechJeb for the launches. I’m only using that to get my ship assembled in orbit fast, since the Jool transfer window is in about 26 days and I don’t want to miss it.

Here’s a stylized representation of my intended mission arrangement (I’ve only built the ascent stage so far):

I’ll launch in three main parts- ICS, then OOMPA/KRASH, then the LLAMA/heat shield. They’ll be assembled at the Kerbal International Space Station and Bar and Grill. I’ll launch and dock extra fuel tanks afterwards as my delta V calculations require. More on that later.

The ICS will drive the whole shebang to Jool with seven Kerbonauts onboard the KRASH, and enter orbit with an aerobrake. Once in a stable Jool orbit, I’ll launch as many probes as orbits allow- likely 2 per moon, maybe saving one for Jool itself. I’ll try to get at least one of each pair on a nice polar orbit to map the surfaces.

Once a favorable alignment presents itself, the craft will maneuver to Laythe, aerobraking as necessary. At that point six intrepid explorers will transfer to the LLAMA and undock. They’ll burn for reentry, aiming for somewhere in sight of land, but in the water itself. After max heating, they’ll ditch the heat shield and guide in the landing on minimal thrusters. Parachutes in the LAS (LLAMA upper stage) will assist as necessary. The goal will be to stay above 50% fuel, so I can launch back out with a full tank (leave one on the surface later).

They’ll explore the surface, go for a swim, repack parachutes, and generally give high fives all around. Next, they’ll draw straws to see which four saps are the ones to stay behind in the Laythe Ocean Base and Buffet. The other two will climb into the LAS, undock, and return to orbit to join up with the main spacecraft in orbit.

From there, the ICS, KRASH, and LAS will return. Depending on how short they are on maneuvering and transfer fuel and if they can handle the mass, I’ll keep the LAS attached as long as possible. If I’m lucky, I may be able to return all those parts to the space station, significantly reducing the number of launches needed for the next interplanetary mission. I’ll make the call then, and land whatever part makes sense.

Looking at the design, you may wonder why I have the KRASH module at all, since it never undocks from the ICS. I could just take six Kerbals and have them in the LLAMA the whole time instead. The thought behind it is that it isn’t much additional mass compared to the fuel and lander, but it gives me an extra maneuver piece to react to any orbital rescue missions that might arise where it would be a pain to use the whole ship for- such as if the LAS reaches orbit, but runs out of fuel before it can complete rendezvous. Alternatively, the KRASH gives me a low mass return option if I run the ICS out of fuel on the way back- engines on the OOMPA may be able to help them return to Kerbin in an emergency.

The next step will be calculating the Delta V required for each phase. I’ll give it a shot first, then throw it up here to see if I’m on the right track.

[UH60guy]

OK, well that was fast. The Kerbal so-called rocket scientists are already resorting to guesswork, based upon absolutely no prior interplanetary experience. I have *most* of my delta V requirements per phase of mission, but there are a few parts from the Delta V chart that I couldn't get an answer from.

Phase 1: Departure (from being docked at KISSBAG already in orbit)

Kerbin escape: 950

Jool transfer: 965

Jool orbit injection 2360

Phase 1 total: 4275

Phase 2: ???

I have all the transfer and orbit delta v requirements to transfer 10 probes to all 5 moons (forgot about Bop in the above plan, I'll now carry 10 instead of 8 probes).

Phase 3: Profit

Laythe transfer: 1600

Laythe orbit injection: 780

Phase 3 total: 2380

Phase 4: Walkin' on the moon

Laythe landing: ???

*This is where I can use some help. what kind of delta V do people usually add here to get out of orbit? I'll be leaving my main ship in orbit here for later rendezvous, so I can't do a straight aerobrake to landing- unless I separate stages after braking but before circularizing, but that may lend itself to some trouble where I'm trying to fly two spacecraft at once.

Laythe launch to orbit: 2800

Laythe orbit rendezvous: *Is there a good amount to plan for in a budget here to fly rendezvous maneuvers?

Phase total: 2800 plus maneuvering.

Phase 5: What happened to those other guys?

Laythe escape: 780

Jool escape/Kerbin transfer: *The delta V chart doesn't have this, but how realistic is it to depart from a moon straight to Kerbin? Would the delta V requirement be similar to a Jool-Kerbin burn? I'm skipping a node here, and assuming Laythe escape has them in Jool's SOI, meaning they can burn straight from there to Kerbin.

Kerbin orbit injection: 950

KISSBAG rendezvous: *optional, may need maneuvering fuel to dock and stay at the space station instead of landing.

Phase total: 2695? plus maneuvering fuel, plus more depending on Laythe-Jool SOI concerns

Mission total: 12,150 m/s, plus extras I'm not sure about, and not counting getting stuff into low Lerbin orbit to start.

(edit: that's 9350 for the ICS and 2800 for the LLAMA, plus maneuvering fuel) That's also not including the KRASH module which may have a thousand or so m/s for emergencies.

Edited August 13, 2013 by UH60guy

[jwenting]

whenever you think you have a number, double it to err on the side of safety

I didn't on my one and so far only attempt to get to Laythe and what was on paper a return capable craft ended up in a Laythe crossing orbit around Jool without fuel.

[Marcosf98]

What did you use to make the diagram in the first post? It'd be helpfur to me when I plan my missions.

[Tw1]

Tip: If you areobrak right at Jool, you can just wait until Laythe comes close, then tweak the orbit to get an intercept.

[UH60guy]

I just used the insert shape tool in PowerPoint. It's relatively easy to rearrange things without having to use image editing software. When you're done, it does let you save as an image file. I had to do it this way because there's always something I forget, be it solar panels, docking ports, etc...

Built and launched the KRASH/OOMPA module today. It has a wet mass of 24.78 tons and 3301 m/s delta V in a vacuum. Should be more than enough for a rescue ship.

Thanks for the tip on doubling delta V. To help me along, I may build a refueling tanker to come along for the trip.

Here's the KRASH and OOMPA (on left) after a midnight docking with the Kerbal International Space Station Bar and Grill. Now to build and launch the other parts, and dock to my extended node on the right.

[UH60guy]

I'm back to the drawing board on the LLAMA. I had built the ascent stage to have around 3300 m/s delta V, which should be enough to get off Laythe and to dock with the mother ship. Tested it by slapping a quick suborbital rocket on it at KSP, it flew and staged perfectly.

The trouble came when I built the surface floating base underneath. I strutted the bejeezus out of everything, so the entire base and ascent stage (LLAMA) was able to blast off for a quick drop in the ocean for a test. It's to the point where it *almost* works. Even with descent thrusters firing, the stack snaps in half when under parachute canopy. Everyone lands alive and the base floats, but the ascent stage isn't attached at the end for a suitable return to orbit platform.

I'm hoping if I can redesign the ascent stage to be a little more squat- radial drop tanks instead of stacked- I can lower the center of mass and make the structure more sound. I guess this is where landing on a moon or Duna might have been better for a first time project, I wouldn't have to carry so much weight on descent to get back into orbit!

[UH60guy]

It is with a heavy heart that I must announce the passing of Bilhat and Kerbin Kerman. On what was supposed to be an unmanned test of the LLAMA where the engineers tested out the base's floatiness and the ascent stage's ability to separate and return to orbit, no one noticed until it was too late that the enthusiastic pair stowed away on the ascent stage. The ascent stage is not intended to be a reentry vehicle, and is therefore not equipped with parachutes, but they must have really wanted to give it a shot. I'll need to pay more attention between tests to make sure I search for and remove any stowaways in the future.

At least the testing of the LLAMA in the waters off KSP is going well- the sudden massive existence failure problem during descent seems to be fixed. I've learned to fly it a little too- I keep the heat shield as a counterweight until the drogue chutes deploy, drop once steady, and ride about 8 big parachutes down. About 100m above ground, full thrust slows the descent to just below 7 m/s for a nice and safe splashdown. I'm hoping the lighter gravity on Laythe makes it even more smooth. Here's the LLAMA in action:

Now the only problem seems to be with physics. My explorers can stand on the platform when it is sitting on land, but when it's floating, they just lay there. I'll try raising the platform and see if it was just due to it being too low in the water. If the above was the LLAMA in action, here is the LLAMA inaction:

[suzin.felipe]

Had a similar problem with a Kerbal stepping down of a rover. Turn RCS on and try to roll him carefully away from the stair. HE should stand up for himself after you do that.

Edit: Nice designs by the way.

[UH60guy]

Curses. No amount of redesign can seem to get these would-be Kerbalnauts upright on the platform when its floating, even with some RCS rolling around and stuff. I'm tired of waiting around, I'll just launch as-is. If I can get one into the water, he can swim to land and plant a flag on Laythe, otherwise he'll be staying indoors for the duration of the mission.

Next, just gotta build the Interplanetary cruise stage. 47 tons for the LLAMA, 23 for the KRASH, so I have to build it to push itself plus 70 tons with sufficient delta V to spare. This one shouldn't be as big of an ordeal, I hope.

[J_Man_X_663]

Curses. No amount of redesign can seem to get these would-be Kerbalnauts upright on the platform when its floating, even with some RCS rolling around and stuff. I'm tired of waiting around, I'll just launch as-is. If I can get one into the water, he can swim to land and plant a flag on Laythe, otherwise he'll be staying indoors for the duration of the mission.

Next, just gotta build the Interplanetary cruise stage. 47 tons for the LLAMA, 23 for the KRASH, so I have to build it to push itself plus 70 tons with sufficient delta V to spare. This one shouldn't be as big of an ordeal, I hope.

Try fast forwarding time (x5) with you're kerbal selected, then he should stand up when you stop warping

[UH60guy]

Ah, that seems to be the problem. Under time warp, the base bobs and flexes in weird ways in the water, despite being perfectly stable in normal speed. Maybe that's why he can't stand up, the game thinks he's falling.

Since this is just my first mission, I'll keep it a land and return with a crew of two, and I'll leave the surface base there behind for posterity.

[Fox62]

Actually, there is a mod called the "Sea Sickness Cure" mod, which can fix the problem with floating platforms, just add 1 part.

[Bothersome]

What about going to the tracking station and back?

[UH60guy]

I installed the sea sickness cure mod on the platform, but still no luck. The mod is supposed to change status from "splashed down" to "landed," which would enable the Kerbalnauts to walk on the platform, but it's not working. Maybe I installed it wrong, or maybe it doesn't work under version 0.21.

In the mean time, I built and launched the Interplanetary Cruise Stage and docked the Kerbal Return and Sumer Home to it. Now I'm just ferrying up fuel to it for the journey.

I've christened the main ship for the journey the Kobyashi Maru.

This should get me enough delta V to get TO Jool, but I'll need more to get back. That's why I launched two more nearly identical cruise stages- the Nostromo and Sulaco- they'll carry the probes to Jool (again to save on mass of the main ship), then act as tankers on site and transfer all their remaining fuel to the Kobyashi Maru for the return trip. I also have about 3000 m/s of delta V on the KRASH alone, so even if the Kobyashi Maru only gets us halfway home, they'll be able to finish the journey in the smaller ship.

I wonder if I'll get good luck from naming all my vessels after doomed ships, or if it'll be a sign of things to come?

[UH60guy]

OK, got a shipment of high delta V probes (have to be able to transfer to all of Jool's moons) on the way to the Nostromo supply ship:

Once transferred, it should be ready to make the journey a few days ahead of the manned expedition.

[meve12]

You are aware the download on the OP is outdated, right? There's an updated version by someone else in the middle of that thread.

[UH60guy]

Thanks for the tip- the update in the middle of the thread worked to fix the platform- it's the one with a giant blue inner tube, not the party hat. Now it's just matter of launching the LLAMA, and I should be off!

[UH60guy]

Well, I got it all assembled in orbit:

But then it failed the "don't explode when you push the button" test simulation I ran. Apparently three docked ships might be too much: even when the thrust is along the prograde axis and there's no rotation, it bends in half at the LLAMA node and all crashes together. At least the Nostromo and Sulaco performed flawlessly with their probe mounts. Luckily, I have a backup plan.

I had built and launched a spare Interplanetary Cruise Stage (because why build three when you can build four?) that I had planned to use for an interim trip to Duna while the main mission was en route to Jool. Instead, I'll deorbit the LLAMA lander from the main mission, and launch it to dock with the spare ICS. I'll have to rename it too- I had named it the Atreides in honor of a Duna mission, but now it'll be the Event Horizon in keeping with my doomed space ship theme for the Jool mission.

So, my mission will now be a convoy of four ships:

Kobyashi Maru: ICS + Kerbal Return and Summer Home (KRASH) module with 3 Kerbalnauts (seats for 7)

Event Horizon: ICS + Laythe Landing and Ascent Module Assembly (LLAMA) with 4 Kerbalnauts

Nostromo: ICS + five probe package. ICS will be repurposed to refuel Kobyashi Maru over Jool after probe deployment

Sulaco: ICS + five probe package. ICS will be repurposed to refuel Kobyashi Maru over Laythe after probe deployment

The mission flow will have to change a little too: The LLAMA and KRASH will go directly to Laythe if moon positions permit. The LLAMA will land from the Event Horizon, but the ascent stage will dock with the KRASH on the Kobyashi Maru after leaving the surface. I'll abandon the ascent stage in orbit, and the only ship to return will be the Kobyashi Maru with the KRASH.

Edited August 26, 2013 by UH60guy

[UH60guy]

KSC, we have a problem: Zombienauts in space.

After having been killed when they snuck aboard what was supposed to be an unmanned test of the LLAMA, Bilhat and Kerman Kerbin were added to the memorial wall. Well, apparently the pair has made a surprise appearance onboard the LLAMA again- this time making it to orbit in the above docking situation with the KRASH before anyone noticed. Needless to say, the crew of the Kobyashi Maru was surprised to see them.

Jebediah Kerman, the mission commander slated to take the LLAMA back to Kerbin and relaunch to join the Event Horizon made the hard decision. It's really the only thing you can do with Kerbalnauts returned from the dead: "Kill it (again) with fire." He plans to vent the airlocks while on a descent trajectory to see if a little reentry heating can help the dead duo finally rest in piece(s).

Those mission commanders get paid the big bucks to make the hard decisions.

[UH60guy]

It was the only way to prevent the zombie apocalypse.

In other news, I messed around with the LLAMA and ended up installing the quantum strut mod so I could keep it stable when docked to the cruise stage on the interplanetary journey. I probably could have gone with a redesign to the large size docking port, but that would entail relaunching the cruise stage and about six fuel transfer missions, so I opted to just replace the LLAMA and do it in one launch.

Luckily, I found a design workaround earlier for the floating base part that made it so I could remove the sea sickness cure mod- I basically just removed the work platform and made it so there's a ladder straight from the habitat to the water, and the struts with the floats connect directly to the hitchhiker module. You can kinda see the redesign in the all-up picture a few posts back, but I'll have some better pictures on Laythe I hope.

So, down one mod, replaced with another. That's not too bad I think: just quantum struts and MechJeb for the calculations. I wanted to keep the mods as minimal as possible while I learn the ins and outs of KSP, so I think that worked out as a good comprimise for a first long-range mission.

Now I'm ready to launch the mission! Just counting down 23 more days until the optimal Jool transfer window opens and I can send the convoy on its way. I just have a few other ships to check in on in that time (a sun diver about to impact and a Mun-Minmus dual rover mission about to transfer between moons) and I should be ready to launch this weekend when I have some time to really sit down and hand jam some transfer nodes.

Edited August 27, 2013 by UH60guy

[UH60guy]

Bilhat (picture above on reentry) and Kerbin are inexplicably back in the astronaut complex, despite Jeb's best efforts to prevent the undead uprising. I mean, he wants to have a safe home to return to after the Jool/Laythe mission, right? Methinks he found some volunteers for a one-way trip during the upcoming Eloo transfer window- but that's a topic for another mission thread down the road.

Not sure if I should keep the black memorial stripe on my Kerbin ribbon if the guys keep coming back after being irretreivably lost twice...

Edited August 28, 2013 by UH60guy

[UH60guy]

One last top-off of monopropellant in the LLAMA, and it should be all systems go!

And the first ship of the convoy, the Nostromo probe launcher and orbital refuel tanker, is underway under 5 of her 7 engines. She's the first iteration of the design, so it's a little underpowered/inefficient and has less fuel than the others, but it should get the job done.

And I very quickly saw how fast it was still burning fuel on the Poodle engines- thankfully the other ships have nukes- I had to shut down two more to keep from running out of gas leaving the Kerbin SOI.

Edit- the seven poodles were a design choice to get it into orbit. I had a hard time building a launcher for the ICS. I had the central core and stack of seven tanks at the top, and to reduce weight, the first thing I needed to do before launch was run two of the tanks completely out of fuel. Then, the other exposed poodle engines would assist in the early part of the launch, plus the added bonus of reducing the mass I had to put into orbit by dumping fuel on the way up (I planned to top it off in orbit anyway). I later redesigned the interplanetary cruise stage to have just four poodles to dump fuel and launch assist, while the other three engines were nukes.

Edit again...

Well, that could have gone better. Late in the nearly 20-minute burn, I got a phone call and *thought* I paused, but hadn't. Overshot Jool and was well on my way to earning my solar escape device on my ribbon. Had to F9 and try again. I used all seven engines out of curiosity- I ended up making the transfer orbit with about 1000 m/s more delta V to spare, and had fuel in all tanks. I guess it works out better as a shorter, almost impulse, force rather than the smooth longer burn.

Edited September 3, 2013 by UH60guy

[UH60guy]

Each ship of the four-ship convoy departed low Kerbin orbit about four hours apart.

Next out of the system was the second probe launcher and refueler, the Sulaco.

That was followed by the Kobyashi Maru- the cruise stage attached to the Kerbal Return and Summer Home (KRASH) module. This is the piece that is there for the recovery of the lander and makes the return trip to Kerbin. It's commanded by Sonwin Kerman (right seat), with Hendan Kerman as KRASH pilot (left seat). Dergun Kerman is the bartender (bottom seat). Hendan need to work on his piloting skills, and the engineers need to work on their docking clamp stability. The combined vessel rode like a bucking bronco and probably wasted quite a bit of fuel, but it held together and made it to a Jool intercept orbit. Sonwin hasn't said it to the others, but he's worried how it will hold up during aerobraking.

Finally, the Event Horizon departed last with the Laythe Landing and Ascent Module Assembly (LLAMA). This is the Laythe surface base and ascent stage that will dock with the KRASH for the return trip. It's commanded by Jebediah Kerman (overall mission commander) with Herman Kerman as the LLAMA pilot. Genester and Billy-Bobbery Kerman will be the poor saps to live in the ocean base until (if?) we get around to retrieving them.

Interestingly, though they all departed orbit four hours apart in the above order, my hand-jammed nodes and flopping space ships have them arriving in different times:

The Event Horizon will actually arrive first, in 274 days. This works out well since they can try to go Direct to Laythe and get the landing done without the others having to wait on them. Where this could lead to trouble is if it needs a refuel before it can transfer to Laythe. The Kobyashi Maru will arrive in 293 days to be able to pick them up.

Unfortunately, both probe vessels, intended to scout the system first, will arrive last. The Nostromo will take 312 days, and the Sulaco takes a year and a day. This means the mission will take some waiting around for a refuel, unless there’s sufficient fuel to be shared between the Kobyashi Maru and the Event Horizon.

Now that I’ve launched my first interplanetary mission, I have another opportunity to learn more before it reaches Jool. A Duna window opens in seven days, I may try to fly a something there to test out my aerobraking an landing on another planet closer to home, before I make any big mistakes a year down the road all the way at Jool.

Edited September 5, 2013 by UH60guy

[Wayfare]

Interestingly, though they all departed orbit four hours apart in the above order, my hand-jammed nodes and flopping space ships have them arriving in different times:

The Event Horizon will actually arrive first, in 274 days. This works out well since they can try to go Direct to Laythe and get the landing done without the others having to wait on them. Where this could lead to trouble is if it needs a refuel before it can transfer to Laythe. The Kobyashi Maru will arrive in 293 days to be able to pick them up.

Jamming and flopping did not cause this. What happened is that you conducted your first transfer at the optimal delta-v window. If you transfer any sooner or later than that, you're trading delta-v for time. Basically you get there quicker but you use more fuel. The small differences at departure translate to pretty significant differences at arrival. If you want your ships to arrive in a specific order (assuming the first transfer is done at the optimal window) you need to transfer them in the reverse order that you want them to arrive. Ain't orbital mechanics something?

Anyway, good job getting all that stuff built and underway. I'm looking forward to see how it turns out!