The Emerald Star: A mission to Jool's moons

[Robin Patenall]

Hello everybody  and thank you all for coming to this party to celebrate our upcoming mission. 

We are proud to announce a new large scale space project, in which we will be sending a crewed mission to land on, and return science from, all the moons of Jool. As this will be a very long multi year mission, the decision has been made that we will be sending a single large ship to the Jool system so that our crew isn’t going to be lonely on the trip out and back.

Speaking of out crew, here we are:

On the left there is me, Pinky Pie. I am the chief engineer and primary astrodynamics officer, which is a complicated way of saying that my job is to keep the ship working and get it to where it is meant to be. The most important being getting us home at the end.

Next to me is Twilight Sparkle who is the chief scientist for the mission and also the mission specialist for Laythe, the innermost moon of Jool. She got to pick that one as long range scrying has shown us that Laythe not only it is warm enough from tidal heating that liquid water is present on the surface, it also has a thick oxygen rich atmosphere which, along with the detection of many other atmospheric chemicals, is a key indicator that there may be life on it.

The next two, Fluttershy (left) and Bon Bon (right), round out our scientists. Fluttershy is the chief medical officer and also the mission specialist for Bop, the fourth moon of Jool, which she thought looked lonely. Bon Bon is the mission specialist for Vall, the second moon of Jool, where her speciality in the physical properties of ice under different conditions will be very useful and she also doubles as the backup engineer.

The last two of our crew are our pilots, Rarity (left) and Rainbow Dash (right). Both are cross trained for piloting but Rarity will generally be in the pilot seat for docking and delicate manoeuvres and Rainbow Dash specializes in things that need to be flown in a more instinctive manner. Additionally, Rarity is the mission specialist for Pol, the fifth moon, as it looks pretty and Rainbow Dash is the mission specialist for Tylo, the third moon, because it is the biggest. 

We will come to the details of the ship, the Emerald Star, as we construct it in low orbit and details of the mission as they come up, but we do need to deal with some specifics now.

[Pinky raps on the fourth wall with a hoof]

Hello out there. Can you hear me?

[Pinky fogs up a bit of the fourth wall by breathing on it, polishes it with a fetlock and presses one of her eyes to it to get a good view before retreating]

We’re running KSP 1.12.5.3190, both DLCs are present and there are a number of mods running. Most mods are visual / sound, informational or quality of life and do not add parts or change anything major so we believe that this should be valid for a DLC Jool 5.

Spoiler

DLC

• Breaking Ground (BreakingGround-DLC 1.7.1)
• Making History (MakingHistory-DLC 1.12.1)

Visuals and Sounds

• Astronomer's Visual Pack (AstronomersVisualPack 3:v4.13)
• Astronomer's Visual Pack-2k Textures (AVP-2kTextures v1.13)
• Chatterer (Chatterer 0.9.99)
• Chatterer Extended (ChattererExtended 0.6.2)
• Docking Port Sound FX (DockingPortSoundFX v2.1.12)
• Environmental Visual Enhancements Redux (EnvironmentalVisualEnhancements 3:1.11.7.1)
• Minimum Ambient Lighting Updated (MinAmbLightUpd 1.2.6.2)
• Parallax (Parallax 2.0.6)
• Parallax - Stock Planet Textures (Parallax-StockTextures 2.0.0)
• Parallax - Stock Scatter Textures (Parallax-StockScatterTextures 2.0.1)
• Scatterer (Scatterer 3:v0.0838)
• Scatterer Default Config (Scatterer-config 3:v0.0838)
• Scatterer Sunflare (Scatterer-sunflare 3:v0.0838)
• Stock Waterfall Effects (StockWaterfallEffects 0.7.0)
• Waterfall Core (Waterfall 0.9.0)

Informational / QOL

• [x] Science! Continued (xScienceContinued 6.0.2)
• Draggable Navball (DraggableNavball v1.0.1.5)
• Easy Vessel Switch (EVS) (EasyVesselSwitch 2.3)
• Kerbal Engineer Redux (KerbalEngineerRedux 1.1.9.0)
• Maneuver Node Evolved (ManeuverNodeEvolved 5.0)
• NavHud (NavHudRenewed 1.4.0.5)
• Precise Editor Continued (PreciseEditor 1:1.5.0.1)
• RCS Build Aid Continued (RCSBuildAidCont 1:0.10.0)
• S.A.V.E Resaved (SAVE 1.11.0.4)
• Sensible Screenshot (SensibleScreenshot 1.2.5.4)
• SOC: Simple Orbit Calculator (SimpleOrbitCalculator 1.6.0.1)
• The Janitor's Closet (JanitorsCloset 0.3.8)
• Trajectories (Trajectories v2.4.5.2)
• Transfer Window Planner (TransferWindowPlanner v1.8.0.0)
• VABReorienter (VABReorienter 1.2)

Dependencies

• B9 Part Switch (B9PartSwitch v2.20.0)
• ClickThrough Blocker (ClickThroughBlocker 1:2.1.10.21)
• Harmony 2 (Harmony2 2.2.1.0)
• Kopernicus Planetary System Modifier (Kopernicus 2:release-1.12.1-189)
• MagiCore (MagiCore 1.3.2.5)
• ModularFlightIntegrator (ModularFlightIntegrator 1.2.10.0)
• Module Manager (ModuleManager 4.2.3)
• SpaceTux Library (SpaceTuxLibrary 0.0.8.5)
• Toolbar Controller (ToolbarController 1:0.1.9.11)
   

The save game is a Normal level Career mode with the only change being that “require signal for control” has been added.

Additionally, the game has been edited to hire the desired crew, grant us all the parts and give us 10 million funds so that once we get back from Jool we should be able to calculate the total cost of the mission and total up the science points returned for a “Jeb” level attempt. We will have a Mobile Processing Lab aboard so we will be transmitting processed data back so we will acquire science points that won’t count for the returned total.
 

[Robin Patenall]

Hello everypony everybody,

Today we started to construct the Emerald Star in low orbit. This is going to take nine launches to build up the structure and then a number of launches to bring up the fuel for the ship.

Launch 1

This first launch contained a return capsule, the Emerald Stars main habitation module, and the engineering module. The initial crew, which is Me, Twilight and Rarity, went up in the return capsule on the top of the stack where the launch abort system could pull us free in the event of a problem.

Once we reached the height of 100km, but before we circularized in orbit, we deployed the fairing and fired off the launch abort system to clear the return capsule’s docking port.

Once we reached a stable equatorial orbit, we need to rearrange the modules slightly. First, Rarity undocked the return capsule from the end of the habitation module and redocked at the middle, allowing us access to the main living spaces.

Next, I undocked the engineering module to move it to a more convenient docking node while Rarity redocked the launch stage to the habitation module. There was still some fuel aboard so we decided to keep it up here until we had empty tanks to transfer it into.

Launches	1
Launch Cost	496,851.70
Recovery Value	0.00
Contract Funds	176,000.00
Total Cost	496,851.70

 

 

 

 

[Robin Patenall]

Launch 2

The second launch consisted of the main drive truss, which will join the three drive modules to the rest of the Emerald Star, and the long range fuel tanks for the Laythe space plane. This launch was uncrewed as it was going to be very difficult due to the drive truss, not because it was heavy but because it was very light.

The vessel was placed into a 75 km orbit where it slowly, over a number of orbits, caught up to the first launch.

Once the vessel rendezvoused with us, I undocked the engineering module from the habitation module and piloted it over to, and docked with, the main drive truss. It was then undocked from the launch vessel and I carefully piloted it back to the habitation module.

If you look carefully you can see I had to get Rarity to flip the habitation module over before I docked as I was approaching the wrong side.

Once the drive truss was docked, the launch stage with the space plane long range fuel tanks were docked and we pumped as much fuel and monopropellant out of the launch stage. Every unit of fuel we can save from these stages is a unit of fuel we don’t have to bring up later.

Once almost empty, the launch stage was jettisoned and dropped out of orbit for recovery.

Launches	2
Launch Cost	186,877.30
Recovery Value	61,198.00
Contract Funds	0.00
Total Cost	622,531.00

 

 

 

 

[Robin Patenall]

Launch 3

The third launch consisted of the lander, with the Vall booster and the Tylo descent stages, and the second return capsule with Bon Bon and Fluttershy. The lander wasn’t fully fuelled as the mass of the everything would exceed the maximum payload mass of the launch stage, so additional fuel will be needed to top it off, but we needed to fuel the drive stages anyway so this won’t be an issue.

The lander consists of three stages. The first (to the left of the return capsule’s orange fuel tank) is the open frame main lander, this can carry two crew to the surface of Pol and Bop, launch back into orbit and make a rendezvous with another vessel. It also carries as many scientific instruments as we could fit on it. The second module, a fuel tank with the light landing legs, is the Tylo ascent and Vall descent / ascent stage. It will carry the lander down to Vall and back and back from the surface of Tylo once the Tylo descent stage, with the large white side tanks, has landed it.

Once they matched orbits with the Emerald Star and rendezvoused the lander and return capsule were undocked remotely by Rarity and docked to the forward node of the habitation module.

The launch booster was remote docked to us, just to unload the small amount of fuel and monopropellant left over, and then deorbited back to the planet. This did not go as well as the last time we de-orbited a launch stage.

Rarity EVA transferred to the return capsule to pilot it, Bon Bon, and Fluttershy to the habitation module while I spent some time on EVA removing parts of the lander that were attached for aerodynamic purposes. These are very light, but every kilogram we lose from the lander (and the Emerald Star) is a little bit more margin. They will deorbit very easily, in fact, as they are so unimportant, they’ll probably disappear as soon as they leave the frame (I tell you that this looks very strange from this side)

The last thing that happened was that the long range space plane tanks were moved from their temporary location to the top of the lander, which is where it will be during our journey connecting to the Laythe space plane. With that, the basics of the Emerald Star was complete.

Launches	3
Launch Cost	227,231.00
Recovery Value	0.00
Contract Funds	0.00
Total Cost	849,762.00

Edited September 14, 2023 by Robin Patenall
Missed to table from the end

[Robin Patenall]

Launch 4 (The Awesome)

The fourth launch differs from the rest because instead of a rocket, it’s a plane. Specifically, it’s an SSTO (Single Stage To Orbit) craft that can use air breathing engines and wings for efficiency in oxygen rich atmospheres (that is, Kerbin and Laythe). Technically, it’s called the Laythe space plane, but Rainbow Dash refuses to call it anything other than “The Awesome” and as she is its primary pilot, it isn’t worth fighting her over.

Out at Jool it will fly down to Laythe’s surface, take readings with the science package and boost back up into orbit, but here it’s being used to bring itself and its pilot Rainbow Dash up to the Emerald Star.

The plane uses two Rapier engines that can either use atmospheric oxygen or stored LOX and will accelerate very fast. This will be needed when launching from the surface of Laythe as we won’t have a nice smooth runway to get up to speed.

Once the plane reached Mach 1.5, Rainbow started climbing and accelerating at steady rate reaching about Mach 4.5 as the atmosphere thinned out so much that the engines had to switch over to internal oxidizer. This provided quite a light show.

After circularisation, and a few orbits, the plane reached the Emerald Star, where Rainbow managed to dock it, with an unexpectedly deft touch, to the prograde docking node and the plane’s long range tanks.

Once we’d got Rainbow out of the cockpit, I went EVA to carefully secure it to the main ship to prevent it wobbling when we fire up the main engines. Rainbow kept shouting “That’s not a load bearing structure” over the radio  as I was fitting the struts until someone cut her off vox. I mean, who’s the engineer here?

Launches	4
Launch Cost	122,624.40
Total Cost	972,386.40

 

[Robin Patenall]

Launch 5 - 7 (Drive cores)

Well, that was interesting…

The fifth launch was the first of the Emerald Star’s drive core. These are just large fuel tanks (up to 22,277 units of fuel and 2,783 units of oxidizer) with four NERV nuclear thermal rocket engines and will push the main section of the Emerald Star about. Their main problem is that they are very long so we strapped boosters on the side to get them above the atmosphere and were relying on a small amount of fuel and the NERV engines to circularize.

Once we launched, had terrible trouble with controlling its flight, mostly as it was mostly empty and therefore very light for its drag. We eventually got it into an orbit, but not the 75km by 75km one we were aiming for but a 75km by 106km, which we corrected to a 75km by 100km phasing orbit to get to the Emerald Star. 

After a couple of orbits we were able to rendezvous with the Emerald Star and perform a careful docking procedure with the center node of the main drive truss.

To improve the drive core launcher, we added a second pair of boosters with a bit more fuel for them, a better probe core and more fuel in the main tanks which will give the drive core more momentum and keep it more stable during flight.

We still had to launch into a 75km by 100km phasing orbit and the docking had to be every careful as we didn’t want to scrape any paint off the first drive core.

The third and last drive core was also launched and docked.

Once everything was docked, I went EVA and added some structs to stiffen up the connections between the drive cores and the main drive truss.

I also pumped the fuel around to begin configuring all the modules for flight,, and as such the Laythe space plane, its long  range tanks, the lander and the return capsules are all now filled to their required level and we have about one third of one of the drive cores filled.

Next, a lot of refuelling needs to be done
 

Launches	7
Launch Cost	183,145.00 + 2 * 245,526.00 674,197.00
Total Cost	1,646,583.40

 

[Robin Patenall]

Launch 8 - 15 (Fuelling)

The next eight launches (8 to 15) were used to bring up fuel to fill the Emerald Star’s tanks. We took our standard launch stage and fitted it with a large tank which we could fill with 7250 units of liquid fuel and 1375 units of oxidizer if needed.

These were launched into a 75km orbit and then rendezvoused and docked to the Emerald Star, where the fuel and any other small items (such as more struts) would be offloaded.

The launch stage was left with enough fuel to de-orbit and attempt, after the main tank was decoupled, to aerobrake and land back near the KSC for recovery.

This didn’t always work out as the margin was rather tight but we made it most of the time.

We currently have the last refuelling stage still docked as there are about 1000 units of fuel and 1300 units of oxidizer still aboard and we still have some preparations to do before we are ready to begin our trip and we’d look really silly if we had to send more fuel to top up with after send some back.

Launches	15
Launch Cost	930,368.50
Recovery Value	404,842.00
Total Cost	2,172,109.9

 

[Robin Patenall]

Launch 16 - 17 (Satellites)

The last two launches to complete the Emerald Star’s fit out brought up four satellites that will be deployed in the Jool system. The first three of them are powerful communication relays that will allow us to ensure that we have connection back even when the direct line of sight is being obstructed by something, for instance Jool. The last satellite contains a set of scientific instruments that can be used by the Emerald Star during its journey but is also designed to see if we can get science from the very top of Jool’s atmosphere by being placed in an orbit that just grazes it.

The first two relays were sent up on a cut down first stage, they aren’t particularly heavy but they are bulky. The launch stage was successfully recovered.

The third relay satellite and the science satellite were sent up on a second launch.The launch stage was also successfully recovered.

A full systems check of the whole ship was carried out and it was prepared for departure. This included:

• All the monoprop RCS systems where shut down and their configurations confirmed
• All engines, except those on the main drive cores, where confirmed to be deactivated
• All fuel tanks (LFO and monoprop), except those for the main drives, where physically disabled to prevent any fuel draw from tanks that we need to keep for later in the mission

All ready to go

Launches	17
Launch Cost	188,411.40 + 216,312.40 404,723.80
Recovery Value	63,362.00 + 64,737.00 + 68,251.00 196,353.00
Total Cost	2,380,480.70

 

 

Edited September 17, 2023 by Robin Patenall
Missed to table from the end (again)

[Robin Patenall]

Leaving Kerbin
We’re off!

We spent some time fitting out and testing the systems aboard the Emerald Star and then went into hibernation for about a year to test  that while we were within easy reach of help.

We’re not going directly to Jool, to save fuel we are actually going the other way down ot Eve where we can perform a gravity assist to pick up speed then pass Kerbin twice to push us out to Jool 

The initial plan we needed was to reach Eve and perform a close flyby and bring our Apoapsis to be near the orbit of Duna.

Because of the ejection to Eve is quite large and the Emerald Star had a low thrust to weight ratio (due to the huge amount of fuel onboard) we couldn’t perform the burn in one go so we made eight burns of 100m/s at closest Kerbin approach to bring our apoapsis up to a point just below the Mun’s sphere of influence.

Eventually we reached the final ejection point and performed the remaining 260m/s of burn

Once we left Kerbin, we performed a small trim burn that will adjust our Eve flyby to bring us back to Kerbin in a year and 176 days. Now we go into hibernation until we reach  Eve. 

[Robin Patenall]

Eve Flyby

Today, we flew past Eve. Using a telescope on Kerbin, it’s a small fuzzy purple blob, up close it’s a large purple fuzzy blob with a lot of gravity. We had to force Twilight into her bunk to stop her performing science experiments using our limited science resources, this is a Jool mission and collecting science from Eve is “not in the rules”. We eventually relented when she promised that she would limit herself to digital photos and observations. We could just about make out the land masses beneath the clouds which, with some calculation, are at about five times Kerbin's atmospheric pressure. The sure is going to be fun designed a lander for.

Once we had past Eve’s gravitational influence, we trimmed our orbit again so that our flyby of Kerbin would put us in a resonant orbit so that we’d return to Kerbin again two years later

Back to hibernation until we reach Kerbin again.
 

[Robin Patenall]

Kerbin Flybys
By now we’ve gone by Kerbin twice, once to get our apoapsis to just over 30Mm (just over half way between Duna and Dres) and the second to get out to Jool.

We had trouble with the second flyby as we entered Kerbin’s SOI as our periapsis was way too high and we needed to make an emergency correction burn, it certainly wasn’t that high when we went past Kerbin the first time. We think we’ve tracked it down to the unicorns using telekinesis, apparently this causes phantom forces on the ship if the unicorn is strapped in. The amount of force is tiny but it’s enough to adjust sensitive orbits by a measurable amount.

Because of the poorly executed second flyby we are going to have to make a deep space correction, but that will allow us to target a gravity assist about Tylo to slow capture into the Jool system

[Robin Patenall]

Arrival at Jool
We’ve eventually arrived at the outskirts of Jool. We still have a huge distance to go (about 2.5 billion meters in fact) to get there, but our travel time is measured in tens of days rather than years. You might not be able to see it but there is a tiny green smudge just off the front of the Emerald Star in the image, that’s Jool.

Twilight has eventually been allowed to run science experiments (“At last!”) and she went on an EVA to collect them from the instruments aboard the science satellite and perform some other experiments herself that she could do while out there. We actually run each experiment three times, twice to be returned to Kerbin and once so that Twilight and the other scientists can analyse the data in the mobile processing lab (having nothing to do with what we’re afraid would happen if Twilight got bored) 

We also made a tiny correction burn to improve our fly past of Tylo, shortening the resultant orbit and putting us on course for a Val encounter, which will allow us to further adjust our orbit.

[Robin Patenall]

Arrival at Tylo
About fifty three days after we reached Jool’s SOI we did a Tylo fly by to slow ourselves and capture at Jool. We didn’t do any science experiments as we passed as we would be back soon and could take our time then.

A couple of small correction manoeuvres were planned that  would bring us back to Tylo after a fly by of Vall and a third manoeuvre to get a very loose capture at Tylo. The total delta V for whole capture is less than 300m/s.

A quick fly by of Vall…

… and capture around Tylo

We are now in a very loose orbit of Tylo with a periapsis of 90km and apoapsis of 10Mm. 

 

[Robin Patenall]

Tylo Landing

As our orbit around was taking us up to apoapsis we decided to prepare the ship for the landing on Tylo. As it would take almost 800m/s of deltaV to change from our highly elliptical orbit to the 50km circular orbit that the Tylo lander was designed for, the plan was to use the virtually empty drive core that we expended getting here to take the lander down and refuel the ascent stage on the way back up. This would leave the drive core in Low Tylo orbit.

Getting this all together required us to rearrange the Emerald Star to get the lander out and to disconnect the central drive core. You can see the Laythe plane on the dorsal habitation docking node and the lander and drive core on the ventral.

Once we reached apoapsis, the lander undocked and adjusted it’s periapsis to 50km.

Over the next few orbits, the drive core reduced the lander’s orbit to a 50kkm circular orbit, where it parked so that the lander’s ascent stage could dock with it to refuel for the rendezvous with the Emerald Star.

Rainbow Dash and Bon Bon spent some orbits waiting for the target landing zone to be in the daylight by taking some measurements  from low orbit. This could be done from the Emerald Start but it would take longer as the measurements could only be taken when near Tylo. One problem that they did discover was that they did not have a negative gravioli detector, but two barometers. Practical upshot, we’ll have to make these measurements from the main ship and we’ll lose the measurement from the surface, but I’ll swap it out from my spares once they arrive back.

Once the landing site was in daylight, Rainbow Dash piloted thee lander down.

Rainbow didn’t get the landing perfect, a few hundred meters further on was flatter but we forgive her as there was a significant amount of fuel left in the descent stage. They spent some time doing the flag planting thing, the tourist thing and the science thing.

As Rainbow had managed to save a significant amount of fuel in the descent stage, she used it to give the ascent stage an initial boost as there was no point leaving there on the surface. She then brought the ascent stage into a 50km by 20km orbit, matched inclination with the drive core and slowly caught up with it and docked. (ignore the deltaV readouts, something gone wrong, the ascent stage has over 3000m/s fully fuelled)

After refuelling the ascent stage, the drive core had just enough deltaV to palace it (and the ascent stage) into a 500km by 50km orbit. The would give the ascent stage a boost and would mean that the drive core would cycle between low and high space. It’s start tracking cameras are great as scientific but with the comms array and the RCS fuel remaining, I’m sure that the KSC will manage to put it to use.

The lander was placed on a phased rendezvous orbit with the Emerald Star and Rainbow docked it back. All the science was offloaded  and it was refuelled ready for its next use as the Vall lander.

[Robin Patenall]

Where are my spares!
I went to replace the second barometer with a negative gravioli detector from my spares and they’re not here! All I found was a Post-it note reminding somebody to schedule the launch of the space instruments.

We should have had five aboard (lander, Lythe plane, science satellite and two spares) and we have two. I took the one off the science satellite and swapped it for the extra barometer, we should be fine so long as we are careful in planning… but Arggg!

[Robin Patenall]

Finishing up Tylo
After the Tylo landing, we had two things to finish up before we left Tylo. First, Fluttershy spent some time in the lander using the refitted negative gravioli detector to finish up the experiments that Bon Bon couldn’t.

We also launched the relay satellites, these will give us better coverage as we explore the rest of Jool’s moons. They will eventually end up in a 85Mm orbit about Jool, the first is almost there, there’s just a bit of fine tuning with the RCS thrusters to do. The others are one their way and will enter an 85Mm by 80Mm phasing orbit to position them at approximately 120 degree intervals.

Once all the satellites were launched I rebalanced the Emerald Star by adjusting the fuel loads on the tanks to reduce the torque generated by the engines.

As it turns out, the next periapsis was a perfect time to eject from Tylo to be moving retrograde with respect to its orbit and bring us down to Vall. There were some issues with us catching Tylo up and potentially reentering its SOI but we eventually managed to thread the needle and arrive at Vall.

We are currently in an elliptical equatorial orbit, like we were at Tylo, of 2Mm by 73km and we’ll be able to plan out our work here with this as a starting point, but that may have  to wait as Twilight is bouncing of the walls of the lab shouting stuff in the language of EggHead.

[Robin Patenall]

Vall orbital survey
Looks like we have a small change of plan.

Once I got Twilight calmed down, it turned out that, during our close approach to Vall, something on the surface triggered her thaumometer. She wasn’t very clear what she actually measured (thaums, apparently, I’m an engineer not a unicorn) but when translated from EggHead it looks like there is something on Vall that is emitting or reacting to magic in a way that is not natural. The only things we know are that this is one of the greatest magical discoveries in a millennium, and whatever it is is not on the equator.

That last point was a bit of a problem as the plan for Vall was to bring the Emerald Star into an equatorial circular orbit (200 to 300km), find a good spot for landing then detach the lander from the mothership to land, do all the surface science then ascend back into orbit and redock with us. This would have limited our landing spot to within a few degrees of the equator.

However, we did have some excess fuel. Not that any space mission has fuel to waste, but our transfer from Tylo to Vall took less fuel than we had budgeted so we had some leeway to use a bit more if we have a reason to do so. The new plan was that we’ll do more or less what we did at Tylo. We’ll detach a drive core and join it to the lander and my engineering module (so that Bon Bon and Rarity have some living space). You can see this on the left side of this image.

This wasn’t an untested configuration, as it is the same setup that we’d be sending to Pol and Bop next, so this was just setting it up early and having Rarity test it before doing a long range mission was a good idea.

This then executed a 90 degree plane change at apoapsis and circularized its orbit of Vall to a 95km polar orbit. Bon Bon (Vall mission specialist) and Rarity (Pilot) will now make a full survey of Vall from orbit looking for Twilight’s magical anomaly. If they find it they can then use that they are in a polar orbit to target it as the landing spot.

This mission will only take about 500m/s of deltaV more out of the drive core than the original plan. As we aren’t moving the whole ship, this may consume about the same amount of fuel. The only issue I had with this change in plan was I had to endure Twilight’s repeated attempts to go down to the surface of Vall. Unfortunately, the lander only seats two and Twilight can’t replace either of the planned crew. Bon Bon is the mission specialist for Vall and we need her expertise in exo-glaciology on the surface and Twilight isn’t qualified to pilot (anything… ever…) so she can’t replace Rarity.

[Robin Patenall]

Vall landing
Well, they found it. 

It took several days of orbital surveying, and an altitude change, but Bon Bon and Rarity found Twilight’s anomaly. It’s about 60 degrees South of Vall’s equator, so we’d never have seen it if we weren't specifically looking for it. They completed the orbital survey and waited until the anomaly's location passed under the lander’s orbit on the daylight side of Vall. They then left my engineering module, boarded the lander and undocked.

Rarity managed a pinpoint landing, with the anomaly only being a short walk away (in fact any closer and she might have landed on it).

I wanted the team to do the planned science experiments first and load them into the experiment containers before going to poke the ancient alien artefact, but I was overruled. Apparently, pointing out if they did the experiments first and the artefact ate them, I’d be able to remote pilot the lander back and we wouldn’t have wasted a landing just got me the stink eye.

Between getting photos of every square inch of the site and Twilight wanting Bon Bon and Rarity to run every experiment she could think of that they could with the limited resources of the lander we did manage to get the planned science done. In fact both of the team made their own discoveries. Bon Boon noticed a cryo-volcano not too far away and managed to carve out a few hours to study it and Rarity’s gem finding spell is apparently one of more generic set of ‘find a valuable thing’ spell and she managed to find a scientifically important ice chunk. (Exactly why this chunk of ice is more important than all the others is beyond me but Bon Bon was ecstatic with Rarity’s find)

By the time that Twilight had exhausted every bit of scientific data that the team could wring out of the artefact, the sun had set and the lander was in a poor position to rendezvous with the drive core, so Bon Boon and Rarity got some rest until Vall put them under the orbit again.

They re-docked the lander to the dive core and returned to the Emerald Star by raising their apiosis, undoing the plane change and entering into a phasing orbit.

[Robin Patenall]

Preparations for Pol and Bop
Once the lander was back, we cleared out the science and refuelled it for Rarity’s and Fluttershy’s mission to the outer moons Pol and Bop. We are carrying extra oxidizer onboard so they can refuel the lander while they are out there to give them the mission flexibility to attempt multiple landings if they find anything interesting during the orbital surveys that they will do. Hopefully they’ll bring some back as the oxidizer level is beginning to become something of a concern, nothing critical but it could reduce our ability to be flexible in our options.

I did move the telescope from the science satellite as it will be able to get observational data from Pol and Bop, and Fluttershy had collected all the science that it could generate from around Vall while Twilight was distracted by what was happening on the surface.

After checking the positions of the moons, it turned out that there was a good transfer to Bop coming up in a couple of orbits, so after some final checks, Rarity and Fluttershy undocked from the Emerald Star and performed an ejection manoeuvre.

[Robin Patenall]

Science Satellite
With Rarity and Fluttershy off to the outer moons, we have some down time. We’re not sure yet if we will wait here at Vall for them to return or whether we’ll move onto Laythe and rendezvous with them there, the decision will probably have to wait until they are ready to leave Pol so we can compare fuel usage.

Bon Bon managed to avoid Twilight for a day before the Purple Pony of Perspicacity grabbed her and proceeded to interrogate her about everything she’d seen and done on the surface of Vall. Don’t worry, if I don’t see them in a day or two, I’ll go rescue her.

With Rainbow keeping a low profile in the Laythe plane, I’ve had some time to look at the science satellite. The plan was to send it through the upper layers of Jool’s atmosphere to collect data and even without its gravioli detector this can still work, we even might be able to get the experiments run in low Jool space if the lander meets us in Laythe orbit. The only issue we might have is control as the relay satellites have not moved into their correct positions yet, we still have dead spots.

Let me check the numbers…

It looks like we have a lucky alignment. In two days there is a course that will eject from our Vall orbit, fly by Laythe to lose energy, scrape Jool’s atmosphere and intersect again with Laythe, where the satellite could wait in orbit for us. Even the relay satellites are pretty much in the best position for control during the dive and the return to Laythe.

I might want to do an EVA and turn the engines over before we launch it though. It’s designed to fly through the atmosphere with the fuel tank forward, acting as a sort of heat shield, and with the engines as they are we can’t boost the satellite’s speed without bringing the instruments into the airstream. Turning the engines around will allow us to command a burn to offset the drag losses without changing the satellite’s attitude. 
 

[Robin Patenall]

Science Satellite Flyby

Once I managed to turn the satellite’s engines around and out a bit of fuel in it (it’s very light so it didn’t need much) we waited until the ejection time, undocked it and executed a burn to have it fly by Laythe

After using Laythe to slow down, we collected science from space low about Jool and dipped, ever so slightly, into Jool’s upper atmosphere to collect samples and other readings. By the way, if anybody asks, we absolutely did not hear somebody saying "My god, it's full of stars" while doing this.

Once out of the atmosphere, we were able to plot a manoeuvre at apoapsis  to raise the  periapsis and put the satellite on course for an orbit of Laythe, So we have a special science present to open once we get there.

[Robin Patenall]

Launching the Spaceplane to Laythe
One of the problems we had while planning this mission was attempting to put vessels into polar orbits of the inner three moons to get as much scientific information that we could. But we found that, due to the small distance between them, it was easier to do an inclination change at the edge of thee moons SOI so the Laythe space plane was fitted with external fuel tanks that would give it the deltaV to make this plane change and circularise around Laythe.
However, having had some practical experience with gravity assists in the Jool system, I was able to plot a set of manoeuvres that would take the spaceplane out past the orbit of Tylo, then flyby Tylo to slow down and adjust its inclination to arrive at Laythe in a polar orbit and do thing using much less fuel than the brute force solution.

Before Rainbow Dash and Twilight left in the spaceplane, I removed some of the struts (those that would be exposed during an aerobrake manoeuvre) and some of the RCS as the plane would not be performing RCS translation in one piece any more.
As we’d be using less deltaV, I attempted to remove as much fuel as I could from the plane’s tanks as I could, pumping into the Emerald Star’s tanks, but there just wasn’t enough space for it all. If I’d thought about it before Rarity left with the Bop / Pol lander, I could have put some there but it looks like we might need to dump (or at least waste) the extra fuel.

Once we reached the departure point, Rainbow Dash and Twilight boarded the spaceplane and made the first burn of that twelve day journey. Once they arrive I’ll take what’s left of the Emerald Star on a much less costly route to Laythe equatorial orbit

[Robin Patenall]

Arrival and landing at Bop
While Rainbow and Twilight were starting on their way to Laythe, Rarity and Fluttershy had reached Bop, going into a circular polar orbit to allow them to do a full survey of the moon. This didn’t take too long as Bop is a small moon and once finished, Fluttershy had identified five different types of area that she wanted to look at.

Rarity, as the pilot, had a reasonable idea about the total resource limit of the mission and with a few hours of mission simulation she’d been able to tell Fluttershy, Bop’s mission specialist) that they should be able to land in all five area types, but there was a hard cut off on fuel and if they reached it the mission the the surface was over.

The first landing zone was on a tall peak near the north pole, which was in sunlight and they would then work their way south toward a large valley near the equator, so when they reached position, they undocked from the drive core and when for a landing

The mission hiccup (because every mission seems to need one) came not long after Rarity lifted off from their first landing. Reviewing the logs, Fluttershy said “Oh, that poor thing”, switched her pilot controls to main and executed a barely controlled burn at almost right angles to prograde. Once Rarity had cut Fluttershy out of the command loop and regained control she decided to set down and, in looking for the nearest sensible place to land, she saw what Fluttershy had seen.

Just to be clear:

• It’s dead
• They’ve taken lots of photos and samples.
• I spent way too long playing Kerbnet ping-pong between Twilight and the Bop team.
• I walked Rarity through setting up quarantined storage for the samples on the lander. We already have one Emerald Star (because Laythe) and nobody is touching the samples until we get back home. The Emerald Star is just not equipped for that level of research.
• It took far too long for Rarity to convince Fluttershy that they weren’t in a position to bury it.

Once they finished examining the remains, Rarity was able to pilot the lander to four other spots on Bop and allowed Fluttershy to collect samples and readings. According to Rarity it wasn’t that interesting (“It’s a brown rock. It’s rocky and brown”) but Fluttershy was diligent.

Once all the samples and reading had been taken, Rarity put the lander in orbit, matched planes with the drive core and redocked. A course for Pol orbit, starting in a few days has been plotted.

[Robin Patenall]

Laythe Aerocapture
Yes, “aerocapture” no “aerobrake”.

My original mission plan had Rainbow doing an engine burn at a Laythe periapsis of 90km and then, if Rainbow was confident, use aerobraking to lower the apoapsis. The idea was to progressively increase the depth that the SSTO went into the atmosphere so we could gauge how safe it was.

Rainbow’s mission plan was to throw all that out of the airlock, say hold my cider, and perform an aerocapture to save fuel.

To her credit, Rainbow realised that she’d bucked up and contacted me on Kerbnet almost the instant they were out of the atmosphere. She was very contrite, and having downloaded the logs and reviewed them, I  see why. The large docking port on the long range fuel tanks had come a hair’s breadth away from a critical overheat, losing that probably wouldn’t have caused an instability but having bits of your ship explode is never good.

I got Twilight out on EVA to inspect the science bay (she was raring to go do that anyway, I don’t think she understood what almost happened) and spent ten minutes informing Rainbow, in excruciating detail, how she and Twilight almost had a Bad Day.

Rainbow promised that the aerobraking manoeuvres to circularise the orbit would be much shallower and they were. It took almost three days to bring the orbit down to 121km by 90km giving Twilight plenty of opportunities to get readings from high space, low space and the upper atmosphere. In fact that went so well that we skipped circularising in a high space orbit as virtually all the readings had been made. (There are some tiny island biomes which hitting from orbit would be a million-to-one shot)

[Robin Patenall]

Moving the Star to Laythe
Absolutely nothing exciting. A very small burn to leave Vall SOI at the right time brought the Emerald Star’s periapsis down to Laythe’s orbit. A couple of loops brought us to Laythe and another small burn to capture in an elliptical orbit. All told less than 100m/s of dV (which would have been done with the fuel I couldn’t take off the SSTO)

I did get some nice pictures. Once before we left and one once we captured.