[KSP fun fact thread]

On 1/26/2024 at 3:16 PM, Zhetaan said:

Anyway, it doesn't amount to much, but it does serve to filter the unrepentant completionist players from the rest because they won't upgrade the VAB until they've unlocked. Every. Single. Science. Experiment. In the game and retrieved all of that delectable, collectible science from the South Complex before it goes away forever.

Yes, this means grinding away without custom action groups until unlocking that elusive Tier-8 tech tree node for the silly gravioli detector.  Good luck if you're using mods that add science experiments and science parts elsewhere in the tech tree.

you make it sound like a lot of effort, but it's a pittance compared to what i've done for every single serious challenge i ever undertook.

like, really, i once spent 2 months tossing over 100 small parts into orbit and assembling them one by one, because i wanted to run a jool5 without upgrading any building, and i needed 500 tons of motherships to account for all the errors of eyeballing maneuvers without maneuver nodes, and I could only make rockets of 18 tons on the level 1 launchpad. unocking every single experiment before upgrading the vab is child's play in comparison.

 

anyway, something even I only learned recently: did you know that if you land a ship on an ocean, and you send out a kerbal and take a sample, if the kerbal is swimming in water it counts as "splashed down", and if the kerbal is standing on top of the ship it counts as landed on solid ground, and they are two different samples. they do sometimes even have different science messages. so you can take two different samples when you land a kerbal in water.

this also works if your ship lands on top of another ship, then all the experiments it will take are landed, not splashed down. but you do need to land another ship first, and the whole setup is a bit complicated. not that it's stopping me from doing exactly that

[Killing relative velocity during rendezvous.]

I downloaded the lastest version, and I have to say, I experienced this bug too. I know orbital drifting, and I suddenly got a lot more acceleration than drifting could be accounted for.

it's something that only happens occasionally, though, so it was fixed on reload. it's just one of many little bugs that are annoying but not critical.

[The Elcano Challenge: Ground-Based Circumnavigation (5th)]

As I approached Ammenon, my latest target in the whirligig world grand tour, I was struck by its beauty and couldn't help circumnavigating it

EDIT: by the way, I looked at the written entries for modded planets, and they always mistake diameter for radius. the number given is radius, not diameter.

For the record, Ammenon is 95 km of radius.

Jifgif has a nominal radius of 6 km, but the lobes extend 10 km more on each side. Its actual size is roughly 35x18 (long and short axis)

Thresomin has a 2 km radius, so 4 km diameter is actually accurate there.

Wolda has a nominal radius of 9 km, but the lobes extend 15 km on each direction - and even the "neck" rarely goes below 5 km of altitude, so 50x30 (long and short axis) is a more accurate count

[Lucy in the sky with deadly radiation 5: strangest sky ever!]

Part 11B: The land of molten rock and frozen water

This spinoff chapter details the circumnavigation of Ammenon. I can drone on how much I liked the little planet without cluttering the main chapter worse than usual.

Spoiler

What attracted me to the little planet is the variety of terrains. On most planets, even good-looking ones, you can expect one type of terrain everywhere. Little variation. My favourite circumnavigation is the one of Slate, because Slate had an interesting geography. Well, I'm now putting Ammenon as number 2.

Landed on Ammenon

Let's get started

All the pics here are in natural light. This is the light of Kaywell, coming from very far, but still enough to see. Without Kaywell, it would be completely dark.

A later picture taken at night, for comparison

Land is quite irregular hills

I landed on the dark side, fairly close to the terminator line, because I wanted to immediately see both types of terrain. So far I'm finding highlands environment, many craters, many irregularities.

Solar panel production

Kaywell is very far, but the solar panels are still decently effective. That's a glitch; they were a lot less effective already around Reander, and here I'm much farther.

That's still not much electricity. On flat land, it's enough to accelerate and keep speed while the batteries slowly recharge. On those hills, I need to accelerate more often, and the batteries eventually get depleted, forcing occasional pauses.

An interesting double crater

One of many explosions

Cigar is a pretty crappy rover, unsuitable for this terrain. The docking port and engine are extending way past the wheels, making them susceptible to hit the ground on steep inclines. I needed plenty of reloads. I was actually very tempted to just give up on this and use instead my trusted Leaping Mantis rover - which I would send here with a crapton of xenon. Even spending hours doing huge burns to get there, Leaping Mantis would be able to go twice as fast on this terrain, and much more safely.

In the end, I choose to use Cigar because it just felt better to have this mission be part of the grand tour. The one saving grace I could hang to is that in whirligig world the altitude limit to time warp is very low; as soon as you are airborne, you can time warp. Sure, you crash if you hit the ground, but for a brief time, you are considered on orbit - and then you can save the game. Normally, you must be at least 500 meters of altitude to save. Instead, I can save the game every time I take a long jump. This let me save every few kilometers, without having to stop every time. And being able to save often brings the risk to a manageable level.

Gememma is starting to appear on the horizon. Kaywell is the bright spot in the sky

Those sci-fi settings where a planet has a tiny habitable strip near the terminator line must look something like this.

Science from dayside biomes

There are four biomes on Ammenon; ice caps, for the dark side. Highlands and maria, for most of the day side. And molten sea, the lake of liquid rock that sits directly underneath Gememma. So far I'm in highlands terrain, maria are smoother. Ice caps also has highlands and maria areas, in that it has smoother and harsher places, but it still only counts as one biome.

By the way, do look how, despite the message on the scorching sun, the recorded temperature is actually lower than it was earlier on the dark side. Well, temperature worked really nice for the lava biomes on Yalthe and Yokane. I won't complain if it glitches here, it's not as important. And I won't have to worry about Gememma melting Cigar as it passed under the zenith.

Gememma peeking gradually out of the horizon

Dayside highlands. Still fairly difficult terrain, but I have functionally infinite electricity

It must be noted that while the terrain is rugged, it's also very level. I don't remember ever coming close to 2000 meters of elevation; I rarely went above 1500. While for lower elevation it's around 900 meters, except around the molten sea where it reaches 0. And except some some glitches that I'll discuss soon.

Even now that I'm exposed to the sun for a while, temperature is still low

What is that bright spot I see on the map? Can it be a mountain so high that it can see the sun from there?

Wow, it actually is! Not a mountain, but a pillar

WIth a monolith on top (I went here with alt-f12 to check, obviously)

At first I thought I stumbled upon an easter egg. Wow, what are the chances? I would have never found this place except for that trick of light in the map, because the pillar was in the exact right spot for it. Who knows how many more easter eggs like this I missed.

Then I checked the coordinates, and realized it's in the same spot as a monolith on Mun. So it just means Mun was used as a model for this planet, and it has the same anomalies. Indeed, I went to check other locations of black monoliths on Mun, and they also have pillars on Ammenon

Like this one

I don't know if it's intentional or a glitch, but I doubt it's an easter egg.

I actually did found a real, genuine easter egg during my grand tour. However, the mod creator has asked me to not disclose it, so I won't say anything except that there is one to find, for all those who may be interested in this planetary pack.

Solar panels drama

Remember, while I'm getting tens of thousands of electricity per second, the panels must still be aligned with Kaywell to produce. When Kaywell goes behind the horizon - or even behind Gememma - the panels stop. When Kaywell is occluded by Limnel, the panels stop. Nothing a short pause can't fix anyway; Ammenon rotates every 7 hours.

Incidentally, I'm driving against the direction of rotation, and almost at the same speed as the planetary rotation (which is around 20 m/s at the equator). So I'm experiencing much longer days. Kaywell days, because Gememma is always sitting still in the sky.

More highlands

Here highlands give way to maria

As you can see, maria are much smoother. I can run a lot faster, and I don't remember every exploding while on that terrain. If the whole planet was like that it would be boring, but it's certainly refreshing to have a breather after much hill driving.

Current position of Cigar. Highlands terrain looks rugged even on the map, while maria can be recognized

Cigar will now turn slightly south, to turn around the molten sea. It will be maria terrain all the way.

On maria, enjoying the easy ride

There are occasional highlands inclusions in maria, but they do look partially submerged

Which is another thing I really liked. Geology is basically random in this game. There are craters, and that's it. Mountains may look good from afar, but from up close they rarely do look like real mountains. Well, those craters do look like craters that were then sumberged partially in lava, with the aforementioned lava filling all the lower ground and covering it with a smooth surface, from which the highest points still emerge. Which hints that in the planet's past there were massive eruptions that covered vast swathes of Ammenon.

First sight of the molten sea

You can recognize this canyon and gulf in the map a few pictures back. I did not went down here, as it would be more difficult to come back on track. Instead I waited until my course brought me closer to the liquid.

Here is where I'll dip in the lava

More evidence that Ammenon may have some sort of water-equivalent cycle with low-melting minerals. But the thermometer data still does not match

Swimming in lava! Wow!

Wheels don't work while floating, so I'm rotating Cigar to provide some limited propulsion and return on the shore

So, wheels do actually work - as paddles. I even considered crossing the sea like this, but I can get to maybe 0.5 m/s, so it's not a good idea.

Directly underneath Gememma, the light is scorching. Sometimes it's painful to see

I tried to compare different light settings. -100% light makes no difference whatsoever. While increasing light does have a visible effect

Going down another canyon

There are a few such canyons leading into the molten sea - more evidence of rocks flowing regularly and carving the land. This is the last one; after this, the shore turns north, and Cigar will keep going west - but turn slightly north to return on the equator. Terrain has been highlands around the molten sea, but will now gradually shift to maria. Slopes have not been a problem due to the low gravity (0.09 g).

Terrain transitioning to maria

More of those semisubmerged craters I like so much

Cigar seen running up the side of one such crater

Speed record. The wheels can't go this far, but there was a slight incline

As Cigar moves westward, I find shadows again. I sort of forgot they exhisted

Weirdly, it's hotter here in the shade than it was in the molten sea

Once more on the ice cap. I passed the halfway point two flags ago - I've been planting a flag every 20 km

Approaching a Mun arch - the one that would be sitting on the northern rim of the east crater. I turned north partially to cross it

Passing through the arch

Now truly on dark side

I was worried about the darkside part of circumnavigation, because I was having electricity problems. But it turned out fine. From the terminator line to almost the first flag, the dark side is uninterrupted flat maria. I was able to drive 20 km, stop, plant a flag, save, repeat. I kept sustained speeds around 25 m/s, and never once I crashed the rover. And since my movement compensated for the planetary movement, I didn't even need to stop for the nigth. It was the fastest part of the circumnavigation. Which, at this point, was a welcome turn of events; one always faces fatigue near the end of such a long trip.

The first flag becomes visible at 100 km of distance

But now the easy part is over, there are mountains again

More highlands terrain

And craters

And suddenly the solar panels are producing a lot less than they used to

I have no idea why. One moment they were working, then they lost efficiency. This is way too little electricity to do anything. Even shutting down SAS and communication, and putting the probe core on hybernation, the batteries are losing charge. Eventually the event passed, I'm not sure what I did to fix it. As much as it can be considered fixed, as we already established the panels are glitching.

Finally, reached the first flag

A side view of the route, showing the turn southward to cross the molten sea

If I could come back, though, I would go for a polar route. I missed the polar terrain.

And now it's time to leave this planet for good!

It was definitely a great place to circumnavigate. Number 2 on my favourite circumnavigation, despite having a crappy rover. Though I doubt it could have beaten Slate as number 1 anyway. But definitely better than any other place I circumnavigated, except Slate.

If you have a mind for it, pack a ship full of xenon and come to Ammenon for a ride!

[Lucy in the sky with deadly radiation 5: strangest sky ever!]

Part 11: The most inaccessible planet

Boundless has to stretch to achieve the 30 km/s necessary to reach Ammenon, the last planet left.

The fuel cost to reach Ammenon is staggering. 5 km/s to lower periapsis, followed by 10 km/s to circularize. And the same amount must be spent on the way back

11.1) Blue planet, red planet

Spoiler

I'm not 100% sure I can reach Ammenon without staging, but there is only one available strategy: first use Lowel and Gannovar gravity assists to reduce periapsis. Afterwards, I may be able to get some kick out of Ammenon itself, but I doubt it; it's smaller than Mun with a tiny sphere of influence. I will have to provide those 20 km/s with fuel. I took that into account when designing the ship: Boundless has 10 km/s, and Traveler has another 10, so if I burn 5 km/s inward, then detach Traveler, then rejoin Boundless on the way out, I should have - roughly - enough fuel. Cigar itself has almost 2 km/s, much more than needed for the actual landing; I expect I may have to finish capture with the lander alone, though that would introduce more complications.

But for now, my goal is to lower periapsis while spending 1 km/s.

Ideally, I would be able to bounce between Lowel and Gannovar, using each other's gravity assists to achieve speed. My issue right now is that a gravity assist does not change my speed relative to a planet; I must leave Lowel at 5 km/s to reach Ammenon, and I need help from another celestial body to achieve that speed. Either that, or I need to spend some fuel to skew my intercept and increase its cost, in a maneuver opposite what I did in 10.2. It was the first time I used that kind of strategy, and it was a lot more efficient than I expected, but will it be enough to achieve 5 km/s of periapsis lowering with jut 1 km/s of fuel?

Trajectory 1: from Ollym to Gannovar

To begin, I eject from Ollym with the least possible amount of fuel to reach Gannovar - it conveniently crosses Lowel's orbit, only requiring a mild plane change and some patience. My intercept on Gannovar will not be in Hohmann conditions - Boundless will cross the orbit. This will entail a higher intercept speed, and with gravity assists I can turn that high intercept speed into a lower solar periapsis.

You can see from the purple dotted line that the resulting orbit will be lower. However, apoapsis will be closer to Gannovar orbit, making the intercept more similar to a Hohmann transfer. That's unavoidable. My intercept speed with Gannovar must stay the same. Right now I have a similar orbit, with an unfavorable approach geometry to cause a high speed. As my orbit will become more different than Gannovar's, approach geometry will improve to keep the intercept speed equal. Eventually I will reach a Hohmann-like intercept, and I won't be able to lower periapsis any further.

Fuel costs this close to Gememma are high, and neither Gannovar nor Lowel are big enough to provide large assists. For this reason, I'm not trying to achieve resonant orbits. My control over my trajectory is too small, and I want to maximize the gain at every flyby. Instead, I am looking at future orbits to see when random chance will bring me close to Gannovar again; then a moderate course correction at periapsis will fix orbital time and provide an encounter.

Trajectory 2: multiple Gannovar flybys. The one in the picture will be the 4th

As shown in the picture above, coming out of the third flyby looking for the 4th. I set the yellow and purple maneuver nodes, both at 0 m/s. Then I click repeatedly "next orbit" on the purple node, going farther and farther in the future looking for close approaches. Eventually Boundless and Gannovar will pass close to each other - those orbits are pretty fast, after all - and then I make a prograde burn on the yellow node to turn the close approach into a flyby. The maneuver on the yellow node has to be prograde because it will raise apoapsis above Gannovar's orbit, increasing intercept speed and allowing to gain more from gravity assists.

Each orbit entails a little gain. Here I'm losing 30000 km of periapsis, but the closer I'll get to Gememma, the more expensive it will be to lower orbit, and individual flybys will be less effective - well, they will be just as effective in deltaV terms, but it will result in a lower periapsis change.

Two flybys compared

As can be seen from the images of the second and fourth gravity assists, this strategy allows to use the correction maneuver deltaV - which I'd have to spend anyway - to increase intercept speed. In this case, I gained 210 m/s of intercept speed while only burning less than 100 m/s worth of fuel.

Inclination may become a problem. In the past, I would often need expensive plane changes. Indeed, dealing with inclination is the only part of orbital mechanics that I feel I haven't fully mastered. A mission like this, where I'm forced to stretch, is a great learning opportunity, and I improved over the previous chapter. In 10.1 I occasionally had to make expensive plane corrections; here I learned to make small corrections away from Gannovar (and later Lowel). The idea is to pass slightly above or below the center of the planet during the flyby, thus adding a normal component to the gravity assist. If properly tuned, this lets me fix inclination - and it often costs less than 1 m/s. In those pictures I have a slight inclination because I hadn't mastered the technique yet.

Bit by bit, I used Gannovar to lower periapsis. Until, after 10 flybys, I couldn't do it anymore.

Trajectory 3: planning the 10th Gannovar gravity assist, targeting Lowel

As you can see, my orbit is now perfectly Hohmann compared to Ganovar. I can't lower periapsis any further. Sure, I can start pushing up apoapsis, but I will have to pay for that. The maneuver of pushing up apoapsis to increase intercept speed and convert it to lower periapsis is more efficient if I am in a more elliptical orbit, so I'll go as far as possible before resorting to it. And you can notice, while Boundless is perfectly touching the orbit of Gannovar, it's still higher than Lowel. So at this point I switch celestial body. Lowel is also somewhat bigger than Gannovar, allowing for stronger effects.

The fuel counter is not accurate; not only I have excluded the fuel tanks on all the shuttles from being used, but the total amount in the orange box is trying to also account for other engines. Running some calculations with the rocket equation, I spent 600 m/s so far. A bit more than I was hoping for, but half of it was just to leave Ollym. I can calculate the periapsis lowering as equivalent to 3500 m/s, with with 3250 m/s still to go; that is, if I plot a burn at apoapsis, it takes 3500 m/s prograde to circularize at Lowel's orbit, and 3250 m/s retrograde to lower periapsis to Ammenon. The sum is greater than 5000 m/s because I'm not getting any Oberth effect from Lowel, but it's useful to estimate how far I have to go - I'm roughly halfway, not bad. But so far, I managed mostly to take advantage of having a large speed relative to Gannovar. With Lowel I will need to build up intercept speed.

Last Gannovar flyby. I gained another km/s of intercept speed. I am passing significantly away from the equator to change plane for Lowel

11.2) Half a million km in nine years

Spoiler

Now that I'm back to using Lowel, flybys are more effective, as can be seen by the greatest amount of periapsis lowering compared to the last Gannovar flyby.

Trajectory 4: from Gannovar to the first Lowel flyby

First flyby of Lowel (I put a number on all the pictures for easier counting afterwards) at 4800 m/s

Trajectory 5: from first to second Lowel flyby

I am already in a Hohmann trajectory to Lowel, so I must start using the rockets more. 58 m/s prograde at periapsis move my orbit upwards so I'm no longer in a Hohmann intercept to Lowel, this increases my orbital speed relative to the red planet by a lot more than the fuel I'm spending.

This procedure is more efficient the lower my periapsis is. At least, I think. It worked that way when I was coming down to Lowel from Mandrake, and it does make some sense - a lower periapsis gives more Oberth effect from Gememma to raise orbit more. Though it can also be reasoned that if my periapsis is a lot lower than Lowel, then being slightly out of an ideal Hohmann intercept won't make much of an impact on intercept speed, making the procedure less effective. I'm not sure, but I think more likely it is indeed better to have a lower periapsis; which is why I'm not making a single big burn immediately to raise apoapsis a lot, but I make a small raising after every flyby. Besides, I'm still going to need course corrections to ensure the next encounter, may as well use those to also raise apoapsis.

The 1.8 m/s is the plane change to ensure I remain equatorial.

At 100k km Ammenon can be seen passing in front of Gememma with the naked eye as the slightly darker spot slightly on the left

The process was slow. Slower than using Gannovar, because I'm dealing with small changes every time. Maybe I could have been more aggressive with those periapsis burns and it would have resulted in less flybys required without significant extra cost; maybe not. This is new territory even for me.

Ollym is an additional factor around Lowel. As I already discovered, I can't really decide where Ollym will be on my next flyby, I have to account for it. Most times I did not touch it; sometimes I'd take a short detour in Ollym SoI. Sometimes I'd have to tread the needle to pass between Ollym and Lowel, and sometimes I'd just have to give Lowel a wider berth and get reduced benefit from that specific flyby. Or maybe I'd have to fiddle with my maneuvers to push the encounter one orbit sooner or later.

The closest example of treading the needle, with Boundless passing between the planets, 2 km outside of Ollym atmosphere, and 1 km outside of Lowel atmosphere

Boundless is speeding straight towards Lowel. The twin planets will move just enough that the mothership will graze Ollym to its left, Lowel to its right

I was hoping I could use Ollym to further change my speed relative to Lowel - just like you can use Tylo both to get captured around Jool, and to get ejected from it. But I can't seem to get any sizeable effect. Probably my speed is too fast, Ollym too small, to have a measurable impact.

With that, I'm doing all I can to save fuel. Depending on orbital times and resonances, it takes from 50 to 200 days to find a new encounter. Fully lowering periapsis was a lenghty process that took a few afternoons to complete.

Trajectory 6: the lower I go, the harder it is to move periapsis. Between 22nd and 23rd flybys, only 6000 km of lowering. The last flyby will provide barely 4000 km

Now Ammenon is close enough that it can be seen, with difficulty, even outside of a solar occultation

During one of many Lowel flybys, spotting a particularly distinctive mountain. If I was still on the surface, I'd try to visit there

Now Ammenon is twice as far as Mun is from Kerbin, it can be resolved with the naked eye (just to the left of Boundless)

It took 29 gravity assists. Including the ones from Gannovar. Counting the times I visited both Lowel and Ollym as a single instance. It became stale after a while. Still, eventually I got there.

The last gravity assist

It took over 8 years, countless orbits, to lower periapsis by 470000 km. Taking into account the different duration of a Kerbin year, this gives an average rate of periapsis lowering of 6 m/s. A normal running speed for a man. I have a super advanced spaceship zipping at tens of km/s, and in the end I moved as fast as a man could run.

Trajectory 7: before last flyby, planning also a final plane change

The above maneuver is before the final flyby. Current periapsis is 137.2k km, and it will be reduced to 134.9k km, a very tiny amount - but one that would still have required a hundred m/s or so. Then I have to make a 235 m/s plane change. Sucks. All those gravity assists had a significant radial component, and I took them all on the same side of the orbit. I mean, Boundless intersects Lowel's orbit in two close points near apoapsis, and I always took my flybys while on the descending side. This moved my apoapsis laterally. It was on the spot where Lowel meets Gannovar orbit when I began. That was a very convenient spot because it was also a planar node with Ammenon; I should have remained there, and I would have been able to make the final plane change for free. I just wasn't paying attention. Anyway, now I have to pay. I hope I'll still have enough fuel, else I'll have to reload from the point when I started taking Lowel flybys.

Running, once again, the calculation with the fuel consumed, I spent 1210 m/s so far, which will increase to 1450 m/s once the final plane change is factored in. I was hoping I'd do it with 1 km/s, but it's still a huge saving over the 5 km/s it would have cost me without gravity assists. I learned a few more things I didn't knew - which, at my level of experience, is a rare boon. If I were to do it again, I'd do it better. I'd be able to skip that plane change, maybe even swap from Lowel to Gannovar again at some point. I could maybe bring the cost to 1 km/s. But I'd rather not reply all the long, painstaking multiple gravity assist process, so I'll try to reach Ammenon with the fuel I have left. It looks like a close call, where a few hundred m/s may make a difference, but it's unlikely that final plane change will be what screws me up.

11.3) Making the fuel last

Spoiler

Before I try to provide 20 km/s with my current means, I want to check whether it is feasible to use Ammenon for gravity assists to repeat the process I just used. In theory it is, but Ammenon is much smaller than Lowel or Gannovar - 95 km of diameter, 0.09 g of surface gravity, and a sphere of influence extending only 70 km past the surface. I doubt it will be big enough to be worth using.

Attempt to calculate a gravity assist on Ammenon. The effect is negligible

As seen from the picture, it would lower apoapsis from 560.9k km to 560.8k km. No, definitely not something I can use.

I run some calculations. Boundless, excluding the fuel in Traveler - and factoring in that this fuel will be burned - has roughly 8 km/s. Traveler heavy stage has 10.5 km/s while carrying a full Cigar. Cigar itself has 1.8 km/s. Looks like an extremely close thing. I still have a few moving parts, though, that I'm trying to figure out how to use. The first one is Ice Cream Cone. After a bit of deliberation, I detach it.

Status after detaching Ice Cream Cone

Boundless required 1.5 km/s to reach this Ammenon transfer orbit. It will likewise take another 1.5 km/s from here to land on Ollym again - something less, because of aerobraking. Coincidentially, that's exactly the deltaV that can be provided by 125 tons of fuel. Which is the fuel that fits inside Ice Cream Cone. So, by detaching ICC, I am dumping over 200 tons of mass that I'd have to bring down and then bring back up. I will rendez-vous with ICC afterwards to recover its fuel. Boundless just gained 1 km/s of deltaV for not having to carry the heavy lander and the fuel needed for the return trip.

And I realize I can do the same for Traveler too: spend some of the fuel within the heavy stage, detach the heavy stage with some leftover fuel, finish circularization with the much lighter basic ship, then recover the heavy stage and its leftover fuel. But how much fuel should I burn before I detach the heavy stage? I was about to handwave it by trial and error, then I decided that I am absolutely capable of that kind of math, and I should not be lazy about it.

Creating a mathematical model to figure out how much fuel I must leave behind and how much deltaV I can get

I run the calculations, and the results are staggering. F't is 20 tons, and it will give for deltaV1... 4 km/s. Which goes both ways. I will have 4 km/s while lowering apoapsis, and 4 km/s while raising apoapsis, for a total of 8 km/s. Adding the 6 km/s from the regular Traveler, I have more than 14 km/s. I gained almost 4 km/s with this trick. Turning a very close call into an easy stroll.

It should not be surprising. The heavy stage has a dry mass of 15 tons, that I won't have to cart up and down for 6 km/s. Adding the 20 tons of fuel, that's 35 tons. Which is the mass of Traveler itself. Traveler is pretty small, most of its dry mass would have been the heavy tank and extra fuel he'd have to lug around.

Boundless starts lowering orbit

I split the burn because my orbit around Gememma is fast enough to entail some significant cosine losses. And because I'm not in any hurry.

Without Ice Cream Cone, there's nothing to compensate for the large asymmetrical mass of Traveler full of fuel; but it was easy to shift some fuel in the tanks to reset the center of mass where it belongs.

Splitting Traveler

A handful of comments on this picture. First, I had brought an ion engine and a couple xenon tanks in storage inside Boundless, just in case I would not be able to reach Ammenon otherwise. Better to lose some pride than to lose the mission entirely. And I'll definitely won't need that xenon, so I'm leaving it back. If this was a movie I'd be tossing it overboard for greater dramatic effect, but what the hell, xenon is expensive, I'd hate to just throw it away. Second, I still have 5 km/s left on Boundless - 5200 if we factor in the emergency fuel I left in Arrowhead. I spent some 3 km/s going down, but deltaV increased upon freeing all the mass of Traveler heavy stage. I initially used up more fuel, then I realized I could stretch Traveler more while still keeping reasonable safety, and I reloaded.

Science report from low Gememma space. Look at how much energy is produced by the solar panels!

The solar panels are still glitching. They should actually produce a lot less electricity than that, but they do produce as if their distance from Gememma was their distance from Kaywell. They still must be pointed at Kaywell, not at Gememma.

Separating the heavy stage. No pics of lowering orbit, but do look at apoapsis

The heavy stage. Calculations stated I had to leave behind 20 tons of fuel, I left 22, for safety. Since the tank has no probe core, the game things it's a piece of junk. Undignified, but not a problem

All the pieces split, and final maneuver for Ammenon. 3000 m/s to capture, 3000 to return to the heavy stage, leaving a few hundreds for safety

I spent a few seconds being concerned that one of the many pieces I left parked in orbit may collide with Ammenon, but seeing how tiny is the planet - and seeing as I won't be spending more than a few days down there - I feel safe. Worst case, I'll notice a piece is missing and will have to reload. I did check that Ice Cream Cone won't collide with Lowel for the next year, though.

Approaching Ammenon

Getting close. But still outside the tiny sphere of influence

Capture burn. The horizon shows mountains

I... have no idea what this is, but I do like it

And the molten sea, on Gememma's side

I already checked on Ammenon a few times, so I knew what to expect, but I was still amazed.

Ammenon is tidally locked. The day side is exposed to the full heat of Gememma, with a lake of lava in the point closer to the star. The night side is covered in ice. And it's more beautiful than I realized.

Landed, and science. For all that the surface is supposed to be ice on the dark side, the thermometer registers 311 K

I liked Ammenon so much, in fact, I decided to circumnavigate it. I did an entire tour of the surface, and it's a really nice little world. However, that will get its own spinoff chapter, like the other circumnavigations I did. Here, I'll just cut back to going back to orbit and rejoining Traveler.

Cigar rejoins Traveler over the molten sea

That was the last flag, the last planet. I landed on 43 different worlds (not including Mesbin, where I started), and I explored the surface of most of them. I run a few circumnavigations. I spent almost one year playing this mod - the first report is from july, but I started working on Boundless on march. Now it's time to return.

And the first step to return is to climb out of this gravity well.

11.4) Step by step, climbing up the gravity ladder

Spoiler

First, leave Ammenon to reach the heavy stage tank. Ammenon does provide a tiny, negligible Oberth effect, so I may as well make this maneuver in Gememma's orbit. But then, I saw leaving Ammenon does raise apoapsis a few hundred meters anyway, and I may as well use it. I brought some extra fuel, but not a lot.

Rejoining the heavy stage. 700 m/s to leave Ammenon, 650 for maneuver, and 1600 of intercept, for a total of roughly 3 km/s

I did burn what fuel was left in Cigar, to make Traveler lighter. I brought plenty of chemical fuel for Cigar planning use it to pay the final capture deltaV, but there was no need.

Back to heavy stage, with 500 m/s left

Now reunited, I have 4400 m/s

And up to rejoin Boundless. This takes over 3700 m/s

Boundless reunited. I have to move fuel around to restore the center of mass again. Anyway, I have 5 km/s available

And 2800 m/s to rejoin Ice Cream Cone completes the 10 km/s climb. I haven't burned so much deltaV since my Jool5 speedrun

It's been a while since I showed the rearward cupola. Now with the distinctive red hue of Gememma

Meeting back with Ice Cream Cone, 50 days after the split. It felt like forever, but this part of the mission was pretty fast

I forgot to deploy the solar panels on ICC, so it was dead. Had to send a crew to open them manually to restore the ship, and I took the chance to snap this nice picture

Boundless reunited, in a Lowel transfer orbit, and I have 3 km/s available. Also, check the ridiculous production of a gigantor here

With that much fuel, going back to Lowel would be a lot easier than going down. However, I don't fancy having to refuel Boundless, only to spend all that fuel just to leave Gememma. So I will try instead of taking gravity assists to leave Gememma entirely, and land on Oshan. This way, I'll be able to land the crew back to Mesbin with only one refueling stop, and I won't even need a full load.

[What did you do in KSP1 today?]

I completed circumnavigation of the most remote world I know: Ammenon, from the whirligig world planetary pack

Ammenon is the innermost planet of the red dwarf Gememma, itself orbiting the main star Kaywell. The reason it's so remote is exactly its being innermost: it sits deep into Gememma's gravity well, at barely 130000 km from the surface. It moves at 35 km/s and completes an orbit in seven hours. It takes 15 km/s to reach Ammenon from the nearest planet, of which 10 km/s are the intercept speed and can't be reduced by gravity assists.

Ammenon is tidally locked on Gememma. On one side it is a scorching desert, and under the star itself there's an ocean of lava. But the dark side is covered in ice. Ammenon is half as big as Mun, a bit low on gravity (and definitely too small to provide gravity assists) but good enough to drive a rover semi-comfortably.

I landed on the dark side, on a mountainous region.

this is natural light, provided by Kaywell despite the distance (the bright dot in the sky). Kaywell also allows using solar panels on the dark side. When Kaywell is below the horizon, it's pitch black. In this picture I'm coming closer to the dayside.

Stopping in twilight. the report describes the surface as very hot, but the thermometer does not seem to agree. Look at how much electricity is producing the solar panel; that's a glitch, though.

Gememma in all its glory

One thing I liked about Ammenon is that it has varied terrain. Most worlds are similar in every place; Ammenon alternates highlands - rugged terrain - with smooth maria. Here shown in the transition between the two. elevation is really low, with most of the surface between 900 and 1500 meters - though it goes down to 0 m around the molten sea. it's probably the world with the least altitude variability I know; despite that, it's remarkably differentiated.

too bad my landed-rover was pretty crappy for long distance driving, it kept exploding in the highlands due to hitting bumps. I regret not bringing a better rover, Leaping Mantis would have been a lot of fun here.

And here, arrival to the molten sea

And taking a swim in the molten sea. it's a lot less hot than I was expecting, it doesn't even overheat the kerbal.

The light is very strong while directly under Gememma, it's somewhat hard to see in perspective.

This rock formation is one of my favourites. it's a crater, but the walls were either eroded (possibly by solar wind), and/or the bottom was filled with lava. it's a sign of ongoing geology. and it's very rare to find on most planets. much less on a small one without atmosphere.

leaving behind gememma, back on the ice

Ammenon starts from the Mun model, so it has all the same anomalies in the same places. here crossing the arc near the equator.

The ice cap is also a mix of rough and smooth terrain. for most of the driving, it was smooth.

while shortly before the landing spot, there was a patch of highlands. which was quite hard to cross, because Kaywell does not provide much solar power, so I kept running out of battery.

 

a very beautiful world, I'd recommend it to anyone. at least, to anyone willing to undertake the trip. With its huge deltaV requirement, Ammenon is exceptionally difficult to reach, but well worth the effort.

 

[Rovers! Post your pictures here!]

the small rover Cigar. It's made to be a minimalistic lander for small planets, with rover capabilities. it's not a great rover, quite frail, but in only 4 tons it has a decent deltaV and thrust as rocket, while being able to move on the ground and run science

 

[Need help on my SSTO]

i'm not an expert of planes, but seems to me like the wings are way too small for the mass of that thing.

and 2 nervs won't be enough to circularize.

[Lucy in the sky with deadly radiation 5: strangest sky ever!]

I haven't updated in a month, so I want to give a quick update.

it took me a couple weeks to gather the courage to start. I was worried I wouldn't be able to reach Ammenon, and being defeated after spending nine months on this mission was a daunting prospect. even in the most positive scenario, I'd still be looking forward to a slow slog of dozens of gravity assists - it took 29, actually.
I safely landed on Ammenon a couple days ago, and I found it a lot more interesting than I was expecting, so I'm now circumnavigating it. I want to stop the next chapter of the mission report when I rejoin Boundless, so I can't write it until I finish the circumnavigation in the first place. So, it will take some more weeks.

there is also the issue of the forum being bugged; editing posts may malfunction, and since I write my reports by gradually editing the post (at first I would just write the post in one go, then I accidentally closed the browser and thus lost several hours of work) I am not sure I can even keep making posts.

so, all this to say that it will take a few weeks to a month for the next chapter.

[editing posts no longer possible?]

I occasionally read my old mission reports. Sometimes I find a typo, and I used to edit the post and fix it.

I used to, because now the forum is telling me the post can no longer be edited as too much time has passed.

it's something that happened a few weeks ago. A couple months ago all was fine. then for a while, probably related to the forum stability problems, editing became impossible entirely. at least, i would get the "post too old" message already after a few minutes. today I checked, and i seem able to modify some recent posts, but not always.

does anyone know what are the actual limitations on editing, and whether they are accidental or they are meant to stay?

furthermore, when i do write a mission report, since I tend to ramble quite a bit, i often post a partial version and then edit and continue writing. I do it since I accidentally closed the browser page and lost hours of writing; by posting, I save the current progress. but it would be mighty annoying if I tried to do that, and got an error message that the post cannot be edited instead.

I'd really like to understand how the forum is working in that regard

[Online rocket construction tool/planner]

I'll further add that the more you become skilled, the less those tools are useful. gravity assists will make a world of difference in where you can actually go. I haven't looked at a deltaV map in a year

[What did you do in KSP1 today?]

 

I established a personal speed record going in low orbit around a red dwarf.

like, a really low orbit. going that low on kerbol would result in overheating, even with good thermal shields.

https://imgur.com/cDyuiNp

it's incredibly expensive to move this deep into a gravity field. I have this small planet orbiting very close to the star, and i must land on it, and it orbits at 36 km/s. so, the intercept speed is 10 km/s.

anyway, I was just going at it, when I realized I've never been this fast. not even the time I made a 10 km/s burn at solar periapsis in an attempt at a jool speedrun. so I took a picture for the posterity.
I am not posting it as some kind of record, for a couple reasons. first, if one wanted to make a record for high speed, it would not be too hard to beat. second, having a modded planetary pack creates a different environment where it's easier to reach low orbit around this star.

 

wait, just as I was about to post, I did realize I already went close to solar periapsis to explore inner planets in this very mission. and while I could not go as close, those stars were a lot more massive. I went to check, and indeed I got a lot faster: 57 km/s.

again, not a real record because of the same aforementioned reasons. but still worth noting

[Why don't I get science point from milestone]

On 1/6/2024 at 7:31 PM, Iso-Polaris said:

Milestones give science and reputations, but I don't get science from them, and only half value of fund and repution.

it may depend on your difficulty setting giving lower returns. you should be more clear on what settings are you using and what milestones are you achieving.

anyway, there is a specific subforum for questions.

[The Ultimate Jool 5 Challenge Continued]

On 1/11/2024 at 3:21 AM, JacobJHC said:

@king of nowhere I want to let you know I am reviewing your submission of the Bolt / Nail grand tour but my wifi is horrible and not loading any of the images. Apologies for the SLS levels of delay on my part.

I saw your upvotes trickling in, and realized that you were reviewing. Pity about the wifi. My reports do tend to be very heavy.

[anomaly hunting]

On 1/3/2024 at 7:10 PM, miklkit said:

I have been entertaining myself by hunting for easter eggs lately.  I discovered that there are 2 on Bop so went looking.  Got to the location of the large orange circle and there is nothing there.  After some digging I found Kerbalmaps.com and it shows only 1 easter egg there.   Nice.  Are there any other easter eggs that are long gone?

https://wiki.kerbalspaceprogram.com/wiki/List_of_easter_eggs

this link lists all easter eggs, present and past.

read only if you don't mind spoilers.

you can hunt for anomalies in the game by activating kerbnet from probe cores functionalities.

[What did you do in KSP1 today?]

I got into a building frenzy and made a barge pretending to be an aircraft carrier.

 the thing is, standing on top of another vehicle counts as landed instead of splashed down, which will let me collect more samples from water biomes. so I planned to send an aircraft carrier to laythe.

but i quickly realized i am too lousy a pilot, i can't even come close to the ship, much less crashing on it, much less landing on it. so I made a barge with a water ramp, where the plane can water land nearby and climb on the barge.

after being done, i set up for beautification by adding landing lights everywhere

unfortunately, adding lights created so many new bugs. autostruts failed everywhere, symmetry keeps changing for no apparent reason, the plane randomly malfunctions when close to the barge-carrier. I'll just have to go back and use the non-beautified, but functional version. was it worth to work one hour just to take some pictures?

 

 

[I started playing KSP in 2012. Now I'm at college for astrophysics. Here's how KSP has changed the course of my life.]

On 1/12/2023 at 7:56 PM, Entropian said:

I never thought that on that evening in 2012 that a random game would eventually set me on a course to where I am now.  Now that we are upon the eve of KSP1's great adventure, I wanted to highlight how KSP has affected me.

I remember the first time I landed on the moon.  At first, I was stupefied and elated at finally - finally! - succeeding where I'd failed dozens of times before.  My lander parked beside me, I looked homeward to that beautiful blue and green marble - Kerbin.

I was introduced to Kerbal Space Program at the age of eight.

jumping in very late, but i must ask...

you started playing ksp at age 8?? like, you could actually understand something of what you were actually doing?

last time i brought my little cousin (age 9) on the trampolines, i could not get her to understand that in order to make a somersault she had to push herself forward, not upward, because forward and upward speeds are different. i thought ksp could be an educational tool for high schools, not earlier. How could an 8 year old understand a maneuver node? what was the trick to get a child to use ksp with some competence so young? I may want to use that in the future

[Rational Resources 2.0.6 [Apr 02, 2024]]

2 hours ago, avectorproductfox said:

@king of nowhere I’m not sure if this is the place for this discussion, but, I’ve been playing with Kerbalism and RR and have been able to mine hydrates just fine! What I’ve found with kerbalism + RR, after I attach drills to a vessel, I can right click on them to change the type of extractor, similar to changing processes like scrubbers/water recyclers, or unmanned experiments. 

The only drills i had available were ore, water, nitrogen, uraninite. No option to drill hydrates.

But my installation is a couple years old - i modified it to create bigger chemical plants needed for my grand tours, and i was loathe to lose all that work. So, it is fully possible that the newer versions did include hydrates drills. Or maybe it worked for you because you installed rational resources separately.

Whatever the reason, i am happy that the mod now works as intended. My missions using it are long since finished anyway, and despite the idyosyncratic resource distribution, the actual purpose I had - that of adding to the challenge by restricting possible refueling spots to a handful of planets - was fulfilled

[Rational Resources 2.0.6 [Apr 02, 2024]]

9 hours ago, JadeOfMaar said:

Howdy. I hope this is the post you mentioned. Let me help clear some air here.

• I stopped patching the stock Surface Scanner and provided additional parts, namely the "RR Gound Scanner" which will detect Nitrogen. But it can only be found on ice planets. (It is only regarded as a thing that occurs in ice form and is not regarded as a hint at the presence of life on a given planet.)
• The case is similar with water. It is largely available or regarded (in a bulk, pure form) in the crusts of ice type worlds but is absolutely available in any ocean that would reasonably be assumed to be mainly water. Instead, this mod pushes you to mine Hydrates which is a primary water-bearing abstract resource and is useful for the various valuables you can get from it via the Hydrates Splitter process in RR Companion. Hydrates is quite abundant across planets covered by RR. You cannot miss it.

I see. Unfortunately, kerbalism does not allow mining hydrates, at least it didn't one year ago.

But that's a kerbalism issue, nothing to do with this mod

[The Ultimate Jool 5 Challenge Continued]

19 hours ago, DennisB said:

The problem is, when I have more than two maneuver nodes or more than one flyby, the next maneuver node doesn't work well. It jumps randomly, when I'm adjusting it. How do you plan sequences of maneuver nodes for gravity assists? Do you use mods for it, or do you get the maneuvers from somewhere else (developed by other users), or don't you have this issue? It took me 1,5 days IRL to get from LKO to Jool SOI .

l @king of nowhere

A big milestone in my skill level came as i learned to make chained gravity assists without knowing the end. 

It takes knowledge of what you can and cannot do with a gravity assist, which comes with experience.  And a bit of a leap of faith. I never plan more than two consecutive assists. 

In your case, i'd go for the first eve flyby knowing that i can keep ejecting in resonant orbits as long as i need to reach jool. Or, if i don't have enough speed, i can fix it with a kerbin flyby, or maybe a periapsis ignition if deltaV is not a big deal. 

 

[[1.5 - 1.10] Kerbalism 3.11]

23 hours ago, ashcanpete said:

Sorry to dig this post back up, but I'm having a related problem where no water (extractable surface water in the crust) is showing up anywhere in the Kerbol system. I even used SCANSat to cheat resource maps of all bodies, and water isn't a resource on any of them. I see the same with a fresh save (same mods). I'm not asking for help troubleshooting my setup or looking at logs or anything at this point, I just have some simple questions:

I see that kerbalism only includes configs for Ammonia and Nitrogen but not water. I don't think the stock game has drillable water, so without a config from a mod like kerbalism, does that mean CRP would just not put crust water in the game then? Is it possible harvestable resources are broken in kerbalism right now (as this post seems to indicate), or am I misunderstanding something about how resource configs work?

Also, Arzielle, if you still have those configs you made, I'd be grateful if you would share them. I also was interested in Rational Resources but didn't want any of the ISRU changes. Thanks!

Water is rare, some planets never have it, but it should be present. I always had water, at least in some biomes. But i haven't updated to the latest version, it is possible that one could be broken. Or it could be a mod conflict.

Regarding rational resources, it should be included wuth kerbalism already. But i found it anything but rational; you get no water in place that are literally supposed to be balls of ice, like vall or minmus. And you often get percentages exceeding 100%. I did some ranting on the topic in some of my mission reports. I also left a message in the mod thread, but got no answer

[[1.5 - 1.10] Kerbalism 3.11]

17 hours ago, BryanAM7 said:

i mean i cant load any scenario propely cause it got lot of bugs, from indestructible vessels to kerbals not loading inside ship. "like dynawing re entry" cant load it propely with this mod. i have to go career mode load a pilot inside and then go back main menu and load scenario to kerbs to load. i guess this mod only works properly in career and sandbox mode.

yes, of course. making mods compatible with scenarios is a lot of work, for something that very few players will even notice

[[1.5 - 1.10] Kerbalism 3.11]

6 hours ago, BryanAM7 said:

Hello i cant use cockpit view C key is not working at all is the only mod installed.... cant see kerbals on the right botttom corner either... i sthat normal?

The bug consist that no kerbals get loaded inside the ship is rare...

what bug? there were no kerbal in the ship, that's no bug. sometimes they load authomatically, sometimes you have to choose them

[The Ultimate Jool 5 Challenge Continued]

3 hours ago, DennisB said:

Do you already have a working design?

I tried a more simple solution, but it didn't work, and to improve it further, I'd have to destroy the aerodynamics of my plane, which I don't want. I also don't want to add a further vessel to my assembly, because I already have six (or more?).

I see, you are close to the end of your Grand Tour, so I don't have much time to beat the record, at least for a short period of time. But if you are fast enough (or I'm slow enough), it's possible, that we will do our missions at the same time.

I haven't tested the flight yet, but my plan is to simply brute force the whole thing.  the "carrier" is just a handful of massive fuel tanks, with structural panels to provide an even ramp for the plane to crawl over from the sea (i am not capable to land the plane on the ship, I'm landing it on water and sliding it over a ramp instead). so if I fill those fuel tanks and strap some rockets to it, I expect to have at least 5000 m/s. that's enough to fly straight up slowly until I'm out of the atmosphere.

So I'm ultimately adding a crapload of mass to brute force a problem. I got used to kerbalism missions with 5000 tons ships, the carrier is going to be in the 1000-2000 tons range, it's nothing new. it's surprising how rare it is that a problem can't be solved by adding mass.

Quote

I see, you are close to the end of your Grand Tour, so I don't have much time to beat the record

I am close to the end, but I don't expect to be done before another couple of months. reaching ammenon requires 5 km/s to lower periapsis, and 10 km/s for intercept. I'm going to spend weeks running gravity assists there.

16 hours ago, Astrogator said:

 

English is not my native language, so perhaps I'm not expressing myself precisely enough. I was referring, of course, to the rules of the challenge. Although there seems to be a rule against such construction,

what? no rule against realism, certainly not. the only relevant rules on ship design are those

Quote

2. No part-clipping of functional parts (fuel tanks, batteries, crew pods, engines, science parts, SAS) into each other. It is okay to clip structural and non-functional parts, wings, and heat shields.
7. On all of the landings, the Kerbal must be able to get out and walk (or swim!) around on the surface.  Make sure your ladders work!

if your ship does not violate those two rules, it's fine

[Lucy in the sky with deadly radiation 5: strangest sky ever!]

Part 10: Air, water and fire

After a lenghty inward trip, Boundless reaches the inner Gememma system, exploring twin planets Lowel and Ollym, minor world Gallant, and Gannovar.

The various bodies in the inner Gememma system

10.1) Inching inwards

Spoiler

My original flight plan for this part involved at this point going from the Mandrake-Rutherford system to the inner Gememma system using a gravity assist from Rutherford, and aerobrake in one of the inner worlds - three of them have atmospheres, and they are all fairly small.

The trajectory to exit the Mandrake-Rutherford system, using a Rutherford gravity assist

Goodbye Tatian, eye-shaped moon

And goodbye twin blue giants

I was assuming deltaV would not be an issue; without a gravity assist, it takes 2 km/s from Mandrake to lower periapsis to Lowel, so I was expecting I'd have 2 km/s intercept speed - low enough to aerobrake in those small gravity worlds, especially as I'd still have some fuel left. Well, I probably have too many achievements to say I am an idiot, but I certainly can still make idiotic mistakes, for all my experience. Yes, it takes 2 km/s from Mandrake to Lowel, so intercept speed on Lowel will be 2 km/s. Just in the same way that it takes 280 m/s from Mun to reach a low Kerbin periapsis, so once in low Kerbin periapsis it will take only 280 m/s to circularize orbit, right? No, anyone who landed on Mun knows it's 850 m/s on periapsis. It takes a lot less deltaV to lower periapsis from high orbit than it takes to circularize afterwards.

And so I discovered I had over 5 km/s of intercept speed. That's way above what Boundless can aerobrake.

I can still make it; Gannovar is nicely positioned to provide gravity assists and lower my orbit to reach Lowel with lower speed. Though Gannovar is only mildly larger than Duna, so it does not provide a big push, it will take a lot of flybys to lower orbit enough. Then again, the alternative is to just return to Oshan, again. Refueling is a slow, boring process, I'd rather skip it.

In retrospect, I wonder if it would have been the faster option after all.

Let's start with the Gannovar flybys

As you can see from the cyan trajectory, representing trajectory after the flyby, Gannovar does not make a big difference. 100 m/s worth of apoapsis lowering, sometimes a bit more. It will require dozens of passages.

And this is Gannovar! Quite beautiful, isn't it? The reddish hue is natural light, courtesy of orbiting a red dwarf star

The bluish hue is the light of Kaywell, while Gememma is under the horizon. The rocket burn is a correction maneuver to refine next apoapsis

It took two years for that first orbit, but I'm on track for another Gannovar flyby

In an infinite time, I could get to Lowel for almost no cost. Unfortunately, I have limited food supplies. I left Oshan the last time in year 116, which means I have to resupply again before year 166. Twenty years are not a lot if I have to perform dozens of gravity assists. I am counting on the orbits becoming gradually shorter, saving time. This means that instead of using the gravity assist to get the cheapest next flyby, I spend some fuel every time to ensure a shorter trajectory.

To achieve the most from every flyby, I try to skim the upper atmosphere. Doesn't go very well at 7 km/s

The aftermath of one aerobraking attempt (yes, I made several. I wanted to test exactly how deep I could go in the atmosphere. Roughly 1 km, it turns out)

It's funny how those engines are still flying in perfect formation after the fuel tank to which they were attached got blown up

The first orbits were easy, because orbital times were long. Gannovar has a orbital time of 28.6 days, so I could always find another flyby with a minimal change of apoapsis. As I got lower, I started having to choose between spending additional fuel to make my orbit shorter, or passing farther from Gannovar to keep the next orbit longer. As long as the cost of shortening was in the tens of m/s, I went for this route. I was concerned about making it for the year 166 deadline.

Boundless using only two rockets, for maximum finesse

For greater savings - and because the game was sucking at calculating close approaches, making them disappear at times - I started planning in greater advance, trying to get ejected already in a resonant orbit without need for course correction. This required very precise maneuvers, sometimes as little as 0.001 m/s. To perform them, I created a new command to shut all engines on Boundless except two.

What happened to the propellers? There are fans all around the place

Unfortunately, I am out of free action groups. I had to overlap with some other command, and I picked the one that seemed most innocuous. My bad, it was the command to lock the propellers on Arrowhead. Propellers have a bug that will bend them out of shape if they are used in a vacuum. To prevent that, I deactivate the rotors as soon as I leave an atmosphere. Guess what, I accidentally reactivated them. I only noticed this a long time later, as you can see from the game time - it's year 154, while I left Beagrid on year 142. At this point I decided I'd just replace Arrowhead.

Action groups are set as such:

1: Activate/deactivate reaction wheels on Cigar. Open/close science cargo bay on Arrowhead. Deploy drills on Ice Cream Cone

2: Open/close propellers cargo bays and activate/deactivate rotors on Arrowhead. Activate drills on Ice Cream Cone

3: Run all science experiments on Cigar and Arrowhead

4: Deploy/retract antennas and solar panels, on all subships

5: Activate engines on all ships except Traveler

6: Activate engines on Traveler

7: Extend/retract the robotic parts that pull solar panels on Boundless inside or outside their cargo bays

8: Open/close solar panels cargo bay and engine nose cones on Boundless

9: Shut down all engines on all subships

0: Deploy/retract solar panels and thermal radiators on Boundless. Retract solar panels and antennas on every other ship

Too many things to do for too little action group keys. Too much lazyness to find and install a mod to get more action keys. But so far it worked. 0, 7 and 8 are pressed in sequence to put Boundless in aerobraking mode; after accidentally breaking some antennas accidentally left open, I added the retract antenna command to 0 too. 9 shuts down all engines on the shuttles, to make sure only the main ones on Boundless are working. And when I deploy one, I activate its engines with 5. When I have a lander coupled with Traveler I can activate only the engines of Traveler by pressing 9 and 6 in sequence. And now that I'm writing this, I realize I could have easily put the activate/deactivate main engines on Boundless on 9 too; it's a key that won't mess up anything if I press it. Also on 4, it would have just opened some antennas in space, nothing bad would have happened. Instead, I fixed the issue by changing the command on Arrowhead to flat deactivate rotors. This way I can't activate the rotors with an action command, I have to activate them manually, it's only two of them anyway.

After seven years, apoapsis was brought down from 11 Gm to 5 GM

It's worth noting that while this represents more than half the amount I have to lower it, since it's going to become more expensive as I move closer to Gememma, I'm still not eve close to half the required number of flybys. On the plus side, orbital time has now shortened to 170 days, allowing multiple gravity assists in one year. I am pretty confident I can make it in 16 additional years at this point, provided I don't dally.

Two consecutive planned flybys

Do notice the 30 m/s maneuver at periapsis to shorten the orbit and make it to the next encounter; the alternative would have been to stay farther from Gannovar and aim at the next encounter, 28 days later. Notice also the Gememma apoapsis being lowered at each passage. This part feels endless, but bit by bit I am moving downwards.

As the orbits kept getting even faster, I could no longer get orbital times that were multiples of Gannovar orbit. I could no longer make sure to encounter Gannovar at the next passage. So I brought out my old datasheet to calculate resonances.

Like this

Current orbit of 50 days, in 200 days Gannovar will have completed 7 orbits. I will exit with an orbital time of 45.7 days, allowing for another encounter in 228 days. It's year 153 now, it still takes time to run so many gravity assists.

The final resonance

As the orbital time of Boundless matches that of Gannovar, it's more and more complicated to find resonances. But I don't have to keep this up forever; I only need to lower Gememma periapsis enough to intersect Lowel. I could have easily intersected Lowel when leaving Mandrake, but I'd be coming down from an 11 Gm apoapsis; using Gannovar, I lowered apoapsis to 2 Gm, allowing a softer intercept.

I could have instead used Lowel to lower Gememma apoapsis, and then I could have occasionally used Gannovar to raise periapsis. It would probably have been more efficient, but a bit harder to do. Planning a resonant orbit is easier than changing your target every time, especially when there is an inclination difference between them. Damn, I have a clear mental picture of what I mean, but I have no idea if my explanations are understandable by some reader. Not that I should worry, because I doubt anyone actually reads this.

Anyway, it's now time to change target and go for Lowel. This requires a significant plane change.

The last Gannovar flyby

This last flyby will match Boundless periapsis with Lowel, allowing a Hohmann trajectory. Lowel has an orbital time of 7 days, encounters will be plentyful. I will beat the deadline by 9 years.

On the other hand, do notice my shrinking fuel budget, from 1600 m/s just out of Mandrake to 1100 right now, 100 of which will be spent for the plane change. While all those maneuvers were small, there were dozens of them, and they do add up.

This felt like it took forever, but judging by the time, and by how much each flyby shortened the orbit, I probably used, like, 15 gravity assists or so from Gannovar. The 21 consecutive flybys I used to reach Io in the real solar system grand tour are most likely still my longest chain of flybys. And likely to keep the record, this is way past the point where it gets repetitive.

The last flyby of Gannovar, taken to minimize the plane change cost, offered an unprecedented view of the polar regions. If only there was something to see there

10.2) Running on fumes

Spoiler

I already knew, from having run previous simulations, that even after lowering apoapsis with Gannovar I'm still too fast to aerobrake immediately. Even if I spend the remaining fuel to slow down first.

Arriving at Lowel. Still 3050 m/s intercept speed. Adding the 2450 m/s of escape speed, I'd hit atmosphere at over 5 km/s

I lost roughly 3 km/s thanks to Gannovar, but I still need to lose another couple before I can get captured.

My first plan was to use Gannovar's moon - or twin, depending on definitions. Ollym rotates around Gannovar every seven hours, and it is much smaller, roughly Vall-sized. Unfortunately, there are a few issues with that. First, I'm still too fast even for an Ollym capture. But it's ok, I planned to use Ollym flybys to slow down relative to Lowel.

More problematic, I can't use Ollym for gravity assists without spending a lot of fuel in correction maneuvers. We all got used to targeting the moons of Jool, but Jool is slow; a maneuver to arrive a couple days later, when Tylo is in the right position, only requires a few m/s. But in this case, Lowel rotates very fast around Gememma. So if I want to arrive and find the right alignment with Ollym, I need to arrive, say, three hours later, in that time Lowel already moved significantly in its orbit. Which means that I won't get away with a small course correction, I would need to change Boundless orbit entirely.

Finally, Ollym has a very thin atmosphere, like Tannor. Which means, I can't really get captured here, not unless I'm already going very slow.

Instead I'm taking a gravity assist to keep lowering Gememma apoapsis

So, I am optim for plan B. Wait, maybe plan A was to aerobrake at Ollym, B was to use Ollym for gravity assists, so this is now plan C? Or maybe original plan was to aerobrake directly from Mandrake to Lowel and I'm now at plan D? Well, regardless. YetAdditionalContingencyPlan is to use Lowel to lower Gememma periapsis. Ok, but my speed relative to Lowel will stay the same. And for a long while I believed that there was no way to reduce intercept cost without using a third body for gravity assists. However, several months ago some other poster (maybe I'll look up who it was and post some thanks) told me that yes, you can reduce your intercept speed just with two bodies. In this case I have to use Lowel to lower my orbit, then burn at apoapsis to raise the periapsis and get again into a Hohmann transfer. This will reduce intercept speed on the planet by more than the amount I spent to raise periapsis.

I've been aware of this option for the best part of an year, but I've never had a chance to try it out. My penchant for kerbalism means time is important, and this kind of strategy requires multiple resonant flybys on a planet. Here for the first time I have a planet rotating fast enough that I can perform this maneuver in reasonable time, while also having low enough fuel that I need to try this. I have no idea how much I can effectively save. This approach still requires spending considerable fuel to raise periapsis, and I'm down to 950 m/s left. I can only hope it will be enough, or I'll have to reload back a couple weeks of real life gaming time.

Wow, Lowel looks super interesting!

Emerging from the planet's shadow, I also see Ollym, Lowel's twin. Actually I took this picture much later, but the actual "first sighting of Ollym" picture is kinda ugly

Trying to aerocapture at Ollym. I just told you I'm still too fast, but back then, I still didn't knew it

Indeed, though I spent all the fuel to slow down, Boundless is still too fast to brake hard. And if it does not get captured, it will crash on Lowel next

So, I aim for more Lowel flybys

5 km/s is slow enough that I can take shallow atmospheric dips. Oxygen atmosphere, straight channels... what the hell happened on this planet?

By the way, this is how Gememma looks from a cupola. The dot slightly under its center is Ammenon. This is the first time in this game I can see a planet while orbiting another planet

60 m/s to raise periapsis. Let's see how much I lowered intercept speed with that. I'm not sure why I also spent 66 m/s at periapsis just to ensure a faster flyby; time is no longer an issue, fuel is

Impact with atmosphere now at 4200 m/s! I lowered my intercept speed by 800 m/s by spending 200 m/s total! I had no idea this maneuver was that effective

But I'm still too fast, let's do it again.

This time 28 m/s to raise periapsis. Again, I'm not sure why I'm spending 42 m/s at periapsis instead of changing flyby earlier. Probably I just thought I could afford it?

Wait, now that I think about it, Ollym was never in the right position to use for gravity assists, but it was often in the right position for Boundless to crash into. Maybe I'm just tuning the time to avoid Ollym? But why not change the flyby trajectory instead of making a course correction later? Maybe because the game does not let you see the trajectory that far in advance? Not sure. 40 m/s would be unremarkable normally, but right now it's 7% of my total deltaV budget.

And intercept speed lowered by another 270 m/s

For the next flyby, for once Ollym is aligned right to take a gravity assist from it. It will slow Boundless some more

Do notice that just because Lowel has an orbital period of seven days, this section is still not fast. In the above picture, it takes 58 days before crossing the red twins again, a 3:8 resonance. The thing is, I have very little control over my orbit. This deep into a gravity field, even slight changes in trajectory cost a fortune. Maybe that's why I need to spend one tenth of my deltaV at every course correction.

Intercept speed lowered to 3600 m/s, which is low enough to spend some significant time in the atmosphere and brake some significant speed

The red color given by Gememma, the atmosphere, and Ollym, all make for an incredible sight. Why there is a green shade next to the water? Could it be vegetation?

Finally, this time it takes 150 m/s to raise periapsis, but afterwards capture speed is as little as 700 m/s. This time I can get captured

I have 500 m/s left, and I'll need to spend 150 of those immediately, but afterwards I'll only need aerobraking and small course corrections.

At 2.8 km/s, I can finally go for a full capture

Lowel is so beautiful when aerobraking over it

Now that I'm captured, a small course correction will send me in an Ollym aerocapture trajectory

Aerobraking at Ollym, looking outward from the cupola. Notice the thin atmosphere

Finally in a stable orbit around Ollym. I had 300 m/s left

Safe with 37 tons of fuel, out of a tank capacity of 1870 tons. Took me almost three weeks of real life to get here, which is why there was so much delay between two updates.

10.3) Fixing the damn plane - and everything else

Spoiler

First order of business is to get some fuel, because I don't even have enough to operate Arrowhead. Ice Cream Cone goes for the landing.

A nice visual of the descent from the cupola on Ice Cream Cone

As I'm doing this, I realize I accidentally entered a retrograde orbit on Ollym. Which really hurts refueling operations, because Ollym rotates fast, at 100 m/s, which I gain if I orbit in the right direction. But it's not a big deal, I reload from before Ollym insertion and go the other way. I didn't have much fuel, but certainly enough for this.

An important discovery I made to increase efficiency on refueling is that Ollym atmosphere is so thin, I can keep the solar panels deployed during descent. This slows Ice Cream Cone enough that it can open the parachutes, and I need then to provide only 200 m/s by rockets.

Using the solar panels to aerobrake

And then the parachutes. I considered ICC engines to be massively overkill, but hre their high thrust allows waiting the last second to open them, maximizing parachute efficiency. They are still overkill

I run a handful of resupply missions immediately, to get enough fuel for the various landings, and the main bulk of refueling in the end. But for practicality, I'm going to just save all the details on refueling to their own subchapter.

Just a great view of Ice Cream Cone rendez-vous with Boundless with Ollym in background

Now it's time to get a new Arrowhead, since the old one got its propellers scrambled.  It's a bug, so I'm allowed to bring in a new one with the cheat menu. I don't expect any particular difficulty.

But when I undocked Arrowhead, Traveler's fuel tank exploded immediately

What happened? While Arrowhead is part of Boundless, its propeller blades are ignoring same vehicle clipping. But the moment I undoc k, they become a whirring cloud of fast moving objects. They slam into nearby fuel tanks, making them explode. it's basically a circular saw. Oh, and they do that because the propellers are still rotating. Despite shutting down the rotors, locking them, and activating the brakes. I suppose they are so out of shape that they rotate powered by microclipping alone. Except they should not have clipping as long as they remain part of Boundless. Well, I suppose their fast rotation is part of the bug. Regardless, I need to find a way to detach Arrowhead without breaking anything. My first attempt is to send and engineer in EVA construction to manually remove all those propeller blades. How do I plan to catch those blades that move too fast to be tracked? Simply by clicking at random, they are zipping around all the time, occasionally I'd just click on one. I detach a half dozen blades this way, before accepting that it will take too long to get all of them.

So I come up with a better plan: I have some struts in storage in case of need, and for a long time I thought I was carrying dead weight. But now I can put them to good use.

Using the struts to block the rotors

With this strategy I could stop the blades from doing damage, and safely detach Arrowhead. Some of the propellers exploded, but they did not damage Boundless.

One detached rotor. Do notice the propeller blades; they still count as attached to the rotor, and are still spinning

Ok, now I just have to teleport in a new plane. And I just found this amazing point to snap pictures

But wait, where are all the solar panels?

From what I could ascertain, using the rendez-vous function of the cheat menu can cause damage to robotic parts in the destination ship. In this case, it disappeared all the robotic hinges that were holding the solar panels. Or maybe they just got moved who knows where, because the game is telling me Boundless still has the same number of parts. Anyway, I solved the problem by teleporting the new Arrowhead close, but outside of physical range, and entering physical range normally.

10.4) A cradle of life

Spoiler

I'll start the landings with Lowel, since it looks most interesting. I send Arrowhead alone, it should have enough fuel to make the full trip without needing Traveler.

Just getting out of Ollym sphere of influence is enough to fall on Lowel

Arrowhead looking good while thrusting

Those canals are a real mystery

Arrowhead looking good while aerobraking

About to land. A bit too fast

Arrowhead looking less good after crashing

Lowel has a decent atmosphere, but not enough for Arrowhead to fly. It would be relatively easy to build a plane that can fly here, but Arrowhead is made heavy by its rocket parts. I tried to get a controlled landing - there's just enough lift that I felt maybe I could do it - but in the end I gave up, reloaded, and picked up some parachutes.

Arrowhead landing in a less dignified fashion. But it works

Landed, with a bunch of science report. Confirmed pluricellular life, full vegetation. I wonder what color would plants actually be around a red star

Too bad the game is not equipped to actually show vegetation. You barely even notice a slightly greener hue on certain areas.

Lowel biome map

The place is interesting, and there is enough air to move on the ground. The biome map is very complicated, but it just means I can explore most of them without having to cross the whole planet.

Driving on Lowel

Going down a canal, you can see it's somewhat greener on the bottom

The white dot in the sky is Gannnovar. Those planets are close enough that you can see them for each other surface, something that normally does not happen

More reports, mostly from water biomes. Wait, microplastics?

There's microplastics on Lowel? So, there was some advanced civilization that built the plastics, built the canals, then disappeared without leaving other traces?

Well, I've covered most biomes, time to leave.

With rockets, Arrowhead can go up

Not a ton of fuel left, but enough to go on Ollym

10.5) The land of volcanoes

Spoiler

Now let's land on Ollym. Ok, not strictly needed for the grand tour because I already landed with Ice Cream Cone, but I want to land with some science instruments. 90% of what I do in this grand tour is not strictly needed.

Arrowhead feels a bit oversized for this landing, and the propellers would be virtually useless to move on the ground. Cigar would be more appropriate; I use an engineer to move the atmospheric spectrovariometer from Arrowhead to Cigar so I'll be able to get atmospheric science.

Cigar about to land, keeping a profile to maximize drag

Drag is a problem, in that there's very little and I still need to spend a lot of fuel. Enough fuel that I'll need to climb a high mountain to be able to launch to orbit again. Good thing I wanted to climb a mountain anyway.

Landed, on the slopes of Helios Mons

IVA view while driving

Gravity is comfortably high, and the ground is flat, I feel comfortable pushing for some speed. In over 100 km I didn't crash once; it's probably a record.

From the slopes of Helios Mons I will go to the tip of Zeus Mons. For a sense of scale, it's 70 km from the rover to the first flag

The ground contact bug struck, but time warping fixed it

Going up Zeus Mons. It does not feel like going up a mountain. There's barely any slope, and the top is behind the horizon. It's likely inspired to Mons Olympus on Mars

The rover is somewhere in the middle of the screen, 27 km from the flag in the bottom, but still very far from the top

To the top! It was a lot of road, but it was also fast

10 km altitude

Now launching

Fuel is a big issue, Ollym is bigger than anything Cigar was meant for. The first few times I tried I didn't make it to orbit. You can see I'm using the RCS to squeeze some additional m/s out of the rover. And before activating the engine I gained as much speed as possible with the wheels.

Still going up, still using RCS. Drag is low, but over several minutes it adds up

Made it, with 17 m/s left. Those 30 m/s I got with the wheels made the difference. Also the RCS

10.6) Not just another glorified asteroid

Spoiler

So far I've never mentioned G1 Gallant, except in the introduction. It's a minor world, of no importance. But I still need to plant a flag on it.

A route to Gallant. First part, 2700 m/s for an intercept

And 3 km/s for capture

I considered using gravity assists to get there, but I'm using Traveler here, I can't make it in one year for the round trip. So I strapped on the heavy configuration tank, that achieves almost 11 km/s, which should be enough here.

The ejection had a significant normal component, and was very long

To make up for the long burn, I periodically deleted the old maneuver and made a new one, more accurate to the new position of the spaceship

Gallant. It's not a tiny rock, but it's not a real world either

Biome map on Gallant. There's only highlands, midlands, lowlands. One side of the planetoid is a giant crater, but it doesn't have its own biome

Landed. The science report says it all

Unfortunately, the gravity is just high enough that I can't point Traveler up with the reaction wheels. Fortunately, sliding on the ground works

The return trip. 2400 m/s, leaving 2500 m/s for capture

Capture is more expensive that the remaining fuel, but I don't have to rocket burn the whole intercept deltaV, I only need to slow enough to aerobrake

Ollym and Lowel lined up

Aerobraking. After spending most of its remaining deltaV, Traveler is sturdy enough to survive at 3 km/s

I always love that red glow on water

Returned to Boundless, with 130 m/s. I could have saved a bit if needed, but not much more

In the worst case I could have sent Boundless, but it would have required many more refueling trips.

10.7) Where ice meet fire

Spoiler

Finally it's Gannovar's turn. I'm looking forward to it; not only it looks almost as interesting as Lowel, but it's also the one world with an atmosphere thick enough to actually fly Arrowhead.

I need to move the docking port to dock the cumbersome shielded small docking port. Then I equalized thrust with center of mass by reducing power to the engine on the opposite side

Docking Arrowhead with heavy configuration Traveler

Route to Gannovar

I raise Gememma apoapsis a bit to become more similar to Gannovar orbit, using Hobert effect from Lowel and Ollym. Then I need 700 m/s to lower periapsis, so that it will touch Gannovar in a Hohmann transfer, and 200 m/s of plane change. It will result in 1370 m/s intercept deltaV, which I will mostly or completely aerobrake.

However, it seems the game engine has issues with planets in elliptic orbit, because Traveler kept being misplaced.

Here it's coming in with a 52 km periapsis

But one hour later, when it actually entered Gannovar, it had a completely different periapsis

Actually, it's not a general problem with the game engine, because while I was taking gravity assists with Boundless I had no such issues. Still, I could not find a fix here, except trial and error.

In Gannovar orbit, releasing Arrowhead

Descent. I'm not sure Arrowhead can take off from water, so I aim for the ice pack

Landing close to a minor body of water, separate from the equatorial belt

About to land. Landing on Gannovar ice is difficult because the ground lacks depth perception, you really can't tell how far you are. On the other hand, dense atmosphere and low gravity helps

And now landing on the brackish water. And yes, Arrowhead can lift off from water in those gravity and atmosphere conditions

Looking out from the window

More reports from the hotspots, the largest areas of water

Then it's fly up to take science on the deep pack ice

Away from water. There are those weird artifact lines on the ground, I suppose it's a visual glitch

On one of the few mountains peeking out from the ice

Arrowhead traveled some considerable distance

I even considered circumnavigating the planet in flight, but there's really nothing to see outside of the equator, and the lack of perspective is very disorienting.

Now it flies up as high as it can to save fuel

Arrowhead keeps flying with 17 kPa of pressure. Lowel had 20% more gravity and 20% less atmosphere, Arrowhead didn't miss too much to be able to fly there. I wonder, if instead of Arrowhead I had brought Not! Albatross, from the Jool 5 science mission, would it have flown? It was a better flyer, but it was definitely worse at reaching orbit. But I could have used it, I think.

Nice light show as Arrowhead goes up in the atmosphere

Meeting back with Traveler

To return, Traveler is pointing in the wrong way, so I devise a way to leave Gannovar in a resonant orbit and return pointing in the correct direction

But once more I get twarted by the sphere of influence bug. It's 255-5:07, and Traveler is supposedly entering Gannovar

It's 2 hours later, and Traveler is still supposedly just about to enter Gannovar

So in the end I just brute forced the whole trajectory

I mean, if the orbital calculations are bugged, the screenshot does not show it properly but Traveler still has 5 km/s of deltaV. Enough to return to Ollym easily.

And this is the last time Arrowhead will fly. Unless I make more kerbalism grand tours in the future.

10.8) Preparing for Ammenon

Spoiler

I refueled intermittently, a few flights here and there, with most of them after the last landing. As usual, it was a long and boring process, and I really wish I could go back in time and slap myself when I was planning the mission. Sure, I need some refueling limitation because being able to refuel on any minor rock is too easy, but I should have done a better job than that.

As I anticipated, I was able to deploy the parachutes. Really surprising, because they should not have opened, they are supposed to only open at 0.01 atm of pressure and Ollym has less than that. Not complaining, it was helpful.

Ollym turned out to be a great place for refueling, better than Oshan. The planetary rotation helps reduce cost, and the atmosphere is so thin, there are hardly any losses.

Here I fumbled a landing. Somehow Ice Cream Cone landed on a solar panel and didn't break it. I was able to mine and fly back like that

Flying up. Look at the total drag (12 kN) despite the high speed and low altitude, the atmosphere is really not an issue

Ice Cream Cone can bring up 105 tons of fuel at every trip. I learned to vent some oxidizer before launching, I don't need it right now

More nice pics

And that's all. Next target, Ammenon, is the most difficult. I need all the fuel I can load. And just enough oxidizer to work Cigar, plus land Ice Cream Cone back when I'll return to Ollym.

Status after refueling

The screen on the left claims 7.8 km/s of deltaV, but that's counting the fuel in all subships as dead weight. Traveler's fuel will be spent, while the fuel in Ice Cream Cone and Arrowhead will be used by Boundless, so it's actually significantly more deltaV. Maybe 10 km/s or a bit less. But the real question is how much of that cost I can reduce with gravity assists.

And how long it will take.

On one hand, I'm thrilled. That's the thoughest challenge in this grand tour, a chance to test myself to the limit. On the other, I already had enough of gravity assists when going down from Mandrake to Lowel, I don't know if I want to spend more weeks running dozens of flybys.