Jesrad

I'm sending a rover (more accurately, a huge mobile science base) to the surface of Eve at the same time, so Grand Tour Star will only get to check out Gilly. She will dip a branch in its atmosphere though !

I know, but they disappear in screenshots if I just mouseover, so instead I try to remember to click them so they stay up. But then, any change in conic patch level vanishes them again. And 9 times out of 10 KSP thinks I'm clicking somewhere else (it tries to add a new maneuver node or set a new target instead).

As for treating a common cold, I suggest a big, one-shot dose of vitamin D3 (thousands of UI). The influx stimulates the immune system and usually the cold disappears in a day or two.

I launched missions following some very interesting contract propositions. First is Marcel, a massive Eve science rover that will hopefully, at some future point, once it has juiced Eve's surface of its science, bring its crew to the tallest plateau for retrieval. And then, I was tasked with ejecting a massive asteroid menace from the Kerbol system.

Dres for Success "Gaaah it won't intercept either !" said a frustrated Jenming. "If I fix another maneuver node I'll puke." was heard from Naissa, slumbered over the nav table, almost passed out in nausea. "Guys, guys, now. So we have no injection window to anywhere, OK, alright I get it." Liniella added. She paused dramatically for attention, and failed to get it. "What about we go nowhere instead ?" "You don't mean..." "Yes. Let's fly to Dres." And dread was in the eyes of the Kerbals. For Dres, to the best of their knowledge, is simply the most atrociously boring rock a Kerbal ever hopes not to visit in his lifetime. After converting my stash of ore from Ike while orbiting it, I noticed this strange thing: the fuel got into each branch after the other, isntead of spreading evenly. So the Star was completely off-balance. Good thing I did not attempt any maneuver yet. So I moved all the LFO on the inside of the branches then circled it across the tips until it was pretty much evened out. First attempt at Dres injection was... discouraging: 1926 m/s ? That cannot be right. So Naissa took a hold of herself and replotted, this time further down and assuming a midway inclination correction: Much better ! The crew launched in the dark as is usual for outbound transits: The inclination and correction burn turned out to be a hefty 580 m/s, yikes. But that is why the Star has such a high fuel fraction, afterall. We knew all along we wouldn't get optimal transit windows. Goodbye rust ! See you soon, ash !

I did not go to space:

I just went with the other threads starting with "PSA" that were around Oh I did that one some time ago. Best parts, energy-wise, are: TR2L for wheels if you need speed VS energy, and RoveXL3 if you just need roving capacity VS energy Okto, Hecs and Mk2 drone for autopilots Comm88 for antenna Always go for the larger reaction wheel you need, than multiple smaller - mind that torques add up just like energy consumption As for ion engine propulsion, it's from memory but I think there's a sweet point on power requirements: at Kerbin distance from Kerbol you should need either 6 OX4 solar panels and 2k battery, or 4 OX4 panel and 6k worth of battery, per engine, for best results (there's no situation in Kerbin space where you would need bigger batteries IIRC). I'll try to find back the exact numbers. On general purposes PB-NUK become more interesting than solar panels when light intensity drops below 10% of Kerbin's, which should happen at 2.3 K.U. or 31,315,000 km from Kerbol (Dres and beyond). Substitute them with the "sweet spot" above for ion propulsion, or overall for mining/ISRU. I'll see to adding fuel cells properly to the analysis.

There's little point refilling big batteries for feeding a ion engine once you've expended all the xenon Sometimes you shouldn't bother recharging batteries.

Did you know ? In KSP, liquid fuel + oxydizer are a much denser form of energy storage than batteries, by a ratio of either 8 or 4 depending on whether you compare LFO to small batteries or to the 4k variant. But whether this ratio is enough to compensate the extra mass and complexity of lugging fuel cells and tankage around, versus the operational simplicity of batteries, may depend on the use context. Let's find out ! LFO converted to electricity by a fuel cell is 80,000 energy / ton Batteries hold less: 10,000 (small batteries) or 20,000 (Z-4k) energy / ton. However, batteries are not constrained by power requirement, whereas fuel cells only output 30 (fuel cell) or 75 (array) energy/second for each additional ton. This means that, in the energy-intensive uses found in KSP, which are ion propulsion and ore drilling + ore conversion, the extra output-constrained mass may obviate the better density edge of fuel cells, in some contexts. For example, in ion propulsion you need 94414 energy to expend an entire PB-750 Xenon tank. That amounts to 4,8 tons of Z-4k batteries (96k charge), or 1.18 ton of LFO, which is 1.31 ton of actual tankage. But then you need at least 6 fuel cells or half a fuel cell array to power a single ion engine at full thrust from LFO, for a total of 1.5 or 1.6 ton, and that is still ahead of batteries. You may use lower throttle settings off a single fuel cell for better efficiencies, but that lowers a LOT the already paltry TWR of the whole contraption. Smaller Xenon tanks require the same power (and same mass of fuel cell) but less LFO/battery mass, so there is a balance point at which batteries become more efficient: this tipping point is at 197 Xenon, which is less than half of the smallest tank in the game. If you have no power source to recharge the batteries, in ion propulsion the fuel cells + LFO will beat batteries everytime. IF you do have some form of external power (solar panel / RTG) then you might recharge batteries between two maneuvers, in which case you'd have to calculate how high a deltaV this precise amount of 197 Xe would give your ship, and how it compares to the deltaV maneuvering you're planning to need at most, in order to decide between batteries and fuel cells. FYI that's equivalent to 96 seconds of ion thrust. To recap: if all your maneuvering will always be done in less than 96 seconds of ion thrust, you should favor big batteries, or else use fuel cells and a LFO tank containing about 20 times less LFO units than you have of Xenon (1 Round8 for each PB150, 1 FLT200 + 1 Round8 for evey PB750, and so on). Simply said, if your TWR times 96 seconds is more than the maximum amount of deltaV you'll need in any single maneuver, go with batteries, otherwise go with cells. Ore drilling and processing is more energy intensive: 15 energy/sec per drill and double that for conversion of a single unit worth of fuel (1 LFO is 0.005 ton, 1 monoprop is 0.004 ton). The thing is, with an ISRU the fuel cells basically become rechargeable. According to wiki data, mining 0.5 ore yields 1 LFO unit, at a total energy cost of anywhere between 12 and 6000 energy for mining, and 30 energy on top of that for conversion. The same unit of LFO gives off 400 energy once converted by a fuel cell. This means that you can only "refuel at a profit", energy-wise, using a level 3+ (advised 4 or 5) engineer off a moon (assuming ~5% ore concentration) operating a single drill, or one unmanned drill off an asteroid (75% or better ore concentration). In these conditions, battery size is meaningless and fuel cells must instead be compared with whatever panel and RTG setup you may consider in their place (and applying the squared distance from Kerbol to your panel output, using Kerbol-Kerbin distance as unit). To recap: if your mining conditions clear the thresholds above (<400 energy per half unit of ore mined) go with fuel cells, otherwise you will need panels or RTGs. If you see any mistake in the maths above please let me know

Remember also to have the object targeted

What about using a Minmus-analog orbit as "exit port", high above Kerbin ? You then don't incur the cost of depature from Minmus, don't need to land your spacecraft at all, and interplanetary injections are much easier to do - they can even take days if needed so your TWR is not constrained at all - - - Updated - - - Good to know, thanks I figured that 2 or 3 drills with a basic engineer are enough to feed a pair of ISRU and a LV-N continuously at 100% thrust.

Nice ! Although, 3098 tons worth of fuel is equivalent to about 31 trips of my Tanker Last from Minmus. More if it's meant fro LKO directly, less if you're meant to refuel interplanetary round-trips. By my calculations, using a similarly ~90% ore asteroid, a 10-drill, 1 ISRU, 1 small ore tank, 10 fuel cell array + 1 48-7 engine can mine, convert the ore and feed its rocket continuously at full thrust, for a minimal mass of a little over 32.5 tons. I need to see whether having an engineer aboard or using a nuclear engine with LF only is more efficient, but that should make it possible to move any rock almost anywhere

And then, it was time ! Linielle reluctantly got to the helm and set course for the very bumpy, grey and unwelcoming ground of Ike, 20 km below. The trick to landing on Ike is to find a spot where there's not too much slope. That's harder than it sounds, especially if you want an easy, visual landing like on Duna: then, it needs to be flat, horizontal AND in one of the light-grey zone. The dark grey zones are too dark to see ground details well enough. And if you end up headed for a dark zone, well, this little thing can save your bacon: Linielle kept her eyes on the ground radar, Naissa kept hers on the altimeter, while Jenming stayed a hand on the main rocket's throttle lever. "Ready !" Linie shouted across the cabin, as soon as the needle started moving. "Brace !" replied Jen as he applied full thrust. "Mark !" continued Linie as soon as the needle passed 2000. That was the signal for Naissa to report the absolute altitude, and for Jen to cut thrust. "9-4-7-2 meters !". "We are go for landing, target 7-4-7-2 meters absolute ground altitude." Linielle confirmed. "I copy, 7-4-7-2 meters, mark" Jenming segued. The team went with a slowdown at 7800 m for a slow, controlled descent over the last few hundred meters: Everyone was tensely waiting for the unannounced impact with the ground, watching nervously the altitude needle drop slowly toward the estimated ground alt... and suddenly: "I have visual !" cried Jenming. "It's faint but I can make out the ship's shadow on the ground !" Both girls sighed with relief and glued themselves to the sole window port. They managed a finely-controlled visual approach: *CRRRRRRRONK* *Psshhhhhhhhhhffffff....* *ClunkclunkclunkCLUNKCLUNK-* "...w...what was THAT ?" "Did we ... ? Tell me we didn't break something expensive !" said Naissa as she curled up into a ball. Nah, nothing broke. But the Star flexed quite a bit as she came to a stop along the sloped ground. The clunking and thumping were from the SAS trying to righten her up futilely, batting the branches on the ground. They had forgotten to disengage stability augmentation along with the rocket thrust. - - - Updated - - - Somewhere on Kerbin, an accountant was doing the happy dance. Cha-ching ! Meanwhile on Ike - Jenming called dibs on flag-planting, and none of the girls contested because it was too dark out there for their taste. The ore concentration turned out a bit above 2%. Besides, the landing had been terrifying enough that no one in the team would dare try their luck elsewhere. All the ore was converted to fuel, and all drills were deployed: The refueling took enough day-night cycles that even Jenming finally got bored of playing "Munar Lander" on the onboard computer. It was finally time to leave ! The ore was then convreted into more fuel, almost topping the tank once again: There was just one last thing left to do... Finally, reluctantly, all three Kerbonauts gathered in the lab and faced the issue that would shape and change their future forever... "Soooo...." Naissa started. "So." Jenming confirmed. "...where are we going next ?" - - - Updated - - - I bow to your keen observation skills I initially intended to make a word-play on some for of "lighthouse" because of the shape of the piloting mast, but settled on Grande Tour since she was to go on a serial exploration of most planets and moons.

Mining went just fine, although at Duna's distance the panels couldn't feed all 12 drills at once. I should have waited to unlock the Fuel Cells prior to launching, in retrospect. Linielle was first to the ground: Followed shortly by Naissa: weeeeeeeeeeeeeeeeee (You can't see it on the stills, but she's laughing maniacally all the way down) And finally Jenming: The refueling took 4 days, and refilling the ore one more day: And then it was time to go visit Ike: Circularizing at 60km altitude: From then on, it's a pretty simple and cheap maneuver to Ike: The Mighty Harvest of Science raged on around Ike shortly thereafter: At that point, the crew was really fed up with collecting reports, shuffling assignments and resetting experiments, so they just laid back and enjoyed the view. Landing could wait a tad.

Same, I had to copy-paste my contracts from earlier saves several times already. I know it happens while playing, even if you don't quickload at all.

Dun'hike The adventure keeps unfolding... We left the Star and her crew as they were slowly tumbling around Kerbol, towards the rusty spot known as Duna, and its angry-eye-in-the-sky moon Ike. About a month before SOI change, Linielle boldly adjusted the trajectory to get an aerocapture on first pass: Periapsis 23km. Meanwhile, Arena and Jenming scienced away quietly in the back seats of the Lab, and when they finally were in range of Duna, this happened: Woops, better empty that bucket. You know all those mission drills the astronauts do over and over and over ad nauseam, until they can do the planned tasks in their sleep ? That's what Linielle had spent her last month doing. When the Star breached the 140km altitude limit, she hurried out the airlock and went through every instrument at an insane pace: She completed all of her assignments in record time, getting back in the hab before the ship reached the upper limit of the atmosphere. In unrelated news, the coffee storage alarms report a breach. The ship, still massing 117 tons, dipped at hypersonic speed into the tenuous and dusty layer of gases, and then something unexpected happened: Oscillations quickly receded and she stabilized in this 30-degree-down stance... Crew double-checked the fuel levels for imbalances, and found none. Oh well. Closest approach was at 22818m altitude, and as she exited the atmosphere it became clear that too little airbraking had happened. She was still on an escape trajectory: A long burn was required, with an antiradial component, to bring her into a closer, proper orbit around Duna: It was time to prepare for landing... - - - Updated - - - One more short burn brought Periapsis to 15km altitude on the sunny side of Duna: The aerodynamic stance of the ship proved unstable once more, but the Verniers quickly tamed it. Overpassing a deep canyon, Jenming spotted a suitable landing site, and Linielle fired the main engine to bring the Star to a standstill: Visual approach landing works a lot better during the day: Touchdown ! But this is not time for celebration - if the site has too little ore, a relocation is in order... 3% is good enough ! We're staying. Margaritas for everyone !

f you've already read the "how efficient is your mining operation" thread, you can skip this, sorry. If you haven't read the Spudis & Lavoie paper on "how and why to develop cislunar space infrastructure ASAP", I can't blame you. But you should go and read it anyway An excerpt: Basically, theirs is a fully laid-out plan on which rockets (mostly Atlas) to use to send what specific crafts and modules where on the Moon and around it and at what estimated cost, in order to build a complete fuel&more extraction ISRU infrastructure on the Moon's south pole, and use it as a stepladder to Mars and the Asteroid Belt. And I wanted to simplify and adapt it to KSP, so I'd have free fuel flowing everywhere in near-Kerbin space, to leverage for future interplanetary (and interstellar ?) missions. As I had no experience at all with KSP's ISRU and mining stuff, I set out to test it, first at the KSC, then in-situ proper: Then came the big work. Echelon #1: Minmus Mining Rig I selected Minmus rather than Mun for the infrastructure because it has a shallower gravity well and I'd rather not waste too much fuel landing and departing, but mostly because it's closer to Kerbin escape, making it more accurate to the Moon w.r.t The Plan. Building on this fresh experience I designed a mining rig for Minmus' flats, figuring I could slap a Klaw on it and worry about what kind of ship it'd feed later: Churn churn churn... This went very well, the rig landed without even using up its landing stage (the two detachable engines on the sides) because I still overengineer stuff badly, for fear of lacking. I blame my college years. Echelon #2: the Orbital Depot The DCSN plan calls for sending the fuel extracted on the Moon to the Earth-Moon L2 point, and from there, drop it into LEO with the very cheap Farquhar route (using just 330 m/s deltaV in a couple impulses, and airbraking at the end): Shown in its reversed form (Earth->L2) here. But there is no such thing as Lagrange points in KSP because it uses a 2-body gravity simulation. I need a fuel depot to store fuel from and then feed it to my future interplanetary ships: putting it inside of Minmus' gravity well would put extra deltaV cost on them, and possibly some TWR constraints. And I need the depot at a near-escape energy relative to Kerbin. So I figured I'd put the depot on a Minmus-identical orbit (47 Mm from Kerbin, circular), just with a phase offset. This way it'd stay fixed relative to Kerbin-Minmus, and be just 40 m/s from interplanetary transits. Here's the automated craft up for the task: And once launched: It leads Minmus by about 16000 km, so it's more of a L5 rather than L2. But I stick to the L2 name nonetheless. Echelon #3: Minmus Tanker I'd need to convert, store and shuttle this fuel away. So I'd need some big ship that would land on Minmus, connect to the rig somehow, have an ISRU, and with enough deltaV to bring her haul to the Depot. I hastily cobbled together this: And launched her thus to meet the Minmus Mining Rig: Also, Bill relieved Phoda at the commands of the Mining Rig: The Tanker Less, as she ended up being called, then departed Minmus for the L2 Depot: Echelon #4: Cislunar Tanker As mentioned before, the fuel also needs to be dropped from L2 to LKO. From there it can power all manner of near-Kerbin, and possibly Munar, operations. Then the tankers would return to L2 and refill, for a new cycle. I opted for an automated, simple yet robust design. OK, I actually just recycled my Depot design, minus the side ports: It launches easily, and even has extra fuel in the ascent stage once in LKO. Echelon 3.5: Minmus Tanker++ I realised the Tanker Less was too small for the task of hauling massive amounts of fuel from Minmus to K-Min L2. So I made a 3x bigger one, the Tanker More: She has crew quarters for those long transit times, too. I may be a pie-rat who press-gangs stranded Kerbals into a life of risky service, I still have to make sure they don't go crazy on me mid-mission. She launches cheaply, using a simple booster stage then her own power: I filled her with every loose green-horned Kerbal I could round up at the time, for the purpose of giving them a taste of what Real Space is like out there. They'd go to Minmus then K-Min L2 and back to Kerbin, as a first test of this whole infrastructure thing. Stopover at the Cislunar Tanker for a refill, as the fuel was expended on ascent: Hmm, this is turning out right, I think. We're already making good use of the first echelons She went to K-Min L2 first, to drop off the empty Tanker: And was quickly joined by the Tanker Less, inbound from Minmus and heavy from her fresh load: After a quick but intense exchange of fluids, Tanker More continues her route to the Minmus Rig: The Rig has too small an ore capacity to make her a tankful, but that's fine, she can refill from the continuous mining in the time it'll take the other Tanker to come around from the Depot. Echelon #5: Crew Shuttle My bundle of rookies (a school of fishies, a herd of cows, and a bundle of Kerbals, is how I call it) is on Minmus, watching the ore get chewed. When they get back to the Depot along with the haul, they'll go their own way, back to Kerbin. But they cannot ride on the Cislunar Tankers (in hindsight, I should have slapped a few seats on those, that would have been hilarious) so I need me some crew transfer capacity to the Depot and back. Thus: She has a smaller deltaV range, as she won't land anywhere and just switch back and forth between LKO and K-Min L2. 20-Kerbal capacity, including the mandatory pilot - she has no probe core. Like the Tanker More, she needed a refill in LKO for the trip to K-Min L2. Fortunately I have 3 different Cislunar Tankers in my rotation: After picking up all the, shall we say, "space-broken" crew, she dived back to Kerbin for a direct aerocapture to LKO (Periapsis 26700m): They've been to the deepest reaches of Kerbin-space, they've seen the arid Flats of Minus, nothing can faze'm. From there, any kind of SSTO works as a shuttle between surface and LKO Echelon #6: LKO-SSTO So I need me a big SSTO for large crew transfers to and from LKO. I suck at SSTOs, honestly, taking no chance I went the brute-force route and made this: Some of it burned on reentry Fortunately, I now have the Ulysse and a few spaceplanes to replace it with. You will probably have better luck and skill than me on this echelon. Echelon 3.999999: Yet-Bigger Minmus Tanker I opted to make yet another, bigger-still, tanker to go between Minmus and L2, so that I could do proper rotations with decently-sized loads of fuel everytime: Final tallies: Here's a recap of the infrastructure: LKO -> K-Min L2 = 1155 m/s K-Min L2 -> LKO = <461 m/s Minmus -> K-Min L2 = 370 m/s K-Min L2 -> Minmus = <450 m/s Surface -> LKO = ~3600 m/s Compare with: My logical next step is to try and get a gravity assist from Minmus to get to LKO cheaply with the Cislunar Tankers. I might have to move the Depot closer. Wish me luck ! The Minmus-L2 circuit gets fuel to the Depot, in 53 or 78 ton chunks, at a ~20% expense. From there it can feed interplanetary projects, or get transferred further to LKO in the Cislunar Tankers, in 23 ton chunk sizes, at a further ~27% expense (which is 42% expense when combined). Lefting that much fuel from Kerbin would cost me ~90% expense, plus the refurbishing / replacement of parts and vehicles. The whole thing costed a little under 1,150,000 to build and launch. Feel free to build your own

Pas mal pour un début Mais je l'aurais plutôt vue dire "Zut alors, quelle accélération !"

Finished my Duna Exploration Push with the snail-probe to Ike: Also I'm swimming in cash now, 7+ meeeellions. Next time: the Grand Tour Star arrives at Duna !

The counter-rotating centrifuges have waaayyy too much cinetic moment and their combined gyroscopic torques will fold your ship around the middle the moment you pivot it around. That is, they would IRL

I landed on Duna ! Mostly. It was quite an adventure, too:

I'm glad you like it ! The first stage went flawlessly, but the second stage being rather limited in TWR I improvised a transfer of fuel from the "tips" of the star to the LFBs and extended that part of the ascent. I cut thrust a lot somewhere around 10 km because she was threatening to flip over, extending the ascent some more, and it was a wobbly ride on the back of just the Mammoth until I dropped it too past the 30+ km mark. From then on the KR-L2 worked beautifully and steadily, and she circularized in a 80x80 LKO easily. I'd already trained a lot at launching large spaceships with the Cislunar Tankers for my Minmus Mining / Kerbin-Minmus L2 Fuel Depot operation.

As it were in the screenshots ? Roughly 250 m/s.

Neat idea, that tail tank thingie But it'd be just a tiny bit more useful if it could take off on its own from the landed, still-mining mothership I think. Or maybe make the whole mothership out of such detachable, self-propelled tanks, so that you can modulate how much fuel to land with, and how much to leave in orbit ?

For the curious, the VAB shot of the Star before launch: It fit into the 530k advance fee for the contract, even ! I told you I'm cheap: I'm making a profit even before the mission begins And a big spoiler: the other design I made, adapted for the outwards-system lack of solar power, and differently styled into an octopus-kind of thing. Lacks a science lab because I have no more scientists to spare, and a single small ore tank because I do not intend to complete contracts with this one: