Warzouz

Yes yes. The topic wasn't about using probes core in our designs, but about lauching a probe/satellite to orbit. What for, except to gather gravity and temperature data ?

I think it's not about implementation, but about eliptic orbits and acceleration.

I had a 900 parts space station around Laythe. It as assemble with 13 different flight from Kerbin to Laythe. The 900 parts inludes the 6 landers and tugs, fuel tanks and return ship for 11 kerbals. Well that was really laggy. Especially the context menus which refused to open. I partially solved that by removing 250 parts (redundant batteries, small engines, rcs packs, solar panels, ladders, science...). I uses Kerbal Attachement System which allow you to EVA and detach small parts. Then I deleted the debris from the space center. Further more, I reduced the game window resolution and some video settings. Now it's playable, even if fuel transfert is still very slow. If I should rebuid the station, I would minimizse the number of parts. As my second stage is able to do the trip up to Layte Orbit, I don't need additional engines, battery packs or RCS on fuel tanks. But as I wanted to have 5 SSTO landers (+ a regular staged one) and some tugs, the part count rises fast. Maybe I wouldn't use as many docking rings and structural adpaters (even if they look great)

In theory, there could be a rescue mission (hopefully, Kerbals can hold their breath for years), but Tylo is hard to land on anywhere, so I can't imagine landing at a precise spot.

Well, I forgot to tell that I use probe core in most of my Tugs, but it's only to not beeing converted to debris while waiting for the carried ship to return. Also, I used a lot of probe core on various mission to ship payload to space station. But again, it's not "really" a probe/artifical satellite.

I use non landing probes for eliptic polar orbits. They have a thermometer and a gravity detector. I use them to get low space temperature and low and high space gravity per biome. Having that before landing max science. I gathered 2500science from 6 joolian probes before my landers got 37500 more What do you use probes for ?

Sometimes, when quitting SOI, there is a "temporary" trajectory which seems to be wrong. This artifact appears at any warp speed (even x1). The trajectory seems to return to the body we quit and give a new SOI (usually very far). The "out of SOI" trajectory is also wrong. Then at the predicted time, the correct trajectory come back. The false trajectory lasts only less than 2 minutes. I think it's nearly always when you quit a smaller SOI to its parent time. I don't recall to have seen this bug (?) when entering smaller SOI. I use MJ, KER, AlarmClock mods. What is it ?

I finished my jumbo Jool mission gathering 41350 science points. The space station is still around Laythe, but the crew is back to Kerbin. And I finished the Eeloo's one too, or nearly 18000 science. I think I'll pause a while on KSP.

I'm not sure you can land any low TWR on Tylo. There is probably a lower limit. You must be able to control you vertical velocity as you horizontal speed is reducing. That require more and more TWR. My 6000m/s DV SSTO for Tylo was meant to be reusable (thus I landed it only once, I was quite fed up with Joolian system.)

You should have tested all your landers on the Launchpad !!!

Maybe there is a way to expurge struts remains from save files to reduce part count after struts are broken ?

Thx I'll do.

I understand the concept or gravity assist but I don't know how to use it. I clearly saw that passing behing tylo would nealy make me escape from Jool SOI. But as the trajectory stops at Tylo SOI excape, I don't see where I go then. Even though, this seems to be very tricky to have an encounter with Kerbin, Tylo should be in the correct spot while beeing in the correct spot to escape Laythe WHILE beeing in the correct phase angle. It sound not easy...

You're right, but drogue chutes are heavy and drag is very low. Further more, they don't exists as radial and my nose node is usually devoted to a docking ring.

What is best way to return from Laythe to Kerbin ? Do I park in a Jool orbit first to wait for the window ? whch orbit ? I opted for as 85000km orbit aaround Jool (above Tylo, near Bop). I hesitate to go under Laythe Orbit to profit from Oberth effect, but I found silly to use escape velocity burn to go lower as I could go higher. Have I done correctly ?

Well it depends what you use chutes for... I use the small chute and/or radial. I don't use the bugger chutes. because I usually stick docking ring on the ship noses. when I get back to Kerbin, I tend to use more chutes to land only with the chutes. When I land on Layth or Duna, I "under" chute and do a final burn with then engines to slow before touch down. But I've a question of my own. I have a return ship with 11 kerbal from a very long mission around Jool, bringing 250 experiments (!). I'll have a very high relative speed to Kerbin. I will aerobrake, for sure, Do I deploy the (8 radial) chutes on the first pass ? Do i deploy the 8 chutes at different altitudes ?

I landed on Tylo with a low TWR SSTO rocket ship. I'm quite happy with it !

Well, the vertical thrust must be greater than 1, but you can kill lateral with less than 1. As you burn fuel, the TWR rises and you'll be able to fight vertical velocity with a TWR higher than 1. The higher the TWR is the easier it is. The parameters of the landing profile are - Starting altitude (lower is better because you'll have less gravity to fight, but you have less margin to stop lateral speed) - Starting TWR (lower means lateral velocity will take longer to kill) - controlled vertical speed (I used -100m/s. If the TWR is lower, it should be smaller). - dV of course : If you have a low TWR, you'll burn much more than with a higher TWR. In theory, you could land and take off with 4500m/s dv, but that's with infinite TWR. With my starting TWR=1 , and 1.6 on ground, ending at 2.15, I burnt 5900m/s of dV. 31% loss because of that low TWR. And finally, with low TWR, autopilots do a poor job it seems.

Take off successful. Final words SSTO lander is a 14T fully loaded (7T dry) TWR is 1 (full) to 2.15 (empty) with 6050m/s dv. I started at 30000m. Used 3100m/s to land at 1800m. I used 2800m/s dv to return to orbit with only 150m/s of fuel left... Hopefully, the tug will do the rendez-vous. BTW Mechjeb failed to ascend to orbit several times... I had to do it manually. I used MJ only for the final suicide burn on landing, under 4000m. Activating landing guidance higher WILL result in "divergent litho-bracking". Horizontal speed has to be handled under 200m/s before returning to retrograde. I'm quite happy with this flight. I had a 5800m/s design before. Hopefully I optimized it to 6050 (mainly removing double science equipment). I still managed to do all the science on surface. Time to return to the space station. Still one landing on Laythe, the back home with nearly 250 experiments on jool system !

Yep, I'm retrying from 30000, and aim for the highlands (I already visited the lowlands with my staged lander). further more, I miss 600m/s of dv tor each orbit... Do you think I should go for 20000 or even 15000 ? - - - Updated - - - Ok starting at 30000, I kill my horizontal velocity keeping th vertical at -100m/s. At 200m/s horizontal, I switch to prograde. At 4000, swith to MJ autolanding. Did well, with 690m/s more fuel in tank. I landed using 3100m/s. I landed in midlands at 1800m. I tried keeping my vertical velocity around 170m/s, but I crashed. It was too fast, I couldn't kill my horizontal speed fast enough. -100 seems to be nice.

I did it with a double LVN. Start from 40000m, reducing horizontal from 2000 to 500m/s while keeping vertical speed under -100m/s then retrograde for a little time. At 6000m, switching to MJ auto landing. It did perfectly. With little practice this can be fully manually. I burnt 3800m/s but I think I could start lower and keep vertical speed around -300m/s. It would save fuel.

For Eeloo, I did with an inclination at launch. - I waited for the correct time in the KAC window - I launched half an orbit before the correct ejection angle is set (to Eeloo, it's on the dark side) - I set MJ for a 100km orbit with 15/20° inclination south. - You have less than half an orbit to plot for an encounter - The ship goes down and arrive at the equatorial node with the upward inclinason and ejection angle. - At that point burn prograde to escape and more. - After escaping Kerbin SOI, check your inclination angle. If it's off course, retry launch. - The plane correction should be quite low. Obviously, the escape burn can't be done witha low TWR or you'll be way off course (or too complexe for me to plan). I've designed a mixed first and second stage with a Kerbodyne engine, 2 LV30 and 4 LVN burning togethers. The TWR is high on the begining of the burn and decrease as I decouple the low efficiency engines. My Payload is 1 SSTO and some refueling mini station with a Lab and a return ship. My goal is to do 3 missions to Eeloo with 2 hops each (so 6 biomes visited). Arriving in 300 days after a 2 year trip. They even arrive after the Jool mission is finished (which is a 400T space station around laythe with 5 SSTO).

I had most difficulties with porkshop. (My station orbits at 500km around Laythe) I asked for an orbit from Laythe to Bop and it offers 1 node which targeted Laythe (!), updated it's calculation and added another very costly node which still been in orbit of Laythe, then again a third node which had a very steep encounter with Bop (which braking should hav been much higher than calculated). I managed to do a classic hoffman to Bop for a third of the DV and a very low capture cost. But I surely not using this tool correctly. Also, I've noticed the calculation of alarmClock don't give me an encounter at the specified date. I'm usually several orbits from an encouter. For now I reverting to simplier trajectories, or guessing it with MechJeb Node Editor. Usually, I try with MJ to see what I get (at the date offered by Alarm Clock or Window Planner). I'm usually not convinced by what I found so I guessing by ploting an approximative prograde escape burn then tweeking with the time setting until I find something nice. Then I fine tune the burn (prograde, radial, normal).

I'm aroud Jool for the moment, doing multiple missions to each moons. Tranfert to other bodies can result in very different costs. I fell short of fuel twice (finishing plan change with RCS... then waited for the station to send a tug). I've noticed that AlarmClock or MechJeb can make poor calculations but maybe I don't use them correctly. The ejection inclinaison is very hard to get right because you have to be in the correct alignment at the proper time. For my Eeloo mission (which isn't arrived yet) I had to redo it several times. Finally, the DV cost is way higher than the number I can find on various tools or sites. I even had to make mid course correction. Even if it's more costly, a basic Hoffman transfert maybe the way to go to avoid bad news on arrival. It's much easier to aim for a shallow angle. But I'm very far to be an expert.

Yesterday I notced that the Sun wasn't hidden by Jool. I think I was orbiting. I could see the sun trough Jool. I didn't check the solar pannels though. But few days ago, the sun was correctly obscured.