tomek1ni

Yeah It was my fifth attempt of landing.. It was the last puff of engines witch saved me from ramming in to the surface. I had like... 7 m/s delta v left while I was right above the surface.. it wasn't moving that fast, but you don't need much to damage the ship. The other thing, approach wasn't too efficient. Think I started the suicide burn too early. When the vessel was in orbit of 10 km over the surface, I still had something around 900-1000 dela v left. So it should be totally sufficient amount to land, but I burnt it all out anyway. This is how the maneuvers look like watching it from the top while I'm back near to Eve. The second one shows form the back how much tilted is the trajectory witch suppose to push me back towards Eve as close as possible. It also shows the inclination at which the ship is being ejected from SOI of Eve. It was the most difficult part, because you need to synchronize everything (angles, burns, and timing). For instance when my trajectory inclination still doesn't align with Moho's orbit, and I needed to decrease inclination of second maneuver (purple dotted line), but then the angle I leave the Eve's SOI at changes either. So I need to move second maneuver nod further along the first trajectory to match the angle. But then you perform the maneuver later. So I need to shorten first trajectory. But then the velocity of I pass by Eve with goes down a little. etc... I had tried to launch directly when I was in high orbit over Eve, but it didn't work that well. I tried to do some math but it was difficult for me to draw any conclusions from those calculation. It was even had to say to me if I did them correctly. So I don't know how much of a role Oberth effect played here, but I can say that only this way I managed to pull it all off. When ship started falling towards Eve it was at an altitude of 44000 km over the planet. Those 3 maneuvers are the most expensive (not counting breaking and landing). Or rather they could have been way more expensive if done later... further away from Eve. There are other 2 on my way between Eve and Moho, but these are fairly minor and are there only to get more accurate interception. The other thing was breaking. I didn't quite realized before i red your post how much of a difference it makes, when the ship moves exactly along planet's orbit during breaking. It was whopping 1700 of delta v of difference. Maybe there were some other factors influencing this, but this is probably the main one.

I LANDED!!! When I have more time I'll describe exactly what I did. In general I performed all the most expensive maneuvers while I was still in Eve's sphere of influence. Including adjustment for Moho's inclination.

Hello! Thank you for that extensive answer. It is way more than i expected. I red it a couple of time and tried to decipher the meaning of it... I'm rather an amateur wen it comes to all that terminology. For instance what does "intercept the higher node" mean? You might get the 356 m/s burn wrong. That one suppose to eject me from Eve's system while I'm in PA going right by Eve. Red somewhere that performing burns there may save me a little delta V. Correction for Moho's inclination is that 3 m/s burn. Was thinking if I manage to intersect it at that point, when in almost aligned with Eve's orbit, would save even more delta V. But later I came to a conclusion - as you said - that is rather fast intercept. So it cost me more when I need to break instead. I is year 1 day 312. An the next window would cost me less fuel indeed. I experimented a little trying to land my vessel. Haven't succeeded yet, but will try again if have some more time. Regards, T

Hello! I've got some problem. My plan was to take almost all of my kerbals on a trip across the system to level them all up. The first point of the travel was Gilly (Eve's moon) because it so happened, that a transfer window coming right about then. From that place, the next closet window was to Moho. But what I didn't do, and what I should have done, was to check the amount of delta V , that is needed to perform that maneuver. Thus while I'm parked in the south pole of Gilly I have 3439 m/s delta V plus around 200 from emptying monopropellant tank and converting ore. I figured that the best moment to get ejected from Eve's system comes In 8 days, because then I almost don't need to correct my trajectory for Moho's orbit inclination. You can also see the way how I get out of Eve's system here. Opposite to the planet's direction of orbiting the Sun. That seems to be the most optimal. That's like the transfer trajectory between planets looks like: And this is the moment when I close the orbit around Moho (not even landing): I reckon that I would need another thousand more to land on the surface. Concluding, in total I'm somewhere around 1500 m/s to short on delta V to pull that off. My question to you guys is... do you see any way of making it work? Maybe some better way of utilizing oberth effect or any tricks of that kind? Thought that there maybe are some space veterans who had some advices. I know I could just refill the fuel in the mid flight with KLM, but I would rather wait for a window to other planet than using cheats. Regards, T