Hohmann transfer is taking a long time

[drew4452862]

I'm trying to get to my docking station around the moon. It is taking a long time for mechjeb to do this. Maybe 30 minutes? Anyway to do this faster? Is it always this slow? Right now I just set mechjeb and watch something on netflix but I have a few ships to fly up there.

[KvickFlygarn87]

[DELETED]

EDIT: You could always do it manually, to pass the time and increase the sense of achievement. I know it takes a lot to actually snap out of using MJ and do this (I used to rely 100% on MJ too), but when you do it's a whole new game.

Edited March 9, 2014 by KvickFlygarn87

[Taki117]

MechJeb plots the most efficient transfer (hence why it takes a while, to transfer from 75km to my station at 200km takes 1.5hrs) however, you can do it manually and then just have MechJeb match velocities at closest approach.

[Vanamonde]

If the rendezvous is taking that long, it's probably just orbital mechanics; you have to wait for time to bring the ships together. If the docking after rendezvous is taking that long, something's wrong with Mechjeb.

[Superfluous J]

Does MechJeb not allow time warp? I've never used it but always assumed it made the game less tedious, not more so.

I do NOT want to turn this thread into a MJ flamewar but flying manual and using judicious time warp you can get from the launch pad to the surface of Mun in 5-10 minutes, assuming you don't need to revert the flight because of forgotten solar panels (true story) or symmetry on landing gear (also true story).

[Claw]

I'm trying to get to my docking station around the moon. It is taking a long time for mechjeb to do this. Maybe 30 minutes? Anyway to do this faster? Is it always this slow? Right now I just set mechjeb and watch something on netflix but I have a few ships to fly up there.

Depends on which part of the flight you are talking about.

If you are saying that MJ is plotting the first burn out of low Kerbin orbit, it might be that you are already close to the optimum transfer point. If you are too close, MJ sometimes jumps to the next opportunity, which may be a whole orbit away. Sometimes when this happens I just build the node myself and fly it (or click execute on MJ).

If you're unfamiliar with building your own rendezvous, I would recommend messing around with it some to get some experience. I'm not saying "dump MJ." But I find that MJ doesn't always give me what I want. If you have the knowledge, you can strongarm MJ into submission.

In any case, you can pass the time in two ways. You can forcebly time warp while MJ is flying, then drop out of warp for it to execute (leave some time for it to adjust). Or you can click on MJ's "auto warp" radio button. When active, it will manage all warping activities so you don't have to walk off and do something else.

[Kryxal]

You didn't say where you're starting from ... if it's Kerbin, you might be better off just moving to the Mun before trying to rendezvous with the station.

[Pecan]

I'm with Vanamonde and 5th Horseman - make sure you've got 'autowarp' activated in MJ and the rest is just how long it takes to get an intercept. If you're in the same orbit height (or close) but far away MJ should make a 'phasing orbit' to change relative speeds. How far does it go? How quickly the positions in orbit coincide depends on the distance (thus orbital period) between the two orbits. Also, if you're low, the game sets a limit on how quickly you can warp - only 2x under 10km IIRC. Try setting your station higher if that's the case or getting your vehicle into a much higher orbit, just so you can warp more.

In close orbits a time-to-transfer of a couple of hours is not unlikely but with warp that should happen in 5 minutes or less real-time. Otherwise everything's just too low or you're not using warp.

[celem]

It can take a little while to be honest, especially if you didnt take the auto-warp. MJ will make a series of manoeuvres to get the RVZ done, some of which can take a bit of time depending on your situation. If both craft start in or near the same orbit then MJ will burn to quite a high orbit to wait for alignment before burning back down.

Also the amount of torque available has quite an impact on these things. If your ship is a dead-weight brick then MJ cant rotate it any quicker than you could and he has half a dozen tweak-burns to align for. If each alignment he makes takes 30 seconds then you lose almost 5 minutes just turning to face. (edit: you really dont wanna try and dock under-torqued/rcs'd parts anyway)

Its also worth remembering MechJeb isnt foolproof, he can and will get it wrong. In particular he struggles to match the default 0.1ms tolerance with high TWR ships and may hunt it back-and-forth to little gain. (I cant use landing guidance module for the same reason, my TWR is so high that he cannot balance the throttle and ends up in hover/climb)

Edited March 10, 2014 by celem

[Rickenbacker]

Does MechJeb not allow time warp? I've never used it but always assumed it made the game less tedious, not more so.

It does, but the OP probably has his two ships in low orbits at similar altitudes. The bigger the difference between the orbits, the faster the lower one will catch up. And the higher the orbit of the ship you're flying, the higher the timewarp you can use. So the secret is to raise your orbit until you get to at least 100x timewarp, IMO.

[drew4452862]

yeah i was keeping a low orbit to get ships on and off the moon fml

trying hyper edit