Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[LoSboccacc]

bravo!

extremely impressed.

also, far will apply drag correctly for popup parts.

anyway. is thrust balanced? I couldn't quite make my rockets go straight

[Siquo]

Thrust is balanced but in this stage (no struts, long rocket) the center part is wobbly as hell when using the bottom thruster. I also wasn't able to reinforce the center part because it both extends left and right but also up and down, and it increases the length of the rocket. So I use the fold-out nukes to pull it, transfer the fuel from below, and that works.

Struts also don't act as fixed-length but moving (rigid in both length and position, alas), but fuel lines are flexible and extendable. I created the "cargo bay" with parts from KAS and fairings from KW rocketry, that are not supposed to fit together (they clip at the top and don't fit at the bottom).

Pushing a button and seeing the whole contraption extend, flex, and move into position feels kinda awesome though. I was aiming for something like this:
http://www.youtube.com/watch?v=jZJczZ6gbVU&feature=player_detailpage#t=82

[puke]

question here:  how do I set my nav-ball to be relative to another body?  And/or:  How do I set my target to be Kerbin?

My current specific problem is that I have a ton of landers on Minmus that I want to bring home, and I want to do so by burning retrograde relative to Kerbin -- but I cant figure out how to do that without first escaping from Minmus orbit.

And if I escape the wrong way, I waste lots of gas.  I can just eyeball it, but I'd rather recalibrate my nav-ball if possible.

[Putnam]

East, IIRC.

[Mono124]

question here:  how do I set my nav-ball to be relative to another body?  And/or:  How do I set my target to be Kerbin?

My current specific problem is that I have a ton of landers on Minmus that I want to bring home, and I want to do so by burning retrograde relative to Kerbin -- but I cant figure out how to do that without first escaping from Minmus orbit.

And if I escape the wrong way, I waste lots of gas.  I can just eyeball it, but I'd rather recalibrate my nav-ball if possible.

Use nodes. I'll give an update with pictures in a sec once I make a craft real fast and get it to minmus.

[Siquo]

question here:  how do I set my nav-ball to be relative to another body?  And/or:  How do I set my target to be Kerbin?

My current specific problem is that I have a ton of landers on Minmus that I want to bring home, and I want to do so by burning retrograde relative to Kerbin -- but I cant figure out how to do that without first escaping from Minmus orbit.

And if I escape the wrong way, I waste lots of gas.  I can just eyeball it, but I'd rather recalibrate my nav-ball if possible.

Burn prograde relative to minmus when you're in minmus eastern orbit on the side of kerbin.

[LoSboccacc]

My current specific problem is that I have a ton of landers on Minmus that I want to bring home, and I want to do so by burning retrograde relative to Kerbin -- but I cant figure out how to do that without first escaping from Minmus orbit.

that would be good but not optimal. you'd want to be retrograde on kerbin and prograde on minmus not to fight nimnus gravity directly ascending out of the soi.

as an estimate maneuver that's easy to visualize (not the best, but better):


wait until the lander is facing the direction minmus travel:

Spoiler (click to show/hide)

burn 70 deg east until the AP sits at 45 degree (the ap should be between minmus and kerbin, if it is outside the minmus trajectory, then you went in the wrong direction)

Spoiler (click to show/hide)

now place a maneuver node on the AP and burn prograde until you hit the soi exit

Spoiler (click to show/hide)

now, to minimize the fuel usage the trajectory when you exit the SOI should be as much as possible parallel to the minmus orbit trajectory
but you can tweak a bit more to tune the PE in kerbin right there when it costs less

[puke]

Thanks for the awesome replies, super helpful.  I will be having the sciences soon!

[Mono124]

I do things very similar to LoSboccacc, but I go into an actual orbit first. Anyway, from Minmus lading landing to Kerbin I only ever use at most 600 dV, and quite often I use less.

Firstly, get into an orbit. I chose 110,000 only because I needed to clear a mountain that was very close by. I always point east west. Ideally you would get into a very low orbit to minimize fuel used. LoSboccacc does it the best way without going into an orbit at all, but it requires you wait until your lander is on top of the direction Minmus travels. Also try to make this orbit as close to 0 inclination at possible, but it does not have to be perfect by any standard (you'll see mine was about 5 degrees).

Spoiler: Like so (click to show/hide)

Secondly, set up a node in any direction, and give it enough dV to escape Minmus.

Thirdly, maneuver the node until it is burning in an escape direction retrograde to the direction Minmus travels. You will know it is set up properly when your projected Pe is much lower than Minmus orbit.

Spoiler: Like this (click to show/hide)

Spoiler: NOT like this (click to show/hide)

Fourthly, add/subtract dV and keep moving the node until the "Minmus Escape" icon is right ontop of the line that shows Minmus orbit, but retrograde to Minmus' actual orbit (You will have to zoom out of the map and back in to check and make sure the icon is ontop of/very close to the line) and you have the Pe you want at Kerbin.

Spoiler: Like this (click to show/hide)

Finally, make your burn and make the minor adjustments to finalize Pe.

Spoiler (click to show/hide)

By doing this, I used roughly 419 dV to go from being on land at Minmus to landing on Kerbin, and that included by my accidental overshot of my node by 1 minute and the adjusted burn that was required to keep me from burning up/pulling over 5G entering the atmosphere (due to a plugin I have that can explode the craft/kill the crew from reentry).

EDIT: Words

[puke]

It looks like your second picture has you pointed to the West?

[Mono124]

It looks like your second picture has you pointed to the West?

Another thing I missed in my edit. You're right.

[puke]

okay, I get it.  It does not make a difference what side of the planetoid I launch from, as long as I am pointed West.  Then I can just orbit until I am headed retrograde in relation to Kerbin, burn prograde relative to my local orbit, and Bob's your uncle.

Actually, I think the same could be said for always launching East, right?  You'd just start your prograde burn while on the other side of the planetoid?

[ank]

okay, I get it.  It does not make a difference what side of the planetoid I launch from, as long as I am pointed West.  Then I can just orbit until I am headed retrograde in relation to Kerbin, burn prograde relative to my local orbit, and Bob's your uncle.

Actually, I think the same could be said for always launching East, right?  You'd just start your prograde burn while on the other side of the planetoid?

Yes

[kaian-a-coel]

My space station had its second part attached! yay!

Spoiler: The Overkill XXXXL, version "stop crashing into my engine clusters, thank you very much" (click to show/hide)

[miauw62]

Less wobbly solution: orange tanks with the smallest rockomax tanks on the bottom.