Slow orbit with mun

[drkblue_shadow]

Help please!! I'm in career mode and miss calculated my mun mission. I sent 3 kerbals and don't have enough fuel (only about 179 m/s worth) to decrease my orbit enough to get back to kerbin. I had a thought about trying to adjust my current orbit as to be influenced by the mun just enough to slow down, but not be pulled into it's orbit. Is this even possible? How would I do that? 

 

note: I know I could just do three rescue missions but I don't really want to. That is my plan B. 

[Espatie]

So I'm guessing that you're currently in an elliptical orbit around the Mun? In that case, no, you likely don't have the Delta-V to escape Mun SOI.

 

What's your Apoapsis and Periapsis about Mun?

[Superfluous J]

It really depends. I suggest playing with maneuver nodes.

Also you could make "rescue mission" your plan C and turn plan B into "get out and push." As in, get a Kerbal out of the ship and use the RCS jet packs to push the whole vessel retrograde, while at your Kerbin Apoapsis. It may take several sessions (you have to get back in to get more fuel) and may even take several orbits, but as RCS fuel is infinite, it is 100% possible to get back home.

[purpleivan]

Personally I'd start up the dramatic music, line up some coffee, head for the VAB and go for the RESCUE MISSIONTM

[soulsource]

It's not possible to be pulled into Mun's orbit in Stock. Unless you decelerate you will always get a flyby.

[cantab]

If you are currently orbiting Kerbin, and your orbit intersects or comes near that of the Mun, then it probably is possible to get a gravity assist to drop your Kerbin Pe low enough to re-enter. It'll take a bit of tinkering with manouvre nodes though.

[drkblue_shadow]

12 hours ago, 5thHorseman said:

"get out and push." As in, get a Kerbal out of the ship and use the RCS jet packs to push the whole vessel retrograde, while at your Kerbin Apoapsis. 

i have tried this an I'm not that good with the RCS jet pack. I am barely good enough to get back to the ship let alone push it. 

 

1 hour ago, soulsource said:

It's not possible to be pulled into Mun's orbit in Stock. Unless you decelerate you will always get a flyby.

I'm not trying to orbit the Mun. I'm trying to get back to kerbin using the mun's gravity to slow me down at Apoapsis with out actually pulling me into its orbit or slingshotting me away.

 

58 minutes ago, cantab said:

If you are currently orbiting Kerbin, and your orbit intersects or comes near that of the Mun, then it probably is possible to get a gravity assist to drop your Kerbin Pe low enough to re-enter. It'll take a bit of tinkering with manouvre nodes though.

I've done a touch a tinkering with maneuvers but can never get it to decrease my Pe. Any suggestions as to how I get it to lower it? 

[Geonovast]

12 hours ago, 5thHorseman said:

"get out and push."

I've done this too many times.  Usually because KER lied to me.

It's tedious, but you could put a kerbal in orbit with nothing but an Mk1 command pod and get to Jool if you had the patience.

[drkblue_shadow]

Sucess!!!! What ended up happening was i had a complex set up to use the mun to slow down enough. What ended up happening was I used the mun to sling shot into a higher orbit where my little fuel went further so i could decrease my pe to do air braking.  I took a few screen shots but dont know how to upload them. 

 

ps. Thanks for the help and suggestions

Edited January 15, 2019 by drkblue_shadow
add ps

[Fearless Son]

48 minutes ago, drkblue_shadow said:

Sucess!!!! What ended up happening was i had a complex set up to use the mun to slow down enough. What ended up happening was I used the mun to sling shot into a higher orbit where my little fuel went further so i could decrease my pe to do air braking.  I took a few screen shots but dont know how to upload them. 

 

ps. Thanks for the help and suggestions

Nice!  I wasn't sure from your initial post what your apoapsis and inclination was, and whether that would (eventually) be affected the the Mun's sphere of influence.

Glad you made that work.  

[Snark]

Moving to Gameplay Questions.

[MaverickSawyer]

Yeah, gravity assists are useful if you can swing them, especially for low dV missions. I recall once doing a triple sling off the Mun to get low and high orbit science data without braking into orbit and then returning. Took nearly 30 days, but I think that, after the transfer burn towards the Mun, I used less than 150 m/s dV to put it into a reentry trajectory.