Duna Cycler Orbit

[Moon Goddess]

I just learned about the Mars Cycler orbit, and think I may try setting up something using it.

I thought I'd ask, has anyone done a Duna Cycler orbit?

I'm not sure if it will really be a benefit, you'll still have to match velocity with the orbiting vehicle in order to dock with it but you could release things that use aerobraking at least.

[Tex_NL]

Try searching the forums for the word 'cycler' and you get more results that you'll know what to do with.

[hobbsyoyo]

There was a thread about this the other day, fyi.

The benefit is that the cycler can be used to move massive stuff like life support for multiple astronauts back and forth between planets and you only have to accelerate it once and then use gravity assists to sling it back and forth. Then you use a smaller-mass shuttle to take astronauts from the surface of Kerbin or Duna and meet with the big, bulky cycler.

Of course, the benefits of the cycler are lost in KSP as we don't have to worry about life support systems and whatnot. So if you can build a vehicle capable of taking astronauts from Kerbin all the way down to Duna (and back) then you don't need a separate cycler. This is entirely possible in KSP and people do it all the time.

The other thing is that I'm not sure you can really do a true cycler in KSP; I don't know if the physics engine will allow you to do a cycle without lots of extra burns to correct physics-engine errors between SoI's and such. So you would probably end up spending a lot of fuel to keep the cycler going, so much so as to negate the benefit of a cycler which is supposed to go back and forth with limited deltaV expenditure. Also, you would still have to have a ship at Duna to go up and reach the cycler and bring astronauts down to the surface or transfer them from the surface up to the cycler. This shuttle will have to refueled and unless you are using the Kethane mod, this will result in multiple launches simply to refuel the shuttle.

In the end, trying to make the cycler work isn't really practical given that you can accomplish the goal of sending Kerbals to and from Duna much simpler without it.

[FellipeC]

Take a look at this post:

http://forum.kerbalspaceprogram.com/threads/51227-The-possiblility-of-a-Mars-Cycler-in-KSP?highlight=cycler+orbit

[Moon Goddess]

My apologies, I just learned about the existence of such an orbit and in my excitement I came and posted without using the search. I bet I'm the first person to ever do that

Of course, the benefits of the cycler are lost in KSP as we don't have to worry about life support systems and whatnot. So if you can build a vehicle capable of taking astronauts from Kerbin all the way down to Duna (and back) then you don't need a separate cycler. This is entirely possible in KSP and people do it all the time.

In the end, trying to make the cycler work isn't really practical given that you can accomplish the goal of sending Kerbals to and from Duna much simpler without it.

I always play with life support mods and more importantly for a cycler, I always require habitat space on my missions, no 3 kerbals in a can for 6 years. Self imposed realism of mine so There would be benefit if that habitat was already orbiting.

Thanks everyone.

Edited November 6, 2013 by Moon Goddess
spelling.

[hobbsyoyo]

I would be surprised if you were not able to make better, more efficient missions without a cycler than with one - even when including mass budgets for life support, crew living space, etc. I was recently able to send a large single-piece space station to Laythe and it would have been a trivial thing to slap on a return booster to come back to Kerbin. It was more than large enough to simulate life support and crew living space for at least 4 Kerbals. (it was designed for 16 without consumables).

Trying to add a cycler and shuttles to get to and from the station at Laythe would have seriously overcomplicated the mission when I could have alternatively just slapped a Kerbin-return engine on it.

[Moon Goddess]

Well one advantage I'm seeing now that I think of it, is I could send up a large habitat craft and get it started on the cycle on super efficient ion engines. Since it will be unmanned at this time, long burn time doesn't matter.

Then on it's first pass back to Kerbin we bring the light shuttle up to speed and dock.

[hobbsyoyo]

Oh gosh, bringing up a shuttle to dock with something whizzing by at faster than escape velocity sounds tricky. Good luck!

[SpaceSphereOfDeath]

I once did this by accident, I flew past Duna that put me into a Duna-kerbin crossing orbit, with a 1:1 ratio with Duna, or a 2:3. And I kept getting random kerbin encounters