Fueling Station: What Is The Best Orbit Around Kerbal?

[Dyingsoul]

Guess what! I'm a fairly new player but I already have some progress in science mode! I've successfully landed on Mun and got back to Kerbin. Now I'm planning to visit Minmus. As a preparation move I've made a cool fueling station around the kerbin. The question is what is the best altitude for a fueling station? I mean: PE and AP should be equal or not? What is the optimal orbit around the Kerbin for a Fuel station? Or is it simple doesn't matter? I'm using mechjeb and it works perfectly! Already docked 2 times at my stations in order to supply it with more fuel. But I just got these questions in my mind because I want to spare as many fuel as I can when I am filling this station (less round of refueling the fuel station, less launch less time). If you can, please explain the why too.

PS.: Planning to make a station around the Mun as well. Do I need a different orbit there than at the Kerbin with a Fuel Station?

Thanks in advance!

Edited May 16, 2015 by Dyingsoul
Answered

[Geschosskopf]

Welcome aboard!

Anyway, all fuel stations should be located for the convenience of intended customers. Usually, this means putting the station at the point where the fuel will be used a lot, such as when doing transfer burns. Because burns are more efficient in lower orbits (Oberth effect), it makes sense to put the fuel stations in low orbits. How low is a matter of taste and style, and how hung up you are on maximizing the Oberth effect.

[Gaarst]

IMO, a slightly elliptical orbit is easier for docking as you can figure out Ap and Pe of target easily.

For a refueling station, it depends on the ship you use to get to your destination: a lower orbit requires less delta-v to reach the station, but a higher orbit requires less delta-v after refueling.

If you plan on using it for further destinations, I advise getting it into a lower orbit to have a less massive launcher, but use big tanks. You'll still have to keep a margin for rendez-vous manoeuvres (obviously docking a ship in a 70x70km orbit isn't easy). An orbit between 100 and 150 km should be fine, but it will also depend on your personal preferences (mine is in a 250x350km orbit which makes it easier for direct rendez-vous, without circularising first)

Keep in mind that you can go almost anywhere and back without refueling and without huge ships (except for an Eve return mission and maybe Tylo). A mission to Minmus can easily be achieved without refueling as it requires about the same amount of delta-v as for the Mun.

Something that will be useful for later missions to do is to get an orbital refueling station and ore extracting station at Minmus that will refuel big ships going to other planets. Any manoeuvre around Minmus requires few delta-v so moving large fuel/ore tanks around is very cheap in fuel.

[Dyingsoul]

Haha I love this community already! I get useful informations in matter of minutes you guyz are awesome!

Well, the Kerbal Space Industries told me that they want at least one station around every planet's orbit, thats why I made one even around the Kerbin. Since there are no other points to make Space stations than nice design and self-entertainment I decided to make Refueling Stations everywhere since it has a good purpose. Even if I (or the mechjeb since I've just started learning that too) mess up manouvers or I design my ships poorly because of the science mode, I think it is a good Iead to swarm the planets with stations.

My station's AP is 350km and the PE is around 250km. I guess I'll lower it to 150 AP and 100 PE to be able to target further with other ships.

Thanks for the detailed answers!

[TK421d]

i actually have 2, i keep a small science station and emergency 'top off' station about 100km. and a much larger fuel depot and mission staging platform at 700km

[vicwarrior]

To minimus you wont need a refueling station, generally your mun lander will easily do the job for minimus.

However that refueling station will be usefull when you start your mining infraestructure and go interplanetary.