Help me with a circularized orbit

[Mikenike]

Hi guys,  I have played KSP for around 6 months, and have made around 20 orbits, but never have circularized an orbit. How do you circularize an orbit? Also, what do you recommend for a lifter for a station with a large Sci lab, a hitchhiker, and batteries and solar panels, with RCS and docking ports?

[James Kerman]

Hello @Mikenike.

I've moved your post to gameplay questions.

[Mikenike]

Ok, thank you

[SRB]

Burn prograde at periapsis and until it matches the apoapsis

[guesswho2778]

or burn horizontal relative to the planet just before you get to the apoapsis (or periapsis if your lowering the orbit) and stop when the periapsis and apoapsis are halfway between "the flip"

Edited July 2, 2019 by guesswho2778

[Vanamonde]

Tidiness is about the only reason to make your orbit fully circular. Real spacecraft often consider elliptical orbits good enough. Don't worry about it.  

[Mikenike]

I wanted to make a station, ( I described the station in the first post) and an orbital relay system to practice that kind of stuff for other planets, and deep space stations.

[guesswho2778]

@Mikenike oh i somehow missed the description of your station completely (i didn't sleep well last night) sorry dont im not to good at interplanetary missions (as my laptop is not a very good computer for ksp) so i cant help you much with that. but ask around im sure someone could help or you could hop on youtube and look around im sure there are some tutorials somewhere on this kind of thing

[Mikenike]

Yeah, that was going to be my starter station, in Kerbin orbit, as I got more experienced in stations and lifters, I would do that.

[Chel]

@Mikenike

[Mikenike]

Wait, does this lower AP or raise PE?

[Guest]

Let me try and remember. (The game isn’t in front of me)

Maybe I can add some tips about what thrusting in some different  SAS orientations will do in relation to an orbit? (I’m not an expert)

Prograde: if the apogee node (the highest point of your orbit) is still in front of you this should raise it. If the apogee node has passed behind you while trying to achieve a stable orbit see below.

Radial Out: If the apogee node has passed behind your craft this means you are now heading back down, to correct this thrusting radial out should pull the apogee node from behind you to back in front. When it’s in front again you can switch back to prograde.

Circularisation: Prograde/Retrograde. When you have a stable orbit and want to make it nice and circular, you might want to make the adjustments at the apogee and perigee nodes by small thrusts either to retrograde or prograde. The adjustments you make will basically effect the opposite side of your orbit. So for example, if your perigee is low you would travel to your apogee and thrusting to prograde would raise the perigee nodes altitude.

(prograde raise opposite node. retrograde lower opposite node.)

Another way of doing it is not to worry about the location of the nodes too much, just your current altitude, then you can make adjustments to bring the node you want to you at your desired altitude, it might save you some time but is a bit more advanced I guess.

Edited July 3, 2019 by Guest

[Rocket In My Pocket]

1. Launch out over the ocean, drop nose to 45 degrees slowly, burn till Ap is 70+k. Cut engines, drift till time to Ap is 30-45 seconds.

2. Burn prograde, keeping time till Ap between 10-20 seconds. Nose up to increase time, nose down to decrease. Burn until Pe is 70+k. (Pretend the Ap is a ball you are pushing along on your nose, you don't want to get in front of it, or too far behind it.)

3. Congrats, circular orbit.

Edited July 3, 2019 by Rocket In My Pocket

[Empiro]

The simplest procedure: burn until AP is about where you want. Point prograde and burn when about 40s out. If time to AP increases, reduce/cut throttle, and try to get time to 35s. If it still increases, cut until 30s, and repeat. When you get down to 5s, you should be moving at almost orbital velocity, and your PE should be pretty close. Burn slowly and you should be able to get within 1km on the AP/PE.