Question about gravity turns and maneuver nodes

[Roastduck]

1) When making a gravity turn, should I go straight over to the 45, or gradually ease the prograde over to it?

2) I have a pretty good handle on using maneuver nodes, there's just one thing that confuses me about them. Should I start my burn right on the node, finish it on the node, or have my burn straddle it?

Edited December 28, 2013 by Roastduck

[nine_iron]

I found this page useful http://wiki.kerbalspaceprogram.com/wiki/Gravity_turn

I think when it comes to gravity turns there is no "right" answer, just an optimal one.

I just lean over around 20* 10,000m then turn more to 30* at 20,000. before cutting my burn when the orbit hits 100km. Then I wait for PE before burning to circularise.

Not optimal but easy to rememeber, I also don't burn until boosters cut out unless I have a nice stable rocket.

Edited December 27, 2013 by nine_iron

[Ravenchant]

1) That depends on you, but a straight-to-45° pitchover is not a gravity turn. Also, in real life or when using FAR, the rocket would most likely disintegrate if attempted

2) Ideally, time it so that about half of the burn is done before the node and half after it. Not exactly 50%, because you're losing mass during the burn, but you don't have to pay much attention to that usually.

[Cashen]

I usually start my gravity turn around 8km or so and slowly ease over, never straying too far from the prograde marker. The goal is to be around 45 degrees by the time I pass 10km or so.

You should have your burn 50% before and 50% after the node. So I divide the burn time in half and start when the countdown reaches that number.

[mhoram]

Doing the gravity turn gradually is more efficient - the straight version is more convenient. Do as you see fit.

alterbaron published some results on ideal gravity turns for a single SSTO rocket on http://forum.kerbalspaceprogram.com/threads/46194-I-need-someone-help-me-do-some-math-for-launch-optimization

[Roastduck]

Thanks, guys! some really great information has been shared.