Craft falls back into kerbin's atmosphere when trying to circularize

[DeclanTheDarkest]

I'm playing a Science save and I just started it, I am also a noob at KSP cause I don't play it much. Also, would going to minimus be easier than going to the mun for my first landing on another planet?

[Vanamonde]

Minmus does not orbit directly over Kerbin's equator, and it's smaller, so it's a harder target to hit. However, once you get to it the gravity is so much weaker that you fall more slowly, which can make the landing itself easier. Oh, and the "seas" of Minmus are perfectly flat, making it less of a risk that your ship will fall over. 

As for being unable to circularize, I suspect the thrust of your upper stage is too low so that you are unable to attain orbital speed before gravity reasserts itself. Pictures of your craft may help diagnose the problem. 

Also, welcome to the forum.  

[Zhetaan]

13 hours ago, DeclanTheDarkest said:

I'm playing a Science save and I just started it, I am also a noob at KSP cause I don't play it much. Also, would going to minimus be easier than going to the mun for my first landing on another planet?

Welcome to the cozy little group!

I don't have much to add to @Vanamonde's advice; I will say that the Mun and Minmus present different challenges, but they are roughly equal in overall difficulty.  Both present general piloting challenges for the early game:  the Mun's is one of landing, and Minmus's is one of navigation.  You can prepare for the Minmus challenges by learning to rendezvous two vessels in Kerbin orbit (especially so with one in an inclined orbit), and many people do that first.

Since you asked about landing in particular, yes, Minmus can be easier on that specific point, but while Minmus has perfectly flat places, it also has its share of hills and uneven terrain.  You need to select your landing site with some care (and pay attention to the area around that site--some players have wrecked landers on the slopes next to the flats).  On the other hand, you won't learn unless you go, so give it a try.  If you like, you can take pictures and post them in Mission Reports!

[OhioBob]

@DeclanTheDarkest, if your craft is falling back into the atmosphere before completing the circularization burn, then it is likely your circularization burn is taking too long.  One way to decrease the duration is to use a higher thrust-to-weight ratio, as Vanamonde suggests.  Though I suspect the better strategy is to try to reduce the size of the burn.  You've given us little information to go on, but I'm guessing the problem is likely in the trajectory that you are flying.  My suspicion it that you are lofting the rocket into a steep arc with a very large circularization burn.  There are two problems with this:  (1) the duration of the burn is long, and (2) the time you spend near the top of the arc is brief.  My suggestion is that during ascent you pitch the rocket over more aggressively and fly a flatter trajectory.  Make the arc of your flight path as long and as flat as possible, without being so flat that your craft is overcome by drag.  Doing so will decrease the size and duration of the circularization burn.  You will also spend much more time near the apex of the trajectory and outside the atmosphere.  This should allow you to complete the circularization burn with ease.  This type of trajectory is also more efficient fuel-wise.  It will take some practice to perfect the technique, but you'll get there.

 

Edited August 31, 2019 by OhioBob

[DeclanTheDarkest]

23 hours ago, OhioBob said:

@DeclanTheDarkest, if your craft is falling back into the atmosphere before completing your circularization burn, then it is likely your circularization burn is taking too long.  One way to decrease the duration is to use a higher thrust-to-weight ratio, as Vanamonde suggests.  Though I suspect the better strategy is to try to reduce the size of the burn.  You've given us little information to go on, but I'm guessing the problem is likely in the trajectory that you are flying.  My suspicion it that you are lofting the rocket into a steep arc with a very large circularization burn.  There are two problems with this:  (1) the duration of the burn is long, and (2) the time you spend near the top of the arc is brief.  My suggestion is that during ascent you pitch the rocket over more aggressively and fly a flatter trajectory.  Make the arc of your flight path as long and as flat as possible, without being so flat that your craft is overcome by drag.  Doing so will decrease the size and duration of the circularization burn.  You will also spend much more time near the apex of the trajectory and outside the atmosphere.  This should allow you to complete the circularization burn with ease.  This type of trajectory is also more efficient fuel-wise.  It will take some practice to perfect the technique, but you'll get there.

 

Thank you! I fixed it, you were right. I didn't do the gravity turn right and the time I spent at the Apoapsis was very little.