long thin rockets or short thick rockets?

[amateur astronaut]

i want to go to the mun with it

[Dman979]

Long and thin works better than short and thick. The thinner your rocket's cross-section is, the less drag it has.

Edited May 11, 2018 by Dman979
Changed wording.

[doggonemess]

15 hours ago, Dman979 said:

Long and thin works better than short and thick. The thinner your rocket's cross-section is, the less drag it has.

I've found that short thick rockets work great if you keep your speed low until high altitude. Check out my Muna RL-9S rocket on Kerbal X.

[Geonovast]

However, short thick ships work better for landing, especially low gravity moons.   Keep your lander short and wide.

[Dman979]

1 hour ago, doggonemess said:

I've found that short thick rockets work great if you keep your speed low until high altitude. Check out my Muna RL-9S rocket on Kerbal X.

Well, yeah, but that's because you have so much drag that it's inefficient to go fast at a low altitude.

Because of the Oberth effect, though, the optimal rocket is designed to pick up as much speed as possible in the lower-and-mid-atmosphere, since your fuel expenditures are most efficient (DV per fuel burned) there.

Assuming everything else is equal, the Oberth effect basically says that if you burn the same amount of fuel at different altitudes, the lower burn will have you end up at a faster speed.

In summation- it's possible to get to the moon in a short, fat rocket, but it's generally best to use a long, skinny one. Think Oliver Hardy vs. Stan Laurel.

[Gargamel]

15 hours ago, Dman979 said:

In summation- it's possible to get to the moon in a short, fat rocket, but it's generally best to use a long, skinny one. Think Oliver Hardy vs. Stan Laurel.

To get there, yes.  But to land, tall thin vessels can be a pain to keep upright.  So you need a short fat lander, on top of a tall thin rocket.   Which isn't that hard to build.   

If your lander has enough Dv to land, orbit, and return, then you just add a transfer/ initial descent stage below that.  Now your vessel is starting to get tall and thin, and then the launcher to get all of that to orbit ends up being tall and thin.

I mean, it's not rocket science or anything.....

[Dman979]

17 minutes ago, Gargamel said:

To get there, yes.  But to land, tall thin vessels can be a pain to keep upright.  So you need a short fat lander, on top of a tall thin rocket.   Which isn't that hard to build.  

Well, yeah. I was only referring to the getting out of the atmosphere part, since you and I both know that there's no air in space.

17 minutes ago, Gargamel said:

I mean, it's not rocket science or anything..... ^{[citation needed]}

 

[Xd the great]

Both works, but on tall rockets be careful not to topple it over during launch.

I have a craft capable of landing on the moon, its on my kerbalX page, feel free to check it out.

I use mechjeb though.