No revert, no quicksave.help.

[Palaceviking]

Hi, I've started a career on hard with all comms settings on most difficult,  no respawn etc, etc.   I've been lucky enough early game and picked up rainbow dash (kerbal space ponies) as an extra pilot/victim but now I've gotta do mùn and have had a few swimming lessons with rainbow dash out in the sea after initial launch failure (about 150,000 spesos so far!)and deciding to decouple everything and play it safe with the parachute. 

For my first munshot on hard what twr at which stage would you go for, I'm a confident pilot but I wouldn't say proficient and need say a 20%(vague?, thought so) safety margin.

[bewing]

The Mun has 1/6th the gravity of Kerbin. So you basically need 1/6th the TWR that you would want on Kerbin to accomplish the same task. (Keeping in mind that a takeoff is the same thing as a landing, if you simply reverse time.)

[DD_bwest]

i use 1.3 for lift off.   .8ish for the orbital insertion and the transfer burn stage.

i like a higher twr for landing, which isnt to hard.  i think the sparks are the best engine for mun shots.  i like a twr around 4ish

 

also you can always make a sandbox save and test the rocket there before bringing it to the real thing lol think of it as a computer simulation test 

Edited January 13, 2017 by DD_bwest

[Tex_NL]

Build and test your craft in a separate sandbox. Then move it to your career. 1+1=2

[Snark]

10 minutes ago, Palaceviking said:

For my first munshot on hard what twr at which stage would you go for, I'm a confident pilot but I wouldn't say proficient and need say a 20%(vague?, thought so) safety margin.

To be clear, you've already become proficient at getting to low Kerbin orbit, yes?  (I'm guessing yes, but your original post doesn't actually say.)

If you haven't... I'd suggest practicing that first, before going to the Mun. 

Assuming that you have, and that getting to LKO isn't a problem for you:  The main difference between going to the Mun and going to LKO is dV.

More to the point:  You need to concern yourself with dV; you don't need to concern yourself much with TWR.  Focus on dV.

Reason:  as @bewing points out, the Mun's gravity is quite low compared with Kerbin's.  Chances are good that your TWR will be plenty if you have even a little bit of rocket power available.  For example, even if you have a heavy 10-ton lander, a single Terrier will give you plenty of local TWR on the Mun.  So TWR isn't much of an issue.

As for dV:  once you get to LKO, you'll need ~850 m/s to get a Mun flyby, then another 200-300 m/s to capture to low Mun orbit, then ~600-800 m/s to land on the Mun, then another ~600-800 to get back to Mun orbit again, and finally another 200-300 m/s to return to Kerbin.

Put it all together, and add another few hundred m/s on as a safety margin, and you end up with ~3000 m/s total dV needed after arriving in low Kerbin orbit.  If you only need a flyby and aren't landing, then you can do a free-return trajectory for a third of that.

 

[Palaceviking]

Sorry didn't say, I've done a couple careers already (last one was interstellar) but this is the first one where I can't spam quicksave and make crappy designs work, I see what @Tex_NL and @DD_bwest are saying about sandbox testing but I love the idea of my r&d actually costing something (about 150k) in losses sometimes.

[Spricigo]

1 hour ago, Palaceviking said:

Sorry didn't say, I've done a couple careers already (last one was interstellar) but this is the first one where I can't spam quicksave and make crappy designs work, I see what @Tex_NL and @DD_bwest are saying about sandbox testing but I love the idea of my r&d actually costing something (about 150k) in losses sometimes.

How about this for a simulation that cost something :