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Efficient ascent.


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8 hours ago, MoridinUK said:

With suggestions to move fuel fro. The terrier stage, wouldn't that mean carrying more mass for longer or is the extra twr worth it? I can't wait to try some of the suggestions! 

Moving fuel from the terrier to the first stage means a greater fuel mass in the first stage, and smaller payload mass in first stage (stages 2+ are payload for stage 1). This gets you more deltav out of stage 1, but less out of stage 2.

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Thanks all!  I have a pretty good idea of where and how the thign 'should' work and I'm relatively happy I can get that up into orbit with 270ish to spare... 

This thread has really helped me understand much better!  Now for the science and then I may actually have what I need to put up a comm network (solar panels etc)

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13 minutes ago, MoridinUK said:

Thanks all!  I have a pretty good idea of where and how the thign 'should' work and I'm relatively happy I can get that up into orbit with 270ish to spare... 

This thread has really helped me understand much better!  Now for the science and then I may actually have what I need to put up a comm network (solar panels etc)

270 is a good amount to have from a low orbit, if you're not doing anything more than returning. Remeber, it takes some fuel to deorbit. You wouldn't want to cut the margins any finer. 
While playing around with your orbit, I had Val in a 71x140Km orbit, with no fuel, and 2 hours life support left. 
She had to get out and push to get back. It worked, then I forgot to deploy the main chutes :(

Edited by Lelitu
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High above Kerbin is 250km or higher.

At your PE try to raise the AP above 250km but keep some fuel for reentry. Do all experiments/reports when higher than 250km, SP for free :wink:

Do your reentry burn at (near) AP, ~30m/s dV needed.

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MoridinUK,

 Glad to see you're getting this all sorted out. A couple more pointers:

- Those goo canisters on the nose make the rocket aerodynamically unstable. It won't want to track cleanly at high speed below 25 km altitude. They should ideally be in a storage bay. 

- I follow the method in that tutorial almost exactly with one difference: I reduce my thrust so that my t/w follows the function t/w= 2sin(pitch).

Pitch/ max acceleration

70/ 1.9
60/ 1.7
50/ 1.5
40/ 1.3
30/ 1.0

This costs a little DV, but pays off big in engine mass and aerodynamic stability. I generally run 1.4g off the pad for my first stage, so it takes a little while to get to the point where I need to start throttling back. I design my second stage for 0.7g. By the time it lights off, there's no need to throttle back except for precision.

Best,
-Slashy

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