Exel

I hope this superb mod gets updated for 1.2!

Brilliang!

Yeah, and there should be an option to switch to the EVA kerbal from the mouse right-click menu. I mean we already have the "control from here" function, so it just needs to be extended to EVAs. Far more intuitive than a keyboard binding for new players.

Yes indeed. I achieved a similar level of efficiency with the 6 km turn start once I steepened the climb from 33% to 50%. So it seems that with any given craft there's more than one, potentially multiple, viable ascent paths to get roughly similar fuel efficiency. I'm sure there's a formula for calculating that, given that TWR, gravity and atmospheric drag are all known factors, but at least MechJeb doesn't seem to be aware of it. Would the optimal ascent path be one where, as Z.K. suggested and as my data seems to also indicate, you can constantly maintain terminal velocity at full throttle but not go over that? In English that would mean that slow craft should turn earlier and with a more shallow profile, while fast craft should climb steep and turn late - so exactly opposite to what the KSP Wiki is telling us to do.

I also found turn start altitude to be a far greater factor than turn shape, again in line with Z.K.'s observations; a 10 km turn start saved almost 200 m/s of Dv compared to starting the turn at 6 km. That was over 10% of the total remaining Dv of the craft at the end of gravity turn, so a significant amount. This was with a slow rocket. A faster rocket doing a steeper climb could well benefit from an earlier turn start, as Z.K.'s graph shows (yellow line).

I ran a few more tests with a heavier rocket (TWR < 2.0 at the start of each stage) and this time a shallower trajectory (33%) was more fuel efficient than the steeper trajectory (50%) that dominated the efficiency comparison with my faster rockets (first-stage TWR > 2.0). The difference to a circular 70 km orbit wasn't significant, but it was noticeable. So it confirms the above findings by Zephram Kerman that slow rockets should use a shallower climb while fast rockets should climb steeper - just don't overdo it.

That's just really counter-intuitive for new players. I mean, if you're playing a new space exploration game for the first time, your first instinct isn't to start collecting soil samples from your own planet right next to the launch pad just to get your first manned space craft. That just doesn't make any sense. KSP already has a steep learning curve, and to appeal to a broader audience it has to hook new players from the first minutes they get into the game. Otherwise people won't bother with learning the more advanced tricks. Hooking players into the game requires giving them a fun experience right off the bat before the serious learning part kicks in - and in this game the fun means rockets. Exploding rockets, yes, but still rockets.

The science lab should be made more useful in the future. As it is, it makes little sense to go through the effort of parking a space station on Mun or Minmus orbit for the lab, since you can only transmit only a fraction of the science you'd get from returning to Kerbin. It's far more convenient and less time consuming to just fly back and forth between Kerbin and Minmus to get all of the science than tinkering with a lab, given its low science return on transmissions. I'd be okay if took two lab-processed science experiments for every one returned to Kerbin to produce the same amount of science, but as it is there's very little incentive to actually use the lab at all. At least when you're not flying to very distant bodies - but even then, I'm not so sure if hauling an entire space station would be less of an effort than flying back and forth several times. The science lab is a fantastic idea, but it needs to be more useful than just a 10% boost on transmitted science returns to be a viable alternative to bringing every sample back to Kerbin.

I did some testing with the turn shape. Turn start was 8 km and turn end at 50 km for all launches, with target orbit either at 100 km or 400 km. Testing was done with a pretty simple 5000 Dv (atmo) rocket and with Corrective Steering on for all launches. TWR in the lower atmosphere was mostly between 2.0-2.5, dropping to 1.5-2.0 in the middle (for 60 seconds) and rising back to 2.0-3.0 in the upper atmosphere. Bolded lines mark the most effective launch trajectories: Target orbit at 400 km: With 33% trajectory the remaining Dv at the end of the gravity turn was 1030 m/s. With 40% trajectory the remaining Dv at the end of the gravity turn was 1092 m/s. With 50% trajectory the remaining Dv at the end of the gravity turn was 1124 m/s. With 66% trajectory the remaining Dv at the end of the gravity turn was 1100 m/s. Target orbit at 100 km: With 33% trajectory the remaining Dv at the end of the gravity turn was 1281 m/s. With 50% trajectory the remaining Dv at the end of the gravity turn was 1335 m/s. With 66% trajectory the remaining Dv at the end of the gravity turn was 1264 m/s. (When the apoapsis was raised further to 400 km from the 100 km periapsis, the craft had 1071 m/s Dv remaining at the end of the maneuver, meaning that launching directly to a target altitude of 400 km was more effective than first reaching a 100 km orbit.) Tweaking the turn end altitude: Considering that 50% turn shape gave the best result in both scenarios, I tested the effect of changing the turn end altitude to 70 km for both launch scenarios: With 50% trajectory the remaining Dv at the end of the gravity turn was 1107 m/s - compare to 1124 m/s Dv remaining when the gravity turn ended at 50 km. With 50% trajectory the remaining Dv at the end of the gravity turn was 1431 m/s - compare to 1335m/s Dv remaining when the gravity turn ended at 50 km. Conclusion: The difference in fuel consumption with different turn shapes is ultimately quite small, with changes in the turn shape saving less than 2% of the craft's total Dv or between 5-8% of the craft's remaining Dv at the end of the gravity turn. The effect of changing the gravity turn end height from 50 km to 70 km was inconsistent, but seems to favor ending the gravity turn lower in the atmosphere if your target orbit is not much above the limit of the atmosphere. With a higher target orbit a longer gravity turn is marginally more efficient. It would be interesting to test the effect of the turn start altitude together with different turn shapes, but with no time warp available during burns it's way too time consuming for me to bother testing it further, given that the differences found in these tests proved to be so small (although not insignificant, depending on your mission and its margins of error your craft has for pulling it off successfully).