Lowest start weight challenge (optimal construction)

[adammada]

Thanks, but most of the flight i use mechjeb!

Recently mechjeb gives me strange results. I order him to end at 3 or 20 km periapsis over mun, but he ends with -199 (hit the mun).

I assume, that circularizing orbit, not direct descent, cost less fuel?

I also think that Nao's lander could be quite usefull. Bigger tank would go on top and could would be decoupled after emptying. I just don't know how he managed to connect those tanks.

Edited September 3, 2012 by adammada

[Apotheosist]

Recently mechjeb gives me strange results. I order him to end at 3 or 20 km periapsis over mun, but he ends with -199 (hit the mun).

I assume, that circularizing orbit, not direct descent, cost less fuel?

I also think that Nao's lander could be quite usefull. Bigger tank would go on top and could would be decoupled after emptying. I just don't know how he managed to connect those tanks.

I dont use mechjeb to do everything, only to keep me pointed in the right direction. I control the amount and timing of thrust. When I do the trans Mun injection, I use smart A.S.S to keep me pointed prograde, and I just wait for the Mun to appear over the horizon. Mechjeb is not very accurate, it does give starnge results. It can still be useful though, you just need to have a mix of useing mechjeb and your own control.

Yes, I think it's more efficient to retro burn at about 3km and circularise orbit before landing.

I think the way Nao connected the tanks was by connecting one fuel line to the decoupler, then from the decoupler to the lower tank. Like in this picture, which I am trying right now: http://imgur.com/tsST3

I tried the one you showed with one jet engine, but I didn't quite make it. I do think that it would be possible if I flew it more efficiently. But using Nao's tank seperation with bigger tank might be better. We will see.

[Apotheosist]

I made it with the design I posted a picture of above.

Nomination: Command Pod Mk1

Ship name: Minimun 16 IV

Start mass: 9.8

Screenshots: http://imgur.com/a/wIvg0 I forgot to upload pictures of the whole rocket here, but it is the one I posted above, 2 SRB's, 1 jet engine.

Craft file: http://www./?kd62ywilic1n3z5

Thanks to Nao and adammada for design ideas on this one.

Im still going to try to fly something a teeny bit lighter...

Edited September 3, 2012 by Apotheosist
Craft file

[adammada]

I will try to learn how to fly efficent on that ship. But it is not loading, i get info about missing part "Engineer", and it is on craft save file.

[Apotheosist]

I will try to learn how to fly efficent on that ship. But it is not loading, i get info about missing part "Engineer", and it is on craft save file.

Sorry about that, it's a part I use to help design ships. I have taken it off, it should work now.

[ako]

Sorry, i too slow :-)

Nomination: Command Pod Mk1-2

Ship Name: Krasnoyarsk-2

Start mass: 57.3 tons

Stages: 5

KSP: 0.16

craft file: https://dl.dropbox.com/u/62695719/KPS-MPL/krasnoyarsk2/KRASNOYARSK2.craft

Edited September 3, 2012 by ako

[adammada]

@ako

I'm impressed. Mine design has less weight, but i do use turbojets. Good job.

[ako]

adammada, thank you. You show good way to great results.

I need little more time for try turbojets. I do not know their capabilities. :-)

1-2 days and i try show my jet powered rocket :-)

[Nao]

Wow very nice design Apotheosist, the only improvement i can see would be exchanging stack decoupler with radial on top tank, that would help shaving one fuel line too. That would make it lighter from 9.775 kg to 9.700 kg

Something like

I don't think i can do anything to improve on that design so ill try the bigger pod challenge.

[ako]

Just by replacing first stage of my "Krasnoyarsk-2" to 6 turbojets i can get 47.4 tonns start mass.

[Nao]

Nice one ako =3

Actually wait , there is 11,6 ton last stage with 2 ton thrust engine ... TTW of 0,17 with burn time of 20 minutes ... it would barely hover over Mun while full , I commend your patience in flying that thing.

Also just a small

I had great fun flying this 43,7 t firecracker, it was wobbly as hell, the first ship to defeat mech-jeb while being controllable by keyboard!.

Unfortunately due to the damn command pod having different drag than other parts, just before Kerbal landing it flipped me over

There is obviously tons to improve, but one thing i noticed SBR > all other propulsion method in terms of efficiency , they have specific impulse of around 460! and zero engine weight.

[Nao]

Sorry for double posting.

My entry for big pod challenge:

Ship Name: Black Mesa

Start mass: 42,05

Stages: 14

Album with 26 pic's some of them are quite colorfull =3 http://imgur.com/a/9SyOD#0

Its still possible to go lighter, for example i used almost whole tank on vertical part of Mun landing at night due to booster almost stopping my craft while completing the transfer (didn't thought he would have such big deltaV).

I really like the staging work on this one: jet engines to 13km then firing 3 boosters, after 25s jettisoning them with jet engines and engaging next 3 SBR's. At the end of their burn there is control problem, as rocket leans hard (idk why since rocket is pretty symmetrical at that point). After some time to regain proper attitude next SBR is fired, this time only one, its mostly used to get proper 80km Ap. The next set of SBR's are set up to fire in pairs (3x2), second pair gives me orbit, and last pair almost makes transfer. At any point between firings, it's possible to turn ship around and use small LFE to make corrections. Last SBR is burned at Mun transfer Pe almost stopping craft still over Mun(next flight i'll make sure to make it around 2km not 50km and on bright side). Rest is simple rocket science.

One more thing is that the damn pod has drag of 0.1 so parachutes are a must (i had to open them at 17km in my flight) to get proper engine downward direction. Landing can be done without destroying engine , but i suck .

cheers

craft file: