Min/Min Mun Challenge!

[Superfluous J]

My ship is similar to Smidge's (the cubic plus mini decoupler weighs less than the radial decouplers) but has some noticeable differences. I couldn't get less than 450 fuel and still return (though made it there with less than 400 once). It still took many tries...

In the end, 450 units of LF and 4:49:50, which I believe will make a 4 way tie for first on the Both leaderboard

Alas no, it's "only" a 2-way tie for first and a 2-way tie for 3rd. I like how the two biggest sweeps (lowest fuel, sacrificing time and lowest time, sacrificing fuel) are tied.

But well done on being one of the two tied for 1st!

Edited January 9, 2014 by 5thHorseman

[tavert]

This time without abnormally glitchy physics, 360 fuel in 2:45:03.

Javascript is disabled. View full album

Parachutes cost you lots of dV on craft this small. Better to just save a couple hundred m/s for a powered landing on the return. The last drop tank stages off the front, you have to cut the throttle and turn off-prograde briefly to ditch it partway through the Munar injection burn.

In case you guys haven't watched this before, you should check out this quite-a-few-versions-old video from Abyssal Lurker where he lands on the Mun in just over half an hour:

(uses SRB's so not in line with the rules here, but damn impressive!)

[magico13]

tavert that is really impressive! There goes my 15 minutes of being (tied) in first I imagine mechjeb helps quite a bit for this since it fly the most efficiently. My piloting skills aren't quite up to par in efficiency. My craft had something like 7 to 8 km/s of dV according to flight engineer, but I was getting substantially less in practice. I applaud your good design and may have to try the powered landing if I go for this again. (Though I had to quickload a few times from the Mun in order to actually get an intercept without running out of fuel...) I for one welcome our new robot overlords (and their human ship builders)

Thinking I might try for shortest time using nothing but mainsails and skippers, maybe just mainsails, just for fun! (Who doesn't love mainsails on a lander? Me, that's a terrible idea, but sounds very Jeb.)

[tavert]

MechJeb isn't absolutely perfect, but it's repeatable and saves me time - I didn't need any quickloads on that trip thanks to MechJeb (once I worked out the launch timing anyway), but if I was flying manually I would've.

Word of warning on the powered landing, it can be fairly tricky to maintain a retrograde heading during re-entry since the Kerbal and the chair have lower drag coefficients than the rest of the craft.

The dV discrepancy you were seeing was probably due to not accounting for the Kerbal's mass. On EVA and when in seats, they mass 0.09375 tons, which costs a decent amount of dV on these tiny landers.

Edited January 9, 2014 by tavert

[magico13]

I tried to "simulate" the kerbal by placing one of the 0.1 ton probe bodies ontop of the flat octo probe to see what that would do to the dV, but was still getting high values. I fully expect that it was my piloting that resulted in the discrepancy, I was doing less than stellar Part of that was because I didnt have the seat perfectly centered. Usually the probe's SAS could handle it, but I had to fight it every now and then. I could have centered it better, but after several hours of trying to get something to return from the Mun, it wasn't a high priority.

I have an idea I may try tomorrow.

[Superfluous J]

This time without abnormally glitchy physics, 360 fuel in 2:45:03.

WOW. Nicely done, got you in 1st on the BOTH board, and somehow moved zorque into 2nd and the rest of us into a 3-way tie for 3rd.

Parachutes cost you lots of dV on craft this small.

I actually thought about looking into putting tiny tiny wings (or even just the smallest control surface) on my craft and flying it to a (probably crash) landing. As long as I could slow it down enough the Kerbonaut should survive, right?

Right?

[magico13]

Well, I tried going for a direct ascent but it didn't really save any time (it actually took much longer than my last attempt) so don't count this one (it also wasn't a valid entry, couldn't take off again). Though, I think if I waste a lot of fuel I could use this method to get there in under an hour.

[Superfluous J]

Well, I tried going for a direct ascent but it didn't really save any time (it actually took much longer than my last attempt) so don't count this one (it also wasn't a valid entry, couldn't take off again). Though, I think if I waste a lot of fuel I could use this method to get there in under an hour.

Cool idea, but I've found that direct ascents (I used to use them all the time instead of orbiting first) use a lot more fuel than doing a gravity turn.

Also, if you spend just a little more fuel after your orbit reaches Mun, you can easily double or even triple your orbit height which drastically reduces your time to Mun. Also, you should burn to ideally impact Mun directly or have a very low (5km or even a little less) so you don't have to slowly come up on it.

I'm also posting this on your video

I really like your ladder to the chair approach. My method of perching the pod somewhere so the Kerbonaut falls onto the craft but the pod falls away from the craft has been pretty clunky.

Edited January 9, 2014 by 5thHorseman

[Superfluous J]

I actually thought about looking into putting tiny tiny wings (or even just the smallest control surface) on my craft and flying it to a (probably crash) landing. As long as I could slow it down enough the Kerbonaut should survive, right?

Right?

Right! And wrong. I made a VERY light descent craft, possibly the lightest possible (for me, at least) at:

1 okto2

1 chair

2 cubic octagonal struts

2 small control surfaces

Total mass: Just over 2 tons.

Then I built a lifter with the same dV as my other entry, and it had 405 fuel! I think I could even scrape it down to under 400 if I optimized it. But I didn't bother.

Because instead I tried to launch it.

And it's so light, that the little wings cause it to spin out of control and crash.

I think I'm done with trying this

[Lazro]

You could just put wings on the back...

[magico13]

I really like your ladder to the chair approach. My method of perching the pod somewhere so the Kerbonaut falls onto the craft but the pod falls away from the craft has been pretty clunky.

Yeah, at first I was trying to drive him over from the SPH, but after it taking forever and me flipping the command pod onto the hatch or having it explode I realized there has to be a better way. Then I tried putting a ladder on the launch clamp, but couldn't get close enough to the chair (also, Kerbals can RUN UP the launch clamps. It's ridiculous!). So I figured, why not put the ladder pointing up and have him climb it, then detach the pod on launch? The platform was needed because he didn't always grab the ladder when exiting and would fall 150 meters, yet always be fine.

My first almost successful run of this challenge required I EVA into escape from the Mun and try to "bounce" on reentry. My latest outro is actually video from the "aerobraking" maneuver

[Superfluous J]

You could just put wings on the back...

I tried to stabalize it with fins (not wings) but there is a TINY weight margin where it's just better to slap a parachute on there. My setup was 1/3 the weight of a chute so I had 2/3 of a chute's weight left before it wasn't worth it.

And has been said before, if you just keep a little fuel, you can probably burn right before landing and maybe lithobrake your engine and fuel tank for the very final landing.

And while I have no desire to do this any more, I should say I'll happily still rank entries. And I'm very happy that building so many versions of this ship has given me this picture:

Edited January 10, 2014 by 5thHorseman

[Tigik]

it took me 7:03:10 to plant my flag on the Mun

<iframe class="imgur-album" width="100%" height="550" frameborder="0" src="http://imgur.com/a/YVXsB/embed"></iframe>

143 deltaV is enough to safe landing without any parachute!

[magico13]

it took me 7:03:10 to plant my flag on the Mun

<iframe class="imgur-album" width="100%" height="550" frameborder="0" src="http://imgur.com/a/YVXsB/embed"></iframe>

143 deltaV is enough to safe landing without any parachute!

To embed imgur albums, just put the "YVXsB" between two tags like this ["imgur"]YVXsB["/imgur"], but without the quotes

(Don't worry, I messed up video tags when I first tried to use them. Youtube's embed option doesn't work here.)

Also, that's so little fuel! You've got enough of a margin that you could maybe fill the tanks a little more and drastically reduce your time, which would get you solidly in the top parts of the BOTH leaderboard!

Edited January 10, 2014 by magico13

[Superfluous J]

it took me 7:03:10 to plant my flag on the Mun

Javascript is disabled. View full album

143 deltaV is enough to safe landing without any parachute!

I made your imgur album work in the forum.

Nice first post ever! 299 fuel, very well done. What was the purpose of the empty tank. Or is it tanks?

[Smidge204]

Pretty sure the empty tank is just there as a base to launch from.

In other news, dangit - bar raised again!

=Smidge=

[Tigik]

I made your imgur album work in the forum.

Nice first post ever! 299 fuel, very well done. What was the purpose of the empty tank. Or is it tanks?

Thank you for embeding my pictures

Smidge204 is right, the tank is only launch pad and holds the craft and MK1 lander can that contains a kerbanaut

Fortunately, i made a trip to the Mun and back by the rocket like this a few days ago. The difference is that current craft has aditional toroidal tanks, engines and a chair instead of a ladder

[PLAD]

I'm new to the forum, but if you're still taking entries here's mine. I assumed Werner Von Kerman was about to retire and didn't care if Kongress fired him over the fuel use. And that the Krussion flight was almost to Mun before Jeb could launch.

Javascript is disabled. View full album

Zero Hours, 43 minutes, 33 seconds from launch to the flag plant. 61425 fuel at launch.

I first tried a huge-DV rocket but I couldn't get the big numbers AND high acceleration all the way. Most important for me was when I began the deceleration. Even 10 seconds too early (at 7km/sec!) will cost you many minutes of slow coasting if you brake too soon, and of coarse a spectacular splat if you're 1 second too late, given the somewhat aggressive landing vector I chose.

I'd have added another stage to the booster but my computer was getting quite slow. What do those people use who have 100+ orange-tank boosters?

[Superfluous J]

I'm new to the forum, but if you're still taking entries here's mine.

I am still taking entries (As far as I'm concerned this is always open) though I obviously wasn't checking the thread and my "new posts" filter missed you as well. Sorry about that!

Very nice run. I love the super over-engineered ships with sub-hour landing time

Edited April 14, 2014 by 5thHorseman