Opinions on my latest landers?

[Brainlord Mesomorph]

* that lander can is very heavy, its better to use 2 small cans

Yes, but it supports the docking port

* You could radially attach the science stuff, and save of adaptor weight and extra docking port weight.

They are modular. One lander can carry several of them on different missions, one lab can process and reset them (while the lander is off somewhere else) or several can be loaded onto a single return vehicle.

* Why does it have parachutes? its not landing on Laythe.

LOL the 1st one I built I sent on a Munar testflight, only to realize it could never come home. As a multipurpose vehicle, it should be able to land on Kerbin. (they may come in handy on Duna, too)

* Why not use a smaller, lighter probe core?

Couldn't find a place to put it!

* Why not use a smaller size docking port?

All my ships (that can) use large docking ports, they are stronger and now a standard.

* Why not use a LV-N? it will use less fuel (since this is meant to be refueled and reused)

it DOES!

* Do you really need all that RCS fuel?

docking and refueling ops use a lot of monoprop.

* Do you really need all those landing legs, do they really have to be the largest size ones?

you're right, I probably don't ( I was originally designing for .8 Gs)

* Why are there docking ports under your lander?

I was thinking it would dock to a Service Module or drop tanks down there, but now that I look at it's delta V, you're right they should go

* Do you really need all those solar panels?

Sunlight is dim on Jool, I decided to double up on my solar panels on all the Jool ships.

I see a lot of weight that could be trimmed.

maybe, but .. why?

EDIT: Yeah, I'll slim it down a bit - for half a G or less. But all-in-all my best work yet as a multi-purpose lander.

Edited November 3, 2014 by Brainlord Mesomorph

[Starman4308]

Yes, but it supports the docking port

See comments regarding the Sr. docking port. Also, a 1-man pod plus a couple Rockomax adapters would weigh less than the 2-man pod.

LOL the 1st one I built I sent on a Munar testflight, only to realize it could never come home. As a multipurpose vehicle, it should be able to land on Kerbin. (they may come in handy on Duna, too)

I suppose if standardized designs are your cup of tea, but you will save enormous amounts of mass and money by making more specialized designs with only as much as they need. I suppose it comes down to playstyle; I don't mind spending six hours designing and optimizing a simple unmanned Duna/Ike land-and-return mission (and I still am not done, courtesy of the unforgiving nature of 6.4x Kerbin dV).

Couldn't find a place to put it!

While the aesthetics are annoying, you can either stick a small probe core in between two stacks and strut the stacks together, or use a radial attachment port to slap on an OTKO2. Do be aware this would make the probe core face sideways, so you'd want to right-click and control from something pointed vertical.

All my ships (that can) use large docking ports, they are stronger and now a standard.

You do realize how blasted heavy those things are, right? They're mostly used for gigantic space stations.

docking and refueling ops use a lot of monoprop.

Are you using MechJeb for docking? I manually do it using Navyfish's Docking Port Alignment tool: even kinda sloppy, hasty docking maneuvers should use less than 15 m/s in monopropellant. It also helps to have small vehicles which don't need huge amounts of RCS to move. One suggestion: switch to your target, right-click the docking port in question, "control from here", and use Smart ASS (or eyeball the target indicator) to point the docking port to the maneuvering vehicle before killing rotation and switching back.

you're right, I probably don't ( I was originally designing for .8 Gs)

It's also the sheer number of legs you have. It's very excessive.

Sunlight is dim on Jool, I decided to double up on my solar panels on all the Jool ships.

Not that dim. At Jool, you'll be seeing about 50% Kerbin power, and 4 1x6 panels should still be more than enough. The only things which might require more than that are ion engines and science labs; the first often requires RTGs or tons of batteries anyways for night-side operations, and the second can be buffered with a relatively small number of physics-less 400-charge batteries.

maybe, but .. why?

Cost/mass considerations. A lot of the people here (like me) are optimizers, who try to design the smallest rocket possible to do the mission. Yours has a bunch of wasted mass.

[Laie]

But all-in-all my best work yet as a multi-purpose lander.

The most important thing about standardization and multi-purpose is knowing when it is enough, when you have to snap out of it.

If you design a lander with 3000m/s and Kerbin-TWR=0.5, it can handsomely land and return from every body except Eve, Tylo, and Laythe. It will be too powerful (=inefficient) for Pol and Bop, but can make up for that by being able to visit both in one go, without needing to meet up with a mothership between the landings.

A Tylo lander has to be more than twice as powerful, both in TWR and delta-V. IMO, it's quite obvious that a dedicated Tylo lander makes sense, as it's capabilities cannot be reasonably used anywhere else.

if you want to stick with the modular approach, I suggest you keep the standard lander module relatively small (see above), and devise a Tylo Extender that can be docked to it.

[Brainlord Mesomorph]

"radial attachment port to slap on an OTKO2" is what I normally do.

IMHO MechJeb is cheating. (Yes, I guess actually playing this game requires more monop than allowing the game to play itself.)

RE: optimizing:

I guess there are different kinds of automobile engineers as well. There are a race car engineers who weigh every sparkplug and SUV designers who can’t put in enough cup holders. (I’ve seen some really weird designs) I personally, I was trying to make something on the order of a space HUMVEE, a go-anywhere, do-anything, land-hard-and-still-take-off kind of vehicle. And yes, HUMVEEs are not fuel efficient. My original goal was one lander for all of the Joolian moons.

(because really, I’m spending far too much time in the VAB - and not piloting spaceships)

So, like I said I’m going to trim it down into half G HUMVEE. And get on with this mission.

I’ll post pics of the final designs soon.

Thanks

[Jouni]

* Why not use a smaller size docking port?

Small docking ports are meant for small 1.25 m modules and stationary space stations. If you use them for bigger modules, you'll start running into problems at around 5-10 tonnes, if you use physics warp while under thrust. Somewhere around 15-20 tonnes, small docking ports start being problematic under thrust even without physics warp.

[KerikBalm]

Yes, but it supports the docking port

So does a small lander can, it won't look as nice though

They are modular. One lander can carry several of them on different missions, one lab can process and reset them (while the lander is off somewhere else) or several can be loaded onto a single return vehicle.

You can still do that without the adaptors, and with smaller docking ports

1 central science JR, 2 radially attached science Jrs, then of course all the other science experiments.

LOL the 1st one I built I sent on a Munar testflight, only to realize it could never come home. As a multipurpose vehicle, it should be able to land on Kerbin. (they may come in handy on Duna, too)

Duna is fair enough, but is it so multipurpose that it will go between the jool system and Duna, and Kerbin?

I custom* build my landers for each body, and put orbiting fuel depots + reusable landers in orbit to shuttle back and forth

*custom is a bit of a stretch, most are just variations on a standard design +/- parachutes, +/- ion drives, +/- a pair of 48-7s rockets for extra TWR at the end (tylo, but it didn't work so well, and I decided to go with a staged lander), +/- tiny winglets for steering on reenty (duna), +/-science instruments (I sometimes use modular science pacakges, that I discard once the science is collected, leaving an unhundered shuttle for future surface activities), and of course, Eve gets a completely custom, non-reusable lander, Laythe gets a custom spaceplane.

All my craft I send to other worlds are never intended to land on Kerbin again. I have many many craft that can't land on Kerbin, and I use SSTO crew shuttles for the final return (granted, my Duna lander could make it back to Kerbin, since reentry heating isn't modeled, the same goes for my Laythe SSTO)

Couldn't find a place to put it!

I see several 1.25m tanks there, including one right under you command pod

All my ships (that can) use large docking ports, they are stronger and now a standard

You can do 3 of the standard ones, and still weigh less.

Also, I don't have a problem constructing 100+ ton ships using just the standard ports to attach the landers (It helps if the lander is smaller, which is what I'm trying to convince you to make.)

Often I send them up as 1 unit with the docking port connection strutted. The struts disconnect after the first undocking, but after that, there are no big burns to make, and the craft will be lighter (propellant consumed + fuel depot detached), and in my mission profiles, the lander stays at the destination orbit (With an exception for my Jool-4 mission, I'm hitting all 4 remaining moons -setting up a large operation on laythe- in one mission, using 1 lander - will shed some parts after tylo- )

it DOES!

Mods? part clipping (thats cheating IMO) - it sure looks like an LV-T45

docking and refueling ops use a lot of monoprop.

I manage to dock my smaller landers using none at all.

Sunlight is dim on Jool, I decided to double up on my solar panels on all the Jool ships.

What do you actually need all that power for?

It shouldn't be the reaction wheels, and you've got no Ion drives.

You can time warp when transmitting science.

maybe, but .. why?

Efficiency, if you want it to be a reusable workhorse, you probably don't want to have to send fuel out to it twice as often as you could if you just trimmed the fat

Edited November 3, 2014 by KerikBalm

[Brainlord Mesomorph]

Mods? part clipping (thats cheating IMO) - it sure looks like an LV-T45

SON OF A B*&%( !

In my last rebuild, I dragged and dropped the wrong part!!

(No wonder this last one isn't preforming in orbit like it's supposed to!)

sigh - back to the VAB!

I'm going to build a half-G muilti-purpose single engine nuclear lander. -- I'll get back to you when I have one,

(%^$#@#$!

(thanks)

[Starman4308]

IMHO MechJeb is cheating. (Yes, I guess actually playing this game requires more monop than allowing the game to play itself.)

The thing is that Mechjeb is really terrible at docking and wastes loads of monopropellant. I was encouraging ​you to fly it manually; I use Mechjeb, but not for docking.

[KerikBalm]

I was trying to make something on the order of a space HUMVEE, a go-anywhere, do-anything, land-hard-and-still-take-off kind of vehicle. And yes, HUMVEEs are not fuel efficient. My original goal was one lander for all of the Joolian moons.

I was doing a Jool-4 Mission, not a Jool-5 mission (Laythe is special and gets its own mission), and I gave up on that.

Tylo and Laythe are the problem -> The LV-N really just doesn't cut it on these two worlds.

Both cases have a surface gravity of 0.8 Gs, while I find Moho/Duna's gravity to be approaching my limit for using these.

Low TWR for Tylo wastes dV due to gravity drag, and you need a lot for ascent and descent.

Laythe: you can save a lot on descent with chuts, but the atmosphere kills you on ascent, particularly the LV-N's ISP.

For Laythe, you really want a lander with airbreathing engines, with its low orbit velocity (relative to Kerbin), you can get to orbit on jets alone.

For Tylo, doing a single stage lander is hard (but doable), you don't want to add useless jet engines and parachutes to it.

In one of my attempts at a single stage lander, I used an LV-N for most of the descent (arresting orbital velocity), and 48-7s in the final stages for their high TWR, but it didn't have enough margin for my comfort, so in the end, I gave the lander drop tanks, after dropping the tanks, the same lander configuration is for Val, Bop, and Pol -> nearly identical to my Mun, Minmus, Eeloo, and Dres Lander. It would be nearly identical to my Ike lander, except that is the same thing as the Duna lander (the dV cost is low, so the added weight of some extra winglets and a pair of radial chutes is not a big deal).

One lander design for all airless bodies except Tylo is fine, but I don't actually intend to move the lander from one planet's SOI to another.

Duna's atmosphere is thin enough in most places, that it can be treated like an airless body (still, a pair of chutes helps a lot, but I do no more than 1 pair)

[Jouni]

Back in 0.23.5, I was flying around a lot in the same ship that was originally designed as a reusable Tylo lander.

Or, technically, it was not a lander, as I landed with the main ship and left the command module and the extra fuel tank in orbit. There were two main ideas:

1. While low-TWR landers waste around 1000 m/s on Tylo, they can save a lot of mass. Delta-v from 800 s engines is simply not comparable with delta-v from 350-390 s engines.
   
2. If you have a nuclear transfer stage with high enough TWR that you don't die of boredom during Kerbin departure, you can use it as a Tylo lander, if you leave the rest of the ship in orbit. Carrying a separate lander around would just be inefficient.
   

Overall, ion engines or nuclear engines are almost always a more efficient choice for landers than conventional rocket engines. They might not be the best choice, however, because low-TWR landings are hard to do right in the stock game.

After the mission, I realized that if I have a reusable ship that can land on Tylo and return to LKO, it can go everywhere except Kerbin and Eve. After that, I visited a lot of places with it.

You may notice that the engine module has RCS in some pictures but not in others. The Eeloo mission highlighted some deficiencies in the original design, so I decided to replace the engine module when the ship was visiting Kerbin the next time. I landed the old engine module safely with the help of an utility tug with a few parachutes, and launched a replacement before the Vall-Bop-Dres mission.

[Yasmy]

This is fairly minor, but it always bugs me. Your large lander appears (I could be wrong) to have the RCS thrusters on the ordinal points (NE, SE, SW, NW) rather than on cardinal points (N, E, S, W).

If you thrust in a cardinal direction, approximately 29% of your RCS fuel is wasted, since your thrusters thrust at 45 degrees to your net thrust direction.

[Brainlord Mesomorph]

This is fairly minor, but it always bugs me. Your large lander appears (I could be wrong) to have the RCS thrusters on the ordinal points (NE, SE, SW, NW) rather than on cardinal points (N, E, S, W).

If you thrust in a cardinal direction, approximately 29% of your RCS fuel is wasted, since your thrusters thrust at 45 degrees to your net thrust direction.

OHH, that explains it. I thought the retros were firing in strange combinations! But that creates quite a design problem. All of the hatches on all of the lander cans are at cardinal points. So your ladders, and retro blocks are always going to have to be in the same side of the ship.

Back in 0.23.5, I was flying around a lot in the same ship that was originally designed as a reusable Tylo lander.

http://jltsiren.kapsi.fi/ksp/0.23.5/tylo_ship_3.jpeg

Those look like my designs. The very big heavy thing they’re telling me not to do. (Why does it have three crew compartments? Looks to me like the entire command module is unnecessary)

Anyway to recap: All the statistics I gave you about the “Gamma 4 Nuclear Lander†were total crap.

I had accidentally placed (and was weighing) an LVT 45,, and then was doing math for LV-N. I thought that last rebuild was coming out substantially shorter than previous prototypes (although I was doing everything I could to make it short) what this really means is: I wasted most of my Sunday. (And then embarrassed myself here.) So now I feel like a total Kerbal. (“You mean that wasn’t the nuclear engine?, Oopsâ€Â)

And here’s another thing that happened:

You have to test things. I was testing my landers at the KSC. So while I was mentally designing for half a G, when I would put a lander on the launch pad, and the gear would collapse under its weight, I would go add bigger struts. So I ended up building for one G. And this then rippled through my entire space program, bigger service modules, bigger boosters, etc. etc.. This led to a massive fuel consumption problem, which I then solved by figuring out how to move massive amounts of fuel around. I am constantly docking and refueling. I have designed massive fuel lifters and 150 ton interplanetary tankers.

I thought that was part of the game.

Another guy in this thread was saying “I don’t you realize how big and heavy these things are†and LOL No I didn’t! So, I tried to follow your instructions, small lander can, just as much fuel as I need, etc. etc and I built this. The Gamma 5 (LOL) Single Engine Nuclear Lander/ Prototype One:

I’m not happy with it. I designed it to specification;. 10 tons fueled. TWR: .496 (Kebin) Max Delta V 3200m/s with a 1.75t (trisci) payload.

Its sluggish, underpowered, and difficult to steer. And doesn’t have nearly enough thrust if you are coming in hot. (realize I’m used to ridiculously large heavy landers, with huge amounts of thrust and torque.) And a 1.75 ton payload top hat doesn’t effect a 30 ton lander much, on a 10 ton lander its quite awkward. (now you’re going to tell me to rethink this whole TriSci idea! &%$@!)

Thanks to the help guys, I’m going to mark this thread answered.

I think I am getting this now, it’s not just a question of delta V, or TWR, or even both of them together, there’s also a question of performance and handling. I’m back in the VAB for now.

I may need a 2 engine nuclear lander, or perhaps a combination of thrusters, with liquid fuel rockets to kick in for extra boost.

I’ll start another thread when I have something to show you.

Thanks again.

Edited November 4, 2014 by Brainlord Mesomorph

[Jouni]

Those look like my designs. The very big heavy thing they’re telling me not to do. (Why does it have three crew compartments? Looks to me like the entire command module is unnecessary)

It's my standard for missions longer than a few days: three kerbals, a Mk1-2 command pod, a hitchhiker, and a Mk2 lander can. I considered installing mods that would simulate life support and kerbal sanity, but in the end I found it more convenient to pretend it by using large enough crews and some extra living space.

[Kerba Fett]

Only thing I'd like to throw in, is to replace the stock ScienceJr and Goo thingies with Universal Storage mod equivalents. Will save you a ton of space, a bit of weight and will look much smarter.

It's true that the Universal Storage wedges are a lot smaller and look better, but you don't get the science instruments in the basic mod. For those you want to get Dmagic Orbital Science.

Considering you can put 8 of the material bay wedges in the same space as 1 stock material bay, it's almost like a cheat.