Going small

[Rocket Farmer]

So I started Kerbals about a month ago. About 3 weeks ago I was very proud of my first mun manned rover with kerbal return mission. My Pre-transfer LKO payload was 115 tonnes.

Last night I finished a Dres mission with a manned rover landing, a permanent satelite, and return to kerbin for Bob. Total pre-transfer LKO payload was under 14 tonnes.

Anybody else find that smaller is better?

[Pontiac]

From a power to weight ratio, yes, always. From a kerbals engineering stand point, I'd have to ask two questions....

"Whachya talking about Willis?"

and

"What do you not understand about toke-toke-pass maaaannnn??"

[SouthPhilly]

I know for me I always try to keep it light and simple. Even if it means sending 2 or 3 vessels and have them meet up at the target. Just makes for more successes for me.

[regex]

I, too, find that smaller ships are much easier to manage (unless you're docking, in which case there is a happy medium that makes everything butter).

[Brofessional]

It's all about delta-v.

The amount of acceleration you need to accomplish a maneuver is the same for a big ship or a small ship; but the less mass you have, the less thrust you need to accelerate.

[katateochi]

I love BIG, massively over-complex and unnecessary. That said, going small is so wonderfully refreshing. Nevermind any of the rocket science reasons, it's just nice to run a silky smooth mission at 60FPS. Going small does eliminate a lot of the frustration from game issues and can be just as rewarding. There's no reason being small has to be limiting (in terms of where you can get to). I just like hulking behemoths, I keep a fire extinguisher next to my computer.

[AustralianFries]

I try to find a mix between the two extremes. Ships that are small enough to have good maneuverability but big enough to look cool.

[llamatoes]

I have to say, bigger rockets= cooler, I occasionally do light missions, such as a Duna landing return for pre-transfer mass of 14 tonnes, needless to say, it was satisfying for purely flying reasons, as lugging around all your plumbing may be really awesome in some respects (the bigger they are, the better), tight is satisfying.

[SRV Ron]

Once a career mode is implemented, going small will be the most cost effective way of conducting most missions especially for probes to all of the bodies in the Kerbal system. It is a matter of tweaking rocket designs to find that ideal medium of thrust, launch weight to orbit, and matching of staging to get the mission done.

Ideally, your design should get your payload into orbit with the second stage having enough fuel left to get you into a Mum orbit or Kerbal escape velocity. From there, you can tweak the design to get a bigger payload into orbit for station construction or smaller to conduct orbital missions at reduced cost.

The smaller, lighter, more efficient designs are much easier to control during launch.

Once there is a bigger selection of engine power ranges, that task of tweaking designs will become a lot easier. Example, a rocket between the power of a T-30 and an T-909 would be useful for a second stage after a T-30 powered first stage and have the power to push a T-909 power third stage efficiently into orbit. Same for something between the power of a Mainsail, a Skipper, and a poodle.

Edited July 4, 2013 by SRV Ron

[MR4Y]

Since the engines are the same, regardless of mass, smaller is better. Logically speaking, you don't need a TWR of 1 in space, but your maneuvers will take more time to do and you're forced to do 50/50 burns.

[SRV Ron]

Since the engines are the same, regardless of mass, smaller is better. Logically speaking, you don't need a TWR of 1 in space, but your maneuvers will take more time to do and you're forced to do 50/50 burns.

While the smaller engine will require the 50 50 burn, you will be pushing a smaller total mass around thus achieving a better thrust to weight advantage in both launch and exploration. That is why an LV-909 can have an overall advantage on long range probes at 1/2 ton then the comparable thrust atomic engine at 2.25 tons even though it is twice as efficient on fuel.

[Rocket Farmer]

@ SRV Ron

I agree completely. Small doesn't mean low TWR at all. My new satelite has a single ant rocket but weighs in at only .25 tonne. That's got a TWR of about .7 and has 1700 DV.

My current moon ascender weighs in at under .4 tonne and has a single 24-77 motor. That's good for a TWR of 5.5 and a DV of 1100.

[bsalis]

More is still more.

Larger rockets have more chemical energy (fuel) to convert into kinetic energy (velocity).

Kinetic energy is a function of mass and velocity...

However if you build big and don't get more delta-V, then what you have done is get more mass moving. So that is more.. but probably not more of what you want.

[SRV Ron]

My Atlas test rocket, designed to almost reach orbit on the first stage, has over 7/8 fuel left in its T-400 fuel tank on its second stage. It's first stage uses the Rockomax tanks and a Skipper engine. That was more then enough fuel to safely do a Mun encounter. But with less then 20% fuel left, I decided not to risk orbital insertion and attempting to come back on thruster power if the fuel came up short. I set the encounter up with a correction burn to place the altered path to a paragee on Kerban under 10,000 meters. Mission was successful with Bob recovered.

I probably could have done a high orbit of Mum, then planned a burn to encounter Kerbin with aerobraking encounter using thrusters for the correction or additional burn if needed. My other design did so on its second stage with a similar amount of fuel remaining. I may try it later with a probe and not risk stranding a Kerbal in space.

Edited July 5, 2013 by SRV Ron

[Paul Kingtiger]

I build as small as possible, adding up all the delta V requirements for the mission then seeing how minimal a rocket I need to achieve the goals.

That's where I find the fun, but of course everyone enjoys the game in different ways, which is one of the cool things about it.

I get a lot of enjoyment out of trying to shave off weight in the VAB.

[SRV Ron]

With the bigger Atlas, it was a test of getting the first stage almost to orbit. The fact that it got the single Kerbal command module second stage to orbit with lots of fuel left to reach Mun was a bonus. The much smaller Redstone design is more then enough to place a satellite into regular or polar orbit with fuel to spare to correct the plane or circularize up to 250K. Its slightly longer first stage cousin has placed a Kerbal in orbit, no thruster pack, with just enough fuel for return. I'll have to test if the probe design can place a Kerbal in orbit or if it will come up just short as removing a T-200 length of fuel tank from the original stage one gave quite a boost in performance on the T-45 rocket engine.

[Moon Goddess]

I use a life support mod, there's no way I can send a light kerballed mission.

[SRV Ron]

Test with the Atlas Rocket using a probe showed an extra T-200 on the second stage was indeed needed if Bob was to return from a Mun orbital mission. The probe is in a 50,000M orbit with slightly more then the fuel needed to fill the T-200 tank.

[Tw1]

Only one of my interplanetary voyages came close to 115 tones LKO in one launch, so if that was one lunch, you must've been doing something right.

[Sof]

Its actually quite surprising how a small change in weight of the payload can make a big difference. I always end up surprised by the endurance of my smaller rockets with little engines when I'm so used to massive spaceships.

[metaphor]

It's all about the mass ratio. A small rocket with small engines will take a small payload to the same place that a large rocket with large engines will take a large payload.

[ScramblesTD]

It really depends on the mission profile.

If I'm just sticking up an orbiting probe or a terrestrial rover then I tend to build just big enough to get it where it needs to go. When it comes to space stations or extraterrestrial habitats though I tend to build big. Big. If I can lift half a space station into orbit with one launch, then that's just two pieces that need docking. Less launches, less pieces, less opportunity for things to wrong.

[acealeam]

Yep. I could make a 2000 ton Eve launcher, or my 11 ton eve launcher. Personally, I dont want to kill my computer.