Is this rocket good enough for any destination?

[OptiSTR]

I just tried to fly to Duna, how is that MEchJeb needs 140 YEARS!!! to get into orbit with Duna?....

And, I just spend half an hour engineering this rocket with my limited parts, do you guys think its good enough

to be able to reach and land on any destination? (and hopefully come back?) Oh and it got 8300dV

Edited November 11, 2013 by OptiSTR

[wasmic]

Land on? Definitely. Return? Maybe from Ike, most likely not from Duna.

[John FX]

Have a look here.

Where can I go

If you know the Dv of your craft, you can find out where you can go. Engineer redux or mechjeb can tell you your Dv.

[Xetalim]

Mechjeb likes to not waste delta V, i think.

Going to another planet takes time, waiting those 140 years might save 10 delta V.

[Pugspaceprogram]

If you are going anywhere with a lower gravity than kerbin, you could do without the ladders, save yourself a little weight. Also, you might want to lose the photovoltaic panels and replace them with the tiny panels, which you have at the top. I suggest replacing the fins with them. Other than this, you should be able to get to eve, duna, and maybe dres or moho. I dont suggest landing on eve though. As long as you spread your ∆v by aerobraking and using gravity assists, you might be able to get to jool, but you would have to stay there a while if you want to get back.

[OptiSTR]

Have a look here.

Where can I go

If you know the Dv of your craft, you can find out where you can go. Engineer redux or mechjeb can tell you your Dv.

Sweet thx, with this rocket I have 8300dV, using your calculator I CAN land on Duna, question is, can I return back to Kerbin later on?...

[John FX]

If MJ gives me silly numbers I`ll often just try to find a burn that will get me out to just outside Duna orbit for the Ap and then I`ll target it and do another burn to rendezvous next orbit. Takes a while (200-300 days, longer than waiting for the window) but gets you there easily. Not the most efficient either but I don`t like doing interplanetary missions without some spare fuel anyway if they are return trips.

[John FX]

Sweet thx, with this rocket I have 8300dV, using your calculator I CAN land on Duna, question is, can I return back to Kerbin later on?...

Sorry for the hugeness of the image

EDIT : According to this you will need 1300+330+30+250+10-130=2050Dv or thereabouts to get home from Duna surface.

EDIT : With 8300Dv you can do it but you must aerocapture and use parachutes to land on Duna. On the way back you must do the same so remember to repack your chutes!

Edited November 11, 2013 by John FX

[Wallace]

It's not good enough to be in the front room unless it wipes it's feet properly!

[Rhomphaia]

If you are going anywhere with a lower gravity than kerbin, you could do without the ladders, save yourself a little weight. Also, you might want to lose the photovoltaic panels and replace them with the tiny panels, which you have at the top. I suggest replacing the fins with them. Other than this, you should be able to get to eve, duna, and maybe dres or moho. I dont suggest landing on eve though. As long as you spread your ∆v by aerobraking and using gravity assists, you might be able to get to jool, but you would have to stay there a while if you want to get back.

Ladders don't cost weight, they have zero physics significance. so no reason not to have them.

[Kerolyov]

Have a look here.

Where can I go

If you know the Dv of your craft, you can find out where you can go. Engineer redux or mechjeb can tell you your Dv.

Hmmmm that guide is a bit basic as doesn't have very accurate figures, particularly Moho you'd likely need more unless your interplanetary intercept is bang on. I use http://alexmoon.github.io/ksp/ for transfers to other planets and http://forum.kerbalspaceprogram.com/threads/41652-A-more-accurate-delta-v-map?highlight=delta can help with transfer between a planet and its moons

[Pugspaceprogram]

I was going to post a porkchop plot, but John Fx ninja'd me.

[Richy teh space man]

Just a piece of advice, check to make sure your thrust to weight ratio is more then 1 before you land on Duna, if it isn't then you won't be able to take off again.

[Commissioner Tadpole]

Have a look here.

Where can I go

If you know the Dv of your craft, you can find out where you can go. Engineer redux or mechjeb can tell you your Dv.

Newbish question, I know, but how exactly can I figure how much Delta-Vs my rocket has?

[celem]

Its pretty tricky without an addon. Most folks use mechjeb or kerbal engineer redux which will give you goodies like twr / dV for each stage. Otherwise your going to need a big bit of paper, a pencil and a calculator, and the help of someone smarter than me.

[SkyRender]

I'd do a bit of a redesign on that rocket if I were you. It looks like you just clipped those tanks on the side of the launch stage straight on; that's a big mistake. You should put them on decouplers so you can drop them when they're empty. Better still, feed fuel lines between them and the central stack so that you have a full load for your main lifter engine once they're ditched.

[andrewas]

Newbish question, I know, but how exactly can I figure how much Delta-Vs my rocket has?

Rocket equation. Google will find it and explanations of how to use it. The math isn't complex, just tedious, the worst part is toting up the wet and dry mass of each stage of your craft. Which is why I let mechjeb do the number crunching.

[boxman]

Land on? Definitely. Return? Maybe from Ike, most likely not from Duna.

Why would it not be capable of getting back from duna?? If you do aerobrake to achieve orbit around duna, then there should be no problem returning.

[Caelib]

You would be amazed at how much less fuel you need to go really far -- avoid falling into the "I must take every piece of science equipment" trap. The "Mystery Goo" and "Science Jr." parts will gain you some decent science, but it's not worth the fuel cost to carry them outside Kerbin and its moons (IMO); at least not for landing -- maybe a free-return flyby. Also, taking any atmospheric science equipment to anything but Lathe, Eve or Duna is also a waste.

Don't underestimate the simplicity and power of the 1.25m rockets!

[Kasuha]

Have a look here.

Where can I go

If you know the Dv of your craft, you can find out where you can go. Engineer redux or mechjeb can tell you your Dv.

That calculator can't be trusted.

If I can get to any planet, I can get to any of its moons too. If I have enough dv to brake in their orbit, I have enough dv to brake in their moon's orbit. If I can get to Eve, Jool, or Laythe, I can get on their orbit because I can aerobrake. And if I bring chutes I can even land of them without spending any extra dv.

[Lewiskerbington]

Newbish question, I know, but how exactly can I figure how much Delta-Vs my rocket has?

Here's the Delta-V calculator I use: http://www.strout.net/info/science/delta-v/

The full mass is the overall weight of your ship and the dry mass is the weight of your ship when it is out of fuel (to find this look at the dry mass vs. the full mass of the fuel tanks you use).

Also make sure you change it from exhaust velocity to specific impulse before you put in your engines isp.

[SyberSmoke]

Why would it not be capable of getting back from duna?? If you do aerobrake to achieve orbit around duna, then there should be no problem returning.

Taking off from any planet with an atmo would be a pain with that setup. He only has four nuclear engines on it and their thrust is trash for anything then traveling great distances. Just judging from the design, he would not have enough thrust to lift off using only the nukes as I do not see any additional stages or engines.

The rough math is that He has a dry mass of at least (Only major parts and tanks) 18.1. while he has a wet mass (with fuel) of 53.1. Four nukes gets a TWR of 1.334 with a single full tank (X200-16) totaling to 18.5 mass with another tank and 9 more mass that TWR drops to 0.89. And that is just two tanks and four engines.

I would suggest looking to make your craft a little lighter, using lighter parts initially to see just how far you can get. Once you have some sense of how far certain things can get you, then you can make a more efficient design. Oh and just so you know, The Rocomax 48-7S can do a very good job. It does not have the ridiculous efficiency of the nukes, but it also does not add 2.25 mass to your ship. Play with them.

Edited November 11, 2013 by SyberSmoke

[Carl]

In a challenge thread i put up someone got a 10 ton lander on my class D booster out to a moon of Jool and down safely, but they where scraping the tanks when they did. So it's certainly possible.

[John FX]

That calculator can't be trusted.

If I can get to any planet, I can get to any of its moons too. If I have enough dv to brake in their orbit, I have enough dv to brake in their moon's orbit. If I can get to Eve, Jool, or Laythe, I can get on their orbit because I can aerobrake. And if I bring chutes I can even land of them without spending any extra dv.

They do say at the bottom that they have put the maximum benefit from aerobraking at 200m/s and assumed you would make a stable orbit around the planet before going to the moon and the reason is to allow extra Dv for safety...

All of these tools are for newer players who need the margin for error. If I can be near a planet with an atmosphere then I can pick pretty much any moon and get to it with hardly any Dv usage. As you say, if you can capture around a planet and your destination is a moon you would just get into that orbit and get captured by the moon for hardly any Dv.

The calculator can be trusted in that you will get there in that much Dv, just not trusted to mean you have the most efficient ship for your mission...

Taking off from any planet with an atmo would be a pain with that setup. He only has four nuclear engines on it and their thrust is trash for anything then traveling great distances. Just judging from the design, he would not have enough thrust to lift off using only the nukes as I do not see any additional stages or engines.

The rough math is that He has a dry mass of at least (Only major parts and tanks) 18.1. while he has a wet mass (with fuel) of 53.1. Four nukes gets a TWR of 1.334 with a single full tank (X200-16) totaling to 18.5 mass with another tank and 9 more mass that TWR drops to 0.89. And that is just two tanks and four engines.

I would suggest looking to make your craft a little lighter, using lighter parts initially to see just how far you can get. Once you have some sense of how far certain things can get you, then you can make a more efficient design. Oh and just so you know, The Rocomax 48-7S can do a very good job. It does not have the ridiculous efficiency of the nukes, but it also does not add 2.25 mass to your ship. Play with them.

Maybe the current craft could be used for a flyby? Sort of like a pre-mission to scout for the main landing?

As you say, it doesn`t look good for ascent from Duna. More TWR and higher atmo ISP.

Edited November 13, 2013 by John FX

[Smidge204]

If you just want to fly by/orbit stuff, it'll probably be more than sufficient. As already discussed, though, for many places you might not survive a landing and you're most certainly not getting home again!

For starters, you should add lightness. Ditch the Cupola, replace it with an adapter (Rockomax Brand Adapter 02, flip it over so the "small" side is up) and put the materials bay on that, or use nothing at all since it's not required. Then stick a Mk 1 command pod on top of the materials bay for your Kerbal. That will save you 3.6 tons or so, which isn't a lot but it's more than nothing.

You should not need that much RCS fuel. Consider some radially mounted cylinders instead. Or, if you got the tech, put in a large SAS module and one ZK-4 battery module in place of the RCS tank and ditch the RCS system all together. Stick some OX-4 series solar panels somewhere, or a pair of RTGs. That'll save you a couple more tons. Every little bit helps!

Nuclear engines are not really appropriate for landing/ascent engines, except maybe on smaller moons. Certainly not anyplace with an atmosphere! You could probably replace two of them with something else like LV-T30s and use action groups to toggle which pair is active; Use the LV-T30s for liftoff and the nukes for interplanetary. It doesn't look like you have any other thrust so unless your fuel tanks are nearing empty I would still not expect you'd make it off of some bodies.

For leaving heavier bodies, consider more staging just like taking off from Kerbin. As a general rule, drop dead weight as every opportunity - but especially when trying to get off the ground!

=Smidge=