What Planets can this ship reach and orbit?

[Pecan]

Jool and Laythe, too.

Duna and Eve are within deltaV capabilities anyway, which is why I'm including them. Laythe is 'probable' with aerobraking, if Stickyhammy wants to push his luck, but I'd recommend not for first interplanetary. Jool is only 'possible', don't you think? Assuming the point is to get back I wouldn't want to rely on aerobraking to that extent if I'd never used the ship-design before, etc. etc.

[Red Iron Crown]

Ah, I wasn't taking the capabilities of the ship into account, was going for completeness. You're right that Duna or Eve makes a better first target for interplanetary transfer.

[GoSlash27]

The math is super- easy. Well... in your case it's complicated by your mixing engines, but other than that, it's a simple equation.

just tally up the mass of your ship when fully fueled and when empty. divide the first total by the second. Then take the natural log of that number.

Now multiply by your Isp* and 9.81. That's exactly how much delta v you can generate.

2 points of advice:

1) Those engines are not ideal for cruising in vacuum and they will severely hamper your range. Like putting a top fuel dragster motor in your Geo Metro. You should really be running the LV-N.

2) be careful using delta V maps, as they can be misleading. If your target planet has an inclined orbit or you attempt the trip at the wrong time, it can cost you a lot more than the map suggests. Also those numbers don't include all the correction burns, which can add up to a lot. But as Allmhuran pointed out, if you can get to Eve, you can get just about anywhere... *IF* you're really sharp with your maneuver nodes and aren't particular about how long it takes.

Best of luck!

-Slashy

2)

* figuring your delta v when using dissimilar engines is tougher. You have to scale the Isp of each engine by it's relative thrust to the total, so the stronger engines will have more of an impact than the weaker ones. In your case, 4 skippers have almost exactly the same thrust as a KR-2L, so you're close enough to split the difference. call it 365.

[GoSlash27]

Oops! Didn't read the last page before opening my yap. Nevermind...

I recommend ditching those SRBs. They are worse than useless because you can't throttle them or turn them off, so they're liable to wreck any burn you use them on. If you want quick acceleration, I recommend toroidal aerospikes. good thrust to weight for an engine that delivers 390 Isp.

Edited June 9, 2014 by GoSlash27

[Stickyhammy]

Okay after sleeping off my disappointment in my last generation of rocket that had bad thrust I made a new varient. This has more than 5 times the TWR with only a 1000 m/s delta V loss. Still enough to get to Eeloo and back.

Going to work on a lander for a bit before I launch this one. Will make sure to check this post before I go just in case someone else has any upgrade ideas.

[Othuyeg]

Your radial tanks are rather inefficient. You do not have any decoupling there. You will be carrying them with you even when they are empty.

Also the massive tank is simply too huge.

Also, I can imgaine that your manovers are hard to execute with such a massive ship without any RCS.

[Oafman]

I would ditch those radial tanks and add a TVR-400L Stack Quad-Adapter to the bottom of your main tank. Then you can have a cluster of 4 nuke engines, which will still be a pretty low TWR, but should be manageable.

And for the long burns, you can always get Mechjeb to execute them while you go and do something more interesting. If you do, first select the utilities menu on MJ, and set max thrust to around 90%, otherwise MJ will go at 100% and the nuke engines will overheat and explode.

[Othuyeg]

I would ditch those radial tanks and add a TVR-400L Stack Quad-Adapter to the bottom of your main tank. Then you can have a cluster of 4 nuke engines, which will still be a pretty low TWR, but should be manageable.

And for the long burns, you can always get Mechjeb to execute them while you go and do something more interesting. If you do, first select the utilities menu on MJ, and set max thrust to around 90%, otherwise MJ will go at 100% and the nuke engines will overheat and explode.

MJ has a "prevent oveheats" option which works aswell.

[Stickyhammy]

Thanks for the ideas. I do have a new question though. If I dropped the size of the main fuel tank, where would I put more fuel tanks to keep my delta V over 10,000? I never looked into the mass of the fuel tanks vs how much fuel capacity they have so I don't know what the best size to use is.

You could say I don't need that much delta V but I have settled on going to Eeloo as my first planet orbit after Kerbin. The chart from this morning someone posted said i need 4700 one way. I am cutting it close as it is since I have no experience in inter-planetary burns. I am sure I will waste a lot of fuel. Wouldn't be surprised if I only had enough to get there after all the puttering around I will have to do. ETA from the only intercept I managed to plot was 5 years in the smaller 1 engine ship. Lots of time to waste fuel.

Btw that 5 year trip time was the reason I added the hitchhiker container. The command module has a snack bay, but it also has a note saying someone ate all the snacks. I don't want my Kerbals to starve! I know they wouldn't but that's not the point.

[Red Iron Crown]

Have you considered how you're going to get the ship into orbit? It looks like it's lacking in places to attach boosters. I would consider eliminating the bottom engine and building the lifter stage below it.

I would also consider adding a docking port somewhere to facilitate refueling and reusing the ship, or sending a rescue refueler if you get into trouble. The claw you have at the top could do in a pinch, but I've had some bugginess with the claw so I'm a bit leery of having it be the only docking option.

You also might be well-served by replacing the hitchhiker with a science lab, that will let you store science results and clean out your goo containers. Maybe an antenna for transmitting results back if you get stranded.

Don't take the above advice as criticism, just refinements. You've built a capable interplanetary ship, it should work fine in its current form.

[Stickyhammy]

Getting the ship into orbit was a pain in the tail. Took 8 orange tanks, 4 mainsails and 12 srb's. Even with that I had to use the nuclear engines to finish the orbit and claw into my station. Was fun though

Oh yeah and lots of struts. Was like balancing an elephant on the head of a pin.

Oh and in case of emergency I just send out another ship and eva my kerbals to it for returning home. Probably not possible if I run out of fuel on the return trip from Eeloo. But first I need to get there. Going to shoot off now and hope for the best.

Edit: For kicks I let mechjeb plan a maneuver. It wants me to wait over a year to launch. Heck with that! I go now!

Edited June 10, 2014 by Stickyhammy

[Kryxal]

Well, if you ever re-create this monstrosity, remember that drop tanks are your friend (and to make your life easier, build something that can lift a full orange tank, then DOCK that orange tank in a pull configuration to an engine framework)

[Stickyhammy]

Launch windows.. Pfffht. Who needs them. I made it to Eeloo! Of course there is the slight problem of having not enough fuel to get home. But... Details.

[Guest]

Launch windows.. Pfffht. Who needs them. I made it to Eeloo! Of course there is the slight problem of having not enough fuel to get home. But... Details.

http://i59.tinypic.com/ixw7pg.jpg

if the Mj readout is correct (you really don't look like you have a lot of fuel), you have pleanty of dV to get home with.

[Red Iron Crown]

Return is possible with that much dV. You won't be able to ignore transfer windows and you'll have to aerobrake when you get to Kerbin, but it's definitely possible.

You could try a gravity assist with Jool, that will cut down on the dV required.

[Oafman]

Even if you don't make it back, you can make your rescue mission much easier if you can at least get close to Kerbin's orbit

[Pecan]

The deltaV map I prefer is in this thread.

With aerobraking Eeloo -> Kerbin 'should' take 2,700m/s so with 3km/s you've still got a bit more than 10% 'margin for error'. Aerobraking = since you won't have enough fuel to slow down and establish an orbit around Kerbin once you get back to it you set your Kerbin periapsis inside the atmosphere instead of in space. The atmosphere (aero) causes drag (braking) so your apoapsis drops. The deeper into the atmosphere you dive the more effect you'll get (but could crash!). Note that it might take several orbits until you've braked sufficiently to feel 'home'.

[Stickyhammy]

I will retire this thread with these last two pictures. I did add 1000 dv with a fuel ship run by a probe before I blasted off for home. As you can see in the pictures I am glad I did Home sweet Kerbin.

[Red Iron Crown]

Congrats on the successful return! Where to next?

[Stickyhammy]

I think after 19 years in space Jeb, Bill, and Bob need a vacation. I might send Melvin to EVE and try to Establish a mountaintop base. Will take research, planning, and lots of extra fuel. I hear that things that get down to the surface of EVE seldom get back up again. I am a bit short of science to get the last structural components so maybe just a quick orbit of Jool. I swear I had 4 different times on the way to and from Eeloo that I could have entered Jool orbit, but since it wasn't my destination I passed it by.

[Pecan]

Congratulations.

Is now the time to mention that I haven't been to Eeloo, or Eve, yet? I'm still waiting for a transfer window to those two as I don't like to time-warp for single mission. My current game has gone longer than any other; it is day 275 (year 1, obviously).