Which ship design is best for Eve?

[Spricigo]

31 minutes ago, XLjedi said:

If the craft is infintely reusable; not too concerned about the cost per engine;

Cost as mentioned for the completeness sake. Is actually hard to be much concerned with cost in KSP, when a expendable rocket can get a dozen times his cost in contract rewards.

OTOH player time is invaluable, going with 'less efficient' options often means doing something early and quicker.

Food for thought. Figure out what is important for you and have fun.

[Foxster]

12 hours ago, Silverwood said:

Ok thanks again. Lots to think about.

I also get the impression a lot of you are using add ons? I only have the basic game, no mods, also my experience of rockets is quite basic. Whilst I have manged to get to both the Mun and Minimus - it was more by luck I think. When you talk about Delta & thrust - I am getting lost! I don't suppose there is  a really simple guide? I have tended to use the same design - simple with just a few extra fuel tanks or boosters and copied the designs from sandbox.

Thanks.

Keith

 

Install a mod that gives you some proper data on your craft. I prefer Mechjeb because that's what I started with, some folks use KER.

Some of the most useful information is:

dV - The range of your craft, sorta. You will need a craft with more dV to go to more distant places and do more stuff once there. 

isp - The MPG of your craft's engines. Nukes have high isp, for instance. Usually though, high isp is offset by a disadvantage e.g. nukes are heavy and useless in thicker atmosphere. 

TWR -  How powerful your craft's engines are compared to the mass of the craft. Pretty important in an atmosphere, where you will need >1 to even start to lift, and 1.5 being a good Kerbin takeoff number. TWR is somewhat less important in space but low TWR means long burn times, usually offset though by getting more dV.  

Apoapsis, periapsis, inclination, true altitude, vertical speed, angle of attack, suicide burn countdown, periapsis in target SOI, etc - All very useful stuff to know on longer missions. 

On 10/07/2017 at 4:59 PM, Silverwood said:

Hello All,

Well I am playing in career mode, and have decided to have a go at Eve. I have tried a few modified rockets, but can't get enough fuel to make it!

Has anyone got a design using any features from the VAB up to 300 science. That is as far as I have got. Or is it too hard at this stage?

Keith

 

Could you post a screenshot of the science tree you have unlocked? I'll make you an Eve craft from that. 

Edited July 11, 2017 by Foxster

[Loren Pechtel]

300 science means you have the Nerva engine.  If you don't need landing engines and are carrying anything of any size I find it the best choice.  For large enough stuff I've been known to use it for the interplanetary voyage and bring along a separate landing engine.

The imperfect nature of the game means you give up some efficiency for using it (there's no easy way to do an interplanetary burn from low orbit with it) but it saves so much fuel that it's worth it anyway.  Interstellar Fuel Switch is highly recommended when using it so you can use the ordinary tanks to fuel it.  The stock game is quite lacking in larger liquid fuel only tanks.

[magnemoe]

On 11.7.2017 at 1:51 AM, foamyesque said:

My own experience is that the best way to get truly massive Eve vehicles down in one piece is to put wings on them, but it takes extensive testing to get the aero- and thermo- dynamics of the entry correct.

Putting them in an fairing also work well, this fairing can also be used during launch, put accent stage in fairing, inflatable heat shield transfer and deorbit stage. 
Multiple airbrakes on top is another. they will not overheat if in the shadow of  the heat shield. 

[Silverwood]

14 hours ago, Foxster said:

Install a mod that gives you some proper data on your craft. I prefer Mechjeb because that's what I started with, some folks use KER.

Some of the most useful information is:

dV - The range of your craft, sorta. You will need a craft with more dV to go to more distant places and do more stuff once there. 

isp - The MPG of your craft's engines. Nukes have high isp, for instance. Usually though, high isp is offset by a disadvantage e.g. nukes are heavy and useless in thicker atmosphere. 

TWR -  How powerful your craft's engines are compared to the mass of the craft. Pretty important in an atmosphere, where you will need >1 to even start to lift, and 1.5 being a good Kerbin takeoff number. TWR is somewhat less important in space but low TWR means long burn times, usually offset though by getting more dV.  

Apoapsis, periapsis, inclination, true altitude, vertical speed, angle of attack, suicide burn countdown, periapsis in target SOI, etc - All very useful stuff to know on longer missions. 

Could you post a screenshot of the science tree you have unlocked? I'll make you an Eve craft from that. 

Can't post a screenshot, tried copy & paste - wont work.

However it did save in steam, but I am not sure how to give  a link to that!

 

[Silverwood]

33 minutes ago, Silverwood said:

Can't post a screenshot, tried copy & paste - wont work.

However it did save in steam, but I am not sure how to give  a link to that!

 

Ok try this:

http://steamcommunity.com/profiles/76561198047418237/screenshots/

[Foxster]

3 hours ago, Silverwood said:

Ok try this:

http://steamcommunity.com/profiles/76561198047418237/screenshots/

Got it. 

Let me take care of some stuff and I'll knock something together for you in a bit. 

[Foxster]

Here you go...

Craft file: https://www.dropbox.com/s/f17timxbnhbp2ia/Evening 1.craft?dl=0

There's loads of dV available, so even if things go a bit wrong on the transfer you should be OK. 

You can either engine-brake into Eve orbit or if you are getting low on dV then try aerobraking in Eve's atmosphere at a Pe around 70km.

There is an RCS final stage because RCS engines work OK behind a heatshield without being occluded. So if you do do some aerobraking you will have some engines afterwards for de-orbiting and such.   

Edited July 12, 2017 by Foxster

[Silverwood]

Wow!

Cheers thanks.

Will try and let you know.

Keith

 

[Silverwood]

Ok downloaded the file and installed - but is is not compatible with the version I am using.

Any chance you could tell me the various parts? I could try building it myself.

Keith

[Bottle Rocketeer 500]

@Silverwood 

What you can do is change the game version of the craft file.

Step 1: Open the craft file in a text editor and locate the "version" line

It should say:

version = 1.3.0

Then, change it to your game version. For example, if you use 1.2.2, you change the "version" line to say:

version = 1.2.2

Voila, you have a craft file for another game version!

Yours should say:

version = 1.2.9

So, your version number would be "number,decimal point,number,decimal point,number" or something like "1.2.9", not like "1.2.9.1800".

 

Edited July 13, 2017 by Bottle Rocketeer 500

[Foxster]

Sorry, too many to list. There is nothing hidden or clipped though and you should be able to figure it out from the pictures. 

Or why don't you just upgrade to the latest version of KSP?

[XLjedi]

5 hours ago, Silverwood said:

Ok downloaded the file and installed - but is is not compatible with the version I am using.

Any chance you could tell me the various parts? I could try building it myself.

Keith

Just as an FYI...  for any .craft file built in 1.3.  You can easily switch it to 1.2 by opening the craft file in a text editor and just change the second line

from this:  version = 1.3.0

 to this:  version = 1.2.2

or whatever appropriate version you happen to be running...  no guarantees that it's always going to be backward compatible, but I do this for 1.2.2 and 1.3.0 all the time.

Edited July 13, 2017 by XLjedi

[Silverwood]

Ok thanks. I have changed the file and it works ok now.

I have tried the rocket & yes it has a huge amount of power, I just need to get the orbital burns right. That is proving hard, it was a lot easier going to Mun & Minimus! Also I lose control of the probe, as I don't have enough Satellites to send a signal. Perhaps trying for Eve is a step too far at this stage.

 

[Foxster]

I forgot about CommNet because I don't see the point of it and just turn it off all the time. 

If you do want to stick it out with CommNet then how do you feel about abandoning a Kerbal on Eve? Would be pretty easy to adapt the craft to carry a crewman, then CommNet issues go away. 

57 minutes ago, Silverwood said:

Perhaps trying for Eve is a step too far at this stage.

Absolutely not! You need to go boldly where no man has gone before (umm, where have I heard that before?). 

[Spricigo]

7 hours ago, Silverwood said:

Ok downloaded the file and installed - but is is not compatible with the version I am using.

Any chance you could tell me the various parts? I could try building it myself.

Keith

let me try(warning guessing ahead):

Probecore HECS is the root part.

on top of the HECS: Small Reaction Wheels, Mk16 parachutes, Comonutron16 (be sure to have relay coverage)

radially attached 2 way symmetry: TT38 decoupler, FL-RC10 RCS tank, Puff (I'd change for TR-2V+(1,2) Oscar+ant below the HeatShield,  maybe would require some adjustment of the fairing )

below the HECS: FL-A10 Adapter, Service Bay, Science Jr, 2,5m HeatShield, TR-18A decouples, Fairing, FL-T400 fuel tank, terrier engine, TR-18A decoupler.

Around the A10 Adapter in radial symmetry: 8x OX-STAT solar panels

Inside the Service Bay, scientific instruments

Around the the Science Jr in radial symmetry: 8x OX-STAT solar panels, 6x Z200 Battery

Around the FL-T400 tank in radial symmetry: 2x(TT-70 decoupler, FL-T400 fuel tank, circular intake on top and bottom of the tank) twice. Fuel lines for asparagus staging.

Below the last mentioned TR-18A: Advanced In-line Stabilizer, C7 Brand Adapter, Jumbo-64 fuel tank; Skipper engine.

Around the Jumbo-64 fuel tank in radial symmetry: 2x Thud engines;  4x Tail Fin;   4x (TT-70 decoupler, Kickback SRB, AV-T1 winglet and Circular Air Intake.

I think that is all.

@Foxster may you provide deltaV and TWR by stage? Appreciated.

 

 

I'd make a small modifications (mostly because my 'taste' differ a bit from @Foxster's):

1.Intead of the least stage with puff and monopropelant, radially atached, I'd goo with a oscarB tank just above the heatshield, with a pair of spider engines radially atached. The engines wold be ofset just enough to the nozzzle apper below the heatshield

2.Intead of the A10 Adapter and service bay I'd use a stack of Z200 battery (maybe some Octagonal Struts), and have the Solar Panels Radially atached to the Octogonal Strut rotated/ofset to point up, the scientific instruments disposed below the solar panel around the same stack. If one is concerned with heat/Aerodinamic protection a 1,25m fairing can be used but some solar panels need to be maintained/added outside of the fairing)

3.I'd use nosecones instead of air intakes and TR38K decouplers instead of TT-70. Maybe use Sepratrons to push the radial stages away.

4.I'd use fuel flow priorities and enable crossfeed on the radial decouplers instead of using fuel lines

4b. I'd move fuel to the top of the SRBs and set to higher priority, to feed the Skipper from those tanks while the SRBs burn. A considerable reworking of the central stack in result of this change.

5. Stuff I'd only notice while messing with craft in the VAB or after some testing. (including implementing my KAt-LP (Komplete Automatic Launch Procedure {so easy my cat can do, have the vessel inclined and full throttle at the launchpad, press space and use Smart Part mod to stage as necessary until the apoapsis is at the desired height} )

 

[Foxster]

3 minutes ago, Spricigo said:

let me try(warning guessing ahead):

Probecore HECS is the root part.

on top of the HECS: Small Reaction Wheels, Mk16 parachutes, Comonutron16 (be sure to have relay coverage)

radially attached 2 way symmetry: TT38 decoupler, FL-RC10 RCS tank, Puff (I'd change for TR-2V+(1,2) Oscar+ant below the HeatShield,  maybe would require some adjustment of the fairing )

below the HECS: FL-A10 Adapter, Service Bay, Science Jr, 2,5m HeatShield, TR-18A decouples, Fairing, FL-T400 fuel tank, terrier engine, TR-18A decoupler.

Around the A10 Adapter in radial symmetry: 8x OX-STAT solar panels

Inside the Service Bay, scientific instruments

Around the the Science Jr in radial symmetry: 8x OX-STAT solar panels, 6x Z200 Battery

Around the FL-T400 tank in radial symmetry: 2x(TT-70 decoupler, FL-T400 fuel tank, circular intake on top and bottom of the tank) twice. Fuel lines for asparagus staging.

Below the last mentioned TR-18A: Advanced In-line Stabilizer, C7 Brand Adapter, Jumbo-64 fuel tank; Skipper engine.

Around the Jumbo-64 fuel tank in radial symmetry: 2x Thud engines;  4x Tail Fin;   4x (TT-70 decoupler, Kickback SRB, AV-T1 winglet and Circular Air Intake.

I think that is all.

@Foxster may you provide deltaV and TWR by stage? Appreciated.

 

 

I'd make a small modifications (mostly because my 'taste' differ a bit from @Foxster's):

1.Intead of the least stage with puff and monopropelant, radially atached, I'd goo with a oscarB tank just above the heatshield, with a pair of spider engines radially atached. The engines wold be ofset just enough to the nozzzle apper below the heatshield

2.Intead of the A10 Adapter and service bay I'd use a stack of Z200 battery (maybe some Octagonal Struts), and have the Solar Panels Radially atached to the Octogonal Strut rotated/ofset to point up, the scientific instruments disposed below the solar panel around the same stack. If one is concerned with heat/Aerodinamic protection a 1,25m fairing can be used but some solar panels need to be maintained/added outside of the fairing)

3.I'd use nosecones instead of air intakes and TR38K decouplers instead of TT-70. Maybe use Sepratrons to push the radial stages away.

4.I'd use fuel flow priorities and enable crossfeed on the radial decouplers instead of using fuel lines

4b. I'd move fuel to the top of the SRBs and set to higher priority, to feed the Skipper from those tanks while the SRBs burn. A considerable reworking of the central stack in result of this change.

5. Stuff I'd only notice while messing with craft in the VAB or after some testing. (including implementing my KAt-LP (Komplete Automatic Launch Procedure {so easy my cat can do, have the vessel inclined and full throttle at the launchpad, press space and use Smart Part mod to stage as necessary until the apoapsis is at the desired height} )

 

Oh, there's lots could be done to make things a bit better - it was a quick and dirty solution. 

I think he has the craft loaded OK now so no need to guess the design

 

[Silverwood]

13 minutes ago, Foxster said:

Oh, there's lots could be done to make things a bit better - it was a quick and dirty solution. 

I think he has the craft loaded OK now so no need to guess the design

 

Yep got it. Just need to get the burns right now!!

[Spricigo]

1 hour ago, Foxster said:

Absolutely not! You need to go boldly where no man has gone before (umm, where have I heard that before?). 

Agree. Of course there will be difficulties to deal with and compromises to be done, part of the fun.

To solve the communication link issue, send a few relay to Eve's orbit (literally a probecore, solar panels and relay antenna), change the communotron 16 for a 16S (you will need it atmosphere). If you need mid-course correction put a stronger direct antenna in the fuel tank above the terrier.

5 minutes ago, Foxster said:

Oh, there's lots could be done to make things a bit better - it was a quick and dirty solution. 

I think he has the craft loaded OK now so no need to guess the design

 

That is what happens when you take hours replying a thread (because RL keep interrupting) and don't check for newer posts before hitting [Submit Reply] .

Anyway, the possible modification I listed are more because I design my vessels that way than I think it will improve the vessel. BTW: in case you missed it in my wall of test:  @Foxster may you provide deltaV and TWR by stage? Appreciated.

[Foxster]

Whoops, yes I missed that. Here you go...

Edited July 13, 2017 by Foxster

[Silverwood]

11 hours ago, Foxster said:

Whoops, yes I missed that. Here you go...

What is this then?

[Foxster]

It is the information about TWR and dV for the craft as requested by Spricigo. It is a readout from MechJeb.

For each stage (7 to 0) it shows the stage's max TWR, sea-level/current TWR, dV if the stage runs in the atmosphere, dV if the stage runs in vacuum, and how long the stage will run at full throttle. 

The available dV is useful to compare to that required for a mission, which can be estimated using this: https://13375.de/KSPDeltaVMap/

There's also useful stuff like the total dV and the vessel's current mass. 

You want about 3500 dV to make Kerbin orbit. The rest is then dV available for transfer to another body, establishing orbit, landing, etc. 

You can play KSP without this kind of information but it is frustratingly hard.