[0.19.1] Zenith rocket family

[Temstar]

0.20 update:

A modernised set of Zenith rockets have been released. Head to the new thread to get the craft files:

http://forum.kerbalspaceprogram.com/showthread.php/33381-0-20-2-Zenith-rocket-family-%28modernised-for-0-20-x-with-perfect-subassembly%29

Also included is a brand new method of setting up subassembly that overcomes the major problem of Subassembly Saver/Loader - missing struts and fuel lines.

With all the positive feedback I've been getting from Nova SHLLV I decided this calls for an expanded family of rockets all built using the same principle as Nova but spanning a wide payload range to suit all the likely needs of a space program. After all in real life space companies are generally separated into launch providers (who build and fly launch vehicles) and payload makers (SATCOM, GPS, space agencies, military, etc) who build payload and buy launch services. By having a family of tested and reliable rockets with well know performance stats ready to be tipped with payload we could save a lot of time that would otherwise go into building custom launch vehicles for each new payload.

Thus, I present the Zenith rocket family. Features common to all Zenith rockets:

• >15% payload fraction
  
• asparagus staging with reliable staging sequence
  
• clustered engine core for sustained high Isp
  
• RCS system for on orbit attitude control, in case payload has low maxRot
  
• probe core and electrical system (including small solar panels) for space loitering and self-deorbiting
  

Due to the common design of the whole family all Zenith rockets have similar ascent profile:

1. Turn on ASAS, throttle up to max and lift off

2. Ascend directly up and stage asparagus pairs once they run out of fuel. If you fly with either the proofing payload included in origianl .craft files or ones with similar mass then all but one pair of booster should run out just after 10k altitude (that's two pairs jettisoned for all except Zenith III, which will lose it's 3rd pair of boosters at 10k). Once you're done on your last pair of asparagus booster pitch down slowly to 45 degrees for gravity turn.

3. By the time your last pair of boosters run out you should be nearly horizontal. Use the core stage to continue to build your orbital velocity.

4. Upon reaching stable orbit. Decouple the rocket from the payload, use [] to change control to rocket, flip it around with RCS and perform an deorbit burn with the remaining fuel to ensure no space junk. All Zenith rockets have been tested to have enough fuel for deorbit burn while using the proofing payload.

How to put payload onto of a Zenith rocket:

I recommend using Subassembly Saver/Loader, but Payloader is okay too.

1. First you have to figure put how heavy of a payload you have:

Here we have the stock Orbiter 1A, coming in at just under 20.5 tons. From our table of rockets at the top we can see that this is greater then what Zenith II can handle but well within Zenith III's capability.

2. Load up Zenith III, grab the rocket (everything from the decoupler down, remember the bit above is the proofing payload) and take your mouse to the purple Subassembly icon and "drop" it onto the icon.

3. Subassembly will prompt you for a name and category to save the subassembly, so give it a good name.

4. Now load up Orbiter 1A again, click on the purple subassembly button, browse to where you've saved your subassembly, clock on it and load. Your mouse will now have Zenith III underneath. Attach it to the bottom of the payload. In this case since Orbiter 1A has some pretty unusual geometry and I have lots of spare payload capacity I've decided to build an interstage between the payload and Zenith III to allow a clean attachment.

5. Unfortunately subassembly has some problems drawing struts and fuel lines going from radial parts to radial parts so these have to be fixed. Last I heard the author is working hard on fix this issue so maybe in the future this step will no longer be necessary.

6. Okay all done, let's fly this baby:

Booster separation

Payload release, notice all resources on payload still ful

Deorbit burn with the remaining fuel in the booster. This ensures no spent Zenith stages are left in payload orbit as space junk.

Craft files:

http://www./download.php?zq8c09oaj0aayc5

Unzip those into your VAB folder. Each rocket comes with a proofing payload which is the heaviest payload I've tested that the rocket managed to successfully put into 75km LKO, the results were used to come up with the chart at the top of the page.

Edited June 2, 2013 by Temstar

[HoY]

Thanks for re-posting this!

[Climberfx]

The thing of not letting parts lost in space is amazing. I try do it here was i can.

Not on every rocket i have this.

Edited April 19, 2013 by Climberfx

[bulletrhli]

Avid follower of your zenith rockets Keep up the good work, because these are the ONLY launch stages that I will be using ever.

[Yuming]

Can you put the info in the table for a 100 kilometer orbit? That orbit is also very common and I'm too lazy to do the math right now.

[drakesdoom]

Can you put the info in the table for a 100 kilometer orbit? That orbit is also very common and I'm too lazy to do the math right now.

I would suggest a nuclear boost stage to move it into your needed orbit. For most payloads only a very small fuel tank will be need for such.

[Valentina Tereshkova]

Thank you for saving us a lot of trial and error -- though I am sure I will continue to experiment with lifters!

However, I can't seem to do the asparagus staging correctly. When I launch the Zenith III as-is, without removing and reattaching the radial struts/separators, tanks, and engines, the pairs appear to run out one at a time (as I'd expect). After training myself to turn off the other engines before separation and then throttling up again, the first pair appeared to stage correctly, but when I tried to stage the next pair the entire lower assembling staged and left me with just the Orbiter.

When I disconnect the engines, tanks, and separators and reconnect them, all the asparagus engines appear to run out of fuel at the time, so I am not getting a staging effect at all.

Any help appreciated...I have barely begun to fiddle with the game, but I have successfully reached orbit once and landed safely using a lifter/capsule combo that I built from scratch. But to get to the Mun, I need to drastically scale up my lifting capacity.

[bulletrhli]

Valentina, if you are using the subassembly loader mod, currently there is a bug where the fuel lines and SOMETIMES the struts disconnect from where they were designed to go. A simple reconnect is all that is needed.

[Valentina Tereshkova]

Valentina, if you are using the subassembly loader mod, currently there is a bug where the fuel lines and SOMETIMES the struts disconnect from where they were designed to go. A simple reconnect is all that is needed.

Yes, I am using Subassembly Loader. The problem is that I don't understand how to connect/reconnect fuel lines, which I haven't used on the lifters that I've build myself (no cross-feeds yet).

Can you point me at a forum post or tutorial that explains the fuel line connection thing?

[Temstar]

Yes, I am using Subassembly Loader. The problem is that I don't understand how to connect/reconnect fuel lines, which I haven't used on the lifters that I've build myself (no cross-feeds yet).

Can you point me at a forum post or tutorial that explains the fuel line connection thing?

You could just load up the particular Zenith rocket with the proofing payload you're interested in and have a look at the fuel lines.

[Valentina Tereshkova]

I'm making progress slowly. I have reconnected all the fuel lines, and now the boosters empty in the correct sequence. I had to make major edits to the destaging sequence to get it to work properly. (It was fine loaded from your Zenith file, but scrambled as it came in from Subassembly.)

I can now fly a complete launch and staging sequence with the Zenith III and an Orbiter 1A on top. I am not successfully reaching orbit, so I'm still doing something wrong, but that's probably a mistake on my part either in flight profile or having somehow put too much mass as payload. (Essentially, once all the asparagus stages are gone, I start losing altitude and am unable to thrust posigrade enough to raise the perikerb to orbital altitude. Eventually I have to jettison all the still-burning stages and open the parachute to avoid killing my kerbonauts. :-)

Thanks for your help putting this together!

[Temstar]

When you load a subassembly with staging already setup it merges the existing stages on the payload with the stages in the subassembly according to stage number. To over come this what you can do is insert x number of empty stages in the Zenith model you want ABOVE all the existing stages, then save that as a subassembly before loading it to payload.

[GusTurbo]

I'm glad you reposted this. I am a huge fan of Nova, and I was sad to see that it was lost in the Great Forum Fire of 2013. I haven't yet tried other members of the family, but they have to be great if you made them.

[Valentina Tereshkova]

When you load a subassembly with staging already setup it merges the existing stages on the payload with the stages in the subassembly according to stage number. To over come this what you can do is insert x number of empty stages in the Zenith model you want ABOVE all the existing stages, then save that as a subassembly before loading it to payload.

Thanks, Temstar -- that sounds like a great idea.

I was able to manually paste the separation sequence back together, reconnect the fuel lines, and after realizing that I had overloaded the Zenith III by using a fuel tank instead of empty fuselage to connect it to the Orbiter 1A, I was able to make a flight out pretty close to the Mun and back. (I had intended to go around it, Zond/Apollo 8 style, but I didn't quite make the burns correctly.) I think everything is working now!

[bonyetty]

Thank you for saving us a lot of trial and error -- though I am sure I will continue to experiment with lifters!

However, I can't seem to do the asparagus staging correctly. When I launch the Zenith III as-is, without removing and reattaching the radial struts/separators, tanks, and engines, the pairs appear to run out one at a time (as I'd expect). After training myself to turn off the other engines before separation and then throttling up again, the first pair appeared to stage correctly, but when I tried to stage the next pair the entire lower assembling staged and left me with just the Orbiter.

When I disconnect the engines, tanks, and separators and reconnect them, all the asparagus engines appear to run out of fuel at the time, so I am not getting a staging effect at all.

Any help appreciated...I have barely begun to fiddle with the game, but I have successfully reached orbit once and landed safely using a lifter/capsule combo that I built from scratch. But to get to the Mun, I need to drastically scale up my lifting capacity.

Kerbal X can get you TO the Mun. Kerbal X also has asparagus staging. Playing with the the Kerbal X craft was how I figured out how the pipes worked. BigER isn't always better except EXPLOSIONS. Squad made Kerbal X so it's Gota be good.

[Giggleplex777]

I have achieved a payload 16.19%! I used the 1.5 staging technique from my MPCV Lite and made a super efficient heavy lift launch vehicle. It also has retro engines to deorbit the core stage.

[Valentina Tereshkova]

I've got everything working. I have successfully launched a modified Orbiter 1A (with an extra upper stage underneath) on a Nova and landed on Minmus. Well, actually *crashed* on Minmus...I have a future rescue project there, as the crew did survive.

I can see that these Zeniths and Nova will be terrific boosters for moving ahead to a full space program.

Thank you all!

[Cannon_Fodder]

Thank you for this. Designing launch systems is where I have been having a lot of issues. These will make a great addition to my space program. It's great the thread survived the "Great Purge."

One thing that has been mentioned before, 75km is an odd orbit. 100km orbits are far more standard. It would be great if somebody could make "Max Payload to 100km LKO" calculations.

[Temstar]

There is some reasoning behind me choosing 75km. The way I figured it, if the goal is to send the largest single piece payload possible on a given rocket one would aim for the lowest stable orbit possible. Once the payload is released into this low stable orbit you can then dock space tugs to it and take it to the final target orbit, where ever that is. 70km is too dangerous and unwieldy to use so I settled for a 75km orbit. It's possible to launch progressively smaller payloads to higher and higher orbits on the same rocket (eg, Nova launching the 70 ton MOLAB to Munar orbit), but it's not possible to launch inert payload much larger than the one on the specification no matter what you do since you're left with only 5km to play with. To launch heavier payload than on the specification you either have to go one size up, or if Nova can't handle it then you will need a new rocket.

[AmpsterMan]

I used to have a line of launchers similar to your line. You've inspired me to renew my line again

You should start a company Temstar. You have very good ideas with high quality productions.

[HoY]

To launch heavier payload than on the specification you either have to go one size up, or if Nova can't handle it then you will need a new rocket.

Or judicious application of SRB's! That's what I did to get Macey's Dreadnaught into orbit without needing to use its own engines and DV to complete its orbit (140t at 90km)

Most people don't like srb's but they are seeing more and more use from me lately as I make heavier and heavier payloads. Liquid tanks tend to break under extra load from more liquid tanks outside them but not from the same thrust as the srb's give me...

Edited April 24, 2013 by HoY

[Chocki]

Awsome lifter family! This let a new player skip the whole "devlop a stable heavy lifter" phase of trial and error. I learned all I could, but trying to upscale had me fighting terminal V, and stability. In hind sight, I was going to big, to much inital power. At one point, I was in orbit in under 3 mins. Very wasteful to say the least.

Just a few issues I have had. Using the Nova lifter, with the decoupler attached directly to a fuel tank. After coasting to ap, starting the engine to circulrize the orbit, the whole thing would explode. Logs reported the mono tanks inside the decoupler hitting the fuel tank (on my payload). I fixed this by just adding another decoupler (and 4 struts) on top of the default one.

If you use mechjeb auto launcher, and the nova, depending on the payload weight, you may want to move the gravity turn to start at a higher alt (edit path). The 2nd to last booster dropped shortly after 10k for me. During the first few seconds of the default gravity turn, leading to a spin, or explosion. Starting the turn at 11k solved the problem. The smaller (compared to the nova) lifters I have used, didnt suffer from this.

I haven't had any issues with zenith 7, or 9, just the nova. I haven't tested every single one, but with the same setup, they should work.

Note on fuel lines from subassembly loader. The fuel lines are in place, but not connected. Just make sure that simitry (sp?) Is off, and reconnect them. Just remember, all fuel leads to the center "main" stack.

Thanks again for a great lifter family.

[Valentina Tereshkova]

These have been tremendously helpful as I get over the initial learning bumps. I now have a small space station in 150 km Kerbal orbit with quite a bit of fuel tankage thanks to the Nova.

The only repeated issue I've had is that if I try to do a timed launch (to rendezvous) with one of these under my payload, it often breaks apart and explodes before even reaching launch ignition. I suspect this is due to some struts somewhere that got left out/deleted/lost in the course of switching from the standard booster to my custom payload. Anyone else seen this problem?

Zenith IX launched my station core. Nova launches additional fuel tankers and my 3-man orbiter (which has enough delta-V to go to the Mun or Minmus, land, and return, and can also dock with the station).

Thanks again for a great contribution.

Edited April 30, 2013 by Valentina Tereshkova

[Valentina Tereshkova]

Also, if you need to launch a payload a little heavier than Nova can handle, you have the option of using a small amount of the payload's own upper stage fuel. This is a double-win, because now none of the Nova stages actually reach orbit so you don't need to de-orbit them. This lets you use the fuel that you would otherwise save to de-orbit the uppermost stage of the Nova.

And I second the notion of adding SRB's to the Nova. It adds a few hundred m/sec of additional delta-V, which means that for payloads that use the upper stage for final orbital insertion, you can save a bit of fuel. Just move the fins up slightly and put the small stock SRB underneath it, and arrange to stage all SRB's before the first asparagus stage goes.

[Darth Lazarus]

i have to say: awesome work on this rocketfamily. i'm totaly goint to use the Zenith's for my nxt space station. it's so much easier if you dont have to worry about good looking, save, and usefull carrierrockets. i already use an inspired Nova-rocket as lifter for my Mun-Mission. still have to workout some minor issues, but the idea about the clustering is awesome!

so big thanks

Edited April 28, 2013 by Darth Lazarus