KKLP (Kerbal Kommunity Launch Platforms)

[Nich]

If you are like me you always forget so save your LKO lifters as subassemblies.  In addition I have seen some nice families of lifters out their however they are quite large gaps between payloads.  As a Kommunity I challenge you all to create a family of lifters.  I plan to moderate and input as little as possible.

 

However to get the discussion going before 1.1 is released here are some topics we need to decide on before we even start designing.

What deltas do we want between lifters?

.5t, .75t, 1t, 1.5t, 2.5t, 5t, 7.5t, 10t, 15t, 25t, 50t, 75t, 100t, 150t, 250t, 500t, 750t, 1000t, 1500t, 2500t (just an example)

 

 

Do we want a common design strategy?

I.e. same number of stages? same TWR for each stage? Stage at roughly the same time? Total dv just short of orbit?

 

 

Recoverable?

I recommend non-recoverable for phase 1 and recoverable for phase 2

 

 

Minimum cost per ton?

Cheap and cheerful challenge says <600 funds per ton is possible however 1.25 and 3.75 may not be possible to get this low or for different payloads

 

Maximum part count? How much are we willing to sacrifice in cost?

 

Do we want to break the Payloads into technologie segments?

If total pad weight is less then xt restric tech to tier y

 

Anything else our family of rockets should consider?

 

Sub assemble naming convention?

I was thinking

"xxxxx.xxt to LKO"

so that all lifters are in order with a description of

"xt to 200x200"

"xt to geo"

"created by Username"

[Jetski]

Something that has come up in nearly every lifter challenge is just how much the payload is allowed to do.  Can it have RCS? Fuel? Engines? Reaction wheels? Probes? Batteries? or does all that need to be in the lifter?  I would make sure that's very clear at the outset.  I think C&C did something like circularization dV was permitted, along with reaction wheels and probe.

Also, this is my standard lifter family as soon as I have Mainsail engines and orange tanks.  I find Type E wings to be excellent low drag spacers to keep my radial boosters from hitting me after decoupling.  If I have a particularly un-aerodynamic payload I put the decoupler at the end of the wing, so I drop the boosters but keep the wings as extra fins, sometimes even put control flaps on them.  Worth noting fins are pointless after about 30K, so attaching them to boosters is better than main stack if boosters will stay with you a while.

I can slap one of these babies together in about 30 seconds these days.

40T, 56000 funds (I use this in 90% of my launches)

15T, 29000 funds (lone mainsail)

100T,140000 funds (asparagus 5 mainsails)

130T, 167000 funds (asparagus 5 mainsails w/SRBs)

Values are for fully circularized, and generally a few drops left in the tanks, especially if payload is a little light. Ascent profile vertical until 100m/s, then tip to 3-5 degrees and keep prograde.  Keep throttling back to stay near 1.5-1.8 TWR until 25K, then wide open, usually burning near flat to the horizon by then or a little after.  Once Ap is 72K, coast until 10 secs before Ap, burn horizontal until circularized.

Plenty of room for optimization here, but it's a quick and easy rig, and doesn't let me down unless I do something really stupid like mess up staging.  Always have good margins, sometimes enough for a kick into interplanetary space.

 

Edited April 1, 2016 by Jetski

[Nich]

@Jetski I love those spacers I may be stealing it in the future.

As for what the payload can contribute I will leave that up to the community.  I would think we would want rational amounts of batteries, reaction wheels, 100-300dv and command authority (probe or command pod) 

As for control on the lifter from what I can tell

the 2.5m reaction wheel is 2100 and .2t

4 thruster blocks and mono prop are 2600ish and .39t

4 tail fins are 2400 and .5t

4 elevon 1s are 1600 and only .02t

In the past I have always used tail fins but a throwaway reaction wheel might be more efficient to control a rocket.

[Andiron]

I like to send small probes to explore the Kerbol system, so my most used rocked family is very light. As powerful solid fuel rockets are available very soon in career mode, I created the Volturnus family for payloads from less than 0.5t to 2.5t to low Kerbin orbit. This is a sandbox version with a better nosecone and a fairing, but the concept is available at tier 4. The efficiency is not great but it's kinda cheap.

Volturnus I : 0.5t payload max @ 5791 ker$

Volturnus II : 1t payload max @ 8451 ker$

Volturnus III : 1.5t payload max @ 11020 ker$

Volturnus IV : 2t payload max @ 9280 ker$

Volturnus V : 2.5t payload max @ 13040 ker$

Edited April 2, 2016 by Andiron