Efficient Spaceplane TSTO

[Spricigo]

Hello community. Welcome to my first challenge.

The objective it's simple,  use a spaceplane to delivery some payload to KEO while achieving the best tonnage/operational cost ratio possible. 

Rules:

A1 . All stock parts. Except for rule A4.

A2. No autopilot. 

A3. No mods that change the physics of the game. Except for rule A4

A4. Mods intended only to manage the control of both craft easier are permitted and even encouraged. In the same spirit any contraption used for the purpose of facility the flight management that don’t give a clear advantage will be accepted and its effect will be considered void for scoring purpose as much as possible (e.g. rocket motor on carrier, fuel used will not be considered for purpose of scoring).

Craft:

B1. The craft must have 3 stages: Carrier,   Shuttle and Payload.

B2.  Only chemical rockets allowed in the Shuttle (2nd stage). Rapier only in rocket mode. 

B3.  Shuttle must be able to archive a stable 100kmX100km orbit,  release the payload and deorbit. 

B4.  Payload must be inert.  No reaction wheels,  SAS, RCS or fuel used from the payload. 

B5.  Keep cliping at minimum. 

JetStream Category:

J1. Carrier need to reach height and speed where it release the shuttle by jet power only. Any kind of rocket assist is forbidden.

J2. Carrier need to reach the condition to release the shuttle without dropping any part.

J3. Shuttle need to perform a unpowered landing at KSC. No parachutes.

RaisingStar Category:

R1. Carrier propulsion and guidance cannot be used past the 30km height and 1500m/s speed. However it can drop parts and use any kind of engine.

R3. Shuttle need to perform a unpowered landing at KSC. No parachutes.

Quasar Category:

Q1. Carrier need to reach height and speed where it release the shuttle by jet power only. Any kind of rocket assist is forbidden.

Q2. Carrier cannot drop any part.

Q3. After separation Carrier must be able to return to KSC and land safely. 

Q4. Payload must be attached to the shuttle by docking ports. One in payload, one in the shuttle.

 

Submissions:

Either video or pictures. All critical phases must be show (staging,  delivery,  landings,...).

Name your craft, preferable name for both carrier and shuttle.

Scoring :

JetStream and RaisingStar: <scoring>=<payload mass(kg) >/(<operational cost shuttle>+<maintenance cost shuttle >)

Quasar: <scoring>=<payload mass(kg) >/(<operational cost carrier&shuttle>+<maintenance cost shuttle >) 

Where the operational cost is launch cost of relevant stages minus cost of recovery. Maintenance cost its 5% of the cost of the shuttle without fuel. 

 

Leaderboard :

 

 

As stated above this is my first challenge,   I'm thinking about it quite a long so I hope it's well designed but I lack experience.  Constructive criticism welcomed. 

 

Edited January 12, 2017 by Spricigo
rules adjustment

[Freds]

i was thinking about this kind of design, to launch something just like Virgin Galactic does. Its cheaper and simpler than traditional SSTO, but the problem is with KSP: You cant control 2 vessels at the same time - in the moment that the carrier goes out physical range, it will be deleted, all kerbals lost

Maybe Airpark mod can help, but i never used it.

But, if someone, somehow manages to do it, i would love to see it in youtube!

[rudi1291]

The rules don´t state that you have to land them in the same run  so maybe a demonstration is enough? or a quicksave just before seperation?

[Spricigo]

30 minutes ago, Freds said:

i was thinking about this kind of design, to launch something just like Virgin Galactic does. Its cheaper and simpler than traditional SSTO, but the problem is with KSP: You cant control 2 vessels at the same time - in the moment that the carrier goes out physical range, it will be deleted, all kerbals lost

Maybe Airpark mod can help, but i never used it.

But, if someone, somehow manages to do it, i would love to see it in youtube!

The mod I have in mind is FMRS,  but I know it has some issues actually.  For this challenge I expect people to just use F5 at the time of separation,  land the carrier,  F9 and conclude mission with the shuttle.  

 

[Adelaar]

Some general concerns about this thread;

- Many people use drones to bring their stuff in orbit, which are lighter than manned ones. My SSTO's are manned, so inherently at a disadvantage. Perhaps introduce a bonus for the type of crew module taken along? No bonus for drones, small bonus for MK I, bigger bonus for MKII and maximum bonus for MKIV?

- The nice thing about an SSTO is that it's supposed to bring the craft back down for re-use. I am a bit disappointed that there isn't an incentive to land back on KSC.

- There is no penalty for parts lost underway.

[Spricigo]

42 minutes ago, Adelaar said:

Some general concerns about this thread;

- Many people use drones to bring their stuff in orbit, which are lighter than manned ones. My SSTO's are manned, so inherently at a disadvantage. Perhaps introduce a bonus for the type of crew module taken along? No bonus for drones, small bonus for MK I, bigger bonus for MKII and maximum bonus for MKIV?

Notice that a SSTO will no meet the requirements since the craft is required  to stage.  I'm under the impression you said SSTO out of habit meaning spaceplane,  but better to make it clear. 

I know manned crafts,  in particular if both carrier and shuttle,  will be at disvantage.  However I  don't see a reason to penalise people for choosing the most effective part in a efficiency challenge. Maybe if we have enough entries in manned category I can split the leaderboard,  but no promises. 

42 minutes ago, Adelaar said:

- The nice thing about an SSTO is that it's supposed to bring the craft back down for re-use. I am a bit disappointed that there isn't an incentive to land back on KSC.

- There is no penalty for parts lost underway.

??  Landing back at KSC allows for 100% recovering,  thus lower operational cost,  thus higher score. Parts lost can't be recovered,  thus higher operational cost,  thus lower score. 

[foamyesque]

The real trick is recovering the airbreather, in a pure-stock non-autopilot scenario; craft below 25km altitude and outside the physics range of the focus object will be autodeleted. It might be possible to do a relatively high-angle ascent and spike the carrier's apopasis high enough that, in the time it takes to fall back under 25km, the shuttle vehicle can push it's apoapsis high enough to let you then turn around and land the carrier, but honestly it's a bunch of faffing about when a much simpler process would be to simply go SSTO, or at least single-stage to suborbital.

[Spricigo]

1 hour ago, foamyesque said:

The real trick is recovering the airbreather, in a pure-stock non-autopilot scenario; craft below 25km altitude and outside the physics range of the focus object will be autodeleted. It might be possible to do a relatively high-angle ascent and spike the carrier's apopasis high enough that, in the time it takes to fall back under 25km, the shuttle vehicle can push it's apoapsis high enough to let you then turn around and land the carrier, but honestly it's a bunch of faffing about when a much simpler process would be to simply go SSTO, or at least single-stage to suborbital.

As pointed out by @rudi1291: the rules don't state that it needs to be done in same run.  A quicksave at/near separation time for the purpose of the challenge is all that is necessary.  

Now,  I understand if you are more concerned about it being  less relevant in actual gameplay.  My idea was to make something different from the typical "spaceplane SSTO challenge" ,  in my inexperience I didn't foresaw this point being a issue. 

 

[Spricigo]

 

Ok people, thank you for the criticism. I waited a bit to see if despite the issues raised someone decided to take the challenge.

But its clear that a rethink its needed. So I decided for those adjustments:

-rule A2 its no more. Lets focus in the design instead of piloting.

-The initial rules will be kept as Quasar Category (Hard Mode). Adding 2 other: JetStream  Category  (1st stage still need to be jet engined) and RaisingStar Category (1st stage can be off any type, but need to be dropped before reaching 30km altitude and 1500m/s velocity). For both JetStream and RaisingStar the 1st stage will be considered expendable and not interfere in scoring.

-A4 rule, a clarification that how do you 'recover' the carrier its not important. As far the challenge is concerned just a demonstration (quicksave before staging) is enough, but if people want to 'do it for real'  I will do my best to not penalize it.

The idea its to focus more in the shuttle and lower the "entry barrier" for the challenge.

About the issue that for some playstiles a recoverable TSTO its not  practical given the limitation of the stock game: I can only apologize to who felt "left out" of found my challenge unappealing.

Also I like to make clear that I don’t pretend to post my entry because: a) so i don't have a conflict of interest as ruler and competitor at same time (while I'm sure my design would be easily surpassed) b) I can focus in making the challenge organized and interesting c) TSTO spaceplane is already accepted as possible, if maybe not practical, and even was done before as we can see in a quick search in this forum( http://forum.kerbalspaceprogram.com/index.php?/topic/92463-shuttles-that-never-were-but-could-have-soviet-maks-amp-lockheeds-ls-a/), my rules may be a bit more restrictive but still give many opportunities.

[AeroGav]

By the way, is there specifically a reason for this rule,  such as enforcing lower tech parts or making something that could theoretically get built today ?

On 09/01/2017 at 10:05 AM, Spricigo said:

B2.  Only chemical rockets allowed in the Shuttle (2nd stage)

I understand banning jet engines from the 2nd stage, but why not allow Nervs or even ions?   The second stage would not need a high TWR which opens up the possibility of using high ISP tech to get really good results.   So long as the lower stage is strictly jet powered, i see nothing wrong with it.    Here's something i built some time ago, a mid tech TSTO system 

 

[Spricigo]

@AeroGav the idea its to allow more variety since the various chemical rockets are somewhat closer in the ISP department while Nervs and Dawn belong to "other league".  The fact it make lower tech more relevant and the designs more closer to something would exist in real life is an added bonus.

 

Also, thanks you for sharing your design.