Abastro

Economy Challenge 1.2 (Reboot)

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This is reboot of @tseitsei89's economy challenge, which was for 1.1.

 

Categories

 There is 4 categories each for Stock and Modded.

I. DISPOSABLE LIFTERS - Recovery doesn't count

IIa. REUSABLE ROCKETS - No airbreathers

IIb. VERTICAL LAUNCHED VEHICLES - Vertical Launch with airbreathers

III. GENERAL - Anything is allowed

 

Score

  Score is given by {Expense for the Mission} / {Payload mass(t)}.

  Expense doesn't include the price of the payload. Recovery cost is excluded from the expense for categories IIa, IIb and III.

 

Rules

1. No cheat menu, No clipping of fuel tank & engine.

2. For stock entries, the craft should work in the same way with stock installs.
    For modded entries, basically only stock-balanced mods are allowed. However, you can request adding new category for mods you want. It will be accepted if it's resonable for this challenge.

3. You must launch from launch pad or runway.

4. You must achieve a stable orbit. (Pe >70km)

5. Payload must be separated from the lifter once in orbit. Decoupler used for this can NOT be a part of the payload.

6. Payload can have 1 pod, cockpit or probe core but nothing else that contributes any thrust or control authority to your craft. Also no lifting surfaces in payload.

7. Payload mass count after it's decoupled. If you had fuel or something disposable on the payload, give enough proof that you didn't throw any of them away.
  (e.g. Show that initial payload mass and final payload mass are same)

 

I. DISPOSABLE LIFTERS

1. Funds from recovery doesn't count.

2. You can use ANY parts you like.

 

IIa. REUSABLE ROCKETS

1. You can use any parts except airbreathing engines. (This includes any kind of scooping)

2. You can recover any parts of your lifter that you can for a refund.

3. If you return parts of the lifter from orbit you don't have to land on runway or launchpad for 100% refund. Just land somewhere on kerbin and you can count 100% refund. This is because once you are in orbit it is trivial (but time consuming and boring/irritating) to land at KSC.

4. If you return parts of the lifter that are dropped while suborbital or in atmosphere you must land them somewhere in the KSC area (not necessarily on the launchpad/runway) for 100% refund (KSC must be within sight from your landing spot). This is because again precision landing is boring/irritating. If it is outside the KSC, recovery cost is calculated as default.

 

IIb. VERTICAL LAUNCHED VEHICLES

1. You can use any parts, and at least one airbreather should be used in lifter.

2. You can recover any parts of your lifter that you can for a refund.

3. The craft should fly vertically to orbit - Pitch should be above 30 degrees under stratosphere(7km)

4. If you return parts of the lifter from orbit you don't have to land on runway or launchpad for 100% refund. Just land somewhere on kerbin and you can count 100% refund. This is because once you are in orbit it is trivial (but time consuming and boring/irritating) to land at KSC.

5. If you return parts of the lifter that are dropped while suborbital or in atmosphere you must land them somewhere in the KSC area (not necessarily on the launchpad/runway) for 100% refund (KSC must be within sight from your landing spot). This is because again precision landing is boring/irritating. If it is outside the KSC, recovery cost is calculated as default.

 

III. GENERAL

1. You can use any parts.

2. You can recover any parts of your lifter that you can for a refund.

3. If you return parts of the lifter from orbit you don't have to land on runway or launchpad for 100% refund. Just land somewhere on kerbin and you can count 100% refund. This is because (IMO) once you are in orbit it is trivial (but time consuming and boring/irritating) to land at KSC.

4. If you return parts of the lifter that are dropped while suborbital or in atmosphere you must land them somewhere in the KSC area (not necessarily on the launchpad/runway) for 100% refund (KSC must be within sight from your landing spot). This is because again precision landing is boring/irritating. If it is outside the KSC, recovery cost is calculated as default.

 

Submission

 - Submission should include enough screenshots or video to prove validity of the mission.

 - Username, brief explanation of the profile and characteristics will be listed. Craft file will be listed as well if it's given.

 - Up to 5 entries will be listed on the leaderboard.

 

Leaderboards

Stock:

I)

  1. 589.8/t, @maccollo, with Skipper augmented with Kickbacks.

IIa)

  1. 378.32/t, @Abastro, with fully recoverable TSTO w/o boostback. (Poodle on the second stage, Skipper&ReliantsX2 on the first stage)

  2. 394.99/t, @Nefrums, with Shuttle second stage on SpaceX style first stage. (Rhino on the second stage, Mammoths&Vectors on the first stage)

  3. 484.231/t (Craft file), @Avo4Dayz, with simplistic recoverable rocket SSTO powered by single Twin-Boar.

  4. 756.10/t, @Abastro, with fully recoverable TSTO with Nerv on the second stage.

III),

  1. 88.46/t, @Wanderfound, with improved version of 'kerbotruck' - more boosters! (8 R.A.P.I.E.Rs and 4 Shock Cone Intakes)

  2. 106.57/t, @OHara, with improved version of @NightshineRecorralis and giving it more cargo.

  3. 109.02/t (Craft file), @Wanderfound, with mk3 cargo bus 'kerbotruck' powered by 6 R.A.P.I.E.Rs and 3 Shock Cone Intakes.
                                                                      with few wings - I guess, it's just not wingless

  4. 113.69/t, @Clancy, with mk1-2 spaceplane powered by 2 RAPIERs supplied by and 1 NERV.
                                             (Just enough Oxidizer to push through the 30-40km, where the NERV can take its time getting to orbit.)

  5. 159.29/t, @NightshineRecorralis, with mk2 spaceplane with 2 R.A.P.I.E.Rs supplied by single Shock Cone Intake.

  6. 378.32/t, @Abastro, with fully recoverable TSTO w/o boostback. (Poodle on the second stage, Skipper&ReliantsX2 on the first stage)

 

Modded:

   - Stock-Balanced

   - with FAR&AJE

Edited by Abastro
Edited Rules to handle mods better.

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4 hours ago, Abastro said:

3. The craft should fly vertically to orbit - Pitch should be above 45 degrees till reaching stratosphere.


Just curious - why?

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10 hours ago, DerekL1963 said:


Just curious - why?

I wanted to see how rocket with airbreather performs. About the exact value, I found the pitch limit practically.

(I should have been removed it from category IIa...)

Edited by Abastro

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12 hours ago, Abastro said:

I wanted to see how rocket with airbreather performs. About the exact value, I found the pitch limit practically.

(I should have been removed it from category IIa...)

My rocket launches usually reach 45 degrees tilt at little over 10km so I think your limit is way too restricting to achieve an efficient launch profile...

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27 minutes ago, tseitsei89 said:

My rocket launches usually reach 45 degrees tilt at little over 10km so I think your limit is way too restricting to achieve an efficient launch profile...

 

EDIT: Just realized that it can be strict for some launch profiles. (Probably with better TWR)

Released the rule.

Edited by Abastro
Realization

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Here goes my (inefficient) entry, with fully recoverable TSTO with Nerv on the second stage (IIa, III):

QbmJyWT.png

http://imgur.com/a/X0fSY

Payload : 3.280t

Total Cost : 33170

Recovered Cost : 30690

Net Cost : 2480

 

Cost per Payload Mass : 756.10/t

 

P.S. There were significant loss from recovery(1550). Should perform more shallow gravity turn next time...

Edited by Abastro
Added the pic.

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Can you use fuel as a weight? I see no movement capability for a payload that has fuel but no engine, and you could just show (in the VAB) that fuel crossfeed is disabled on the decoupler.

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I have a 3 stage asparagus rocket. In trying to make my early stages recoverable, I put parachutes on the early booster stages, attempting to use the "Deploy when Safe" setting on the radial parachutes. However, I deploy the parachutes before, they don't come out as it's not safe, but the moment I decouple the stage they deploy and are destroyed. How can I prevent this?

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9 hours ago, bob132435465768798 said:

What I'm getting from this is that this is all for rockets (vertical launches). Can you do spaceplanes or no?

Spaceplanes will be in General category(III), as they are totally different thing in efficiency.

Or, you can make a fully rocket-powered spaceplane. (For IIa)

9 hours ago, bob132435465768798 said:

Can you use fuel as a weight? I see no movement capability for a payload that has fuel but no engine, and you could just show (in the VAB) that fuel crossfeed is disabled on the decoupler.

In the case, you can still transfer the fuel if you don'don't enabled 'fuel transfer obeys crossfeed rules'

There are many utility parts which provides decent weight. Why don't you use them? Also using ore will be allowed if it doesn't have

7 hours ago, bob132435465768798 said:

I have a 3 stage asparagus rocket. In trying to make my early stages recoverable, I put parachutes on the early booster stages, attempting to use the "Deploy when Safe" setting on the radial parachutes. However, I deploy the parachutes before, they don't come out as it's not safe, but the moment I decouple the stage they deploy and are destroyed. How can I prevent this?

They will just deploy while staging if pressure is high enough. You should find a solutiom since they will be deleted if you are 1km away from the craft.

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I'll try to make an entry for at least the disposable category later today:)

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Submission for category 1. Same old sustainer, except this time I used the offset stack trick to reduce the drag on the boosters. As a result I was able to push it below 600 funds/ton.

booster cost: 36488 funds

Payload: 61.87 tons

589.8 funds/ton

 

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Posted (edited)
1 hour ago, maccollo said:

 snip

Wow, that looks really efficient! I didn't know that Skipper becomes good when it gets thrust augmentation.

By the way, you used fuel tanks for payload(Rule 6), but obviously didn't use the fuel contained there in the entry. So I'll accept this one and change the rule to 'prove the payload mass is unchanged'.

EDIT: this is what kept bothering me as well.

Edited by Abastro

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21 hours ago, NightshineRecorralis said:

Here's an Ore Transporter I built, it has a cost to orbit of ~160 funds/ton.

Here's the horribly out of order album: http://imgur.com/a/RLKxp

7 tons to orbit, cost of fuel = 1115 funds.

cost per ton: 159 funds.

Wow, mk2 spaceplane to lift heavy cargo cheaply? Impressive!

All conditions checked for General Category(III); You'll be added to the list.

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Posted (edited)

 

Ok, so I think I did this challenge right but here is my attempt for reusable rocket. Hope I met the requirements.

MechJeb was used for Ascent and Deorbit, because let's be honest... That many attempts at a landing to get a suicide burn right is painful (I tried it when MechJeb wasn't playing nice). Also means I can search for next challenge or build ideas while it flies.

Using version 1.2.2 on Mac (laptop I can play form couch vs my PC :P )
Parts mods and realchute installed, but only mechjeb used in this build
Lifter + Payload Mass including Fuel is 134.2t
Lifter with Fuel but not Payload is 116t (Payload mass = 18.2t)
Lifter with Payload but no Lifting Fuel = 38.2t (Lifting Fuel = 96t)
Payload was a Fuel Section + Nosecone with fuel locked
Fuel cost = (Full ship and payload cost) 42,510 - (Full ship and payload but no fuel) 33,697 = 8,813
Cost = 8,813/18.2 = 484.231 Funds/t (recovery = 98% so if using recovered cost then it becomes 517.47 f/t)

TLDR: stock with autopilot, 100% recover cost = 484.231 f/t. With recover percentage factor = 517.47 f/t

Link to all relevant photos to prove my ship, I do play with modded parts usually, but wanted to attempt this with full stock set up
http://imgur.com/gallery/W6vyW

Edited by Avo4Dayz
Incorrect math

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I have been wanting to try to do a spaceX style boostback thing.      So here is a fully reusable first stage with a equally reusable shuttle on top.

Not the cheapest possible but a fun way of doing it :)   comes in at about 395 :funds:/t

L3cmuTf.jpg

http://imgur.com/a/5UDFF

 

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Posted (edited)

Hey Nerfrums,

Awesome lifter design! I love it...couldn't be bothered with boostback myself didn't think I could manage it.....

Edited by Avo4Dayz
Answered my own question

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Posted (edited)

Doing the boost-back is a bit hard as both first and second stage needs to be above the atmosphere in order to switch back and forth between them.  It took a couple of attempts to find a ascent path that left the first stage with a AP >70km, and at the same time the shuttle had to have enough time to do most of the circulation burn before the first stage dropped back down.

The dV cost for doing a boost-back was way less then I expected. 

 

Edited by Nefrums

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Posted (edited)
18 hours ago, Avo4Dayz said:

Under 500/t with SSTO rockets? Looks great! Though, you didn't take any screenshots of the launch profile. There's an issue with validity there... Please post the screenshots on the launch profile.

8 hours ago, Nefrums said:

snip

Good (old?) SpaceX style there, with Shuttle on the second stage? Like it, you got both aesthetics and efficiency!

So reusable category now goes with under 400/t!

 

13 hours ago, NightshineRecorralis said:

@Abastro

Lol, I put two photos of a different SSTO in that imgur album. It's just 2 Rapier engines.

Oops; I'll fix that.

 

54 minutes ago, Nefrums said:

Doing the boost-back is a bit hard as both first and second stage needs to be above the atmosphere in order to switch back and forth between them.  It took a couple of attempts to find a ascent path that left the first stage with a AP >70km, and at the same time the shuttle had to have enough time to do most of the circulation burn before the first stage dropped back down.

The dV cost for doing a boost-back was way less then I expected.

What about switching back just after performing boost-back? Doesn't it work?

Besides, the dV cost should be small enough since the first stage won't pick up horizontal speed. This is why SpaceX launch is practical, I think.

 

EDIT: By the way, I should fly economic mission in my own launch profile. I want to see how good and competitive it could be!

Edited by Abastro

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42 minutes ago, Abastro said:

What about switching back just after performing boost-back? Doesn't it work?

Besides, the dV cost should be small enough since the first stage won't pick up horizontal speed. This is why SpaceX launch is practical, I think.

There are two factors to consider

  1. you can only switch to a object (outside of physics range) if the current craft is above the atmosphere.
  2. A craft will dissiperar if it goes below ~35-40km? without being in focus.

So the flight plan is like this:

  1. Drop first stage when AP is outside of 70km and more than a minute away.
  2. Boost the second stage for that minute. Try to keep AP more then a minute ahead.
  3. Switch to the first stage and preform the boost-back. Aim about 30km short of KSC to compensate for Kerbal rotation.  Before reentering atmosphere switch back to second stage.
  4. Complete the circulation burn of the second stage and switch back to the first stage before it disappears.

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2 minutes ago, Nefrums said:
  • you can only switch to a object (outside of physics range) if the current craft is above the atmosphere.
  • A craft will dissiperar if it goes below ~35-40km? without being in focus.

Yeah, I know, I played with those limits. My question is that it is feasible to perform the full boost-back burn before getting out of physics range or not.

Besides, the limit is about 25km.

 

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That should be possible as a almost empty first stage has lots of twr,  Doing it with any kind of accuracy will be very hard thou.

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