To Mun on a Budget

Amoral · December 10, 2011

Using a Gamma III rocket with 6 strapped on boosters, I was able to land on Mun and return safely to Kerbin for $41,134 ($14,904 of which was recovered). Ominivore has the record for lowest total cost at $31,854 ($26,004 recovered). Jellycubes has the record for initial costs $13527 ($3972 recovered). The challenge is to beat one of those records.

I want to acknowledge Szyzyg\'s tutorial

for my mission plan, and Trydyingtolive\'s tutorial

for influence on my lander design. They are both great videos, I urge you to check them out and give them a like.

Mission Notes

After ignition, the rocket wants to spin and tilt off vertical. I needed\'
to make constant corrections. The winglets give lots of control, so I kept caps lock on. I burned straight up at 100% throttle until 9 of the 15 1st stage tanks were exhausted. After that I began a very slow rollover, letting off the throttle to keep at 200m/s. I time my roll over so that I am at 45degrees when Stage 1 is exhausted. It takes 3/4 of Stage 2 fuel to get into a 100km orbit, and then boost up to 3000 m/s to get my apogee up to 12,000km. I wait for Mun to capture me. My periapsis is already inside Mun, so I wait until he is 100km away, and then do a steady retrograde burn until my orbital path hits Mun roughly perpendicular.
During the descent from 100km down to 5km I kept my speed at 400ms, retroburning when needed. At 10 kms I burned hard to slow my rate of descent. Stage 2 is exhausted and jettisoned. I was over dark terrain which is usually smooth, so I killed off lateral velocity. Touchdown 9h and 45 mins into the mission.
To return to Kernin I blasted off at 45 degrees and boosted until my apoapsis was a long way from Mun, about 1/4 of the way back to Kerbin. Then I waited. As I waited My apoapsis stayed the same distance away from Mun, but swung slowly around so that it no longer pointed back at Kerbin. Not knowing quite what to do, I waited some more. I climbed away from Mun, and just about at apoapsis, Kerbin recaptured me. This left me in an Orbit with a perigee around 12,000km, and an apogee in deep space. Not wanting to risk my limited fuel, I waited some more. Mun and I completed our orbits in about the same time, and he briefly recaptured me again. This time He flung me more directly at Kerbin. When Kerbin recaptured me again It was a simple matter of retroburning until my perigee was inside the atmosphere. I jettisoned the final stage at about 40 km with 10% fuel remaining.

Budget

Lunar Stage
$422 Mk16 Parachute
$1600 Command Pod Mk 1
$975 TR-18A Stack Decoupler
$550 1 FLT-2500 Fueltanks
$950 LV-T45 Liquid Fuel Engine
$3825 3 x TT-38K Radial Decoupler
$1500 3x AV-R8 Winglet
----
$9822
Stage 2
----
$975 TR-18A Stack Decoupler
$2200 4x FLT-2500 Fueltanks
$850 LV-T30 Liquid Fuel Engine
---
$4025 ($2022 recovered)
Stage 1
----
$975 TR-18A Stack Decoupler
$680 TVR-1180C Mk1 Stack Tri-coupler
$8250 15 x FLT-2500 Fueltanks
$2550 3x LV-T30 Liquid Fuel Engine
$750 3x EAS-4 Strut Connector
$1500 3x AV-R8 Winglet
----
$14405
=$28252 Gamma III Rocket
Boosters
----
$2532 6 x Mk16 Parachute
$2700 6 x RT-10 Boosters
$7650 6 x TT-38K Radial Decoupler
----
$12882 (recovered)

Newe6000 · December 10, 2011

As soon as my comp is fixed. Accepted.

Although right now I could crash on my way to the mun for less? (and by crash I mean a 10 year old computer having a heart attack at the idea of a 3d game).

EDIT: Do you have to make it back to kerbin? I know its probally easy enough to do but the thread title implys you just have to get to the mun

Tosh · December 10, 2011

Just calculated my good old Mun Stock rocket. It\'s 35477 34127 (it has only 9 SRBs, not 12).

It flies, lands and returns... though not allowing to choose a landing site on Kerbin.

index.php?action=dlattach;topic=4756.0;attach=8133;image

[table]
[tr][td]
Return stage[/td][/tr]
[tr][td]
Mk16 chute [/td] [td]
422 [/td] [td]
422 [/td][/tr]
[tr][td]
Mk1 pod [/td] [td]
1600 [/td][td]
1600 [/td][/tr]
[tr][td]
TR-18A decoupler [/td][td]
975 [/td] [td]
975 [/td][/tr]
[tr][td][/td] [td][/td] [td]
2997 [/td][/tr]
[tr][td]
Mun stage[/td][/tr]
[tr][td]
ASAS [/td] [td]
2300 [/td] [td]
2300 [/td][/tr]
[tr][td]
FL-T500 tank [/td] [td]
550 [/td] [td]
550 [/td][/tr]
[tr][td]
3 TT-38R decouplers [/td][td]
3x1275 [/td] [td]
3825 [/td][/tr]
[tr][td]
3 AV-R8 winglets [/td] [td]
3x500 [/td] [td]
1500 [/td][/tr]
[tr][td]
LV-T45 engine [/td] [td]
950 [/td] [td]
950 [/td][/tr]
[tr][td]
TR-18A decoupler [/td] [td]
975 [/td] [td]
975 [/td][/tr]
[tr][td][/td] [td][/td] [td]
10100 [/td][/tr]
[tr][td]
Orbital stage[/td][/tr]
[tr][td]
3 FL-T500 tanks[/td] [td]
3x550 [/td] [td]
1650 [/td][/tr]
[tr][td]
LV-T30 engine [/td] [td]
850 [/td] [td]
850 [/td][/tr]
[tr][td]
TR-18A decoupler [/td] [td]
975 [/td] [td]
975 [/td][/tr]
[tr][td][/td] [td][/td] [td]
3475 [/td][/tr]
[tr][td]
Atmospheric stage[/td][/tr]
[tr][td]
TVR-1180C tricoupler [/td][td]
680 [/td] [td]
680 [/td][/tr]
[tr][td]
12 FL-T500 tanks [/td] [td]
12x550 [/td] [td]
6600 [/td][/tr]
[tr][td]
3 LV-T30 engines [/td] [td]
3x850 [/td] [td]
2550 [/td][/tr]
[tr][td]
3 EAS-4 struts [/td] [td]
3x250 [/td] [td]
750 [/td][/tr]
[tr][td]
3 TR-18A decouplers [/td][td]
3x975 [/td] [td]
2925 [/td][/tr]
[tr][td][/td] [td][/td] [td]
13505 [/td][/tr]
[tr][td]
Launch stage[/td][/tr]
[tr][td]
12 9 RT-10 boosters[/td] [td]
9x450 [/td] [td]
4050 [/td][/tr]
[tr][td][/td] [td][/td] [td]
4050 [/td][/tr]
[tr][td]
[/td][/tr]
[tr][td][/td][td][/td][td]
34127 [/td][/tr]
[tr][td]
Returned[/td][/tr]
[tr][td]
Mk16, Mk1[/td][td]
1600+422[/td][td]
2022 [/td][/tr]
[/table]
EDIT: added a screenshot, updated rocket cost.

Newe6000 · December 11, 2011

[table]
[tr][td]
Return stage[/td][/tr]
[tr][td]
Mk16 chute [/td] [td]
422 [/td] [td]
422 [/td][/tr]
[tr][td]
Mk1 pod [/td] [td]
1600 [/td][td]
1600 [/td][/tr]
[tr][td]
TR-18A decoupler [/td][td]
975 [/td] [td]
975 [/td][/tr]
[tr][td][/td] [td][/td] [td]
2997 [/td][/tr]
[tr][td]
Mun stage[/td][/tr]
[tr][td]
ASAS [/td] [td]
2300 [/td] [td]
2300 [/td][/tr]
[tr][td]
FL-T500 tank [/td] [td]
550 [/td] [td]
550 [/td][/tr]
[tr][td]
3 TT-38R decouplers [/td][td]
3x1275 [/td] [td]
3825 [/td][/tr]
[tr][td]
3 AV-R8 winglets [/td] [td]
3x500 [/td] [td]
1500 [/td][/tr]
[tr][td]
LV-T45 engine [/td] [td]
950 [/td] [td]
950 [/td][/tr]
[tr][td]
TR-18A decoupler [/td] [td]
975 [/td] [td]
975 [/td][/tr]
[tr][td][/td] [td][/td] [td]
10100 [/td][/tr]
[tr][td]
Orbital stage[/td][/tr]
[tr][td]
3 FL-T500 tanks[/td] [td]
3x550 [/td] [td]
1650 [/td][/tr]
[tr][td]
LV-T30 engine [/td] [td]
850 [/td] [td]
850 [/td][/tr]
[tr][td]
TR-18A decoupler [/td] [td]
975 [/td] [td]
975 [/td][/tr]
[tr][td][/td] [td][/td] [td]
3475 [/td][/tr]
[tr][td]
Atmospheric stage[/td][/tr]
[tr][td]
TVR-1180C tricoupler [/td][td]
680 [/td] [td]
680 [/td][/tr]
[tr][td]
12 FL-T500 tanks [/td] [td]
12x550 [/td] [td]
6600 [/td][/tr]
[tr][td]
3 LV-T30 engines [/td] [td]
3x850 [/td] [td]
2550 [/td][/tr]
[tr][td]
3 EAS-4 struts [/td] [td]
3x250 [/td] [td]
750 [/td][/tr]
[tr][td]
3 TR-18A decouplers [/td][td]
3x975 [/td] [td]
2925 [/td][/tr]
[tr][td][/td] [td][/td] [td]
13505 [/td][/tr]
[tr][td]
Launch stage[/td][/tr]
[tr][td]
12 9 RT-10 boosters[/td] [td]
9x450 [/td] [td]
4050 [/td][/tr]
[tr][td][/td] [td][/td] [td]
4050 [/td][/tr]
[tr][td]
[/td][/tr]
[tr][td][/td][td][/td][td]
34127 [/td][/tr]
[tr][td]
Returned[/td][/tr]
[tr][td]
Mk16, Mk1[/td][td]
1600+422[/td][td]
2022 [/td][/tr]
[/table]
Why didnt you put parachutes on the solid boosters so they were recoverable (along with the parachutes)?

SkyRender · December 11, 2011

Work on a low-budget lunar round-trip vehicle is progressing nicely. It\'s looking like I might be able to pull this off with a total cost of 17,747 (salvage 6,852). Maybe. We\'ll see how far I can stretch things.

EDIT: Okay, I\'ve a proof-of-concept now that works. It\'s 18,297 total cost (7,402 salvage), and can get into a landing orbit around the Mun with a full 2 fuel tanks to spare. Now I just have to land the damn thing and get it back to Kerbin in one piece...

Tosh · December 11, 2011

Why didnt you put parachutes on the solid boosters so they were recoverable (along with the parachutes)?

Just because I don\'t care for these boosters))

Newe6000 · December 11, 2011

Just because I don\'t care for these boosters))

Buh, buh its cheaper $_$

SkyRender · December 11, 2011

For a budget challenge, you should probably avoid boosters entirely. Though they do get you off the ground faster, they also cost a lot since you have to get rid of them somehow after the fact. Decouplers don\'t come cheap, especially not radial decouplers! My current model of budgetary efficiency lacks a single one:

Lunar Arrow V3
16 Liquid Fuel Tanks @ $550 ea.: 8,800 (2,200 salvageable)
4 Liquid Fuel Engines @ 880 ea.: $3,520 (880 salvageable)
1 Parachute @ 422 ea.: 422 (422 salvageable)
1 Command Module @ 1,600 ea.: 1,600 (1600 salvageable)
1 ASAS Module @ 2,300 ea.: 2,300 (2,300 salvageable)
1 Decoupler @ 975 ea.: 975
1 Tri-Coupler @ 680 ea.: 680
Total Expense: 18,297 (7,402 salvageable)

I can get this bad boy to the Mun with 2 tanks left even without a Hohmann transfer orbit. If I were being so efficient, I could probably drop a tank from the top rocket. The only thing keeping me from finishing this challenge thus far is that soft-landing with no lander legs and having the rocket survive in one piece is hard. I\'ve managed that feat exactly once.

Omnivore · December 11, 2011

I believe this is a new record: My pure stock Minima IIb has a total cost less salvage of 0, although I suppose you can\'t really salvage explosive decouplers so I count the total after salvage as 5850 kerbits. Not counting any salvage the total cost is 31854.

Fuel was awfully tight on the way home but I had just enough to make a successful parachute assisted powered landing on *water*!!!

Bill of material/budget:

Minima IIb

1st Stage:
1x Parachute 422
1x Pod 1600
2x LFT 1100
1x LV-T45 950
3x SRB 1350
3x AV-R8 winglet 1500
----------------------
Sub Total: 6822
Salvaged: 6822

2nd Stage:
3x Stack decoupler 2925
12x LFT 6600
3x LV-T30 2550
3x SRB 1350
3x Parachute 1266
3x Strut 750
-----------------------
Sub Total: 15441
Salvaged: 12516 (stack decouplers non salvageable)

3rd Stage:
3x Stack decoupler 2925
12x SRB 5400
3x Parachute 1266
----------------------
Sub Total: 9591
Salvaged: 6666 (stack decouplers non salvagable)

=================================================
Total: 31854 kerbits
Salvaged 26004
Total less salvage: 5850 (cost of 6x stack decouplers)

Highlights of the voyage:

Just noticed from some of the other stock designs I\'ve seen lately that evidently not too many people realize you can \'weld\' SRBs to other SRBs or LFTs, I\'m attaching the Minima IIb craft file here in case anyone wants to see how its done.

SkyRender · December 11, 2011

Very nice! Only problem, of course, is that the vanilla parachutes as they\'re coded now can\'t really handle much weight. Indeed, pretty much any scenario more complicated than 'command module over low altitude' or 'single empty fuel tank over low altitude' is usually going to result in lots of booms. Then again, the game doesn\'t even keep track of any discarded objects that get too far from your ship, so who would know?

Omnivore · December 11, 2011

Very nice! Only problem, of course, is that the vanilla parachutes as they\'re coded now can\'t really handle much weight. Indeed, pretty much any scenario more complicated than 'command module over low altitude' or 'single empty fuel tank over low altitude' is usually going to result in lots of booms.

Thanks. However your conclusion on the chutes seems to be a bit in error - pod weighs 1 ton, empty LFT 0.3 tons, burnt out SRB 0.36 tons. I\'ve landed with a total weight of nearly 5 ton using parachute before losing only the engine. I\'ll grant you the engines - though at 2 tons they\'re drastically overweight for their volume and thrust.

With stock you have to do with what you have available. Stock doesn\'t have heavy/triple chutes or side mount chutes so not much you can do beyond what I did with the Minima II design.

JellyCubes · December 11, 2011

I think stock parts are quite powerful if used correctly. The challenge is to find a solution that overcomes the limitation.

You know parachutes can only be attached on top of SRBs, so your craft design should tend towards having more SRBs than LFTs.

Omnivore · December 11, 2011

You know parachutes can only be attached on top of SRBs, so your craft design should tend towards having more SRBs than LFTs.

Only problem, of course, is that the vanilla parachutes as they\'re coded now can\'t really handle much weight.

Too avoid argument/misunderstanding, it\'d be nice if the authors of challenges like this one and http://kerbalspaceprogram.com/forum/index.php?topic=3927.msg43807#msg43807 would specify the max weight that a stock parachute can handle for salvage purposes.

It was worth welding one SRB onto a stack of 4 LFT\'s + LFE in order to provide a parachute mount for salvaging the stack, question is - for purposes of the salvage rule(s) can one parachute handle 3.56 tons?

Amoral · December 11, 2011

Too avoid argument/misunderstanding, it\'d be nice if the authors of challenges like this one and http://kerbalspaceprogram.com/forum/index.php?topic=3927.msg43807#msg43807 would specify the max weight that a stock parachute can handle for salvage purposes.
It was worth welding one SRB onto a stack of 4 LFT\'s + LFE in order to provide a parachute mount for salvaging the stack, question is - for purposes of the salvage rule(s) can one parachute handle 3.56 tons?

Doesn\'t the end misison log say that 'Foo crashed into the ground' if it was destroyed, and says nothing at all if it survived? That\'s what I have noticed anyways.

SkyRender · December 11, 2011

Doesn\'t the end misison log say that 'Foo crashed into the ground' if it was destroyed, and says nothing at all if it survived? That\'s what I have noticed anyways.

It does if the part was within draw distance when it collided with the surface. I\'ve noticed that parts which had no parachutes at all ended up not getting recorded as having collided with anything even though I dropped them back to the surface when I\'ve launched away from the planet quickly enough. These things were definitely on a collision course at very high speed, to boot.

Newe6000 · December 11, 2011

For a budget challenge, you should probably avoid boosters entirely. Though they do get you off the ground faster, they also cost a lot since you have to get rid of them somehow after the fact. Decouplers don\'t come cheap, especially not radial decouplers! My current model of budgetary efficiency lacks a single one:
Lunar Arrow V3
16 Liquid Fuel Tanks @ $550 ea.: 8,800 (2,200 salvageable)
4 Liquid Fuel Engines @ 880 ea.: $3,520 (880 salvageable)
1 Parachute @ 422 ea.: 422 (422 salvageable)
1 Command Module @ 1,600 ea.: 1,600 (1600 salvageable)
1 ASAS Module @ 2,300 ea.: 2,300 (2,300 salvageable)
1 Decoupler @ 975 ea.: 975
1 Tri-Coupler @ 680 ea.: 680
Total Expense: 18,297 (7,402 salvageable)
I can get this bad boy to the Mun with 2 tanks left even without a Hohmann transfer orbit. If I were being so efficient, I could probably drop a tank from the top rocket. The only thing keeping me from finishing this challenge thus far is that soft-landing with no lander legs and having the rocket survive in one piece is hard. I\'ve managed that feat exactly once.

Technichly if you attach parachutes to the boosters their entirely re-useable.

But If we want to get technical they would probally only get you a quater of what they cost back due to some of the cost being fuel.

But since I dont think we are being THAT technichal as long as you use parachutes with them then they and the parachute would cost you nothing.

Amoral · December 12, 2011

In the Mun landing thread jellycubes posted his ultralight lander. It is the new record holder for lowest initial cost.

$1600 - 1 command pod

$422 - 1 parachute

$975 - decoupler

$680 - 1 tri-coupler

$4950 - 9 x LFT

$3400 - 4 x LFE

$1500 - 3 x struts

----------------

$13527 ($3972 recovered)

CarolRawley · December 13, 2011

Do we have to go to the Mun? Can the Mun just come to us?

Switchblade88 · December 25, 2011

My entry is expensive at $72,024, but I can recover everything bar the TMI stage ($40649) giving me a total of $31,375.

I\'ve knocked up a spreadsheet for costings; I\'ll try and get it onto Google Docs and share it publicly if anyone else was interested...

samstarman5 · December 28, 2011

I have actually attached parachutes to LFT\'s so those can be 'recycled.' I have been able to reach the Mun\'s orbit on just two stages and that is with some waste still in the calculations. Refined down I bet I could do it with two stages of nothing but LFB\'s. I am not placing bets on it, though. I never bet blind where lack of experience is concerned. But those who are experienced might be able to lend something.

Do we have to go to the Mun? Can the Mun just come to us?
How you do dat?
I don\'t think the cost of the disasters from the overwhelming change in the tides and the kerbquakes would make that cost effective.

Switchblade88 · December 28, 2011

Here\'s my basic costing spreadsheet for public consumption:

http://dl.dropbox.com/u/20800917/KSP%20parts%20sheet.xlsx

This should make it quicker to calculate and prove total costs and recyclables.

WX_Echo · December 29, 2011

If you\'re trying to maximize the payload ratio delivered to the Mun, make sure you utilize minimum-fuel transfer techniques like the Hohmann or Bi-elliptic transfers methods.

In some cases, these maneuvers can save you a non-trivial amount of fuel and ensure you maximize the payload delivered to the target. Alternatively, you could deliver the same payload with a smaller launch/delivery vehicle.

Alchemist · December 30, 2011

The absolute minimum could be this... Just made a semi-successful trip: bounced of the Mun (if attempted to land again it would end in laying horizontally), flew back, splashed too hard at 18 m/s (Munar escape was not very successful - so there was a bit less fuel left than needed for final braking). Somebody with a joystick definitely should try this thing (keyboard is not enough for landing this without falling on the side).

To Mun on a Budget

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