Roads to Duna: No Moar Boosters (UPDATES!)

[sevenperforce]

The Red Planet has captured the imaginations of space pioneers ever since the first days of high-powered rocketry. There's a long and auspicious list of proposed Mars missions, dating all the way back to Werner Von Braun's wildly optimistic plan to use over 400 launches to construct a massive artificial-gravity space station for Mars colonization transport.

Any of us who have played KSP for a while can probably put a single-launch mission of arbitrary size on Duna easily enough, because Moar Boosters. However, the real world doesn't work like that. You can't just add more boosters; typically, mission planners have to work within the capabilities of existing (or planned) launch vehicles, which can only throw a certain amount of mass into orbit at once. As a result, most of the proposed Mars mission plans involved some degree of in-orbit assembly.

The challenge is to design and execute a flags-and-footprints Mars mission with the lowest-massing payload per launch.

You can assemble your mission using up to five separate launches; the goal is to make each of those orbital payloads as small as possible. There is no bonus for using fewer than five launches. For example, if you use four orbital payloads massing 8 tonnes, 12 tonnes, 6 tonnes, and 9 tonnes, then your score is 12 tonnes. If you use three orbital payloads massing 4 tonnes, 7 tonnes, and 14 tonnes, then your score is 14 tonnes, even though you did it in fewer launches with lower total mass. Obviously, lowest score wins. Thus, the incentive is to make all the launches roughly the same size in order to maximize the amount of mass you get into orbit while minimizing the size of any one launch, just like real-life mission planning requires you to work within the payload capacities of existing launch vehicles. This will require clever planning, so think ahead!

A few rules to keep things more true-to-life:

• You can use whatever mission architecture you want, but it needs to have at least three Kerbals delivered to Duna orbit and at least two delivered to the surface. Crew must be sent up in the final launch from Kerbin.
• The transfer and lander (or whatever you use) must have actual crew space. It's fine to use command seats for rovers or for a separately-landed ascent vehicle.
• On-orbit payload is anything that goes with you toward Duna. If your upper stage is jettisoned after reaching LKO, then it's part of your launch vehicle, not your payload. If you refuel the upper stage to use for your transfer burn, then it's part of your payload.
• Assembly in LKO means assembly between 70 and 200 km.
• No ions except for unmanned probes, and then only for orbital adjustments (e.g., no spiraling out over the course of months).
• If you want to use nukes, you can do so, but only before leaving Kerbin's SOI. NERVAs can't be reliably restarted after a long period of time.
• ISRU can be used, but with some restrictions:
  • Astronauts can't wait forever for ISRU, so if you manufacture your own fuel and oxidizer, you'll need to send an unmanned ISRU unit ahead of time.
  • If you bring your own liquid fuel and only want to manufacture oxidizer, it's fine to have the ISRU unit on the manned lander (it's considered feasible to do this for Mars missions since cracking LOX out of the Martian atmosphere is straightforward). If you take this route, you can turn on infinite fuel when you activate your Convert-O-Tron (no need to use a drill).
• If the ascent vehicle lands on Duna separately from the landing craft, then you must bring a rover or other vehicle to take your crew from the lander to the ascent vehicle; no hundred-mile treks.

You can earn bonuses to improve your score:

• On Tongues of Fire. Use no chutes; propulsive landings on both Duna and Kerbin. 10% decrease in highest payload mass. ^{Conflicts with Wing It.}
• Wing It. Winged, rolling landings on Duna and Kerbin. 5% decrease in highest payload mass. ^{Conflicts with On Tongues of Fire.}
• Old School. No nukes or ions. 3% decrease in highest payload mass.
• Brute Force. Assemble a Direct Ascent vehicle in LKO; no ISRU, no propellant transfer, no Duna orbit rendezvous. 12% decrease in highest payload mass. ^{Conflicts with Loop the Loop & Justin Case.}
• Slow Climb. Put ladders on your vehicles, if necessary, so you don't have to jetpack around on the Duna surface. 4% decrease in highest payload mass.
• Elon Style. Make the whole system fully reusable without using nukes, ions, or airbreathers. 25% decrease in highest payload mass. ^{Conflicts with Justin Case & A Solid Plan.}
• Stayin' Alive. Bring extra living space (at least one extra seat per Kerbal) for the transfer to and from Duna. 18% decrease in highest payload mass.
• Loop The Loop. Make your transfer vehicle a fully-reusable solution that can brake back into Kerbin orbit and be used again for the next trip. 15% decrease in highest payload mass. ^{Conflicts with Brute Force.}
• Consistency, Good Sir. Make all of your launches with the exact same launch vehicle. 6% decrease in highest payload mass.
• Justin Case. (NEW) Provide your crew with a separately-landed ascent vehicle as a reliable way to get off Duna (inspired by The Martian). 18% decrease in highest payload mass. ^{Conflicts with Brute Force & Elon Style.}
• A Solid Plan. (NEW) Make the Duna Ascent Vehicle (whether separately-landed or not) solid-fueled to orbit. 9% decrease in highest payload mass. ^{Conflicts with Elon Style.}
• They See Me Rollin'. (NEW) Bring a rover for your crew to get around Duna. 15% decrease in highest payload mass.

If you find you need more than five launches, that's fine, but you'll have to assess a 15% penalty for each additional launch to represent the added real-life cost of adding an additional launch contract. There is not, however, a bonus for doing it in fewer than five launches.

No part mods for the actual Duna package, although you can use part mods for your launch vehicle if you like. 

I may continue to add additional bonuses to enable increasingly-lower scores as the challenge goes on.

Good luck!

Smallcraft Leaderboard:

Spoiler

1. @Mesklin Five launches, highest payload was 4.6 tonnes. Eligible for On Tongues of Fire, Old School, Slow Climb, Elon Style, Stayin' Alive, Loop The Loop, Consistency, and Rollin', score is 0.18428.
2. @Kergarin Five launches, highest payload was 1.695 tonnes. Eligible for Old School, Elon Style, Brute Force, Slow Climb, and Consistency, score is 0.8136.
3. @mk1980 Five launches, highest payload was 4.850 tonnes. Eligible for Old School,  Elon Style, Stayin' Alive, Wing It, and Loop The Loop, score is 1.455.
4. @Laie Five launches, highest payload was 2.33 tonnes. Eligible for Old School and Slow Climb, score is 2.1669.
5. @sevenperforce Four launches, highest payload was 11.745 tonnes. Eligible for Brute Force, score is 10.3356. 

Largecraft Leaderboard (20+ kerbals):

Differences: Entries must have 20 or more kerbals. At least 2/3 of your crew must land on Duna. Stayin' Alive only requires that you have one extra seat for every 2 kerbals. You divide your total score (after bonuses) by half the total number of kerbals you take.

Spoiler

1.  

 

Edited September 15, 2017 by sevenperforce

[Laie]

5 hours ago, sevenperforce said:

NERVA can't be reliably restarted and won't last all the way to Mars, so you can't use the LV-N for Duna capture.

Will periapsis-kicks on nukes still be alright, or does it need to be a single burn? (if you want to somehow reflect real-life storage issues, just say so)

5 hours ago, sevenperforce said:

If you bring your own liquid fuel and only want to manufacture oxidizer, you can do this from the atmosphere, so it's fine to have the ISRU unit on the manned lander.

Hmmm. I'm afraid some clarification is needed. If fuel can be refined from thin air, ore concentration should not be an issue. Do I still need to use in-game ISRU in that case (specifically, locating and landing on top of a good deposit)? Do I even need to bring a drill?

[sevenperforce]

8 minutes ago, Laie said:

Will periapsis-kicks on nukes still be alright, or does it need to be a single burn? (if you want to somehow reflect real-life storage issues, just say so)

Hmmm. I'm afraid some clarification is needed. If fuel can be refined from thin air, ore concentration should not be an issue. Do I still need to use in-game ISRU in that case (specifically, locating and landing on top of a good deposit)? Do I even need to bring a drill?

I'll say LV-Ns can be used as long as you're still in Kerbin's SOI. I was thinking of NERVA-to-Mars plans which were set up like asparagus staging but only fired a pair at a time. But I don't want to make it too hard.

You definitely still need a drill, etc. for ISRU. I was just saying that if you bring your own liquid fuel and only manufacture liquid oxidizer, then you can have it in your manned lander; if you manufacture both, you need to land your ISRU unit ahead of time. Current Mars Ascent Vehicle plans with ISRU typically require the MAV to go ahead of time because digging up soil and cracking water for hydrogen/methane is risky and time-consuming.

[Laie]

I currently consider a direct landing at Duna, let the vessel fall where it may. Hence the question about ore. Hey! Has the Brute Force category been there the last time I looked? IMO that's a whole lot easier than aerobraking me into a Duna orbit. 12% off totally pays for bringing my own oxidizer.

After tinkering with go-anywheres for so long, I'm amazed at how small a one-shot mission may be, and wonder how to split it into five pieces (also, crew has to come up last -- makes sense, but complicates matters). Not sure if an entry will come of this, (selecting and posting pictures is tedious) but you successfully sent me off planning and designing. Thanks!

[Grand Ship Builder]

I'll do this. Do I get points for semi-reusability?

Bring it on!

8 hours ago, sevenperforce said:

• Safety First. LES on Kerbin crew launch vehicle. 5% decrease in highest payload mass.
• On Tongues of Fire. Use no chutes; propulsive landings on both Duna and Kerbin. 10% decrease in highest payload mass.
• Wing It. Winged, rolling landings on Duna and Kerbin. 5% decrease in highest payload mass.
• Old School. No nukes or ions. 3% decrease in highest payload mass.
• Brute Force. Assemble a Direct Ascent vehicle in LKO; no ISRU, no propellant transfer, no Duna orbit rendezvous. 12% decrease in highest payload mass.
• Cherry Bomb. Use explosive decoupling for all your post-LKO staging events. 4% decrease in highest payload mass.
• Slow Climb. Put ladders on your vehicles so you don't have to jetpack around on the Duna surface.
• Elon Style. Make the whole system fully reusable without using nukes, ions, or airbreathers. 25% decrease in highest payload mass.

What is this? For amateurs?

 

Edit: I'll actually do this challenge, just give me a few more years.

Edited September 7, 2017 by Grand Ship Builder

[qzgy]

Oooh, a well thought out challenge. Might have to do this one.

[sevenperforce]

3 hours ago, Laie said:

After tinkering with go-anywheres for so long, I'm amazed at how small a one-shot mission may be, and wonder how to split it into five pieces (also, crew has to come up last -- makes sense, but complicates matters). Not sure if an entry will come of this, (selecting and posting pictures is tedious) but you successfully sent me off planning and designing. Thanks!

Bringing crew up last makes it trickier for sure! You have to worry about making sure each of your probes can dock together properly, and they have to have solar power or some other persistent source of electricity. I had considered making a disposable ion-powered tug one of my launches, just to do it all.

I think I have my Brute Force version down to under 8 tonnes payload per launch but it's going to be tight. And I won't get any other bonuses.

3 hours ago, Grand Ship Builder said:

I'll do this. Do I get points for semi-reusability?

Bring it on!

I just added a category that rewards semi-reusability, Loop The Loop.

EDIT: Paging the usual suspects to see if they'd be interested in this challenge: @DAL59 @Bottle Rocketeer 500 @eloquentJane @GoSlash27 @Nucleartaxi @Nik75 @mk1980 @53miner53

Edited September 7, 2017 by sevenperforce

[Kerbalstar]

I might do this one. 

[53miner53]

Expect an entry from me at some point. Not sure when, but I'll enter.

[Laie]

12 minutes ago, sevenperforce said:

I think I have my Brute Force version down to under 8 tonnes payload per launch but it's going to be tight.

I've got a tinkerer's solution capable of carrying six; smallest piece of hardware is 5t, gross mass 27t with nukes. With the bare minimum, Mk1 pod plus Mk1 cabin, I'm down to a good 2t for the crew module and 20t overall without nuke; with, it would be 18t.

Both are brute force, direct impact and return. There should be a bonus for circularizing, really. In theory it should save some mass, but in practice the savings are small-to-nonexistent. The small vessel needs ~1t of fuel to get home, the overhead for parking that amount in orbit (probe, transmitter, ...) is like 400kg.

Heh. Will it be acceptable to launch a manned crew module last and just attach it, or does the crew need to come up in a separate capsule/pod/whatever and only board the vessel after it's finished (maybe bringing some fuel)? Given how crew modules are the heaviest bits, this one is sure to make a huge difference.

And, may I suggest some alteration of the rules? The parts involved are small enough that noone has to re-use an upper stage. I'd suggest to make that an requirement: lifter comes up, decouples parts, and the mass of these decoupled parts then counts. Main purpose is to keep bookkeeping easy: Just look at the mass when decoupled (which should be the same as in VAB) and that's your payload. A welcome side effect will be that if you send up drained hardware first, and fuel later, you will have overhead for the extra tanks. No direct fuel transfers from the LV with before/after comparisons.

 

[sevenperforce]

47 minutes ago, Laie said:

I've got a tinkerer's solution capable of carrying six; smallest piece of hardware is 5t, gross mass 27t with nukes. With the bare minimum, Mk1 pod plus Mk1 cabin, I'm down to a good 2t for the crew module and 20t overall without nuke; with, it would be 18t.

Ooh, impressive!

Smallest piece of hardware is 5 tonnes...what's your largest piece of payload?

47 minutes ago, Laie said:

Both are brute force, direct impact and return. There should be a bonus for circularizing, really. In theory it should save some mass, but in practice the savings are small-to-nonexistent. The small vessel needs ~1t of fuel to get home, the overhead for parking that amount in orbit (probe, transmitter, ...) is like 400kg.

Yeah, target-orbit rendezvous is much different for Duna than it is for the Mun. With the Mun, you need to carry propellant for capture, downward journey, upward journey, and return, making Direct Ascent twice as fuel-expensive. With Direct Ascent from Duna, you can aerobrake both for capture and for entry, meaning that you only need to carry propellant for the upward journey and the return. Direct Ascent saves the fuel that would be required for an orbiter's capture burn, too. Of course, if you're using a separate transfer hab, this makes Duna Orbit Rendezvous more attractive, because the fuel to capture-burn that hab is probably less than the fuel to reorbit it.

The lowest-mass solution, assuming you use a separate transhab, is to stow your solar panels, aerocapture using your lander's heat shield, lower your apoapsis gently with successive passes, and then allow your lander to break away and drop to the surface while your transhab raises its periapsis to await return.

47 minutes ago, Laie said:

Heh. Will it be acceptable to launch a manned crew module last and just attach it, or does the crew need to come up in a separate capsule/pod/whatever and only board the vessel after it's finished (maybe bringing some fuel)? Given how crew modules are the heaviest bits, this one is sure to make a huge difference.

Oh, absolutely. My current plan is to have a probe core and RCS on my Duna-to-Kerbin transfer stage, use it to dock serially to each of the lower modules (Duna launch, Duna Entry, and Kerbin Escape), and then send the crew capsule up to dock on top of everything else.

47 minutes ago, Laie said:

I'd suggest to make that an requirement: lifter comes up, decouples parts, and the mass of these decoupled parts then counts. Main purpose is to keep bookkeeping easy: Just look at the mass when decoupled (which should be the same as in VAB) and that's your payload. A welcome side effect will be that if you send up drained hardware first, and fuel later, you will have overhead for the extra tanks. No direct fuel transfers from the LV with before/after comparisons.

The only trouble with this approach is that some people (cough, cough, myself) will want to dock the orbiting modules directly to each new module before decoupling from the LV's upper stage, thus saving the mass of an extra probe core and reaction wheels on successive modules.

[Laie]

27 minutes ago, sevenperforce said:

Smallest piece of hardware is 5 tonnes...what's your largest piece of payload?

I haven't pursued this further, but started work on the tiny vessel -- with chutes and without reusability, I think I can get it down to about 4t per launch. Maybe 3700kg.

For the six-person thingy, I'd guess it to be on the order of 6.5t.

15 minutes ago, sevenperforce said:

The only trouble with this approach is that some people (cough, cough, myself) will want to dock the orbiting modules directly to each new module before decoupling from the LV's upper stage, thus saving the mass of an extra probe core and reaction wheels on successive modules.

Yeah, but you could... what I wanted to get at is that there should be a clear distinction between LV and payload. If you want to send up fuel, you should put the desired amount on top of your LV, rather than count on something being left in the upper stage and only counting the precise amount you take out of it.

[sevenperforce]

2 minutes ago, Laie said:

Yeah, but you could... what I wanted to get at is that there should be a clear distinction between LV and payload. If you want to send up fuel, you should put the desired amount on top of your LV, rather than count on something being left in the upper stage and only counting the precise amount you take out of it.

Well, alternately, something like the SpaceX Interplanetary Transportation System doesn't ever have fuel "on top of" the LV, so that wouldn't work.

Edited September 7, 2017 by sevenperforce

[mk1980]

i formed a rough mission plan and have some questions regarding the "achievements"

i might build a small-ish winged glider to land on duna and later on kerbin (for "Wing It") and use some sort of mothership that will stay in duna orbit and will circularize in kerbin orbit after return - which i guess would also fulfill "Loop The Loop".

assuming i can pack enough fuel for the transfer to duna and back (which may or may not be possible - depending on how much dV i can realistically save by carefully aerobreaking), both the mothership and the glider would arrive in kerbin orbit after the mission

the glider would then return to kerbin surface with the whole crew while the mothership stays in the parking orbit. so in theory, the system would be fully reusable since the mothership could be refuelled and the glider could land on the KSC runway and launched again later (similar to a space shuttle). would that also count for "Elon Style", then?

what if the glider only has 2 seats an can only return 2 of the 3 kerbals down to kerbin surface? does it still count if the third guy stays in orbit (or picked up by some other ship later). also, i guess it would make more sense to not land the glider at all if the mission is supposed to be re-usable (launching some extra fuel is cheaper than launching the whole glider again)?

 

i guess "Stayin' Alive." could be squeezed in. it would increase the scale of the mission and would probably make the individual launches heavier - so amere 9% discount seems counter productive (i have a feeling the ship will need much more then just 9% more mass to haul an extra hitchiker container or similar all the way to duna?)

also, it's unclear whether Cherry Bomb would apply for a mission that doesn't use extra stages/droptanks at all (ie. something like the proposed mothership & lander glider)

 

splitting the launches to minimze the payload per launch will be difficult. how does the "heaviest module" rule handle fuel launches? assuming i launch my glider with empty tanks and split the mothership into two parts

 

for the sake of argument, let's say the glider is 8 tons dry weight, the hab/engine module of the mothership is ~5 tons and the partially empty tank section (separate launch) of the mothership is also 8 tons. the glider might need 4 tons of fuel and the mothership might need another 10 tons of fuel, so i could send up 2 refuelling missions. one with 8 tons tons and one with 6 tons and a capsule that brings the 3 kerbals to the ship (including a LEV at liftoff  )

the glider is now technically ~12 tons and the main ship tank is ~20 tons, but they were not actually launched with that weight. 

would that be a "legal" way of bypassing your rules or would the main tank still count as the heaviest part with 20 tons or do the (multiple) 8 ton launches count as the highest launch payload?

 

guess i'll fire up the game and start working on it. see if i my mission profile is viable at all. i think it would work fine with nukes, but may be too ambitious for chemical engines.

 

EDIT:

did some testing before i fully commit. made a small-ish mk2 glider with enough wing surface to land on duna unpowered and enough fuel to return to orbit and (probably) rendezevous

https://imgur.com/a/6qj9j

so that part of the plan should work. that thing can carry 4 kerbals down and masses a bit less than 10 tons fuelled (~6 tons empty). landing on kerbin should be easy if it even manages to land on duna 

EDIT 2: some more planning

command and hab module will be a hitchhiker, probecore, solar panels, big reaction wheel and a 3.75meter heatshield. the heatshield will probably be launched "empty" - should have enough heat resistance even without ablator. the module is ~5 tons, so even with a full shield it would be smaller than the other modules. i don't think it's possible to refill an empty heatshield in orbit, though (concerning the "full reusability")

then 3 tank sections. basically 3 almost identical launches. 9t tanks +2 docking ports (0.1 ton if i use the mod sized ones, 0.4 if i stick with the larger oes that look better)

and the glider i already testet - which will will be the last launch and bring up the kerbals. it's engine is powerful enough to push the whole train to duna, so no real need to slap on more engines on other parts of the vessel.

https://imgur.com/a/XMuRK

you know, that might actually work. deltaV is a bit low-ish, but if i can make good use of the heatshield and cut most of the cost of the orbital insertions via aerobraking, it should be more than enough for a roundtrip.

 

won't execute the mission today. maybe tomorrow if i have time to play.

 

Edited September 7, 2017 by mk1980

[icantmakemodels]

Mods allowed?

 

(Placeholder)

[sevenperforce]

51 minutes ago, mk1980 said:

i formed a rough mission plan and have some questions regarding the "achievements"

i might build a small-ish winged glider to land on duna and later on kerbin (for "Wing It") and use some sort of mothership that will stay in duna orbit and will circularize in kerbin orbit after return - which i guess would also fulfill "Loop The Loop".

assuming i can pack enough fuel for the transfer to duna and back (which may or may not be possible - depending on how much dV i can realistically save by carefully aerobreaking), both the mothership and the glider would arrive in kerbin orbit after the mission

the glider would then return to kerbin surface with the whole crew while the mothership stays in the parking orbit. so in theory, the system would be fully reusable since the mothership could be refuelled and the glider could land on the KSC runway and launched again later (similar to a space shuttle). would that also count for "Elon Style", then?

Very nice plan! This is exactly the sort of thing I was hoping to see -- lots of different paths and plans to try and get to Duna and back.

Elon Style doesn't allow nukes, which complicates things. Also, note that if you do have nuclear engines on your mothership, you cannot use them for a capture burn at Duna or once you come back to Kerbin; they may only be used before leaving LKO. Real-life NERVAs are not generally considered to be low-maintenance affairs, and the likelihood of restarting a NERVA after a lengthy cruise is very low. Of course, if your mothership can aerobrake and use chemical propulsion for the return transfer, that's fine!

51 minutes ago, mk1980 said:

what if the glider only has 2 seats an can only return 2 of the 3 kerbals down to kerbin surface? does it still count if the third guy stays in orbit (or picked up by some other ship later). also, i guess it would make more sense to not land the glider at all if the mission is supposed to be re-usable (launching some extra fuel is cheaper than launching the whole glider again)?

It's fine to have just two seats on the glider if it is fully reusable and lands at KSC since it could always (in theory) be refueled and head back up to get the third Kerbal.

51 minutes ago, mk1980 said:

i guess "Stayin' Alive." could be squeezed in. it would increase the scale of the mission and would probably make the individual launches heavier - so amere 9% discount seems counter productive (i have a feeling the ship will need much more then just 9% more mass to haul an extra hitchiker container or similar all the way to duna?)

The reason I only gave a 9% reward for Stayin' Alive is that it will push entrants to do a Duna Orbit Rendezvous, which is more efficient to begin with.

51 minutes ago, mk1980 said:

also, it's unclear whether Cherry Bomb would apply for a mission that doesn't use extra stages/droptanks at all (ie. something like the proposed mothership & lander glider)

It would not. I intentionally made several of the bonuses exclude each other so that people would have to choose.

51 minutes ago, mk1980 said:

splitting the launches to minimze the payload per launch will be difficult. how does the "heaviest module" rule handle fuel launches? assuming i launch my glider with empty tanks and split the mothership into two parts

Entries are judged based on the highest single launch payload, just like real-life mission plans are limited by the capabilities of the chosen launch vehicle. So your first "payload" would be your glider's dry mass (or total mass with remaining fuel when orbit is reached, if it uses its own engines for the final push into orbit). Your second payload would be the mass of the first part of the mothership, your third payload would be the mass of the second part of the mothership, and each subsequent payload would be the mass of whatever fuel is transferred to the mothership in a single launch.

1 hour ago, icantmakemodels said:

Mods allowed?

No part mods, for obvious reasons, but anything else is fine.

[Grand Ship Builder]

Is FAR allowed?

[sevenperforce]

25 minutes ago, Grand Ship Builder said:

Is FAR allowed?

Sure, go for it. Since most of the maneuvering and planning deals with on-orbit assembly, it's not going to make much of a difference in scoring.

[sevenperforce]

My own entry is a work in progress.

Brute Force.

Here's what I think the Duna Transfer Vehicle will look like once it is assembled in LKO. Capsule up at the top with a heat shield, a tank and engine, a small round monoprop tank, chutes, and some thrusters. Probe core with parallel-staged Duna landing-and-ascent module; 3.5-meter heat shield underneath for aerocapture and entry at Duna. Nuclear transfer injection stage with drop tanks underneath.

Of course, I have to break it up into pieces. I'll launch the Duna ascent module (with heat shield) first, followed by the parallel stages for the descent and partial ascent, then the nuke stage. Finally, I'll send up the crew module to dock.

[Laie]

Teaser:

 

Edited September 8, 2017 by Laie
updated link

[sevenperforce]

My four modules:

Spoiler

11.4 tonnes. This will be doing the bulk of the rendezvous work.

11.415 tonnes. The parallel-staging module looks a little ungainly but it'll get the job done.

11.67 tonnes on the transfer stage. This one's a beast...and has dV for days.

 

Last launch is the heaviest, with a payload of 11.745 tonnes. Probably could have gotten away with less fuel, but oh well.

If I can pull it off, my score will be 11.745 * (100% - 5% - 12%) = 9.748 tonnes.

 

[Laie]

Hint hint: on your transfer stage, just enable crossfeed on the decouplers and remove the fuel lines. The game will do the right thing.

[Kergarin]

Does the RCS to assemble the ship in LKO have to be part of the payload, or may the ascend vehicles dock the parts together?

Do ladders give any %?

And may I transfer the crew in the last launch from the ascend vehicle to the Duna ship? Or do they already need to sit in a part of the final Duna ship while ascending from kerbin?

[sevenperforce]

13 hours ago, Laie said:

Hint hint: on your transfer stage, just enable crossfeed on the decouplers and remove the fuel lines. The game will do the right thing.

I remember to enable crossfeed on stack decouplers but I always forget that you can enable crossfeed on radial decouplers.

13 hours ago, Kergarin said:

Does the RCS to assemble the ship in LKO have to be part of the payload, or may the ascend vehicles dock the parts together?

Do ladders give any %?

And may I transfer the crew in the last launch from the ascend vehicle to the Duna ship? Or do they already need to sit in a part of the final Duna ship while ascending from kerbin?

The terminal stage of your launch vehicle can complete the rendezvous using its main engine(s), then provide attitude and roll control during docking, but it cannot provide RCS translation. The Falcon 9 upper stage can provide roll and attitude to its payload prior to decoupling, for example.

Whoops, I forgot to add the 4% bonus for ladders. Adding now...

And yes, you can transfer crew from the ascent vehicle if you like. Kerbals don't weigh anything in capsules, so it wouldn't make much of a difference either way.

[mk1980]

a bit late for a rule suggestion, but did you consider a rule/achievement that gives a %bonus if all launches use the same launch vehicle (same rocket up to the fairing that holds the payload. or same space shuttle / SSTO except for the stuff inside the cargo bay/cargo fairing).

in the real world, design of the launch vehicle is a big deal and it would seem likely that a space agency would try to use the same vehicle for launches of payloads with similar sizes.

judging from the teaser image posted by Laie, it looks like he's doing that already and i think that's a pretty cool little detail that should be rewarded.

i probably won't be able to use the same vehicle for all launches, though. strapping a plane on top of a rocket is usually a recipe for disaster...

Edited September 8, 2017 by mk1980