sturmstiger

Just made another belated update the entries sheet & scoreboard. Looks like more interesting entries are still on the way! KeithStone, Borisperrons and kookoo_gr: Your entries have met the challenge requirement, but to put them properly on the scoreboard I'll need your calculated scores and claimed achievements. BlazingAngel665, Could you provide some information about your schedule, your lifter's capability and weight of your launched modules? djnekkid, Optimizing the capability of the lifter vs. weight of various modules is a indeed a BIG part of the challenge.

Welcome to the challenge, rileym65! Can I ask why your prefer not to have too much hardware sitting in LKO? Launching hardware to LKO as soon as they are available is good for mission robustness, in that if a launch failed early, you'll have time to adjust your plan and build & launch replacements. IRL launch failures(excluding pad aborts) always result in total loss of hardware, whereas problems with hardware already in LKO have a chance to be fixed. Of course it would be your responsibility to consider which ones to launch first. For example in my schedule fuel / interplanetary tugs are launched late to reduce the imaginary "propellant boil-off". Also for the sake of keeping rules simple, I'd prefer to stay with just a "minimal time between launch" rule rather than having separate times for building hardware and readying launch. Make sense?

As Weegee and borisperrons has said, stock supply & re-entry heat rules no longer apply if you simulate them using mods, so you're fine. Looking forward to see your designs!

Wow! It's amazing to see the challenge still going strong, with month-long projects getting completed, new people joining and even 2nd tries. I've been busy with RL and have been away from the exciting world of little green men and burning rocket fuel for the last few months, but otherwise I've been doing quite well. I'm really sorry for causing some concerns about my well-being due to my inactivity. Also a big THANK YOU for the "old-timers" of the challenge (ThreeMartiniLaunch, Death Engineering, Speeding Mullet, meyst, Patupi, etc) for care-taking the challenge and answering questions during my absence. I've updated the scoreboard. I probably missed a few things so if you believe your entry is missing / outdated on the scoreboard let me know. I'll try checking back and updating it at least once a week. But obviously for most people doing the challenge the scores / rankings do not matter that much - everyone has his own takes on the relative importance of realism, efficiency & aesthetics. And most importantly, most people seemed to be having fun with the challenge

Did you draw inspirations from the Apollo Lunar Escape System?

Finally somebody brought this up... No according to the rules if you don't see reentry heat effects you don't need heat shields. And I also find that Duna aerocapture from a Kerbin Hohmann transfer orbit and then descent from a low Duna orbit don't generate visible effects. But, for fairness (everyone else is using heat-shields for components which land on Duna), realistic feel (being able to land with parachutes suggest a heat shield would be needed for descent) and the safety of your Kerbals (what if somebody screwed up the aerocapture and turned it into a direct descent) I would strongly recommend you have them.

Well I don't have anything else similar to this at the moment. In fact I barely had anytime to play KSP lately due to RL commitments. The obvious extension is to use a refinement of the rules / scoring system for another body, for example, Laythe, which provides some differences in terms of transfer window, deltaV, a mostly ocean surface & potential jet engine use - but otherwise it's similar enough to be probably quite boring for people who have already done this challenge. Of course anybody's free to start their own challenge using some ideas or variations of rules used in this challenge. The other thing I had been thinking about is a forum-based cooperative space program with a focus on realism. The idea is that we'll have two groups to players, one presenting the "scientific community" and the other presenting the "aerospace industry", and they'll be working together to explore space. At each "phase" (modeled as several years of in-game time) I'll announce a very high-level exploration objective. The "scientific community" will propose a number of missions which may further that objective, and there will be a forum vote to select a few of them to fund. Then the "aerospace industry" will compete to design & build the hardware for these missions and to get those funding. Again there will be a forum vote to decide who will be awarded the contracts. The companies will be able to use the awarded funding (minus the costs) to design and build hardware for the next phase, which will have new objectives and missions based on the "discoveries" from the successful missions. The total funding will be very limited, thus only the best designed missions will be flown, and the most efficient (in using the limited funding to develop the technologies and build the hardware) aerospace companies will survive after a few rounds. Again, this is is unlike anything done before, and will need some thinking to make it work, so it probably won't happen anytime soon - the upcoming career mode may also affect how this will work out.

1. Yes. 2. Anything other than crew to LKO, no matter how small it is, must be launched with your standard (cargo) lifter. If that lifter happens to be a (fully reusable) SSTO it will be considered a reusable lifter but doesn't get any additional bonus.

1. I remembered somebody asking if 100% reusable LV gets any extra bonus beyond the existing reusable LV bonus, but I couldn't find who was asking anymore. Well the answer is no - this is not a "reusable LV challenge", and at this point there will unlikely be any change to the rules anymore. 2. There were somebody asking if we should separate stock only entries with those using mods. For this challenge many mods bring greater realism to the entries and do not necessarily make it any easier than full-stock, thus I do not wish to discourage use of mods in general in anyway. 3. I am having a bit trouble keeping track of who has completed the entry requirements. Besides those already on the leaderboard, who else has completed the entry requirement? Patupi? Speeding Mullet? If anyone believes his/her entry is complete but did not see it on the leaderboard please let me know.

Indeed. You'll need to fill it up in before launching it.

Sorry people I've been really busy with RL lately so haven't got a chance to update / reply until now. Good to see the great progress, with several entries nearing the completion of their design phase or are already flying Duna missions and several more joining the great race to Duna. I have updated the Entries in Progress section in the OP and will update the leaderboard tomorrow. I'll also get to some questions and other updates tomorrow. Also I recently got a PM from one of main authors of the MarsDrive Consortium's "Ready For Mars" reference design for manned missions to Mars, which I referenced as an important inspiration for the challenge. This is the guy behind the idea of landing many small and mobile payload, to permit manned mission to Mars with today's launch vehicles (e.g. without SHLV) and Mars EDL technology, and to lower the cost (through high launch frequency) and increase safety / redundancy. Apparently he has also been following this challenge!

Yes they will not affect base mobility achievement. Saw your recent designs and really liked the ingenuity and their safety / redundancy features!

If your launcher can send an orange tank to 100km circular orbit then it shouldn't be rated 27 ton, UNLESS you never send anything more than 27 ton to your LKO parking orbit (100km is okay). Reducing the payload capability of a launcher should be easy - just use a smaller tank. As you said The current rule on LV's nominal lift capability has loopholes: the "LKO parking orbit" is indeed vague, and allowing the "payload" to do the final circulization burn is also open to exploit. There are in fact many places in the rules which are exploitable, but I don't think people doing this challenge will try to exploit them, thus I'm not going to try close them all which will make the rules unreadable. The challenge is intentionally quite permissive, but if I see anyone taking things too far with a loophole I'll let them know.

1. Deadly Re-entry can completely substitute the stock reentry rule which is based on reentry visual effect. In another word, if the parts survived reentry with Deadly Re-entry, then they are considered good for use (and reuse) even if there's reentry visual effects. 2. Ion-cross can also completely substitute the stock supply rule, which is how it is used some current entries. See my reply to KeithStone in Post 146 for details. 3. Yes you can launch Remote Tech Sats completely independent of the rest of your missions. They are not restricted by the rules of challenge as long as their purpose are to provide comm relay. It is assumed that before the crewed missions there were already a number of probe / robotic missions which had done preparatory work such as surveying landing sites and building a communication relay system.In fact, you are welcomed to present the outpost missions as a stage of a larger Duna exploration program, proceeded by various orbiter, lander, rover and perhaps sample return missions, although only the outpost missions will be scored for this challenge.

No problem, I'm glad to clarify any issue people have with the challenge. I believe the turn has to do with the drag and mass distribution among the parts: just like in real life, the higher drag and lower density parts will be pushed away from the incoming air. However, since you (hopefully) have torque producing parts, you can adjust the attitude as needed. For example, when my Duna payloads enclosed in Dual-Use Shrouds and my Duna Descent & Expedition Vehicle enter Duna atmosphere, I would pitch them up and lock them in that attitude until the end of supersonic flight, just like how the space shuttle and the proposed slender-body aeroshell for Mars are suppose to work. Source: http://journalofcosmology.com/Mars146.html Using structural panels is a pretty standard way to build "heat shield" with stock parts. My Interplanetary Tug and Duna Transfer Habitat both have heat shields made of structural panels installed at front, just in case they need to use aerocapture in an emergency (they are not intended for reentry normally). I tested them for Kerbin aerocapture (coming back from Mun) and all the visible reentry effects were concentrated on the structural panels (I'll upload a pic later today), thus I would consider the rest of the ship protected. In another word, you should be able to see if you comply with the rule through testing.

Hmm...from my experience aerocapture at Duna tend to cause flame effects whereas descending from low Duna orbit generally don't, because it flying through dense atmosphere at higher speed with aerocapture. The thermal shielding rule (if you don't use deadly reentry mod) asks you to use some otherwise useless parts to shield the rest of your vessel from reentry effect flames. I'm not sure what you meant by "ships tend to turn retrograde while in atmosphere" - it's up to you to place the thermal shielding and adjust the vessel's attitude so the thermal shielding can do it's work.

Yes. I don't think FAR affects this challenge much.

Sounds reasonable. Since nobody is using EPL yet I added a klause to Rule 10 to ban it. All parts must be launched from KSC. You are more than welcome to make your design more realistic than required by the rules. Thus you can use either the "stock" supply rule, a life support mod, or some combination of them, for example, a relaxed "stock" supply rule (say 0.5 units of supply per Kerbal per day when you use Ioncross to generate oxygen). If we consider the challenge as a simulation of the initial manned Mars missions in 2030s timeframe, a regenerative oxygen supply system would be quite possible, but a greenhouse system that produces enough food for crew would seem unlikely. Considering such factors may not help the scores, but people including me would appreciate this added realism.

To get really mathematical I'd recommend the current "challenge of the month" the Voyager Grand Tour challenge. It would be tough but the amount of science & math one could learn from it is far more than most challenges.

Looks like it's gonna take a while before we get to Duna, and some Kerbal deaths would probably be engineered along the way. But with mission reports this funny I'm totally subbed to this thread

I have added NeilC's entry to the leaderboard. The mission value and efficiency scores are an order of magnitude higher than the second place. Congratulations, NeilC! Besides using Kethane, Ioncross life support and the reusable LV bonus, which seemed common amount current entries, NeilC made several unusual design decisions to achieve such high score: 1. Launching most payloads almost "dry" (w/ empty fuel tanks) and getting fuel from a Kethane extractor from Minmus in Kerbin orbit. 2. Housing (most) early crews in the habitats designed for Duna surface operations during their flight to Duna. 3. Sending the first crews to Duna without any existing habitation infrastructure or any means to return. These design decisions are perfectly legit according to the rules and are also technically feasible. However, it creates a situation where designs which do use them would unlikely get a higher mission value or efficiency score. Because I (and I guess most people) would like to see highly varied architectures in this challenge, I would encourage people to think about not only designs to achieve very high scores, but also designs with potentially lower mission value or efficiency scores, but are innovative or "good" in some other ways. At some point we could probably start a poll for people to vote for their favorite designs, so things not easily reflected in the scores can also be judged.

You're welcome. The ones I'm using are the 1300KN engine for 2.5m core (replaceable with the 1500KN mainsail), the 230KN engine for the 1.5m core/booster (replaceable with the 215KN LVT-30), and the 120KN engine for the upper-stages which is indeed quite a bit better than any stock engine, but for the medium launchers can be replaced 2 to 1 by the Poodle. The slightly lower ISP of the stock engines can be compensated by adding more fuel to the 2.5m core thanks to the more powerful mainsail. And my design was just to show some more ideas of on all-liquid designs - you should be able to optimize for your specific needs.

May I suggest taking a look at my Modular ELV Family (see my signature) for some ideas? The medium lift configurations, e.g., M102, M122 and M142 are simple and reliable non-cross feeding designs which lift 15, 20 and 25 tons to LKO. They are very similar to real world rockets such as configurations of the ESA Ariane 4 and the Chinese CZ-2 and CZ-3. I was using KW parts but they can be easily duplicated with stock parts. From my experience, efficient, low part count, non-cross feeding designs should be quite easy for payloads less than 50 tons, but for anything above ~25ton to LKO, a pure serial (stock) design would make likely be very tall or involves a large number of parts (e.g. most Saturn V recreations). One general suggestion I have for efficient (high payload ratio) rocket is to keep a good TWR: takeoff TWR of 1.2 to 1.4 and upper stage TWR of 0.7 to 1.0 seemed to be sweet spots for my experiments, and also typical for real world lift vehicles. Very high takeoff TWR means you're wasting your engine's power - you can either put more fuel or use less powerful but higher ISP engines.

Unfortunately, the real world SLS (if it ever got built) would definitely not be "economical" / "budget" LV, like the one you described. And it will hopefully not be used to transport crew and cargo to ISS.

Congrats for completing your design! I'll need a few clarifications before I put your names on the (first place of the) leader board. 1. Is an IPT launched the Day 100 launch? You said the dry mass of the IPT/MIRV/IPHAB payload is 36 ton, which your 30 ton LV would not be able send to LKO. If you fuel (partially) the IPT and use the IPT for the circulization burn, are you sure the 2 NERVAs provide enough thrust for that burn? 2. Are the RCS fuel tanks just outside of the payload fairings considered fuel or life support supplies? 3. How does your O2MOD provide enough supplies for Kerbals for the Kerbin->Duna transfer and Duna stays? Note that it would not be able to extend the solar panels when enclosed in payload fairings.