DBowman

Cygnus has it's own SM (and 3.5 kW of power @ Earth) - it might be enough for the 70 m/s fly by tweak (and 'Earth approach' tweak buffer). I'm having trouble finding out how much propellant it has though, enough to do GEO circularization of big sats at least.

So far I was thinking mounts for extra PV, extra thermal control, O2 & tanks, and some minimal pressurized cargo space (since it's natural to use the docking port, maybe at most make it storm shelter sized. Really all I'm using the Soyuz for is 'getting someone up' and reentry - maybe it's worth just ditching the 3 ton Service Module prior to Mars injection and use a Cygnus as starting point for the IPM? I'll have to try the math to see if the reduced propellant in the Briz from larger IPM is balance by the reduced 'transfer payload'.

More volume is always better and new heavy lift would help a lot (and cheaper hopefully). However I'm not shooting for the best flyby, I'm shooting for something flyable with current vehicles - I'll sure take advantage of newer launchers and vehicles as they become available. Soyuz (8.3 m3) has more than the NASA tolerable rating (5.1 m3) and almost their performance rating (9.91 m3). A lot of the 'cargo' would have to be in the interplanetary module - which is kind of playing the role of the inflatable - but smaller. I really should do a detailed look at volume but feel like the Soyuz Orbital Module would end up pretty clear - which at 5 m3 is 'almost tolerable' on it's own. Without the heavy lift the inflatables and even a half vol Cygnus is just too massive, maybe if the reduced PV mass panned out and I could 'do something about O2' it might free up enough mass margin to use a half size (one segment) Cygnus - but that would for sure take the mass margins back to 0.

kind of, except bone goes further: The micro latices is 'just' a regular 'crystalline' structure. In the bone each 'strut' is placed and sized so as to minimize mass and maximize strength given the loads actually experienced by the structure. The bone is a composite and the collagen / mineral (fiber/polymer) ratio and fiber 'wrap' direction is also tuned for the actual loads experenced I guess that micro lattice is just a 'demo'/'proof of concept' and could in practice be fabricated to provide #1. The metal vs composite is a different question, probably there are some applications where metal would be more suitable.

printing something like this would probably be useful for printing something light and strong - it's mostly empty space and the different parts of the bone have different stiffness etc. It's a collagen fibre & mineral composite material. Maybe a carbon fibre + ceramic + polymer resin 'spun'/'printed' with a small scale structure suitable for the particular loads (mechanical and thermal) it will have to take. I think foam is sort of by definition a pretty random bulk material formed from a collection of bubbles, the bone above is 'foamy' but not at all random - all the structure has grown in response to stresses in life (or at least to global plan modified in response to stresses in life).

I think the NASA BVA doc kg/kW power system doesn't make sense for the transit legs - at least for a flyby. They must include batteries and/or regenerative fuel cells - perhaps assuming that the transit vehicle will be in a low orbit at 'the destination' and require eclipse handling. For my application the vehicle will be in sun all the way except for the brief Mars occultation. This shows TRL 9 (e.g. JUNO) PV only systems at 15-40 kg/kW (at Mars distance) vs BVA 237 kg/kW. I planned 3 kW additional power => 711 kg - 28% of the non Soyuz mass - looks like I could take back 590 kg. Also 46 kg of food packaging and 74 kg of faecal disposal bags seems like a missed opportunity. Rather than collect food packaging trash we should be able to package food in faecal disposal bags and then use them, take back 40 kg. I think this brings the mass buffer/contingency/margin up to 980 kg. The top remaining contributors to non Soyuz mass are: 35% O2 (+ it's tankage) 670 kg (maybe time to look at PEM electrolysis per @AngelLestat) 16% food 10% additional ablator 06% additional PV 05% CDRA re the costs I'm not sure why a Proton launch is 105 MUSD and a Soyuz 188 MUSD - but that's what NASA will be paying for Soyuz. I've seen 'space tourists' priced as low as 25 MUSD - so maybe there is up to 100 MUSD excess cost budgeted. If only there was a small light one man reentry vehicle that was flyable one could use something lighter (and more voluminous) than a Soyuz.

It's a bit circular. I wanted to be 'realistic' so I did some research to find out what seemed a reasonable volume of algae laden water to support 1 guy. Then I plugged those masses into my arrays. To make it plug into TAC-LS I used @TaranisElsu's numbers for production and consumption of stuff - he has some spreadsheets and such which explain his reasoning. The numbers have such 'high rez' because of the short time between simulation 'hits' and because you have to make the the inputs and outputs of the conversion mass the same or else 'conservation of mass violation'.

um you mean just the stock filter thingies? I never really looked at what happens there, I'm not sure if it wants an actual 'manufacturer' defined somewhere or if it just 'collates' things based on the manufacturer string in the config. I'll have a bit of a poke around. Conceptually the parts are created by MM as copy of a 'template' part and then 'tweaked' with the info that is different. It's a very common MM usage pattern - it shouldn't make it any harder to modify with MM configs. It will mean it automatically is in synch with any changes/additions made to the 'template' part - squad adding drag cubes to the solar arrays for example - so that's a good thing.

I allocated 95 million for developing the 'docking module + some radiator + solar arrays + maybe some tanks' and 'running the program' - it seems like a lot of $$ but maybe it's not enough - that will take further study. re the volume - I think it's in the 'functional' range from NASA's BAV doc - apparently they think 5 m3 would be 'tolerable' over that time scale - it looks like 'tolerable' or better is doable.

I think you could actually (or very nearly actually) do a one man 500 day Venus and Mars flyby for about 400 million USD using current Russian hardware plus a custom 'InterPlanetary Module'. I've been investigating this for a while and have all the details for mass and cost estimates in this thread post. The nice, and under appreciated, thing about a Venus flyby is that Venus is easy to see most every day but Mars is harder to find. It would make it easy for a parent to be able to point out the 'first star of evening' and say we threw someone right around that little star and caught them again, maybe ignite a fire in someone to do more.

I worked up a pretty complete mass & power budget for a 500 day Venus & Mars flyby (paper) using data from current NASA Advanced Life Support Baseline Values and Assumptions Document (NASA BVA) and a 1967 Apollo Applications Manned Venus flyby paper (paper from nasaspaceflight.com). Radiation shielding sarcophagus style storm shelter is from remaining food and accumulated 'bio waste', it should provide near NASA mandated levels of protection from Solar events though I'd be inclined to spend buffer mass on H2O to be sure (paper). Excluding solar events the astronaut will get about an 833 msv radiation dose - this is below the NASA lifetime does for the 'worst case' 25 year old female astronaut (they'd 'happily' send an old man 4 times before he hit his limit - paper). I chose a 0.7 atm normal O2 partial pressure cabin atmosphere; with budget for 3 full re-pressurizes (post fire or EVA) and leakage. The O2 and N2 are pressure stored for simplicity. CO2 removal is via a ISS style (but half mass) CDRA, or I could consume all the mass buffer by switching to LiOH for more simplicity and more radiation shielding. Water is mainly from vapor H2O and forward osmosis urine recovery (HTIWater.com). I've included budget for clothing, fecal 'handling', food packaging, communication equipment, power for communication bandwidth, etc - see below. Then I used that mass estimate to design mission around Russian current hardware - no current USA tech can make a viable mission. Soyuz and Proton Briz M (non-cryogenic upper stage) can get the job done going by data from astronautix.com. Some of the mission payload mass and volume won't fit on a Soyuz launch so I put 1800 kg of it in an 'InterPlanetary Module', it has a docking adapter for the Soyuz capsule. The Briz upper stages need to be able to dock to each other to create a two stage Flyby Injection Stack: 1 Proton + Briz M + IPM - the Briz is under-fueled by the mass of the IPM 1 Proton + Briz M - this Briz is fully fueled the two Briz dock to form the Flyby Injection Stack Soyuz launch, the capsule docks to the FIS 4.3 km/s 'eyeball out' injection burn, probably in at least two 'kicks'. Ideally while in an elliptical and abort-able orbit final 'go' checks can be done on any IPM elements (radiators, extra deployed solar array, any internal hook ups, any boot-able elements, etc). about 70 m/s tweak is required while en-route by Soyuz engine a very fast & hot Soyuz re-entry is made - I've budgeted mass for more ablation material based on the NASA Venus flyby plan imagine the problem of Soyuz H2O2 for it's turbos and RCS decomposing is 'solved' somehow This mission profile works deltaV wise with a 350 kg mass buffer. If you allocate: 045 MUSD for IPM and Briz 'stacking' hardware (just a guess) 210 MUSD TASS Proton launch cost estimates x 2 (link) 188 MUSD NASA cost for Soyuz 'hire' (link) 050 MUSD for 'the rest' (just a guess) then the whole thing comes in at 500 MUSD. Mass budget details: 7200 kg Soyuz Capsule -700 kg propellant - we don't need all it's propellant 0491 kg O2 0179 kg O2 tank-age 0044 kg N2 0020 kg N2 tank-age 0098 kg CDRA CO2 removal 0057 kg Forward Osmosis 'driver' solution (concentrated sports drink) 0355 kg packaged dehydrated food (near 50kg is packaging - maybe could be used for fecal after) 0028 kg Apollo style 'kitchen' 0104 kg Hygiene & fecal treatment supplies 0016 kg Medical and tool kit 0032 kg exercise equipment 0040 kg clothes ( 16 monthly changes ... ) 0010 kg emergency O2 masks 0195 kg additional ablation material (NASA Venus, this will be a hotter entry, but Soyuz is smaller - needs numerical simulation to get a better number) 0080 kg light weight radiator cooling for 4 kW thermal rejection 0050 kg communication equipment, 3 kW power required 0711 kg solar arrays etc for additional 3 kW communication power 9010 kg Total - 'regular Soyuz' + 1800 kg 0600 kg additional 'structure' mass for IPM & a Briz to Briz stage-able docking adapter 0350 kg additional 'buffer' mass Volume of a Soyuz is 8.3 m3. NASA BAV doc has 5.1 m3 as 'tolerable', 9.91 m3 as 'performance', and 18.41 m3 as 'optimal'. Some internal volume is going to be consumed by 'stuff' that won't fit in the IPM, It seems likely we could hit the 'tolerable' range of free volume. My feeling is that with multiple people you'd need more volume per person than for a solo mission, but I've not come across any data for solo missions.

now on spacedock.info http://spacedock.info/mod/355/Soylent

Oh man, monster effort; the 'quad in one' boosters are a great idea, I like the use of solid motors on the Duna landings, and Duna village - score and aesthetics!

Here is my entry: DERP Interrupted I thought to: minimize my cost and time by using cheap parts, standardization of design, reuse, and minimal craft maximize my score through prestige and by 'science-ing the sh*t out of Duna' I went with: TAC-LS; I like it being real-ish, and @TaranisElsu did his homework on the consumption / production rates. simple core and boosters; the boosters land pretty close to KSC, the core circularizes and then lands at KSC. maxing a single VAB; the 26 day rollout would be used start building payload, then the recovered booster parts would be used to complete the vehicle each payload was a transfer stage, Duna descent/ascent propellant, and a reusable SSTO one man lander. In the end I sent only two landers to Duna, both in the first window. Things went wrong but there was enough contingency propellant and improvised landings at biome boundaries to get more science per landing and achieve almost all the program goals. Even so the fickle public got bored and Kongress shut down the program. They didn't even build the Kerbin-LKO shuttle that was supposed to get the boys down, however dedicated brainstorming from the remaining skeleton crew came up with a procedure for doing a recoverable Kerbin EDL in the Duna landers - but only just. score: Prestige: 7 +2 two Kerbals landed on Duna before Y2 D40 +1 one Kerbal landed on Ike before Y2 D40 +3 all the above back home safe before Y4 D80 +1 flag on Duna above 7000 m +0 Bill misread the checklist and landed above 8000 m on Ike Science: 25 +5 Atmosphere Science from 5 Duna Biomes +10 surface samples from 5 Duna bimomes +10 surface samples from 5 Ike biomes Survivability: 11 +2 Kerbals in Duna orbit +6 Kerbals landed on Duna +3 Bill on Ike total = 33 Costs: +73288.00 Jeb's DERP ReLander I -10752.88 booster recovery -10731.31 booster recovery -15663.19 core recovery +74649.00 Bill's DERP ReLander II +02194.50 simulations =112984.12 Final Score 804.478 = 112984.12 / 33^sqrt(2) (140.444)

A light weight reactor (therefore nuclear potent and fragile) barreling toward a precision aero brake at super Luna return velocities - what could possibly go wrong...

Also you could use an NTR to boost almost to escape and stage it. The NTR would naturally fall back, aero break, circularize, refuel, boost something else, and repeat. The boosted 'payload' could be a lower thrust vehicle that would complete it's transfer burn.

I think the LEO-GEO propellant market is only like 500,000 USD per annum ( an earlier post of mine ) I'm all for phased development and implementation. I feel like everyone knows 'it will work' it's just a case of 'will it pay?' - it just doesn't seem like projected demand is enough to convince. We need 'some big new driver' for spending the $$$.

I read the MIT paper and thought it had two significant errors in it around the 'contingency spare parts' (things that might or might not break), their logic seemed solid for consumables. My logic is as follows; name the 4 man crew + Habs + life support chunks C.1, C.2, etc. To be 99% sure you can fix what breaks for C1 you have to take S spares. The MIT paper said C.2 had to bring 2*S spares (S for C.2 and another S for C.1), C.3 had to bring 3*S spares. This logic works for consumables but not for contingency items: When you have 2 Crews and each has S spares then you are 99.99% sure to fix what breaks. The crews are co-located and can share a common spares pool. The chance of not being able to fix things is 0.01 for C.1 and 0.01 for C.2, one percent of one percent. So MIT increased the safety factor by 100 every window - mass does not need to be sent. I feel like 2 Crews only need 21/2*S spares, 3 Crews only 31/2*S, etc. but I haven't proven it to myself. When C.2 launches you know what already broke for C.1 and what didn't (yet), so C.2 only has to take enough spares to bring the total up to 21/2*S - if they were lucky and nothing actually broke for C.1 then C.2 only needs to take 0.41*S not the 2*S MIT was computing with. I don't know how far the contingency spares tip the balance, designing for minimal consumables and ISRU is going to be key.

I think SLS is launching 130,000 kg of propellent in the Exploration Upper Stage, which makes a total market of 520,000,000 USD @ 4,000 USD / kg (lets ignore that this is more than the 500 MUSD estimated SLS launch cost). If you wanted a ten year payback period you could afford to spend 'only' about 5 billion to develop, deploy, and run some kind of asteroidal / luna water mining operation, orbital H2O storage plus LH2&LOX manufacturing depot, & orbital propellent transfer tech and equipment. It seems 'pretty optimistic' to think anyone could put the orbital depot operation together for that kind of money, which means they'd need a much bigger market.

and the whole planet is kind of a disaster area to start with

I think buried radiators could be the way to go for Mars, conduct straight into the ground / permafrost.

This problem is exacerbated in most current mission designs because we need to launch the H2 tanks on long thin rockets, resulting in long thin tanks with high surface area to volume ratios, and often a collection of them. Big spherical tanks would not be hit as hard by the insulation mass penalty.

I'm skeptical of the economic viability of ever mining Venus surface for Earth bound materials, however if you don't assume ISRU for propellant then it undermines your argument - because everyone will reflexively say 'hey ISRU' and dismiss you. If $50,000 is propellant lift cost that is eliminated by ISRU then by your other numbers you'd expect to quintuple your money ...

Sorry to ask a nubish question but I never play 'science'. When you say 'recover' science what do you mean? For a surface sample any 'pod' will only hold one surface sample so can I transmit that? or is the point to bring the samples back to Kerbin (surface? or orbit will do?) maybe by loading them into the Lab and returning that? The wiki says it can store infinite experiment results - does that mean surface samples? For the atmospheric data I guess you mean that I can transmit what I get from doing a crew report 'flying over Duna Highlands' (say)? I guess they can be loaded into the lab also...

Do I understand right using career is just to open up being able to buy upgrade points? maybe it's simpler to tweak the preset to have more points and then account for the $ that would cost? On the other hand maybe you found all the kinks now.