[1.12.x] USI Life Support

[infinite_monkey]

11 hours ago, strudo76 said:

Red P is never good. Could be a urinary tract infection, or point to some sort of kidney problem 

LMAO

[Space_Coyote]

On 8/5/2018 at 10:00 PM, strudo76 said:

Red P is never good. Could be a urinary tract infection, or point to some sort of kidney problem 

I guess they forgot to take their Sudafe.d For that head cold .(Walter Marty 'Wally' Schirra pilot for Apollo 9 had a head cold so the boys at nasa had packed away a bit of Sudafed for him to experiment with.. worked like a charm. that's why It's now in the over the counter section of your local pharmacy).

Edited August 10, 2018 by Space_Coyote

[Loskene]

Having a bit of an issue with EC calculation and not sure whether it's a bug or a conflict, wondering if you've heard this one before. (Latest KSP version with everything installed and updated through CKAN)

 

I have a station in LKO with 2 crew onboard and for some reason, whenever I'm not actively controlling it, the electricity in the life support window ticks down as if it's not being resupplied by the solar panels. It runs out of EC and when I switch to it to check, the batteries are full and the EC timer goes back to normal, only to immediately begin counting down again when I switch to another craft. Haven't tested this extensively as I've been in the middle of a career save and didn't want to lose my kerbals over it, so I'm not sure if it's just a display bug or if it thinks they're actually out of power and is going to kill them over it.

I've been setting up more space stations and preparing a Duna mission and I'm hesitant to crew any of them now because of this, because it'd mean switching to each of them every 2 weeks to make sure they don't randomly die.

If it is a mod conflict I don't know what could be causing it. The station is mostly made out of Tantares parts, which otherwise work fine with the life support, the solar panels are the stock 1x6 deployables, and the only mod I can see messing with the electrical system is Dynamic Battery Storage, which is a dependency for Near Future Electrical I believe.

If anything jumps out at you there as an obvious cause please let me know, otherwise I can do some more detailed testing and get back to you. Thanks.

[Wyzard]

4 hours ago, Loskene said:

I have a station in LKO with 2 crew onboard and for some reason, whenever I'm not actively controlling it, the electricity in the life support window ticks down as if it's not being resupplied by the solar panels. It runs out of EC and when I switch to it to check, the batteries are full and the EC timer goes back to normal, only to immediately begin counting down again when I switch to another craft. Haven't tested this extensively as I've been in the middle of a career save and didn't want to lose my kerbals over it, so I'm not sure if it's just a display bug or if it thinks they're actually out of power and is going to kill them over it.

It's a display bug, caused by a game limitation: when the station isn't loaded, the game doesn't actually keep track of what resources (like EC) it's producing.  That gets handled by "catch-up processing" when you switch back to the station later.  Since the life-support window doesn't know how much EC your station is producing while unloaded, it pessimistically assumes that it's producing none (to err on the side of caution).  That avoids the possibility that the window could mistakenly show EC time remaining when there's actually none (which could lead to disaster), but it also means that the EC timer is generally not useful for vessels that aren't loaded.

(The same is true for supplies, btw, though that's less obvious since supplies are consumed more slowly.  If you have a greenhouse producing supplies, the life-support window won't notice until you switch to the vessel.)

[Loskene]

13 hours ago, Wyzard said:

It's a display bug, caused by a game limitation: when the station isn't loaded, the game doesn't actually keep track of what resources (like EC) it's producing.  That gets handled by "catch-up processing" when you switch back to the station later.  Since the life-support window doesn't know how much EC your station is producing while unloaded, it pessimistically assumes that it's producing none (to err on the side of caution).  That avoids the possibility that the window could mistakenly show EC time remaining when there's actually none (which could lead to disaster), but it also means that the EC timer is generally not useful for vessels that aren't loaded.

(The same is true for supplies, btw, though that's less obvious since supplies are consumed more slowly.  If you have a greenhouse producing supplies, the life-support window won't notice until you switch to the vessel.)

Ah, I see, thank you. So is it safe to just let the timer run out then, my kerbals won't actually die if I don't check up on them for a long period of time? Dropping out of timewarp and switching back and forth 30 times during a Duna transfer would do my head in lol

[Johould]

1 minute ago, Loskene said:

Ah, I see, thank you. So is it safe to just let the timer run out then, my kerbals won't actually die if I don't check up on them for a long period of time? Dropping out of timewarp and switching back and forth 30 times during a Duna transfer would do my head in lol

 

If a ship relies on solar panels, would we need to make sure to switch to it when it is in sun to avoid running out of EC? - In particular, if the Supply supply relies on greenhouses, what does it take to make sure they won't run out of EC during catch-up processing?

[DStaal]

38 minutes ago, Johould said:

If a ship relies on solar panels, would we need to make sure to switch to it when it is in sun to avoid running out of EC? - In particular, if the Supply supply relies on greenhouses, what does it take to make sure they won't run out of EC during catch-up processing?

Yep, and this can be gamed - if it would run out of EC during the night, you can avoid ever switching to it during the night and it will never run out of EC.

 

But in general: The window is only estimates based on last time the Kerbals were 'seen' by the game.  Nothing actually happens until the ship with the Kerbals in it is loaded into the game, by being within range of it.  (Or switching to it directly.)

[Loskene]

6 minutes ago, DStaal said:

Yep, and this can be gamed - if it would run out of EC during the night, you can avoid ever switching to it during the night and it will never run out of EC.

 

But in general: The window is only estimates based on last time the Kerbals were 'seen' by the game.  Nothing actually happens until the ship with the Kerbals in it is loaded into the game, by being within range of it.  (Or switching to it directly.)

Perfect, all I needed to know. Thanks everyone for the swift replies.

[Johould]

22 hours ago, DStaal said:

Yep, and this can be gamed - if it would run out of EC during the night, you can avoid ever switching to it during the night and it will never run out of EC.

Cool, that's what I thought. For long transfers the worry would be "anti-gaming" it, if the ship has been on a nice sunny transfer orbit for months but happened to be in the shade when you switched to it for a capture burn.

23 hours ago, Loskene said:

So is it safe to just let the timer run out then, my kerbals won't actually die if I don't check up on them for a long period of time?

I assume your "die" is accurate, but if so I'm curious how you like that difficulty setting. I went with the "Normal" career default of Kerbals just getting "grumpy" because I wanted to leave things easy for myself, but I think it has also made life support failures or poor planning more interesting, by leaving living tourists that need a rescue mission (maybe losing parts to "mutiny" would make things even more interesting).

[Cooper42]

Habitation calculations?

 

I've got a bunch of mods installed, many of which include support for USI-LS habitation values, some which don't.

 

But, going through them, the values are all over the place. Some objects are loosely in line with similar parts from RoverDude, or the changes to stock that USI-LS makes, some not at all.

 

The habitation multiplier value varies widely for similar parts. The ratio between electric charge / s and habitation multiplier varies widely too.

In addition, the habitation module seems to include calculations based 'Kerbal months'. However, the base line habitation-per-seat has since been changed to 7 days, not a month as it used to be, which seems to mean that some habitation modules add a comparably huge amount of hab time for the space they provide.

 

So, I'm planning on going through my mods and creating custom USI-LS habitation support patches (and I'll offer these to mod authors if they want them).

 

But to do so, I'd like to get some sense of what calculations are behind how USI-LS modifies stock parts and the various USI parts which include habitation and hab multipliers.

 

Obviously it's not straightforwardly based upon part volume or crew space, given things like cupolas rightly add more hab multiplier.

But some sense of how to set baseline kerbal months get decided, and then work out a reasonable hab multiplier and elec / second use would be really helpful.

[mcortez]

It's possibly out of date, but you might want to start here:

https://github.com/UmbraSpaceIndustries/MKS/wiki/Supporting-MKS-in-your-mod

I know there also used to be a Google Spreadsheet floating around for this, but a quick search through my bookmarks failed to find it.

 

[DStaal]

11 minutes ago, mcortez said:

It's possibly out of date, but you might want to start here:

https://github.com/UmbraSpaceIndustries/MKS/wiki/Supporting-MKS-in-your-mod

I know there also used to be a Google Spreadsheet floating around for this, but a quick search through my bookmarks failed to find it.

Luckily, the spreadsheet and a video on how to use it are the top link on the page you linked. 

And @Cooper42 - thanks and good luck to you.  I did a fair amount of that (including writing up the above wiki page) a while back - but then everything got rebalanced and I haven't had the time to get back in to it.  (Especially since on a 'support existing part' basis, the spreadsheet is backwards: You have to plug in the life support systems values and get the mass/volume of the parts - which are what you already know.  If you wanted to really help, a spreadsheet that could start with the mass/volume for common cases would make supporting USI-LS *much* easier.)

[Cooper42]

Thanks for the links @mcortez and @DStaal.

I've started to reverse-engineering the habitation part of that spreadsheet to take Mass & Volume and produce habitation & multiplier guides.

 

 

 

Really basic question: A 1.25m radial part is named as such because it has a 1.25m radius, right? Not 1.25m diameter...

 

Less basic question: Does anyone know of any mod which can show the volume of a part?

Edit: I'll start with cylindrical parts, because at least I can get the height for a single part from the VAB...

Edited September 18, 2018 by Cooper42

[Wyzard]

2 hours ago, Cooper42 said:

Really basic question: A 1.25m radial part is named as such because it has a 1.25m radius, right? Not 1.25m diameter...

No, it's diameter.  1.25m parts are 0.625m radius, and 2.5m parts are 1.25m radius.

[Terwin]

On 9/17/2018 at 9:05 PM, Cooper42 said:

Really basic question: A 1.25m radial part is named as such because it has a 1.25m radius, right? Not 1.25m diameter...

A 1.25m radial part is a part with a 1.25m diameter which can be surface(aka radially)-attached.

Other parts can only be attached to nodes(aka in-line), such as most LF engines, nose-cones, and ISRU parts.

Although many parts(most fuel tanks, SRBs, and many structural parts) can be attached both in-line and radially(allowing multiple parallel stacks).

[Cooper42]

Okay, first version of the tool to calculate hab / multiplier:

https://docs.google.com/spreadsheets/d/1jKZmfTO7y3rbAxDKcnhO2PH7fvvtJrceVwzyLpgq4ec/edit?usp=sharing

Not trialled it much, so very certainly needs some tweaking, but I'm not gonna get to work on it for a few days, so thrown out here for comments / suggestions

Edited September 21, 2018 by Cooper42

[quasitonality]

This little ship will keep three little kerbals entertained for a little over three years.

And these are the supplies required to feed them:

(The supply load becomes more sane-looking with a big 'ol recycler, but 18+ ec/sec...? Not really practical for my basic first Duna-orbit-return mission in career mode.) 

Something about these proportions had me feeling a little skeptical, so I decided to get my Google on and crunch some numbers.

According to an educational document from NASA (see pg. 5), an astronaut requires about 5.03 kg of supplies a day in the form of food, water, and oxygen (1.77kg, 2.42kg, and 0.84kg respectively). This is less than half the 10.8kg/day required by kerbonauts on USI-LS default settings; if a kerbonaut consumed the same supplies in one Kerbin day as a huma-naut does in one earth-day, the above ship would look like this:

But in fact, kerbals are smaller (and I think I can say hardier and sturdier) than humans, and kerbin-days are much shorter. Assuming that a kerbal consumes half the supplies a human does in the same amount of time, then the mass of supplies needed per Kerbin-day is further reduced, by a factor of eight in fact:

(It'd be more practical to store these 2500 supplies in a single 2.5m can, but this is for visualization purposes.)

This may look like a small amount of supplies (if you're used to the massive quantities in the first pic), but in rocket design mass is usually more important than volume, and USI-LS supplies are quite heavy. For example, with the containment area having an estimated radius of 1.25m and a measured height of 90cm (measured against the 26.6cm cubic family strut), the 2.5m Life Support Tank has a capacity of ~4.91m^3 and holds 4.5t of supplies, giving a density of 916 kg/m^3, not too far off from the density of water, and pretty darn close to the density of typical foodstuffs afik.* But if we assume that supplies also contain the kerbals' supply of oxygen, the density could be much lower. O2's density at NTP is 1.331 kg/m^3. Of course, it would be pressurized in storage; keeping temperature constant and raising the pressure to 200atm (2939.19psia),** we get up to 266.2 kg/m^3. According to the above source, an astronaut's food/water/oxygen supply is 16.7% oxygen by mass, so 1t of supplies contains 167kg->0.627m3 of O2 and 833kg->0.833m^3 of food/water, for a total density of approximately 685 kg/m3.*** (And lord I just spent WAY too much of my day working that out!) TLDR, if aesthetics are a concern and you just like looking at those huge cans, then decreasing the density of supplies by 30%-40% could help increase their volume footprint on a craft's design even if the mass/consumption rate is dropped to a more realistic level.

*If my calculations are correct, then including the mass of the container, these food cans might not even float in water. Anyone care to test?

**3000psia seems to be a typical pressure for pure O2

***Of course, there are more efficient ways of storing oxygen than with pressurized tanks, but that could be accounted for with recyclers and such.

Here are some shots of the above ship at default settings, making use of recyclers:

^ This looks more reasonable from the outside, but has an ungodly ec requirement, especially early-game (and I do consider Duna a fairly early-game goal).

These recyclers are a more economical choice, but the supplies still make up over half of the craft's mass, and the kerbals are still consuming supplies almost four times as quickly as a human would, considering that kerbin-days are only six hours long.

p.s. Love the mod by the way; otherwise wouldn't have spent this much time messing with the numbers

Edited October 2, 2018 by quasitonality

[RoverDude]

@quasitonality - Hey, glad you like the mod   One thing your calculations miss.  The vast majority of water is not for drinking, it's actually for hygeine, food prep, etc. - NASA restricts their astronauts to about 3 gallons (11L) per day.  It's the reason water recyclers (which MKS has, for example, and the balance sheet includes calculations for) can drop supply usage by a significant amount.

 

 

[therealcrow999]

4 hours ago, quasitonality said:

This little ship will keep three little kerbals entertained for a little over three years.

And these are the supplies required to feed them:

(The supply load becomes more sane-looking with a big 'ol recycler, but 18+ ec/sec...? Not really practical for my basic first Duna-orbit-return mission in career mode.) 

Something about these proportions had me feeling a little skeptical, so I decided to get my Google on and crunch some numbers.

According to an educational document from NASA (see pg. 5), an astronaut requires about 5.03 kg of supplies a day in the form of food, water, and oxygen (1.77kg, 2.42kg, and 0.84kg respectively). This is less than half the 10.8kg/day required by kerbonauts on USI-LS default settings; if a kerbonaut consumed the same supplies in one Kerbin day as a huma-naut does in one earth-day, the above ship would look like this:

But in fact, kerbals are smaller (and I think I can say hardier and sturdier) than humans, and kerbin-days are much shorter. Assuming that a kerbal consumes half the supplies a human does in the same amount of time, then the mass of supplies needed per Kerbin-day is further reduced, by a factor of eight in fact:

(It'd be more practical to store these 2500 supplies in a single 2.5m can, but this is for visualization purposes.)

This may look like a small amount of supplies (if you're used to the massive quantities in the first pic), but in rocket design mass is usually more important than volume, and USI-LS supplies are quite heavy. For example, with the containment area having an estimated radius of 1.25m and a measured height of 90cm (measured against the 26.6cm cubic family strut), the 2.5m Life Support Tank has a capacity of ~4.91m^3 and holds 4.5t of supplies, giving a density of 916 kg/m^3, not too far off from the density of water, and pretty darn close to the density of typical foodstuffs afik.* But if we assume that supplies also contain the kerbals' supply of oxygen, the density could be much lower. O2's density at NTP is 1.331 kg/m^3. Of course, it would be pressurized in storage; keeping temperature constant and raising the pressure to 200atm (2939.19psia),** we get up to 266.2 kg/m^3. According to the above source, an astronaut's food/water/oxygen supply is 16.7% oxygen by mass, so 1t of supplies contains 167kg->0.627m3 of O2 and 833kg->0.833m^3 of food/water, for a total density of approximately 685 kg/m3.*** (And lord I just spent WAY too much of my day working that out!) TLDR, if aesthetics are a concern and you just like looking at those huge cans, then decreasing the density of supplies by 30%-40% could help increase their volume footprint on a craft's design even if the mass/consumption rate is dropped to a more realistic level.

*If my calculations are correct, then including the mass of the container, these food cans might not even float in water. Anyone care to test?

**3000psia seems to be a typical pressure for pure O2

***Of course, there are more efficient ways of storing oxygen than with pressurized tanks, but that could be accounted for with recyclers and such.

Here are some shots of the above ship at default settings, making use of recyclers:

^ This looks more reasonable from the outside, but has an ungodly ec requirement, especially early-game (and I do consider Duna a fairly early-game goal).

These recyclers are a more economical choice, but the supplies still make up over half of the craft's mass, and the kerbals are still consuming supplies almost four times as quickly as a human would, considering that kerbin-days are only six hours long.

p.s. Love the mod by the way; otherwise wouldn't have spent this much time messing with the numbers

It could be Kerbals have a faster metabolism than ours. Smaller creatures tend to eat and consume more and have a faster metabolism than larger animals. I mean think about a Hobbit whom is, about as large as a human leg and they eat more than twice as much as a human, but weight less. So saying a Kerbal is smaller than a human should consume less than a human, can't totally be accurate, its all how a creature metabolizes their food. 

To add on my comment above, I never saw Kerbals in my minds-eye as slow stocky people. I saw them as these energetic, brilliant goofs, who want to explore the stars and have the brains to do it. They zip around and can be clumsy at times. With That brain power and physical energy they have, there is good reason for them consuming so much nutrients, lol.

[quasitonality]

11 hours ago, RoverDude said:

@quasitonality - Hey, glad you like the mod   One thing your calculations miss.  The vast majority of water is not for drinking, it's actually for hygeine, food prep, etc. - NASA restricts their astronauts to about 3 gallons (11L) per day.  It's the reason water recyclers (which MKS has, for example, and the balance sheet includes calculations for) can drop supply usage by a significant amount.

 

 

That's an excellent point! Last night as I dug around a little for more specific info, I happened across NASA's Life Support: Baseline Values and Assumptions Document, which gives a set of starting-point estimates for pretty much every life-support-related thing you can think of, focusing on hypothetical Mars and Moon missions, for the benefit of their engineers and of random nerds on the internet (on account of it being publicly posted online). It's surprisingly easy to read considering the subject matter, and organized into neat sections and tables that make it easy to find and contextualize the information you're looking for - it's like the Dungeon Master's Guide to Space! Estimates for total water consumption/crew-member-day (CM-d) are given for short term flights (< 30 days), a transit vehicle (to Mars), early planetary base, and mature planetary base, with a dramatic difference between the low and high ends. In that order and sparing the gory details,* the oxygen/water/food estimates total at 4.135 > 4.605 > 12.135 > 29.515 kg/CM-d, with water being 65% of the mass at one extreme and 95% of it at the other. (Of course this is due mainly to such frivolities as brushing teeth, showers, and dishwashing.)

@therealcrow999 made a good point that Kerbal biology/metabolism leaves a lot to the imagination, but personally I'd still cut those numbers in half (~2.05 - 15/d), since I think that would roughly fit with the way Kerbals and their rockets are scaled-down in size from real life. In either case 10.8 supplies/day would fall somewhere between consumption at a brand-new base and a moderately mature one. I think the tight rations short missions can use are fairly well-approximated by the grace-period mechanic, no problems there; but unfortunately the difference between conservative and comfortable lifestyles on an interplanetary transfers versus a stable base is so huge, I'm not sure a middle-ground value does either of them justice. Maybe it would be interesting if, beyond a certain vessel habitation rating, kerbals started scaling up their resource consumption? Using a Mars (read: Duna) mission as a reference point, it might start at four years; this would allow for there-and-back-again trips to the inner planets on a Spartan supply ration, but if the Kerbals feel any more comfortable in their vessel they might be tempted to settle into a more comfortable lifestyle and splurge on water. Supply use could continue to increase with habitation rating until maybe the ten-year mark; this would make Jool or Eeloo trips interesting to plan for, since the Kerbals would be using a lot more supplies and thus require a more sustainable life support system. Good idea, bad idea?

Anyway, for now I think I'll set my supply rate to about half the default; I'll probably crank it up later for a challenge on longer missions

*Unless you want them; the gory details are in tables 4.1, 4.20, 4.21, and 4.54.

Edited October 3, 2018 by quasitonality
added reference

[RoverDude]

tbh, once you plug in recyclers, supply weight drops significantly.  The behavior being driven is that you should not count on lofting massive water tanks into orbit   

[quasitonality]

Yeah, three of the radial recyclers reduces the supplies for a 3-man orbit-and-return mission to Duna from 45t to 18t; the big recycler takes it down to 9t, but the level of efficiency it generates (and the power requirement) seems like it should be a bit overkill for a Duna transit. I just think it would be nice if the consumption rate could alter to fit the nature of the mission; 10.8kg a day is a good number for a small base! But on the one hand, it's over twice as much as a crew would need during transit, and on the other hand, it's less than a third of what a fledgling colony would consume; I definitely don't think it would be better if it was simply lowered, especially for a player planning to use MKS.

Edited October 3, 2018 by quasitonality
whoops, I can't a grammar

[quasitonality]

btw, I want to be clear that I don't mean to suggest that the mod should be made easier - actually, for some missions (especially long-term bases), it would make sense if Kerbals consumed more supplies per capita. Mission- or vessel-dependent supply consumption would give a player some interesting design choices to make, both early on when available LS tech is limited, and later on when dealing with entitled kolonists who insist on twice-a-day showers and brushing after every meal, and could result in unforeseen mission complications. (Jeb and Vall go down in the lander for a week of the science, leaving Bob alone on the ship. The habitation value of the ship shoots up as soon as they leave, and Bob gets a little too comfortable in his suddenly opulent living space... When his shipmates return, they find he has burned through three weeks' worth of supplies in the form of long, hot bubble baths in the RTG bay.)

Also thought I'd mention, I found a passage in the DM Guide NASA LS Document on habitation space that corroborates the basic concept behind your habitation mechanic; values are given for "net habitable space" on both a moon mission and a mars mission; the "tolerable" cabin space is nearly two times greater for Mars than for the Moon, and the "optimal" cabin space is over four times greater, something I wouldn't normally consider in stock ksp.

My interplanetary ships will all need to be bigger and heavier - not necessarily a bad thing, but I probably should have stayed in Kerbin's SOI until I got a feel for it, instead of sending this low-tech death trap to Duna. But I need the sciiience, Bob...

Edited October 3, 2018 by quasitonality

[Terwin]

45 minutes ago, quasitonality said:

btw, I want to be clear that I don't mean to suggest that the mod should be made easier - actually, for some missions (especially long-term bases), it would make sense if Kerbals consumed more supplies per capita. Mission- or vessel-dependent supply consumption would give a player some interesting design choices to make, both early on when available LS tech is limited, and later on when dealing with entitled kolonists who insist on twice-a-day showers and brushing after every meal, and could result in unforeseen mission complications. (Jeb and Vall go down in the lander for a week of the science, leaving Bob alone on the ship. The habitation value of the ship shoots up as soon as they leave, and Bob gets a little too comfortable in his suddenly opulent living space... When his shipmates return, they find he has burned through three weeks' worth of supplies in the form of long, hot bubble baths in the RTG bay.)

Also thought I'd mention, I found a passage in the DM Guide NASA LS Document on habitation space that corroborates the basic concept behind your habitation mechanic; values are given for "net habitable space" on both a moon mission and a mars mission; the "tolerable" cabin space is nearly two times greater for Mars than for the Moon, and the "optimal" cabin space is over four times greater, something I wouldn't normally consider in stock ksp.

My interplanetary ships will all need to be bigger and heavier - not necessarily a bad thing, but I probably should have stayed in Kerbin's SOI until I got a feel for it, instead of sending this low-tech death trap to Duna. But I need the sciiience, Bob...

I remember a lot of USI-LS being configurable, is the daily resource consumption not one of the configurable values?

I know that time per seat is configurable, but I don't think per-kerbal EC usage is.  Perhaps instead of asking to change the value for everyone, you should ask for per-kerbal supply usage to have a slider bar or some-such allowing adjustment to taste for those who find the default too easy or difficult.

 

Have you tried adding fertilizer and a nom-o-matic?  I have made many trips to Duna and do not remember ever needing that much in the say of supplies.

The fertilizer -> supplies ratio is 1(+10 mulch)->11  so even with no recyclers you would still only need 1 bin of 4500 fertilizer.(and that small recycler pod is really very weight-efficient for the benefits it gives, so any extended trip should have enough of those to cover the crew)

[quasitonality]

2 minutes ago, Terwin said:

I remember a lot of USI-LS being configurable, is the daily resource consumption not one of the configurable values?

I know that time per seat is configurable, but I don't think per-kerbal EC usage is.  Perhaps instead of asking to change the value for everyone, you should ask for per-kerbal supply usage to have a slider bar or some-such allowing adjustment to taste for those who find the default too easy or difficult.

Yeah, I've been playing around with configuring supply consumption, and I'm explicitly not asking the value to be changed for everyone:

7 hours ago, quasitonality said:

In either case 10.8 supplies/day would fall somewhere between consumption at a brand-new base and a moderately mature one. I think the tight rations short missions can use are fairly well-approximated by the grace-period mechanic, no problems there; but unfortunately the difference between conservative and comfortable lifestyles on an interplanetary transfers versus a stable base is so huge, I'm not sure a middle-ground value does either of them justice. Maybe it would be interesting if, beyond a certain vessel habitation rating, kerbals started scaling up their resource consumption? Using a Mars (read: Duna) mission as a reference point, it might start at four years; this would allow for there-and-back-again trips to the inner planets on a Spartan supply ration, but if the Kerbals feel any more comfortable in their vessel they might be tempted to settle into a more comfortable lifestyle and splurge on water. Supply use could continue to increase with habitation rating until maybe the ten-year mark; this would make Jool or Eeloo trips interesting to plan for, since the Kerbals would be using a lot more supplies and thus require a more sustainable life support system. Good idea, bad idea?

In reality, supply consumption varies drastically depending on the nature of the mission; I think it would be interesting if supply consumption were vessel, mission, or colony-dependent in some way, rather than being a fixed rate for all situations. Not to replace recycling or farming systems, but as an additional factor to consider - basically, a kerbal's life-style determines their base rate of supply consumption/unit-time (how often do they shower, do they demand cake for dessert, are they washing laundry/dishes, etc), and that number is then further modified by recyclers just as it is currently.

16 minutes ago, Terwin said:

Have you tried adding fertilizer and a nom-o-matic?  I have made many trips to Duna and do not remember ever needing that much in the say of supplies.

I would, but I'm playing a new career save and haven't unlocked the tech yet. The three-kerbal manned mission was a hypothetical example - in my career save I settled for a compromise of a two-man mission with a scientist and pilot, and a mobile processing lab that can double as a recycler. Probably a little overly ambitious now that I have USI-LS, but stretching how far I go on limited tech is one of my favorite parts of the early game!