Power and Propellent Degradation

[Matayoman]

As the title says, "Battery Life Degradation & Propellent Degradation." Or "Battery Life Cycles - Solar Panel Efficiency Decay - RTG efficiency decay - Propellent Degradation."

I think it would be cool to include some of the realism of maintaining the fundamentals of space exploration. Below I will list off the four things I am interested in seeing for the sustainability of both Orbiting and Deep Space mission Spacecraft.

1. If Batteries appropriately decay during their cycling. Giving a defined lifespan of the satellite based on how many orbits it can survive before the battery can no longer hold a charge.

Eg. If the battery is rated for 1,000 life cycles, and you burn 0.05cycle/1orbit, then the satellite will survive 20,000 orbits before the battery approaches failure. But lets say you waste an entire 1cycle/1orbit, then you will only last for 1,000 orbits. That could be the difference of a 5 year mission against a month long mission, and an important part of spacecraft today.

2. Solar Panel Decay in orbit. Give panels a defined solar efficiency life, and the panels will slowly reduce their efficiency as they orbit over time until you barely receive a trickled charge.

Eg. A Kerbin Satellite with an appropriate battery, operating for several years begins to lose it's solar efficiency. This in turn causes it's power regeneration to become slowly reduced; This in combination with suggestion 1, would result in reduced orbital efficiency until eventually it doesn't fully recharge on an orbital pass and destroys the battery even faster.

LINK

3. RadioIsotope Thermoelectric Generator's in the very science of what they are, should decay. I know that the RTG in KSP does show an efficiency item on it, but I have yet to get that efficiency to drop with any spacecraft.

Eg. This in combination with degrading batteries could result in more realistic operations of the spacecraft, particularly rovers.

4. Propellant Tanks consuming power to keep the propellant from degrading. When a propellant tank has propellant in it, it will consume an amount of power proportional to it's propellant.

4.A. A Propellant Tank without power will slowly become unusable in proportion to its amount of propellant against the time power was not applied.

Eg. A space probe is sent to another planet and needs to perform a deltaV at a defined point. It will provide power to it's propellant tanks to keep them operational, if the power to the tanks is lost then the spacecrafts propellant will slowly become unusable while increasing the spacecrafts dry-mass.

4.B. Propellant Tanks consuming themselves to remain operational. When a spacecraft no longer has power applied to the propellant tanks, the tanks will consume propellant into increased dry-mass to keep the remaining propellant usable.

Eg. A spacecraft in orbit disables power to it's propellant tank to conserve power. The propellant tank then begins to waste propellant to conserve it's remaining propellant over a period of time determined by the propellant tank size.

4.C. Propellant Tank's no longer connected to a command module nor a power source will then go entirely bad and will not be usable at all after a short amount of time.

Eg. A spacecraft ejects a propellant tank in orbit and returns to it several hours later. The propellant tank, unmaintained by a command module instantly decays with full propellant and doesn't preform 4.B.

_________

Thank you for reading my humble suggestions. I would hope that after some Ker-refinement they can become reality in the Kerbal Universe. Thank you.

TLDR: Make Batteries, Solar Panels, and RTG degrade in a semi-realistic fashion.

How do you think these Power and Propellant Degradation could interact with the Kerbal Universe?

Edited August 26, 2013 by Matayoman
Added TLDR : To Long Didn't Read

[Tophir]

I can't agree with this more, especially the solar panel, battery, and rtg decay as it would give missions I life span rather than you send a satellite up and it will continue to work for eternity. It could also be part of the tech tree so that when you start you can only build missions which will only work for less than a year and then progress until missions can last 20-25 years.

Edited August 26, 2013 by Tophir

[Matayoman]

Yeah, I was thinking about these things when we were working on our satellite and then it hit me, why hasn't this suggested for KSP. Power Systems is one of the first steps in space-craft design. KSP already has the parts to do this, it just needs some refinement into them to make the parts slowly become inoperable.

It could also bring greater meaning to short duration satellites similar to the one I am working on. Our lifespan to work with is less than a year so we can focus on the science and less on the infrastructure.

[Designer225]

If some (or all) of those would be implemented, there is a need for a slider that optimizes efficiency (lower charge rate or lower power storage for longer operation period, while higher charge rate or higher power storage for shorter operation period) so that ships can be optimized based on the needs (more power for shorter mission while less power for longer mission).

[ZigZagJoe]

Seems like un-needed complexity, overall; dev time could be more profitably spent elsewhere. Everything you've listed has degradation measured over tens of years - even batteries (look up nickel-hydrogen batteries). With mission times in KSP typically being far short of that, it's just unneeded complexity. If KSP was a 110% realistic space exploration simulator, sure, it'd be a good idea to implement degradation due to age and environmental factors. But, KSP is a game, and so it doesn't make sense to add a glut of parts and mechanics that add so little.

The stuff about fuel tanks I've got no idea where, how, or why you've come up with; it's complete nonsense. Fuel tanks do not require electricity to maintain the fuel; it does not degrade. Technically, if you want to be anal about it, they can require stirring (the part which failed in apollo 13) to maintain consistency when on standby for immediate use, but again this fails the complexity test. Likewise, we can safely assume that fuel tanks are designed with an appropriate degree of shielding to deal with solar heating concerns.

KSP is not a graduate level course in spacecraft flight and design, preparing to work at JPL - it's a game.

[OdinYggd]

Worth noting- kerbal engines likely use a substance similar to real world RP1 (Kerosene) with LOX for their liquid fuel engines, while RCS is likely nothing more than compressed helium for use in a hot-gas thruster.

Although RP1 and compressed gas helium would have very minute losses over long periods of time, you would definately have to factor in LOX boiloff when planning a mission.

Ultimately at that point you're getting to a level of realism that would make the game confusing for new players and irritate people who just want to do things in space without worrying about the details, so it might be better to implement this as a game mod rather than a stock feature. It wouldn't be hard to do either- work out equations to determine boiloff rates based on a percentage of the current fuel volume in a given time period applied as a very gradual frame by frame rundown.

RTG and solar panel degradation would be treated the same way, in effect your 'durability' then becomes implemented similar to ISP changing in response to hardware age instead of atmospheric pressure. It's completely do-able that way for people who want to experience it.

So yes, this is a very achieveable suggestion. However I think it would be better implemented as a game realism mod rather than as part of the stock game so that people who don't want to have to worry about such things don't have to.

[Matayoman]

Worth noting- kerbal engines likely use a substance similar to real world RP1 (Kerosene) with LOX for their liquid fuel engines, while RCS is likely nothing more than compressed helium for use in a hot-gas thruster.

Although RP1 and compressed gas helium would have very minute losses over long periods of time, you would definately have to factor in LOX boiloff when planning a mission.

Ultimately at that point you're getting to a level of realism that would make the game confusing for new players and irritate people who just want to do things in space without worrying about the details, so it might be better to implement this as a game mod rather than a stock feature. It wouldn't be hard to do either- work out equations to determine boiloff rates based on a percentage of the current fuel volume in a given time period applied as a very gradual frame by frame rundown.

RTG and solar panel degradation would be treated the same way, in effect your 'durability' then becomes implemented similar to ISP changing in response to hardware age instead of atmospheric pressure. It's completely do-able that way for people who want to experience it.

So yes, this is a very achieveable suggestion. However I think it would be better implemented as a game realism mod rather than as part of the stock game so that people who don't want to have to worry about such things don't have to.

Very well put, and yeah, good point here dude. The fuel loss would be a tricky and friggin annoying topic to cover with every flight. But at a minimum, I think the topic of power should be of concern. Any newb player wouldn't have to worry about battery degradation at first, because they will be way more excited they could even get to orbit in the first place. But when a few months of kerbal time passes and their launches get more efficient and better payloads developed, then they will notice their old satellites are becoming dysfunctional. It could be a mod, and hopefully soon will be a mod, (even if i have to team up with somebody to make it happen), but it could very well become a part of gameplay.

A topic we always harp on in the lab is that "there is no random failures." Having a degrading power system would be a perfect opportunity to introduce that to KSP. If properly planned for, it won't be an issue immediately. If you cycle the power on each orbit to the battery, full discharge, full recharge, then you will have problems very soon and very similar to what we deal with in reality. It won't mean that you're entire satellite fleet would die, but they may begin to operate less and less with each pass until they only operate in the sun.

These could also be repair opportunities for EVA missions just like repairing the parachute and repairing the wheels.

[OdinYggd]

A topic we always harp on in the lab is that "there is no random failures." Having a degrading power system would be a perfect opportunity to introduce that to KSP. If properly planned for, it won't be an issue immediately. If you cycle the power on each orbit to the battery, full discharge, full recharge, then you will have problems very soon and very similar to what we deal with in reality. It won't mean that you're entire satellite fleet would die, but they may begin to operate less and less with each pass until they only operate in the sun.

These could also be repair opportunities for EVA missions just like repairing the parachute and repairing the wheels.

Or it could result in lessons in good engineering- making your designs serviceable. For instance instead of putting a stack of batteries right in the main column of the ship where they cannot be removed, you instead put them on docking ports on short pylons along the main beam. That way when the packs have gone bad you can launch replacements, dock on, and replace them while in orbit. Already my solar arrays use this approach, I launch a lightweight vessel containing 4x 2 meter trusses each carrying 2 gigantors, and a module tug to install them. Like so I can build any size array in orbit with relative ease, and if my solar panels eventually degraded it would be a simple matter to remove and replace the worn out segment.

But other than RTGs decaying, most types of depletion/wear accumulation are better left to game mods meant for people who seek the increased realism they offer.

Actually I'm not 100% certain on where to hook the API for batteries to make a wear-out mechanism for them. Solar panels and RTGs could get by using an ISP-like correction factor, and would apply that factor based on the time they've been in service. Fuel boiloff is even easier, fixed percentage per tank in a given time period.

KSP recommends C# for making game mods. Although the API isn't terribly well documented, you can usually get help from other people familiar with it here on the forum or on the IRC at #kspmodders

[itsme86]

Have you considered how annoying this would be with timewarp? You fly one mission to Jool and all the crap you had on other planets and in orbit is all decayed and broken. Unless you're the kind of person that works on other missions while your craft is drifting to the next burn. I don't think most people play that way though.

[Beeman]

This would be something I would LOVE to see in an additional options menu wherein you toggle various features on and off to fine-tune your vanilla experience. Then mods could perhaps expand upon the system in some way.

I don't know, either way, I think things that kind of necessitate more intelligent design of rockets and things like resupply missions and what-not are all really good because they just add more depth to the gameplay and that's always good, so long as it's not too monotonous.

[John FX]

I like this in terms of a career mode where you develop better panels, batteries and RTGs that last longer and produce more power as part of a research tree.

[John FX]

Have you considered how annoying this would be with timewarp? You fly one mission to Jool and all the crap you had on other planets and in orbit is all decayed and broken. Unless you're the kind of person that works on other missions while your craft is drifting to the next burn. I don't think most people play that way though.

Then that is something you would have to account for if you decided to go to Jool...

Remember the idea is to be able to develop stuff that can last over 25 years, a Jool mission is under 5 years if you don`t mess about. I always have other missions going to fill the time while my craft is on the way to Jool or similar. Alarm clock really helps as you can do other stuff then go back to a craft with a maneuver node still in place.

[boomerdog2000]

Personally I'm against this because I feel it falls under the random disasters sort of category, but on a more technical level wouldn't this make all the inline batteries useless if you have to remove the whole part to replace them?

[shand]

there is already a mod that gets boil off of LOX. i think its the modular fuels mod?

and with batteries ect its probably a good idea, but do a mod of it first - proof of concept so to speak. shouldnt be too hard - but remember that modern batteries the "cycle" is not the number of times the battery has been discharged/charged. its the number of full discharge/charge cycled you would have to do the same amount of power transfer. IE: 2 half cycles are 1 cycle.

Anyway, this would be fun to play with. dont think propellent degredation would be of benifit - but electricity would work, espeically given how OP solar panels are ATM. if they degraded over time (years) that would make their values much more viable.

[lajoswinkler]

Stuff degrades. Either by chemical equilibrium or by mechanical degradation (micrometeoroids, dust). Voyagers and Pioneer are probably looking less shiny and new at this moment.

This is a great idea and I'd like it to be implemented as a "hardcore" option, both for the sandbox and future career mode.

What I wouldn't like is you could not turn it off. It would create lots of problems.

One consequence of such option would be that the players would more often start more missions at once, and not use few years of game time for a single one. That's an interesting consequence, IMHO.

[boomerdog2000]

But what about time warping for planets to be in the right place for an injection burn? If I get it in my head that I want to try and go to Moho, I don't want to be interrupted because my refueling stations are now falling out of the sky. Also since we can launch so many rockets so quickly wouldn't most of your ships fail all at once?

[shand]

Planning Boomer, planning. i do agree that vaguely shortterm concerns (fuel boiling off) would be far too intense for me.

batteries on the other hand fit the bill - especially in an environment where in order to pay for your trip to moho you have to launch 10 satellites or 2 mun landings or something. giving a spacecraft an end of life means its worth doing again. otherwise you'll run out of missions to do around LKO very quickly!

and replacing batteries should be a thing - not even undocking them and docking a new one. walking up with a "battery replacement kit" or something. or for the solarpanels "a cloth" to get their efficiency back should be a thing. that way you can decide its worth replacing the battery (space station) or sending up a new one (small sat). equally you could have "backup" batteries that dont get used unless the primaries are out - thus protecting them again degradation until they are needed or perhaps so they replace the primaries automatically when they reach a certain level.

THOUGHTS!

obviously i'm talking career mode here.

[lajoswinkler]

^^oh, repairing/replacing kits would be great. Kerbals would actually do something useful.

Now imagine if you could pay someone to fix it for you, either by docking to his station or welcoming him on your ship. Kerbal handyman. Failed battery on your important station around Moho? No problem, that would be 50,000 coins (or whatever the currency will be called) or units of some resource.

This game really has a huge potential for economy.

[King Arthur]

As long as this is optional and there's a way to reasonably fix/replace the degradation of stuff already in-orbit without tearing the damn thing apart, as has been already pointed out and suggested, I wouldn't mind seeing some form of degradation.

[Hannu]

In real life planet probes use some hydratzine variant and dinitrogen tetroxide as propellants. They stay liquid in normal pressure and can be stored decades without significant degradation in spacecrafts. However, they give less ISP than LH2/LOX and need very exotic and expensive materials to prevent corrosion, which limits their use in large booster stages. Hydrazines are also very poisonous and need strict (and expensive) safety precautions on every phase when there is possibility to human contact.

If devs consider this, I hope that they include different propellants in game. Maybe volatile but high ISP LH2/LOX for medium to large engines. Some very large Kerosine/LOX -engine for big dumb boosters. And then long living stuff for space (also for LV-N). But it would increase number of parts and complexity of game. In every case, I hope that they keep possibilities to make also very long missions.

[manskal]

I like this in terms of a career mode where you develop better panels, batteries and RTGs that last longer and produce more power as part of a research tree.

Exactly. Also, make it so that kerbals can fix those parts that have degraded, swapping out old batteries and solar cells with new ones. In fact, that can be the objective of some missions in career mode (maintaining a space telescope ala the Hubble). That would also be an increased advantage for crewed missions.

Fuel boiling off? There's a mod for that.

[Morty_jhones]

Sounds interesting but ultimately I feel will be implemented as a realism mod when this game is finished.

Like a lot of other players i run 1 mission at a time trying to run multiple missions at once in the un-moded game is currently imposable due to the way the game handles inactive flights and timings. All fight path data and flight nodes are unsaved when you change craft and this mean that at each switch you need to rework the flight and can easily miss burn points.

[manskal]

Like a lot of other players i run 1 mission at a time trying to run multiple missions at once in the un-moded game is currently imposable due to the way the game handles inactive flights and timings. All fight path data and flight nodes are unsaved when you change craft and this mean that at each switch you need to rework the flight and can easily miss burn points.

Get Kerbal alarm clock - a must for running multiple missions. Don't worry, it doesn't add any parts or ruin the stock feeling.