draeath

Hi folks! Here's my first tool for KSP. It does what it says on the tin - give it data, and it gives you other data Specifically you provide vessel information and a desired delta-V, and it gives you back the burn time, mass change, and what fuel you'll have remaining. For fuel, if you do not know the mass - take the tank wet mass, subtract the dry mass. Then divide by the number of 'units' stored - this will give you the mass per unit for that fuel type. Be sure to combine any components used - for example, you would combine liquid fuel and oxidizer and consider it to be a single unified "fuel" since it's the mixture that's expended. It may not be obvious, but this works for using RCS as well - just look up the thrust and Isp of each RCS cluster that would be used and input them as "engines" - for fuel mass, use the combined monopropellant across all of your enabled RCS tanks. This was written for Python 3, so I can claim no support for Python 2. You can try, at your own risk. The license is in the script, hard to miss. Feedback (and someone verifying my math) is highly appreciated Note that you can use this for real rocketry as well, if you tweak standard_gravity to the real-world value in m/s2 - though of course there's no warranty that this program won't cause half the city to catch fire or the like. Example session: C:\Users\draeath\Desktop>python KSP-FireMarshal.py Welcome! This utility will compute burn time and fuel usage for a given delta-v. Tip: Mg = metric ton = 1000kg Tip: combine expended resources for these calculations. (eg fuel+oxi) Tip: liquid fuel and oxidizer mass is 5kg per unit. Tip: monopropellant mass is 4kg per unit. Tip: specify only the fuel mass for the current stage. Tip: (wet_mass - dry_mass) / capacity = mass per unit Desired delta-v in m/s? 500 Vessel mass in Mg? 5 Fuel mass in Mg? 2.5 Thrust and Isp entry will loop - make one entry per engine. Provide value of 0 to stop adding engines. Engine 1 thrust in kN? 25 Engine 1 specific impulse in seconds? 800 Engine 2 thrust in kN? 10 Engine 2 specific impulse in seconds? 350 Engine 3 thrust in kN? 10 Engine 3 specific impulse in seconds? 350 Engine 4 thrust in kN? 100 Engine 4 specific impulse in seconds? 280 Engine 5 thrust in kN? 0 Calculated thrust: 145.0 Calculated specific impulse: 325.4509 Burn time: 15.96 sec. Initial mass: 5.0 Mg. Final mass: 4.276 Mg. Fuel spent: 0.724 Mg. Fuel remaining: 1.776 Mg. Press any key to continue . . . C:\Users\draeath\Desktop> Code is on github Changes: 1.0 - initial release. 1.1 - added support for multiple engines. 1.1b - fixed derp - we only iterate through engines once now. 1.1c - tweaked tips see github for any future updates

No images, here...

It isn't really 0.23 compatible, I wouldn't even go there.

Yep, target a docking port and BAM! Instant indicator.

Indeed. In the physics realm units are of dire importance, they really should go through and make sure units are, if not consistent, at least labeled everywhere.

It does not vary, we are talking about Standard Gravity. 9.80665 m/s2 in real life. Squad either rounded/truncated or mistook it for another value, but as stated I've seen 9.81 and 9.82 - but I would like to know what is actually being used. EDIT: ninja'd by UmbralRaptor - thank you for the confirmation! EDIT2: I should point out this whole time I've been asking about g0 not g - UmbralRaptor understood what I meant apparently.

So the fuel quantities exposed in the VAB and right-clicking tanks appears to be in liters, going from your "200 = 1ton" figure above. Just to make sure my brain isn't, well, not braining... can you confirm if I'm correct on that?

ISA MapSat is currently* not being actively developed, and the "best" replacement that I am aware of us still a Work In Progress. * - author has other things going on, but has made it clear that neither has he abandoned it nor does he want anyone taking the reigns.

I see people using both 9.82 and 9.81 for g around here. Which one is it actually? It would be so much nicer had Squad used the real g value instead :/

You're never going to get rid of all the idiots, the goal is to reduce the number somewhat. I fully support this, provided there is a way to continue - whether it's a dialog or an obscure ritual that must be performed on the first full moon of a new year. I do have to say though, a big part of releiving the crappy-bug-report pain is having an actual bug tracker that people can see and submit to. Handling bug reports on a forum is like herding cats - never going to end well. It's so much easier to just mark "INVALID" and move on. Bitbucket (and I presume github?) have bugtracking features, and if not it's not to hard to keep a flyswatter or bugzilla page up somewhere. Assuming you have hosting. If you don't, that's not your fault at all. Heck you should go all the way and use a project management tool anyway - no sense keeping your ideas and plans scribbled on a napkin when the tools software development houses use are available, right?

What are these 'units' then? Also, I almost never use the stock tanks - so I'd need to know what unit the quantity is represented in. See the post just prior to this one.

There are no units, and when I've looked up threads regarding them, I've found completely different results between tanks. (eg not the full/dry mass, but the quantity value)

Now THAT is handy!

Ah, so if I'm ever in doubt about the actual capacity of a specific tank, I can just slap a pod on said tank, "launch" it, and view the resources display. Just so long as I remember the conversion "factor" for said tank, I can then easily determine exactly how many equivalent liters of fuel+oxy is in said tank.

Thank you, folks! I forgot all about that wiki page!!

"op·ti·mize - verb: make the best or most effective use of (a situation, opportunity, or resource)." Wrong word choice Did you see my link here? This may solve the problem for you. Grab the 'experimental-basic' package and give it a try. You should notice little-to-no quality difference, but a huge RAM usage difference. Less RAM used means you can push things further before hitting that magical 3.5gb wall.

*cough* In other words, it's a 32-bit executable, so It is subject to a ~ 3.5gb addressable memory limitation. This has nothing to do with optimization (though optimizing things - something that should really not be done early in development (and KSP is on 0.23 right now) would delay being impacted by it.) This might help you.

Hardest thing is determining what your current in-flight "state" is without constantly checking and resetting experiments. I would love to know that I am "in orbit above the grasslands" without having to prod the goo 50 times.

How does one calculate the "combined" thrust and Isp when multiple (differing) engines are in play? For example, let's say I have a 120kN engine with a 400 second Isp, and two 50kN engines at 350 second Isp. How would you work this into a single "engine" to then use in delta-V calculations?

I've read that liquid fuel and oxidizer comes in at around 5kg per liter... but I have yet been unable to figure out what the relation between in-game fuel quantity and liters. Eg, if I right-click my tank and see those numbers - how do I go from that to liters? Is this actually consistent or does it seem to differ per tank? I'm trying to do some number crunching to pre-plan things such as burn time and fuel expenditure for given delta-V values, and I think this is the last bit of knowledge that I need. Alternatively I can give up on this part and not have any way to determine remaining/used fuel for a given maneuver, which isn't really necessary but it's certainly nice to know. I am trying to reduce my dependence on Mechjeb's autopilots. It does give me fuel mass, vessel mass, and empty mass - but I have no way to ignore tanks/engines that would not be used during the burn - and it does not display them with the precision that I would like.

* MechJeb when used responsibly (eg no autopilot junkies apply), * RemoteTech2, * Ferram Aerospace, * Deadly Reentry Continued, * Ioncross Life Support, * Either (or both) Lazor Docking Cam or Navyfish's docking alignment indicator, * and TAC Fuel Balancer (if you resist the temptation to do things you shouldn't be able to do, such as "balance" ablative shielding or dumping CO2) Basically things that increase "realism" or at least add some more challenge, provide information and data entry (MJ's maneuver node editor for the win!), or make streamlined existing things (fuel balancer - you can try to do this manually, albeit with much hair-pulling)

Is there a way for me to exclude resources from operation? Some things are too easily delt with via the fuel balancer mod and I give in to temptation, and others just don't make sense - solid fuel, CO2 and other life-support mod related resources, ablative shielding from FAR and so on.

When it comes to color coordination I find myself quite challenged, though this would help you choose some alternative colors? Though I think the real change that would be helpful is to use a different symbol for rotational orientation -or- prograde. Perhaps an X shape, or a partial circle like you see in this scope reticule? As it is everything is all on the axis which makes things get crowded, but is still workable because of the color contrasts. I'd say taking any one reticule and tweaking it so it doesn't "fight" for the same space on the display would fix it without having to worry so much about color.

It's not a hard wall with FAR anyways, if you're the least bit aerodynamic. You'll also get visible supersonic shock wave effects if you're pushing too hard.

You know, copyright is not trademark... but I don't see SABRE on their site called out as a trademark. It's probably a non-issue, but it's not a bad idea to play it safe. A rose by any other name...