What measurements does KSP use? (i.e. Does 215 thrust means 215 lb-f?)

[Evenger14]

Basically what the titles says. I'm trying to build some rockets as close to specs as the real things as I can in the game, and would like to know what the thrust measurements are in. Like the Falcon 9 (SpaceX) has 9 SpaceX Merlin engines power that Falcon 9 first stage with 147,000 lbs-f sea level thrust per engine for a total thrust on liftoff of just over 1.3 Million lbs-f.

Thanks.

[melaus]

I believe all units in KSP are metric, I'm guessing its Newtons

[simplemunrockets]

I believe KSP uses Newtons.

[AmpsterMan]

I believe it uses Kilonewtons seeing as the only unit we have in game is a metric one (the Meter). I imagine mass refers to "Kilograms" and 1 ton of mass refers to "1000 Kg"

On the note of real life space ships, though commendable and very fun, I think you will find that it is not really practical in KSP. Real life engines almost across the board have higher ISP, weigh less, and produce more thrust than the KSP ones. The counter part is that KSP fuel is like SUPER dense. This means that staging is not as critical as in real life and allows for a wider range of acceptable builds. It also means you probably won't be able to build real life replicas.

[Moach]

I think engines are defined in newtons, while mass is in metric tonnes....

But its not really set in stone... Your mileage may vary, specially when dealing with addons - although there is a comprehensive effort and guidelines for modders to produce well balanced parts, but every now and then you still get the errant "cheat part" sometimes....

Fuel mass is very poorly defined, still... The "capacity" scale dictates how much fuel there is for engies to burn in a given tank, but the relation of this value to the mass of the full tank is defined only by the full/empty mass properties, rather than accounting for the density of the fuel directly

This makes it hard to know exactly what to expect from a novel combination of engine type and tankage.... I find it a rather major inconvenience, but not a dealbreaker anyhow...

Remember, experimenting with trial and error is what this game is all about (however many kerbals you end up killing in the process)

Cheers

[MaverickSawyer]

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SNIP

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This makes it hard to know exactly what to expect from a novel combination of engine type and tankage.... I find it a rather major inconvenience, but not a dealbreaker anyhow...

Remember, experimenting with trial and error is what this game is all about (however many kerbals you end up killing in the process)...

Even the stock parts have varied between versions. I have a V0.13.2 install as a backup, and the stock LV-T30s are more powerful in the older version, IIRC.

[AmpsterMan]

I think engines are defined in newtons, while mass is in metric tonnes....

Not that I mean to be contentious or anything, but i myself weigh 774 newtons on Earth. By that measure if I put on a Mainsail engine under me it would barely lift me off the ground XD

[cardgame]

I think someone already said/guessed engines are in KiloNewtons, not just Newtons.

[Evenger14]

Okay guys, thanks, just thought it would be really cool to build a replica of the Falcon 9, but so far I have not done so well. I did manage to build a replica of a Space Shuttle, but only the orbiter. Had to stick it on my HLS (Heavy Launch System) to get it into orbit. [ATTACH=CONFIG]34270[/ATTACH]

Thanks!

[Kosmo-not]

If mass is in tonnes, then thrust has to be in kN.

[AmpsterMan]

I think someone already said/guessed engines are in KiloNewtons, not just Newtons.

Yeah it was me XD

Okay guys, thanks, just thought it would be really cool to build a replica of the Falcon 9, but so far I have not done so well. I did manage to build a replica of a Space Shuttle, but only the orbiter. Had to stick it on my HLS (Heavy Launch System) to get it into orbit. [ATTACH=CONFIG]34270[/ATTACH]

Thanks!

That's a nice looking shuttle you got there.

[phoenix_ca]

Um, the OP brought-up SpaceX...while yes, they do provide Imperial units of measure, the primary units on their website are all given as SI standard (metric). Well, most of them anyway. The big important ones at least. Sometimes they flip back to Imperial for things which just makes their documents confusing. (Not that I mean to crusade against Imperial measurement units but...really? Really? I live in Canada and am perpetually confuddled because we mix the two in all sorts of weird ways.)

[Majiir]

Imperial units are used for a lot of American rocketryâ€â€and given how much the U.S. has done in space, it's arguable that using metric units actually falls outside the norm.

[Evenger14]

Yeah it was me XD

That's a nice looking shuttle you got there.

Thanks.

Um, the OP brought-up SpaceX...while yes, they do provide Imperial units of measure, the primary units on their website are all given as SI standard (metric). Well, most of them anyway. The big important ones at least. Sometimes they flip back to Imperial for things which just makes their documents confusing. (Not that I mean to crusade against Imperial measurement units but...really? Really? I live in Canada and am perpetually confuddled because we mix the two in all sorts of weird ways.)

Yeah, just used SpaceX as an example because I was checking out their website lately in anticipation for the upcoming launch.

Haha even with all the new planets, I haven't even tried to go beyond the Mun. Main reason is because I am horrible with different planes and such. Anyway thanks for all the replies guys!

[phoenix_ca]

Imperial units are used for a lot of American rocketryâ€â€and given how much the U.S. has done in space, it's arguable that using metric units actually falls outside the norm.

Doesn't mean they're any smarter for it. Imperial units don't have the same base for different units of the same measure. O.o Take length. In metric, it's base 10. Always, base 10. Every measure of length can be represented with a different unit easily (that is, you can convert Mm to km, or mm, merely by multiplying/dividing a certain number of times by 10). Imperial is just plain weird; 12 inches in a foot, 3 feet in a yard, 1760 yards in a mile. It doesn't follow any predictable pattern, nor one standard rule for all possible conversions. SI units do not suffer these inconsistencies.

Your example also depends on generalizing a very specific use-case. Most of the world uses SI units, as do practically all scientists. I'd argue strongly that the USA should stop the non-sense and convert these important calculations to SI units. It makes cooperation with other nations easier, makes writing software to compute these units easier and less prone to error, and avoids blowing-up their precious spacecraft.

[Enture]

Imperial units are used for a lot of American rocketryâ€â€and given how much the U.S. has done in space, it's arguable that using metric units actually falls outside the norm.

Doesn't mean they're any smarter for it. Imperial units don't have the same base for different units of the same measure. O.o Take length. In metric, it's base 10. Always, base 10. Every measure of length can be represented with a different unit easily (that is, you can convert Mm to km, or mm, merely by multiplying/dividing a certain number of times by 10). Imperial is just plain weird; 12 inches in a foot, 3 feet in a yard, 1760 yards in a mile. It doesn't follow any predictable pattern, nor one standard rule for all possible conversions. SI units do not suffer these inconsistencies.

Your example also depends on generalizing a very specific use-case. Most of the world uses SI units, as do practically all scientists. I'd argue strongly that the USA should stop the non-sense and convert these important calculations to SI units. It makes cooperation with other nations easier, makes writing software to compute these units easier and less prone to error, and avoids blowing-up their precious spacecraft.

And +1 to all that, I wouldn't have been able to put it in a better way (and I may have been slightly less civil, so yeah...)

Edited October 5, 2012 by Enture

[Kosmo-not]

I hope someday the United States will convert to using only SI units. At least in my engineering classes, most of my coursework is in SI units. Imperial units require too many conversion factors.

[AncientAstronaut]

The fact that NASA uses imperial has always escaped me... What? Are we building rockets in the 1500s? I live in America and I use the metric system as much as possible. The imperial sucks like a brand new vacuum cleaner.

[Lord Strange]

Imperial units are good for human-scale measures, which is where they came from - feet, horsepower, stone all have their uses, but for larger/smaller things, and for ease of use, metric is better.

Horses for courses!

[Neomatt]

The fact that NASA uses imperial has always escaped me... What? Are we building rockets in the 1500s? I live in America and I use the metric system as much as possible. The imperial sucks like a brand new vacuum cleaner.

I think NASA uses metric, the same as any scientific organization in the USA.

NASA's subcontractor (Lockheed Martin), however, used imperial for the Climate Orbiter, thus causing the mishap.

But yeah, the rest of the world will continue to make "forty rods to the hogshead" jokes until you guys go metric.

[EndlessWaves]

Doesn't mean they're any smarter for it. Imperial units don't have the same base for different units of the same measure. O.o Take length. In metric, it's base 10. Always, base 10.

I don't think that's the correct terminology, base is the number of digits in your system and not the units used. Imperial and metric both use the digits 0-9.

Imperial units are good for human-scale measures, which is where they came from - feet, horsepower, stone all have their uses, but for larger/smaller things, and for ease of use, metric is better.

Horsepower was designed to tell mine owners how powerful the original house-sized steam engines were in comparison to their pit ponies.

And we tend not to use the SI system for very large things, astronomers use Fractions of c, AUs, Lightyears and Parsecs instead of Gigametres and above.

[Misterspork]

Imperial units are good for human-scale measures, which is where they came from - feet, horsepower, stone all have their uses, but for larger/smaller things, and for ease of use, metric is better.

Horses for courses!

Right, it's a lot easier to say 5 foot 8 than 1.7272 meters for someone's height, and easier to measure a foot or an inch without a ruler than a meter or a centimeter.

But of course any time you have to upscale or downscale beyond inches and feet the system falls apart.

[ramipro]

Right, it's a lot easier to say 5 foot 8 than 1.7272 meters for someone's height, and easier to measure a foot or an inch without a ruler than a meter or a centimeter.

But of course any time you have to upscale or downscale beyond inches and feet the system falls apart.

I personally think metric isn't that bad. There's an easy rule of thumb for measuring meters. A meter is the distance from your fingertips of one hand to the shoulder of the other arm. I also like the imperial, but I think it is a bit outdated

[RoboRay]

I personally think metric isn't that bad. There's an easy rule of thumb for measuring meters. A meter is the distance from your fingertips of one hand to the shoulder of the other arm. I also like the imperial, but I think it is a bit outdated

This kind of thing is exactly how the outdated imperial system got started.

[ramipro]

This is just a coincidence, the meter wasn't designed after that length. It is that, somehow, it happened to be the same. I think the meter is (or was) defined by the circumference of Earth divided by something i think.