What your velocity truely indicates in KSP2 Science update (Updated)

[Mikki]

SPEED CHART ... Conversion and conclusions (Updated)

I have calculated the given speed indication of m/s (meters per second) into some better digestible units, so people can better imagine what they are doing to their Kerbals (and mostly the crafts) in atmospheric conditions... I added Mach numbers for the technical intrigued.

@PDCWolf mentioned correctly: "The sound barrier is dependent on the medium, this varies by atmospheric pressure (which can be modulated by altitude and temperature) so whilst Mach 1 is always the sound barrier, the speed in kmh and mph can vary a lot (1234kmh at sea level, 1060kmh at altitude, 5309kmh in water). Atmospheric heating mostly comes from the shock bow in front of the body compressing the air, not friction."
 

10 m/s	36 km/h	22 mph	Mach 0.03	A fresh breeze in your face
25m/s	90 km/h	55 mph	Mach 0.07	Falling from a motorcycle  really hurts, gentle landing with lighter aircrafts
50 m/s	180 km/h	112 mph	Mach 0.15	Heavy speed fines, take off speed light aircraft
100 m/s	360 km/h	225 mph	Mach 0.3	Top speed of F1 race cars on the longest straights
300 m/s	1`080 km/h	670 mph	Mach 0.9	Civil jet top speed, close to supersonic. Fighterjet in cruise mode
600 m/s	2`160 km/h	1`350 mph	Mach 1.7	Fighterjet with afterburner, top speed SR-71 is Mach 3.3, "Turbo Jets"
1`500 m/s	5`400 km/h	3`360 mph	Mach 4.4	Multiple supersonic speed, aluminium and mild steel melt due to compression heating in atmosphere, "Ram Jets", X-15 at Mach 6.7 rocket propelled
3`000 m/s	10`800 km/h	6`720 mph	Mach 8.8	"Hypersonic regime", steel alloys melt, titanium alloys may still stay solid, "Scram Jets", rocket propulsion
6`000 m/s	21`600 km/h	13`440 mph	Mach 17.6	This speed in atmosphere is not sustainable, 2/3 to low earth orbital velocity, "Scram Jets"?, rocket propusion, meteorites
15`000 m/s	54`000 km/h	33`600 mph	Mach 44	This speed in atmosphere evaporates basically any material in seconds, fast meteorites
30`000 m/s	108`000 km/h	67`000 mph	Mach 88	This is 0.0001 c, or a ten-thousands the speed of light, Parker Solar Probe at 86`000 km/h or 54`000 mph, fastest man made object ever
100`000 m/s	360`000 km/h	224`000 mph	Mach 294	0.0033 c. Three-thousands the speed of light in vacuum. Not fast enough to get to proxima

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Any thoughts? I think we need speed conversion in the game at some point.

Thanks to PDCWolf for some corrective input in the chart.
@cocoscacao added to the chart.

 

Edited January 5 by Mikki
Mach numbers corrected, another one, and another typo, ana another

[The Aziz]

What do you need the speed conversion for? m/s is universal, most well known and most useful for ingame purposes.

[Mikki]

3 minutes ago, The Aziz said:

What do you need the speed conversion for? m/s is universal, most well known and most useful for ingame purposes.

So you can drive your car/bike with a tachometer in m/s? Wow, me not!

[cubinator]

I actually gained an intuitive understanding of m/s from playing KSP. Any use of mi/h and km/h outside of cars is basically meaningless to me until I convert it to m/s and can compare it to how fast my rockets go.

Now, Mach units would actually be interesting, especially if the game actually treats the transonic regime in a realistic way for jet engines and aerodynamic surfaces. (I haven't noticed anything different happening around it.)

Edited January 3 by cubinator

[The Aziz]

1 hour ago, Mikki said:

So you can drive your car/bike with a tachometer in m/s? Wow, me not!

Yeah but.. I don't drive car or bike in the game. I fly rockets.

40 minutes ago, cubinator said:

Any use of mi/h and km/h outside of cars is basically meaningless

basically that.

[Audaylon]

I appreciate the chart as I have no clue what 10 m/s feels like.  All the roads in my area are in miles per hour. 

[Malathion]

KSP has forced me to learn about relative velocities in m/s, but tbh it has no frame of reference for me.  When I used to build planes in KSP with my son, we would always convert the number to mach-figures because that was a language we were used to.   2000 m/s ... 3000 m/s were just numbers to us, but mach 2... mach 4.... is a language we spoke.

Thank for building this chart @Mikki. 

[PDCWolf]

On 1/3/2024 at 4:34 PM, Mikki said:

SPEED CHART ... Conversion and conclusions

I have calculated the given speed indication of m/s (meters per second) into some better digestible units, so people can better imagine what they are doing to their Kerbals (and mostly the crafts) in atmospheric conditions... I added Mach numbers for the technical intrigued.
 

10 m/s	36 km/h	22 mph	Mach 0.03	A fresh breeze in your face
25m/s	90 km/h	55 mph	Mach 0.07	Falling from a motorcycle  really hurts
50 m/s	180 km/h	112 mph	Mach 0.15	Heavy speed fines, take off speed light aircraft
100 m/s	360 km/h	225 mph	Mach 0.3	You should really stop sticking your head out and close the window
300 m/s	1`080 km/h	670 mph	Mach 0.9	Civil jet top speed, close to supersonic
600 m/s	2`160 km/h	1`350 mph	Mach 1.7	Speed for fighterjet in cruise mode
1`500 m/s	5`400 km/h	3`360 mph	Mach 4.4	Multiple supersonic speed, aluminium alloys melt due to friction heating in atmosphere
3`000 m/s	10`800 km/h	6`720 mph	Mach 8.8	"Ram Jets", "Hypersonic regime", steel alloys melt, titanium alloys may still stay solid
6`000 m/s	21`600 km/h	13`440 mph	Mach 17.6	"Scram Jets", this speed in atmosphere is not sustainable, 2/3 to low earth orbital velocity
15`000 m/s	54`000 km/h	33`600 mph	Mach 44	This speed in atmosphere evaporates basically any material in seconds
30`000 m/s	108`000 km/h	67`000 mph	Mach 88	This is 0.0001 c, or a ten-thousands the speed of light
100`000 m/s	360`000 km/h	224`000 mph	Mach 294	0.0033 c. Three-thousands the speed of light in vacuum. Not fast enough to get to proxima

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Any thoughts? I think we need speed conversion in the game at some point.

 

I think it's important to distinguish that there's also multiple speeds and multiple ways to measure speeds. Very few fighter jets actually cruise at mach 1.7 for example, with the F-18 cruising at 1250kmh , and F-16 at 928kmh. The sound barrier is dependent on the medium, this varies by atmospheric pressure (which can be modulated by altitude and temperature) so whilst Mach 1 is always the sound barrier, the speed in kmh and mph can vary a lot (1234kmh at sea level, 1060kmh at altitude, 5309kmh in water).

360kmh would be better exemplified by saying that's near the top speed of a formula 1 car (~370kmh in the Mexico straight is the max in competition I think).

No piloted turbojet aircraft has gone faster than Mach 3.3, that record being held by the SR-71 (X-15 and similar being rocket aircraft) is a bit that could be added to the table as well.

Atmospheric heating mostly comes from the shock bow in front of the body compressing the air, not friction.

 

[Mikki]

31 minutes ago, PDCWolf said:

I think it's important to distinguish that there's also multiple speeds and multiple ways to measure speeds. Very few fighter jets actually cruise at mach 1.7 for example, with the F-18 cruising at 1250kmh , and F-16 at 928kmh. The sound barrier is dependent on the medium, this varies by atmospheric pressure (which can be modulated by altitude and temperature) so whilst Mach 1 is always the sound barrier, the speed in kmh and mph can vary a lot (1234kmh at sea level, 1060kmh at altitude, 5309kmh in water).

360kmh would be better exemplified by saying that's near the top speed of a formula 1 car (~370kmh in the Mexico straight is the max in competition I think).

No piloted turbojet aircraft has gone faster than Mach 3.3, that record being held by the SR-71 (X-15 and similar being rocket aircraft) is a bit that could be added to the table as well.

Atmospheric heating mostly comes from the shock bow in front of the body compressing the air, not friction.

 

Thank you for your input, my chart is quite simple since i didn`t want to go too deep in details, but all the above is true, clearly.

I`ll change the chart to conform to your correction, thank you! I¨ll mention your additions too. 

[cocoscacao]

On 1/3/2024 at 9:50 PM, The Aziz said:

I fly rockets.

You also drive rovers...

23 hours ago, Audaylon said:

I have no clue what 10 m/s feels like.

Average human walking speed is roughly 5 km/h, which is 1.4 m/s. Hopefully, you can get some sense from there.

[Kerbart]

3 minutes ago, cocoscacao said:

You also drive rovers...

Average human walking speed is roughly 5 km/h, which is 1.4 m/s. Hopefully, you can get some sense from there.

I think it's especially relevant for rovers, and to some extend for rendez vous. Aside from realizing that 300 m/s is roughly the speed of sound (“fast”) the higher numbers are meaningless in the sense that it’s hard to relate to.

But complaining that wheels are bugged because your rover can’t traverse rough terrain at 30 m/s is silly when you realize it’108 kmh (or 68 mph in mickey mouse units). In similar fashion you might not want to close in at that speed at close range. So maybe even more granularity at lower speeds and less at higher

Also, consider throwing in travel time at higher speeds. How long will it take to reach Jool? Or a nearby star (which is guessing as we don't know how far way they are located)? That makes them far more meaningful.

[cocoscacao]

22 minutes ago, Kerbart said:

I think it's especially relevant for rovers, and to some extend for rendez vous. Aside from realizing that 300 m/s is roughly the speed of sound (“fast”) the higher numbers are meaningless in the sense that it’s hard to relate to.

Add gentle landing to the list. However, I don't think it's necessary to... "form a relationship" here. You can quickly memorize orbiting speeds, and how fast you should enter the atmosphere of the certain body on certain height... Going 3000 m/s or 10800km/h makes zero difference to me. Both are equally unintuitive.

 

22 minutes ago, Kerbart said:

How long will it take to reach Jool?

That depends on the orbit...

Edited January 5 by cocoscacao

[Mikki]

@Kerbart and @cocoscacao, thank you for your input, this will be considered soon and the sources mentioned, clearly high speeds are hard to imagine, i hope the forumers can extract here some common conclusion what a QoL extension would look like to the given speed indicator in the game.

Travel time to a certain celestial body is as we all know more ore less given by the phase angle when executing a Hohmann transfer, so i`d have to think about and calculate brachistochrone trajectories given the propulsion methods with higher specific impulse, which we don`t know by this moment... But some examples could be made nonetheless, i`d still have to explain what brachistochrone means and make a new chart. This is a bit too much, i`d like to keep the conversion chart as light as it is at the moment, but anyway it is a very good idea...

Edited January 5 by Mikki

[Kerbart]

27 minutes ago, Mikki said:

@Kerbart and @cocoscacao, thank you for your input, this will be considered soon and the sources mentioned, clearly high speeds are hard to imagine, i hope the forumers can extract here some common conclusion what a QoL extension would look like to the given speed indicator in the game.

Travel time to a certain celestial body is as we all know more ore less given by the phase angle when executing a Hohmann transfer, so i`d have to think about and calculate brachistochrone trajectories given the propulsion methods with higher specific impulse, which we don`t know by this moment... But some examples could be made nonetheless, i`d still have to explain what brachistochrone means and make a new chart. This is a bit too much, i`d like to keep the conversion chart as light as it is at the moment, but anyway it is a very good idea...

Remember that we‘re not making train schedules, but rather an impression of what a certain velocity means. A baristochrone assumes constant acceleration, for this exercise you just need constant speed. For instance, to travel to the moon (300,000 km), you'll need:

Speed	seconds	time
10,000 m/s	30,000	8h, 20m
50,000 m/s	6,000	1h, 40m

For planets you can either provide a range (shortest/longest) or the median distance. Shortest would be the difference between the SMA, longest would be added together

[Mikki]

3 minutes ago, Kerbart said:

Remember that we‘re not making train schedules, but rather an impression of what a certain velocity means. A baristochrone assumes constant acceleration, for this exercise you just need constant speed. For instance, to travel to the moon (300,000 km), you'll need:

Speed	seconds	time
10,000 m/s	30,000	8h, 20m
50,000 m/s	6,000	1h, 40m

For planets you can either provide a range (shortest/longest) or the median distance. Shortest would be the difference between the SMA, longest would be added together

Oh yeah this very true, i did not remember that.  It spells "brachistochrone", btw , you are correct about the layout for a understandable traveltime comparison for respective velocity... Another chart with some travel times could fit beneath the first. I will look deeper into this tomorrow, and your example is very helpfull. I would go for the shortest distance in orbit, since it happens at least once in a year for the planets which is sufficient i think... 

[Kerbart]

1 hour ago, Mikki said:

I would go for the shortest distance in orbit, since it happens at least once in a year for the planets which is sufficient i think... 

Technically, furthest distance or any of the other ones would happen at least once a year as well... it probably doesn't matter that much, it's more how they relate to each other.