Goddard-Problem: Maximal launch altitude Challenge

[mhoram]

Not sure how I feel about being here alone. Not sure how I'd feel if others were in here with me...

You are right, it might be interpreded in a wrong way. Altered the title.

[MadChris48]

You are right, it might be interpreded in a wrong way. Altered the title.

Aww man. I got a good laugh out of that one. Going to give it a few more tries when I get home later. Kweller's altitude is gonna be tough to beat (care to share your flight procedure?).

[MadChris48]

Alrighty!!! Turned on the terminal velocity read-out on KER and played around some more. I hit an amazing altitude of 61478m. I had a few more launches +61km but this one was the best this session. Behold!

This makes me really wonder is 62km is possible. I've never used MechJeb, but I think it could beat a manual launch. I believe you can use MechJeb to create launch profiles? If so, I'm sure you can get better throttle control by automating it. I can get a fairly smooth reduction on the throttle by tapping ctrl quickly and gently, but its not 'analog' (or digitally controlled) smooth. Would be cool if there was a way to have the throttle mapped to the mouse wheel (I tried and couldn't get it to map).

Edited July 13, 2015 by MadChris48

[mhoram]

Alrighty!!! Turned on the terminal velocity read-out on KER and played around some more. I hit an amazing altitude of 61478m. I had a few more launches +61km but this one was the best this session. Behold!

This makes me really wonder is 62km is possible. I've never used MechJeb, but I think it could beat a manual launch. I believe you can use MechJeb to create launch profiles? If so, I'm sure you can get better throttle control by automating it. I can get a fairly smooth reduction on the throttle by tapping ctrl quickly and gently, but its not 'analog' (or digitally controlled) smooth. Would be cool if there was a way to have the throttle mapped to the mouse wheel (I tried and couldn't get it to map).

Gratulations on the new record! 62km is now really the new goal. I also believe that MechJeb or kOS would help with throttle control.

And it seems like I misunderstood your comment about the Attic.

Handling thrust with the mouse wheel is an interesting idea. Perhaps Malah would extend his list of quick mods with one that maps modifier-key+Mousewheel to throttle control in flight- and map-view.

Edited July 14, 2015 by mhoram

[littlebuddy0]

Here Is A Re-Upload From Imgur

Edited July 14, 2015 by Specialist290
Ninja-edit to make image format properly

[mhoram]

@littlebuddy0: thanks for your submission. Added it to the leaderboard

[HoloYolo]

http://imgur.com/gallery/wl2RzZE/new

Not the best, but I wanted to participate.

Edited July 14, 2015 by HoloYolo

[mhoram]

@Kaboom!: Added your entry to the leaderboard. Thanks!

[SkyRender]

Umm, the .craft file does not appear to actually work. KSP is saying it's incompatible with 1.0.4. I'm guessing this is a quirk of the download service in use...

EDIT: Yes it was. Why would a download service ever require you to click a link for a file to go to a page with another link for the same file? Madness.

EDIT 2: I think we need to make sure we're all using the same physics values... I did three launches, and here's the best one:

I'm sure you can see the discrepancy between my results and the next-best on the leader board. The other two were 71,228m and 72,361m respectively, also higher by some margin. In light of this, here are the values that my KSP has listed as stock for the Aero and Drag tabs:

Aero

GLM: 0.038

LDM: 0.030

BLM: 8.000

Drag

* Apply drag

* Apply drag to non-physical parts

* Apply non-physical part drag at parent CoM

GDM: 6

DCM: 0.6

ADM: 2

Edited July 15, 2015 by SkyRender

[mhoram]

I'm sure you can see the discrepancy between my results and the next-best on the leader board. The other two were 71,228m and 72,361m respectively, also higher by some margin. In light of this, here are the values that my KSP has listed as stock for the Aero and Drag tabs:

Aero

GLM: 0.038

LDM: 0.030

BLM: 8.000

Drag

* Apply drag

* Apply drag to non-physical parts

* Apply non-physical part drag at parent CoM

GDM: 6

DCM: 0.6

ADM: 2

Thanks for providing the physic-numbers.

I just doublechecked with a clean install without addons that the numbers you specified are NOT stock-defaults.

So most likely you have installed an addon that tweaks these numbers.

Sorry, but this means that I can not accept your entry for the leaderboard.

May I ask you which addons you have installed, so that we can figure out which addon causes this trouble?

Edit: Have a look at this thread for possible problems and where a correct physics.cfg is available:

http://forum.kerbalspaceprogram.com/threads/92231-The-Linux-Thread!?p=1380984#linuxthread03

Edited July 15, 2015 by mhoram

[SkyRender]

Thanks for providing the physic-numbers.

I just doublechecked with a clean install without addons that the numbers you specified are NOT stock-defaults.

So most likely you have installed an addon that tweaks these numbers.

Sorry, but this means that I can not accept your entry for the leaderboard.

May I ask you which addons you have installed, so that we can figure out which addon causes this trouble?

Edit: Have a look at this thread for possible problems and where a correct physics.cfg is available:

http://forum.kerbalspaceprogram.com/threads/92231-The-Linux-Thread!?p=1380984#linuxthread03

I figured it was probably the case. The mods I have installed are:

Asteroid Day

EnvironmentalVisualEnhancements

Hull Camera

Kerbal Attachment System

Kerbal Inventory System

Kerbal Engineer Redux

TAC Life Support

SETI Greenhouse

Kerbal Alarm Clock

None of those seem likely to have modified the physics settings, but who knows?

[mhoram]

@ SkyRender: Thanks for the list. Lets compare it with the next entrant that has the same problem.

I have KER and KAC installed on a 32bit KSP-Windows version and don't have these problems.

Feel free to submit a new entry with a clean install.

[Nao]

Oh my that was hard... had to modulate throttle up and down several times and make sure to launch at a small angle east to be completely vertical etc... big kudos to MadChris48 for his launch!!!

But i don't think 62km would be possible (or is it ?)

(ps: i checked the physics file just in case and it's the same as in the link mhoram posted so it should be ok~)

The only two mods i have are engineer and hyperedit. (second ofc not used)

Edit: As for flight profile i used [X] to cut throttle at 0.9ma and immidiately throttled up with shift... then after ~2-3s there was second throttle reduction, by ~20% for just a second (then full again) From there i did gradual reduction in throttle so that acceleration would go down from 5g to 3g near end of burn. Increased the throttle by shift again at the end so that burnout occurred near 100% power. Most likely overdone it, but "welp" it worked

Edited July 16, 2015 by Nao

[mhoram]

@Nao: We have a new record! Thanks for participating and your detailled flightplan!

I also updated the OP to mention the physics.cfg issue.

[Padishar]

I tried a few more variations but the best I managed so far was this:

I've got a couple more ideas to try...

[MadChris48]

Oh my that was hard... had to modulate throttle up and down several times and make sure to launch at a small angle east to be completely vertical etc... big kudos to MadChris48 for his launch!!!

Oh my indeed! My competitive nature may make me have to go at this again. Nice throttlin' Nao .

[mhoram]

@Padishar

Another one who surpasses 61km. Great entry!

For people who want to use MechJeb, kOS or Telemachus I added a ModuleManager config file in the OP.

Edited July 17, 2015 by mhoram

[mhoram]

Here is the first kOS-entry: 61137m

SET THR TO LIST(
1, // 0
1, // 1
1, // 2
1, // 3
1, // 4
1, // 5
1, // 6
0.34, // 7
0.33, // 8
0.32, // 9
0.31, // 10
0.30, // 11
0.29, // 12
1.00, // 13
0.93, // 14
0.89, // 15
0.83, // 16
0.79, // 17
0.73, // 18
0.69, // 19
0.63, // 20
0.59, // 21
0.53, // 22
0.49, // 23
0.43, // 24
0.39, // 25
0.33, // 26
0.29, // 27
1, // 28
1, // 29
1, // 30
1, // 31
1, // 32
1, // 33
1, // 34
1, // 35
1, // 36
1, // 37
1, // 38
1, // 39
1, // 40
1, // 41
1, // 42
1, // 43
1, // 44
1, // 45
1, // 46
1, // 47
1, // 48
1, // 49
1, // 50
0).

LOCK THROTTLE TO 1. // 1.0 is the max, 0.0 is idle.
LOCK STEERING TO HEADING(90,88.125).
WAIT 1. // give throttle time to adjust.

PRINT "Launch.".
STAGE. // same as hitting the spacebar.

declare i to 0.
UNTIL STAGE:LIQUIDFUEL < 0.001 {
print i.
LOCK THROTTLE TO THR[i].

set i to i + 1.
wait 1.
}
PRINT "Fuel Depleted @ ".
PRINT i.

declare maxalt is 0.
until maxalt > SHIP:ALTITUDE {
lock steering to SHIP:SRFPROGRADE.
set maxalt to SHIP:ALTITUDE.
wait 0.1.
}
log maxalt to alt.txt.
log i to alt.txt.
PRINT maxalt.
print "Ending".

[Padishar]

I had to have a play with kOS...

Unfortunately, these scripts don't seem to give anything like consistent results, I tweaked the script which made it worse, tweaked it back and now I can't get over 61400...

[Nao]

Nice one Padishar . The consistency is becoming a problem for me too. I've tried doing three identical launches and by comparing video footage, some drag values between same parts at the same points in flight have been different by 10+% (which gave the final altitude error of +/- of 100+m). With this kind of random factor it's hard to guess if a new profile is better or just the drag was lower. At this point i wonder if running the game at different warps, physics delta or framerates (im locked to 30 atm to limit air temperatures in my room haha) could be changing stuff too.

Anyways congrats on top spot !

[mhoram]

@Padishar: 62km is coming closer ;-) Grats!

Consistency was also a problem I encountered. Made it difficult to improve on the results.

@Nao: I seem to have gotten better results without timewarp, but this might just be a subjective observation.

[MadChris48]

The consistency is becoming a problem for me too.

Anyways congrats on top spot !

I can fourth this as well. I never used time warp because I was concerned of physics flubs. I'm going to try maxing out the physics delta slider and see if that improves consistency.

[SpaceWeaver]

*waves* Hello KSP forum members!

I normally remain quiet while I spend time on the forums, but this challenge made me want to post!

After trying many different things ,so far I have been able to get this as a best result!

I used a straight up prograde launch, with engine trust set at 100 and gimble set at 0. I trottled down a little after achieving 500 m/s and trottled back up for a final boost!

Getting any higher will be a challenge as I'm not exactly able to achieve consistent results!

[mhoram]

@SpaceWeaver: Welcome to the forum! Great first entry and I am happy to have provided a challenge of your liking. Added you to the leaderboard.

Yes these consistency problems arise - you are not the first one who has them. ;-)

[Pds314]

Interesting that, while in theory, this vehicle has 1715.12 Vacuum Delta-V, thus far, it only reaches about the height of a perfectly aerodynamic cannon ball launched at ~1050 m/s.