1.02 Kollier Trophy (reset for the updates)

[AngusJimiKeith]

pffffffffffffffffffff. This from the new physics thread:

• Night time air is less dense than day time air. Planes may be able to go Supersonic at night and perhaps not during the day.

No wonder all these pitch black midnight runs where you can barely see anything in the screen shots. "Oh I don't know why I did that" bahaha. Sure. Too funny. Anyway isn't that backwards? Shouldn't squad have made warmer air less dense where your speed runs have better odds during they day?

That does seem backwards. Keep in mind that less dense air means less thrust and less lift as well, which somewhat offsets the gains. (IRL, lower density performance is actually worse, but that may not be the case in KSP).

[MunGazer]

Good info there Angus. Yeah I remember reading something about the "hot and high" conditions of Afghanistan making things tougher for helicopters.

Also, that's something I didn't think of - the trade off involving drag, lift and thrust. Probably should try running the same craft at high noon and midnight to see which yields better results.

I really hope what you said about the thermometers giving temperature readings for the part they're on is true in ksp 1.0. I briefly slapped one on the nose of a craft and if I recall correctly it said 263 degrees and stayed at that temp as I shot the craft off the runway and burned up supersonic. At that point, I had given up on it and decided the thermometer only gives me the ambient air temp and doesn't give me the part temp. Maybe there's something I'm doing wrong. Anyway, it would work in real life how you said.

Regardless, it's really cool having you in this thread since you're going to school for something that requires knowledge in aerospace science.

[AngusJimiKeith]

I really hope what you said about the thermometers giving temperature readings for the part they're on is true in ksp 1.0. I briefly slapped one on the nose of a craft and if I recall correctly it said 263 degrees and stayed at that temp as I shot the craft off the runway and burned up supersonic. At that point, I had given up on it and decided the thermometer only gives me the ambient air temp and doesn't give me the part temp. Maybe there's something I'm doing wrong. Anyway, it would work in real life how you said.

I'll be honest, I read that tidbit on the forums, but haven't had time to try it myself. 263, if Celsius, is awfully high for ambient...And if Kelvin is below freezing! It doesn't really make sense in Farenheit or Rankine either...Huh. Needs further investigation.

Regardless, it's really cool having you in this thread since you're going to school for something that requires knowledge in aerospace science.

I'm not exactly the best aero engineer around (not even on these forums...), but man do I love this stuff. I'm happy to be around and provide some insight.

(Especially now that, you know, the stock atmosphere is at least a reasonable approximation of reality!)

[MunGazer]

Yeah 263 didn't seem right to me either. iirc I had placed it on the bottom of a shock cone intake which was at the front of my craft. I remember thinking oh well maybe that's just the part's temperature for some reason. I was sitting still on the runway. So I thought I'll punch the throttle and see if the displayed temp changes beyond supersonic when i see flames everywhere. "iirc" it didn't. Anyway, seriously second guessing myself now and will definitely investigate that further as soon as I get home from work.

[MunGazer]

Well, I placed a thermometer on a crazy fast vertically launched rocket, right on the angled face of a size adapter exposed to the high pressure air, and it only went up to about 299° (Kevin?) from the 283° (Kevin?) or so that it started at while sitting still on the launch pad. It reached 299° (Kevin?) before exploding due to overheating. I was reading somewhere else that they use a unit called Kevin as opposed to Kelvin, I guess a fictional temperature scale. And it seems as though the slight increase in temperature might have been just from proximity to the part, but a 6% increase in temperature most certainly shouldn't be right for that slanted surface of a size adapter that exploded from overheating before anything else on the rocket.

So, assuming that it is a fictional temperature scale and that it can't be used to measure the actual temperature of the part itself, I wonder if maybe I could make a mod that will display a list of the heat of all your parts in real time during flight. That'd be cool. I'm figuring it would be no more of an exploit than, say, the flight engineer mod which simply displays numerical data about the craft. I know how to code a little bit but I've never made any mods.

Of course, any attempt at displaying real time part temps in a competition run - I'd only do that with Slashy's approval.

Edited April 30, 2015 by MunGazer

[Aetharan]

Ironman Attempt: Skybreaker

Stock physics, all stock parts. MechJeb functionality is provided to all of my command modules via Module Manager. The plane herself is a bit of an air hog, out of necessity, and I learned the hard way after the speed-run portion was complete that it starts getting very, very flip happy after the fuel's run down a bit. Note, I'm an inexperienced pilot, so this probably could have gone better, but MechJeb served only to provide information windows until it was time to turn around and go home. On the return trip, Smart A.S.S. was employed, as was the navball guidance back to the runway, but experimentation before the run showed me that the computer can't actually fly this thing-- tolerances are too tight to do more than hold a heading it's already on or change one axis at a time by a few degrees, tops.

All that said, have a slide-show!

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[Aetharan]

(Double-post, please delete.)

Edited April 30, 2015 by Aetharan

[FlipNascar]

Ironman entry with the FN-1D. The intakes disintegrated on the return leg, however the first run (outbound) hit 27,418m and 1,381m/s. On the return to KSC I was going for more speed at a lower altitude as I hit around 1,500 the ram intakes exploded. However, did recover to KSC as pictured. I should have saved that flight log picture too, somewhere around the 10minute mark is when the intakes exploded.

[zekes]

I don't have a pic of exactly level flight, tired to get it close... (908 m/s, Iron Man)

Just outside of KSC, safe and sound.

Also note this was done with two external fuel tanks still attached.

EDIT: Should there also be a low- altitude speed record? Like, under 1000m say?

Edited April 30, 2015 by zekes

[Pds314]

EDIT: Should there also be a low- altitude speed record? Like, under 1000m say?

I managed to reach 725 m/s with a single-engine plane under 1000 meters. It didn't even use Turboramjets, just the J-33. Of note, was that it had microscopic wings and used a slanted-up tail as a nose cone. I'm not sure if it is more aerodynamic than the NCS cone and adapter, but it's a lot more heat tolerant. You know you've done something weird when a basic jet at under a kilometer is cooking your nosecone off.

Putting either of the other engines resulted in exceeding mach 1.5 by the end of the runway and reaching Mach 5 near sea level, and scorching everything but the fuselage and engines almost instantly.

[MunGazer]

So, I've been holding myself to a high standard for the ironman competition. I won't submit it until it reaches my definition of "level flight" at a target altitude. My definition of the aforementioned in this context is 0 m/s vertical speed (slight oscillation of 5 meters of altitude up and meters down for a margin of error/buffer) and ​the ability to maintain that altitude (definitely no extremely long flat lofts to squeeze out extra altitude in a long, flat arc. This, in my opinion, is no better than a ballistic trajectory) and consistent airspeed (continuous deceleration would indicate a simple "momentum plateau", where you loft up, hold pitch to maintain, but your thrust can't overtake your drag for consistent airspeed ... so if you're continuously accelerating that's fine) for at least 60 seconds. Any opinions on this standard or something like it for ironman? I just think it would show the true virtue and airworthiness of any submitted crafts and reward the best engineer rather than the best slight of hand. Not saying the submissions so far have been slight of hand, I just think it would be a great thing to add to the competition.

Edited April 30, 2015 by MunGazer
forgot to mention airspeed. no coasting on a plateau.

[AngusJimiKeith]

Plus or minus 5 m/s vertical speed for some time is a good limit, yeah. That is for altitude. Not being able to maintain speed doesn't bother me so much on altitude runs because you're generally pushing the craft to its limits, so it might not have the thrust to stay that fast. As long as it maintains lift, I'd say that counts.

For speed runs, however, consistent airspeed does become a factor, and I'm much more inclined to say it needs to be maintained.

(Also, note that I am separating "speed" and "altitude" runs here - while doable on the same flight, they are different objectives and should have different constraints.)

EDIT:

In the interest of fairness, I've just noticed this:

Error in the leaderboards: Slashy, the 803 m/s on my flight was not in level flight! That was in a dive on the way back to KSC. My max in level flight is essentially what was shown on the navball in the altitude picture: 761.8 m/s.

I don't anticipate that record will stay for long, anyway.

Edited April 30, 2015 by AngusJimiKeith

[MunGazer]

Plus or minus 5 m/s vertical speed for some time is a good limit, yeah. That is for altitude. Not being able to maintain speed doesn't bother me so much on altitude runs because you're generally pushing the craft to its limits, so it might not have the thrust to stay that fast. As long as it maintains lift, I'd say that counts.

For speed runs, however, consistent airspeed does become a factor, and I'm much more inclined to say it needs to be maintained.

(Also, note that I am separating "speed" and "altitude" runs here - while doable on the same flight, they are different objectives and should have different constraints.)

EDIT:

In the interest of fairness, I've just noticed this:

Error in the leaderboards: Slashy, the 803 m/s on my flight was not in level flight! That was in a dive on the way back to KSC. My max in level flight is essentially what was shown on the navball in the altitude picture: 761.8 m/s.

I don't anticipate that record will stay for long, anyway.

Very good point about simply maintaining the altitude for a minimum accepted time duration and not worrying about deceleration. I'd agree with you there. My only beef is that it will steal the thunder from craft that can sustain. I'm honestly not sure what the best option is here. Maybe Slashy will weigh in.

Edited April 30, 2015 by MunGazer

[MunGazer]

Ok, so I've given it some more thought. Let's say hypothetically we have a craft that can maintain 1200 m/s airspeed and 28 kilometers altitude for 60 seconds. However, if he lofts up, voilla. Now he's at 30 kilometers altitude, and he just sits there and holds that while his craft continues to decelerate. My thinking is you could make anything that ballistically hits, say, 36 kilometers and then just use your momentum and aerodynamics to hold that for a certain relatively small plateau, all the while decelerating from drag despite the best efforts to maintain airspeed. My thinking is we wouldn't want to see something like that in the number 1 position. But this is just my opinion.

Edit: I've already had prototypes that can "plateau loft" well over 28 kilometers, and for quite some time too because they can get up a lot of speed at 25 km, and they are extremely low drag so it takes a pretty long time to lose enough speed that they can't hold that lofty 28, 29 or 30+ altitude any longer. But, I've chosen not to submit it because of my concern with this metric of performance.

Edited April 30, 2015 by MunGazer

[AngusJimiKeith]

I see where you're coming from. It's definitely possible to "lob" craft up to ridiculous heights (The SP-1C I used in my entry broke 40k on an entirely unintentional zoom climb once - I had stopped paying attention for a bit too long. )

My argument is that as long as it is lift, and lift specifically, that keeps the plane up, then speed doesn't matter - if you drop below the speed required to hold altitude from lift, you either fall or go ballistic.

Showing a Lift/Weight ratio >= 1 would be the ideal solution. However, in KSP, there's no easy way to measure lift. I've been spoiled by the likes of KER and now AeroGUI but stock obviously doesn't have those tools.

I don't know what the best solution to this issue would be. Any other thoughts? (Slashy?)

[MunGazer]

Ok cool, well at this point I suppose which way we think the competition rules should go is a matter of preference. No doubt, some very interesting designs could come out of either option. On the one hand you could have masterpieces of lift to weight ratio, and on the other you would have crafts that excel in lift to weight, drag, and thrust all together.

In the former, I suppose a relevant question would be: do your engines have to be even running at all? Or could they have died a few moments ago just before reaching the maintained altitude portion of the run?

[GoSlash27]

All,

I'm comfortable with you folks having a "gentleman's agreement" on what constitutes level flight. I don't want to make the rules so stringent that they turn off entrants who maybe don't have the skills to maintain tight tolerances.

I'd say we can generally tell the difference between someone who's zoom- climbing/ diving and who's operating in good faith.

If I miss an entry that looks suspicious, just hit me up on PM and I'll have another look at it. It will be strictly confidential and nobody will ever know who requested a review of a particular flight or even if the review was requested or if I just decided to review it on my own.

"Level flight" to me means that it has achieved an equillibrium state where the altitude and speed will not degrade over time.

This is your competition and I'm just housekeeping (and shamelessly stealing all of the tribal knowledge you're generating ). It's in your own best interest to keep it fair.

With that said, time to update the leaderboard. Good job and excellent entries!

Best,

-Slashy

Edited April 30, 2015 by GoSlash27

[AngusJimiKeith]

Ok cool, well at this point I suppose which way we think the competition rules should go is a matter of preference. No doubt, some very interesting designs could come out of either option. On the one hand you could have masterpieces of lift to weight ratio, and on the other you would have crafts that excel in lift to weight, drag, and thrust all together.

In the former, I suppose a relevant question would be: do your engines have to be even running at all? Or could they have died a few moments ago just before reaching the maintained altitude portion of the run?

I hadn't actually thought about that. My inclination would be "on," though I can't give a good reason.

Additionally, another question for my own scenario: what's preventing someone from diving from a higher altitude to pick up speed and then pull up into level flight? Ok, the F3 menu probably helps prevent that, but it is a possible exploit.

EDIT: Alright, that sounds good Slashy. I confess I'd never be able to hold steady at one altitude within +/- 5 meters for long - can't even do that in the low atmosphere!

[zekes]

Very good point about simply maintaining the altitude for a minimum accepted time duration and not worrying about deceleration. I'd agree with you there. My only beef is that it will steal the thunder from craft that can sustain. I'm honestly not sure what the best option is here. Maybe Slashy will weigh in.

I got up to about 1100 m/s on one flight, but later lost the tail and had to bailout....

[GoSlash27]

A couple extra notes:

Zekes, I'm thinking it's not any more difficult to achieve high speeds at low altitude than at high altitude, so I'd rather not split it. I'm... well, let's face it: I'm a lazy man!

AngusJimiKeith, thanks for the correction. It's been fixed.

Leaderboard updated!

Best,

-Slashy

[MunGazer]

Lol zekes. I saw your creation earlier and I must say that's an incredible work of art. Looks strikingly like a mig-15

[zekes]

Leaderboard updated!

You didn't add my flights

Lol zekes. I saw your creation earlier and I must say that's an incredible work of art. Looks strikingly like a mig-15

Danke! It's actually a MiG-19, just one of a set of Soviet planes I'm making for a big release pack.... pretty much every Cold War soviet jet will be there...

[GoSlash27]

Oh, poop. It didn't take.

I gotta do it again

-kickin' rocks,

-Slashy

*edit* all fixed. Leaderboard really updated this time.

Apologies,

-Slashy

Edited April 30, 2015 by GoSlash27

[Lesbiotic]

A couple extra notes:

Zekes, I'm thinking it's not any more difficult to achieve high speeds at low altitude than at high altitude, so I'd rather not split it. I'm... well, let's face it: I'm a lazy man!

With how silly the thrust scaling is on jets now, I'd go as far as to say it's far easier to get high speeds at low altitude than the other way around. The lower the better. Long gone are the days of the ~57km sweet spot!

[zekes]

With how silly the thrust scaling is on jets now, I'd go as far as to say it's far easier to get high speeds at low altitude than the other way around. The lower the better. Long gone are the days of the ~57km sweet spot!

Not completely true - my Mig-19 does 340 on the deck with tanks, and at 20,000 it does 850+ - its a matter of managing that altitude.