What did you do in KSP1 today?

[Lt_Duckweed]

38 minutes ago, Nazalassa said:

Wow. You should probably do something in collaboration with @Stratzenblitz75.

I actually did a few years ago!  We did a collab project for the Jool SSTO video on his channel

[swjr-swis]

3 hours ago, Hotel26 said:

for some (most) craft, physics warp (4x) may give stable/accurate performance gauging with shorter production time

Stable maybe, accurate nope. Physics doesn't get calculated quite the same with warp enabled. I've noticed differences in drag, lift, and fuel/EC usage, and seeing how warp also causes (more) RUDs, probably force/joint calculations too. My guess is it's due to less actual physics steps being calculated.

 

Edited July 1, 2023 by swjr-swis
forum did a douple-post

[kurgut]

Today, I spent some time making a tutorial, for IVA enjoyers out there, which covers a full flight only IVA launch, rendez-vous & docking to space station, then landing back at KSC runway, with a SSTO.

IVA is in a retro style, so no fancy displays, only manual piloting !

I hope you find it useful ! Also feedback appreciated  

All these buttons is making kerbals really go crazy, so they smash their head against the cockpit instruments panel to keep the stress down.

 

* Always match your inclination first with your target before doing the Hohmann transfer burn, I didn't tought about it since I knew the station was in a equatorial orbit, but still, the small deviation was enough to make the rendez-vous phase trickier.
* 5:10 : of course DPAI has it I'm dumb ^^ it's the little yellow pro/retrograde symbol that moves around !
* 21:14 : velocity relative to the targeted docking port but only in the X and Y axis.
* 22:45 : I didn't mention it, but on this IVA, the screen display actually shows X, Y axis distance and vel in precise numbers, which is very practical, as well as the X, Y, Z rotation angle. it's a numerical aid to the instrument to the right, which is more visual.

Cheers

Edited July 2, 2023 by kurgut

[Hotel26]

OK, I have some test results and I'll make some prefaratory remarks and some conclusions as well as summarize the results.  (Most of it in the spoiler so that the disinterested can skip on by.)

I [running ChatGPT gag discontinued] built an aircraft I called "QF9E Fling".  I built & tested it in 1.11.2; not 1.12.  It bears only a superficial resemblance to any work of @QF9E.

It is powered by a single Wheesley, carries 1,600 units of LF and has long range capability.  'Fling' cruises at 9.3 km at somewhere around 309 m/s.  It is transonic, unable to exceed Mach 1.

My assertion is that a useful approximation of maximum range can be given by R = r0 + speed * (fuel / consumption).  I think this is of general utility to any KSP airplane designer.
 

Spoiler

Furthermore, since performance may change (hopefully: improve)  as the fuel load diminishes to zero, conducting the initial estimation (i.e. climb to cruise (covering a distance of r0) and then measuring speed, fuel remaining and consumption rate), BUT with half fuel and then multiplying the resulting estimate by 2 might provide slightly better accuracy.

I did both.  I ran a full-fuel estimate followed by a half-fuel estimate and derived max range estimates of 6711 km and 6832 km respectively.

Then I ran an overnight test (about 6h 25m?), I departed KSC with full fuel and NOTE BENE ~40 minutes already on the MET clock before departure.  I computed a likely finish time and set a wake-up alarm in advance.

When I returned to the test, I found it at 9.3km, gliding with fuel exhaustion, speed reduced to about 135 m/s -- so not long to continue in that state.  Longitude was immediately read at -141.1.

Dividing the circumference of Kerbin (3769.91) by 360 gives 10.472 km per degree.  Falling 66.5 degrees short (141.1 - 74.6) of completion of the second lap of the equator subtracts 696.39 km yielding a total distance covered of 6843 km.

Comparing this with the estimate of 6832, noting that the craft was already (just?) in glide, (marring but not fatally wounding the test) represents a strong positive for the validity/utility of the estimation technique.

The estimate was based on a cruise consumption of 0.0702 and the actual looks like 0.0693, which is pretty close also, particularly since it includes some glide distance.

                                                         

Wing AoI is 4 degrees and there is strong evidence it has reserve power to climb higher (and burn less fuel) with e.g. AoI=5 degrees but I have a strong preference not to build general-use aircraft to comply to  "challenge conditions".  My initial draft had significantly less AoI, cruising at only 7.5 km.

It is worth me stating that I have not challenged the notion that the original aircraft engineered by QF9E is capable of a double circumnavigation.  I accept QF9E's opinion that it can, finding that opinion wholly reasonable (even before the fuel extrapolation chart was added).  Not only are the two airplanes different, and mine being run in 1.11 (not e.g. 1.12), but my full-length range test was performed on auto-pilot, with no hand-tuning during the flight once cruise had been attained.  Apples and pears.  (And I just had to make the ChatGPT joke, of course!  )

So the above has been merely a demonstration of an estimation technique.

Next from me, a recognition that everyone has their own preferred personal methods.  Extreme accuracy in range estimations is somewhat pointless.  Except on espionage missions, there is little KSP reason to fly more than 1885 km (180 deg).  Endurance for commuters between refueling is a factor, but that's why I prefer to build some airplanes that perform better at lower altitude on shorter hops (and potentially faster cruise speed).

However, in a public forum, I recognize and hope that some/any reader may benefit from a technique I use and am willing to share at large (without particularly directing it at only the person I may be responding to in the first instance).

 

Edited July 1, 2023 by Hotel26

[QF9E]

@Hotel26, that's a neat bit of analysis, thanks for that! Apparently, a double Kerbin circumnavigation is not to be then.

Edited July 1, 2023 by QF9E

[QF9E]

Today I built all the necessary ground support equipment to be able to turn a Space Shuttle around and launch it a second time.  My shuttle lands and is raised to the vertical position using nothing but gravity and several 100 tons of ore. It is then integrated with a new payload and mated to a new booster stack before being launched into orbit once more.

 

Edited July 1, 2023 by QF9E

[Poppa Wheelie]

7 hours ago, kurgut said:

a full flight only IVA launch, rendez-vous & docking to space station, then landing back at KSC runway, with a SSTO

Very nice!

Two questions:

1.  How did you raise and lower the seat?
2.  How did you get the landing guidance?

Does each of these requires an additional mod?

 

[Hotel26]

2 hours ago, QF9E said:

turn a Space Shuttle around and launch it a second time

Outstanding and brilliant!

[Krazy1]

Pic dump for last couple of Vizor 200 flights. Last one, I accepted all the flight contracts offered (11 I think) and flew this absurd 9-leg trip to satisfy all the conditions. 

More pics:

Spoiler

1 hour ago, Hotel26 said:

'Fling' cruises at 9.3 km at somewhere around 309 m/s.  It is transonic, unable to exceed Mach 1.

KSP actually makes an attempt to model drag differently at sub-, trans- and supersonic speeds. Drag is high from about Mach 0.9 to 1.5. Above Mach 1.5-ish if you fly faster you can fly higher (lower air density and less drag) at zero AoA, so faster and higher is generally better for range. But if you can't get above Mach 1.5-ish then it might be better to stay subsonic despite not being able to fly as high. So you might get a little better range at about 280 m/s at lower altitude. Maybe Chat GPT can fly another test flight. I wouldn't ask a human to bother with such trifle. Links to more drag info: 

Spoiler

Old, probably changed since KSP 1.0 but supports my point about high transonic drag: 

 

 

[JcoolTheShipbuilder]

I came back from a long break, and worked on my mod a bit.

Introducing: Bink and Bonk! a (nearly) contact binary rocky planet and its four moons, Gongi the swamp moon, Dringo the desert moon, Rammus the shattered moon, and Maledictus the straight up anomalous moon (its a cube!)!

I still do not really know what type of terrain Maledictus should have on top of its... cubeness

[kurgut]

3 hours ago, Poppa Wheelie said:

Very nice! Two questions:

1.  How did you raise and lower the seat?
2.  How did you get the landing guidance?

Does each of these requires an additional mod?

Thanks a lot !  

1. at 6:10, you can see there's a knob "SEAT POS UP/DOWN" I'm pressing (it happens fast). and no additional mod required for that. Useful for female kerbal for instance (as they're smaller) / other situations where you'd need more visibility.

2. the landing predictions for the physical kerbin map is tied to mechjeb ! so you'll need it for it to work

Cheers

Edited July 2, 2023 by kurgut

[Hotel26]

@Krazy1 thank you for the "drag" references.

6 hours ago, Krazy1 said:

Maybe Chat GPT can fly another test flight

(You had me at "Chat GPT".)

Spoiler

ChatGPT has noted that the Wheesley consumption drops off a cliff north of 10 km.

  9.3km: 0.07022
 10.0km: 0.05738
 11.0km: 0.05206
 12.5km: 0.03921
 13.0km: 0.03544

ChatGPT has indeed recommended increasing wing AoI to attempt to climb higher for at least the final phase of cruise.

ChatGPT is predicting 282 m/s @ 13km for consumption of 0.03544, after 600 kallons remaining, for a (second-half) range of 4775 km.  Predicted body AoA is -0.081, which will be close to the end of the line.

ChatGPT has further warned, cryptically, that "aerodynamic competitors are now prowling" and advises 'this matter be concluded with haste'... 

(@QF9E thank you for all the fun with your beautiful machine.  You may yet be vindicated!)

ChatGPT has agreed to conduct another overnight run...

Spoiler

UPDATE:

A preliminary "full/half test", just conducted, is estimating 3,303 km on the first 800 kallons @ 9.3km and 6,324 km on the second 800 kallons @ 13km, totaling a max range under power of 9,627 km. 
2.55 circuits.  Let's see what ChatGPT comes up with tonight in an actual run.

 

 

Edited July 2, 2023 by Hotel26

[QF9E]

55 minutes ago, Hotel26 said:

ChatGPT has noted that the Wheesley consumption drops off a cliff north of 10 km.

I noticed some of that as well - when I flew at 10.5 km altitude rather than my original 9 km my craft used significantly less fuel. Good to know that even higher is more efficient still.

55 minutes ago, Hotel26 said:

thank you for all the fun with your beautiful machine. 

I'm glad you like it!

Edited July 2, 2023 by QF9E

[SpacePixel]

4 hours ago, JcoolTheShipbuilder said:

 

Introducing: Bink and Bonk!

These are some magnificent planets you've made, but I could help jumping at the chance to ask you what's with the craft?  This retro rocket looks magnificent, does it work? If yes, how?

[JcoolTheShipbuilder]

5 hours ago, SpacePixel said:

These are some magnificent planets you've made, but I could help jumping at the chance to ask you what's with the craft?  This retro rocket looks magnificent, does it work? If yes, how?

the craft is a VTOL rocket fighter that uses throttle control avionics to hover with several spark engines and can fly like a jet with the aerospike. the nose is three procedural fuel tanks. It does work, but for two minutes before running out of fuel

[Poppa Wheelie]

10 hours ago, kurgut said:

2. the landing predictions for the physical kerbin map is tied to mechjeb ! so you'll need it for it to work

 

I'm interested in how you got the functionality to set radio frequencies and then have the navigation cues on the navball to guide you to a runway landing

[SpacePixel]

Things can only get bitter

The Turtleback a different kind of landing craft -- it isn't meant to come up to shore to offload its cargo; instead, it's an orbit-capable aircraft carrier. 2-unit cargo bay at the bow opens to reveal an elevator that moves aircraft up to the flight deck and down to the hangar bay. You can cram up to half a dozen aircraft in the hangar, but this is rather much, unless you plan on conducting adversarial engagements, in which case it's rather too little. Usually, you'd put there a couple folding helicopters or tiltrotors, and use the rest of the space to place a submarine and/or a mining rover for a more balanced and sensible mission profile.

This vehicle is yet another study on Laythe operating base -- a project that's about to turn half a year and is yet to produce any meaningful result, -- which was primarily motivated by the fact that sea-spaceplanes with ramps looked rather ridiculous trying to deploy the contents of their cargo bays on the ice sheets surrounding Laythe islands. The Turtleback treads a very fine line between looking cool af and utterly insane, but at least I'm happy with how it looks -- a relatively rare occurrence. 

[kurgut]

29 minutes ago, Poppa Wheelie said:

I'm interested in how you got the functionality to set radio frequencies and then have the navigation cues on the navball to guide you to a runway landing

This is part of ASET avionics, so you already have it : )
All you need is to refer to the "Jebbesen® Kerbin Aerocharts" found on ASET consolidated opening post, to find the correct frequencies.

Then once in flight, insert the freq in the NAV radio, set it to ON, change the instrument course to your landing heading. (as I did in the video tutorial)

 

There's also the mod Nav Instruments (something like that), which has this functionality for RPM screens only (with changeable glidescope. But sadly no radio frequencies/cool DME sounds !)

[N_Danger]

A crew was sent to Iota.

Coasting out to the course correction

Separation and docking after the course change.

On Iota with Bobert and Val.

Science was done.

And the meet up to go home

[Duke MelTdoWn]

One of my designs, the Science Junkie 3000, made it to "Most popular this week" in the workshop

Thanks to everyone who subscribed, this made me very proud!

Over the past months, I have uploaded a whole slew of low tech vessels that I hoped might be helpful for fresh careers and beginners. I am glad that some turned out to be useful.

Meltdowns Minimalist Career Ships:
https://steamcommunity.com/sharedfiles/filedetails/?id=2995073286

[Hotel26]

Referring back to the prediction (2.55 circuits) made in: https://forum.kerbalspaceprogram.com/topic/27292-what-did-you-do-in-ksp1-today/?do=findComment&comment=4299207

 

the following shot shows QF9E Fling on its third pass over104E Netherania (opposite side of Kerbin from KSC) after 2.5 circuits of the equator, commencing from KSC.
 

 

Fuel exhaustion finally occurred at 138.2E, equating to 2.59 circuits of the Kerbin equator and a total distance covered of 9,768 km.

 

That's the good news.  (And hat's off to @QF9E...)

 

The other news is that the few samples I took, as I checked in on this long-running test flight, indicate that an earlier leg-up from initial cruise to the final cruise at 13 km (and even then higher) -- indicated by negative pitch -- suggest that this craft could be hand-flown for at least 3 circuits.

 

Spoiler

ChatGPT is not taking my calls at the moment. 

 

[QF9E]

8 hours ago, Hotel26 said:

QF9E Fling on its third pass over104E Netherania (opposite side of Kerbin from KSC) after 2.5 circuits of the equator, commencing from KSC.

That is amazing! I had no idea that my simple design that I did not spend more than about 30 minutes designing (and which I mostly designed for looks), would be capable of that, if properly optimized. Thank you for all the work you put into this.

If I may ask, which mods did you use to design, analyze, optimize and fly this craft?

[Hotel26]

7 hours ago, QF9E said:

If I may ask, which mods did you use to design, analyze, optimize and fly this craft?

Thank you for the entertainment!!  Which, by the way, caused a major diversion for what I had been doing (and which was getting quite 'stale'!).

Thank you also for noting the fuel priority consideration.  I put that to good use.

I'd say "all stock" except I do use AtmosphericAutopilot to somewhat automate the iterative flight testing process.  You can also try using SAS ORB Prograde while flying easterly which works for many craft to 'automatically' fly to a premium altitude.  (I tried it this morning with this aircraft hoping it might automate a completely-optimized test and possibly crack the 3-circuits barrier but no joy.)

I also use PreciseEditor in the hangars which allows fine-tuning of position and angle of parts.^[1]

But in the case of your marvelous craft, the only thing I had to do was tinker with the wing incidence.  In your original, I did not see much incidence if any.  Unlocking the higher altitude, once less heavily fuel loaded, required 4-5 degrees.

I wrote an article about this but, in brief, the KER head-up display will show pitch -- or you can open the Alt-F12 Aero Data GUI in flight and see pitch.  In very near level flight, pitch is equivalent to body AoA and indicates its parasitic drag quite well.

The purpose of wing incidence is to use wing AoA to develop lift whilst still keeping the body (fuselage) incidence at or very near zero to minimize parasitic drag.  This makes a crucial difference and is one of the very early things one must do in developing a design -- to a "finely-tuned pitch".  (Ha ha.)

Which brings me to the craft itself: QF9E Fling.  I shamelessly posted this to KerbalX early in the cycle after a half-hearted attempt to find a publication by you.  Later did discover that you do have a KX account.  I would be very happy if you care to try this version, tune it as you like and then post your own result to KX.  If you do, I'll gladly take my copy down!

Spoiler

[1] let's say you are at what you think is best cruise (for the moment), but you notice that the (body) pitch is +0.7 degrees.  If you return to the hangar and increase the wing incidence by 0.7 degrees, you will effectively lower the nose to the null point and reduce drag, whilst still getting the same lift.  Crucial?!  Of course, what then happens is that your airplane flies better and wants to climb higher and so the wing AoI goes out-of-whack a bit.  So you resolutely tune it again.    Some nameless people just say "plus five" and done and they are almost always right, especially for clawing very high.

But now let's say you have a Panther engine craft that sustains super-cruise at a lower altitude without afterburner, once you get it there; let's further say you prefer that mode to hell-for-leather at high altitude, afterburners all-the-way: you can only tune the AoI for one regime.  That's when you might prefer a fine-tuned AoI.  Generally, 5 is easy to do with stock, though.  (And ChatGPT wryly chimes in here to suggest that sometimes AoI=5 can ruin the appearance of some craft, especially replicas.

I am following your KX page, so I'll take this one down if I see you post your own definitive version at KX.

What makes this aircraft fun & good, after all, is your serendipitous design!  Kudos.

Spoiler

ChatGPT suggests that "Fling" might be a contraction of "flying wing".

Ha ha, that is so far off the mark.  "AI is never going to read my mind, man!!"... 

 

Edited July 3, 2023 by Hotel26

[Watermel00n]

Did some goofing in 0.1X scale.

Spoiler

Also built my most low-tech SSTO yet!

 

[Duke MelTdoWn]

1 hour ago, Watermel00n said:

Also built my most low-tech SSTO yet!

Two months ago I found that I can make it to orbit with 2 Wheesley and a Swivel. My lowest tech design requires General Rocketry + Aerodynamics research (tech level 5; 183 total science) and no facility upgrades. It does not have any decent landing gear though, so touching down in one piece is a challenge.

How about yours? What tech did you use?

Minimalist SSTO I:
https://steamcommunity.com/sharedfiles/filedetails/?id=2968514518