Hooligan Labs

September 17, 2012

Well, I made the "Cat Bus" (see signature), but I'm confused how docking works here. Mods?

September 17, 2012

Hooligan labs, I like your octopus a lot and thanks very much for a great video which gets to the point and shows off the capabilities of the very purposeful looking Cat Bus 4, but even as I am thanking you for that I am sorry to have to point out that both bottom engines were knocked off and exploded when you landed on Kerbin, luckily noone was injured however you must not have realised that brave attempt though it was it does break one of the cardinal rules of the K Prize that you have to land the craft intact to have a 100% reusable craft. Which leaves me with the troubling task of describing to the bouncers why someone of your undoubted standing in the community is on the gate crashers list! Sorry if you have a save you could reload and try the landing again. Your word will be good enough and then you would be entitled to the kudos your otherwise excellent piloting skills certainly deserve.

The collision detection of Tordial Aerospikes is silly! I re-read the rules and am sorry, would a quick loop of the planet and a landing be sufficient or should I redo the whole thing? Whatever gives 100% credit.

September 17, 2012

My condolences on Jeb. Once the family is done grieving, talk to his brother Jeb, also an excellent pilot.
And thank you for the applause; the experimental measurements have three major advantages over the parts file. First, they allow those who look at the code to see the actual math involved. Second, they don't care how many engines of what specific impulses you have on rocket. Third, they are _actually_ accurate within a reasonable margin of error... unlike the Parts file in 0.16, which lies!
For example, an LV-T45 on a rocket starting the test at approximately 13.3 tons:
At thrust: 10% Isp is: 3490.6740910247
Used 0.407934188842773 kg fuel, for 1.05126962080158 DeltaV, or 2.57705691151756 DeltaV per kg fuel and 1.40169282773544 DeltaV per second
At thrust: 20% Isp is: 1797.90199416966
Used 1.45530700683594 kg fuel, for 1.9319236255069 DeltaV, or 1.32750245579261 DeltaV per kg fuel and 2.57589816734253 DeltaV per second
At thrust: 30% Isp is: 1215.11984362804
Used 3.66973876953125 kg fuel, for 3.29362980189717 DeltaV, or 0.897510697285376 DeltaV per kg fuel and 4.39150640252956 DeltaV per second
At thrust: 40% Isp is: 903.884828955461
Used 6.70003890991211 kg fuel, for 4.47590106928692 DeltaV, or 0.668041056099723 DeltaV per kg fuel and 5.96786809238256 DeltaV per second
At thrust: 50% Isp is: 725.654721031727
Used 10.1935863494873 kg fuel, for 5.47232665973979 DeltaV, or 0.536840173038317 DeltaV per kg fuel and 7.29643554631972 DeltaV per second
At thrust: 60% Isp is: 608.021967457222
Used 14.2822265625 kg fuel, for 6.43367939469454 DeltaV, or 0.450467535054168 DeltaV per kg fuel and 8.57823919292605 DeltaV per second
At thrust: 70% Isp is: 521.458302751379
Used 20.519495010376 kg fuel, for 7.94516284354404 DeltaV, or 0.387200700578959 DeltaV per kg fuel and 10.5935504580587 DeltaV per second
At thrust: 80% Isp is: 460.325639631327
Used 26.8013477325439 kg fuel, for 9.1855244198191 DeltaV, or 0.342726213304021 DeltaV per kg fuel and 12.2473658930921 DeltaV per second
At thrust: 90% Isp is: 410.633801563746
Used 33.0276489257813 kg fuel, for 10.1319807593941 DeltaV, or 0.306772691636706 DeltaV per kg fuel and 13.5093076791921 DeltaV per second
At thrust: 100% Isp is: 370.224071690755
Used 41.8767929077148 kg fuel, for 11.6319489877646 DeltaV, or 0.277765993527688 DeltaV per kg fuel and 15.5092653170195 DeltaV per second

Can you break that down for us?

That looks a lot like the v0.16 fuel bug. Are you running the fuel bug fix?

... What?

September 17, 2012

Here is my submittal for the K-Prize, a single stage spaceplane that goes to the Mun and Minimus without any mods!

September 16, 2012

You can easily calculate the I_sp by looking at the part files.
For small SRB: I_sp=442s
For large SRB: I_sp=204s

Yes, but Nadrek is looking to experimentally prove it, which I applaud!

I'm playing without mods at the moment, so I did another test... Looks like the air resistance theory was right. Bad news is, we've lost Jeb.

September 14, 2012

Thanks for the spoiler explanation! Yes, I was able to attach the pictures no problem. However, it says that .xlsx files are not permitted.

September 13, 2012

Here is my test craft! Need to learn how to wrap this stuff in spoiler tags on this forum...

[ATTACH=CONFIG]32872[/ATTACH][ATTACH=CONFIG]32873[/ATTACH][ATTACH=CONFIG]32874[/ATTACH]

It can make it to about 97km at 1000 m/s. No where near capable of even going to the moon.

And thanks for the tip Ziff. Maybe part of the problem is that I'm going 500 m/s in atmosphere.

Darn, it won't let me upload the excel sheet I've been using for calculation. :sticktongue:

September 13, 2012

You need about 4500 m/s to get into Kerbin orbit (without overspeeding).
It sounds like you are forgetting some mass in your calculations.

Yes, and the delta v was calculated here as over 6000 m/s?

You would know, weren't you one of the original authors of the tutorial?

Edit: As an example, this morning I built a ship with 6 trashcans, a '16 fuel tank and an aerospike. I took all the parts into account and still had a delta v of over 9000 m/s. However, when I went to fly it I couldn't even fully achieve orbit with it.

I would link the excel file, but I appear to be not yet allowed attachments.

September 13, 2012

Thanks to everyone for checking my calculations! This is a very useful tutorial, I use it to check my ships now before I fly them. It helps check for glaring problems with efficiency.

My problem is when I try to actually use SRBs to get somewhere. The spaceplane I have been working on uses 5 aerospikes (same ISP in and out of atmosphere) and can reliably get to the moon, land and return. It calculates to ~6000 m/s, which is significantly less than the 7000 m/s recommended by the tutorial but hey I'll just say I'm an awesome pilot.

So I re-calculated with a rocket assisted takeoff (still single stage). Suddenly it seems I should easily get over 7000 m/s! However, if I build the same plane but with SRBs, fire all rockets and aerospikes, and get out of atmosphere.... I actually have less fuel than if I did not bring the SRBs! Same thing happens if I take off, go vertical and then fire the SRBs.

As a final check, try taking off nothing but a few SRBs. You might calculate as having enough delta V to go to the moon and back, but you actually will have just enough to leave the atmosphere.

Anyone want to double check my findings in-game?

September 13, 2012

If you take the delta V equation from here....

http://kspwiki.nexisonline.net/wiki/A_Guide_to_Basic_Kerbal_Rocket_Design_Through_Rocket_Science

... You would think that the trash can o' boom was the most efficient thing. However, if you try to actually fly through space with them it doesn't work so well.

I'm not talking about the inability to throttle them, I am just curious if solid fuel needs to be calculated differently when it comes to determining its performance.

Update: It looks like the issue was with too much drag from high velocity at low altitudes:

September 11, 2012

Ah! over 50k club finally !
Using that double engine trick helped get a huge boost at the start, however the fps are crippling with this ship.
It runs less than 1 fps on the launch pad with a stock i5 2500k. Also mid flight.. parts seem to fly off at around 10k but it's hard to make out.
Also I can only seem to get 1 in 6 launches off as it explodes most of the time .
http://imgur.com/a/dTD9J

Yeah, as you can see from my video the FPS dies pretty quickly.

But you have to get your weight and drag down! Until someone comes up with an even more radical idea than literally jumping out of your ship for extra height (thanks Nao!) there is nothing more important than your thrust to weight ratio. It does not matter how many engines you have if everyone one is weighed down by structure.

September 10, 2012

Using iplop's idea of double mounting engines i managed 52,8 km with capsule and 55.262m with EVA boarding again at 17km.
Craft design is roughly the same , just double number of engines, also somehow its easier to place tanks near each other with engine inside , one more trick i used is making pod be shot upwards at decoupling with the engines giving me extra speed (not much thou, probably 100-500m more). EVA burn upwards is only 25s rest is getting into the craft, so there is a room for another ~1km with perfect EVA , and maybe other pod (with drag of 0.1 - the same as Kerbals)
3 more pics: http://imgur.com/a/fyKgE/
Magic turbines are awesome thing indeed but for me they feel like cheating, so ill not use them, still impressive results
The problem with parabolic or even more space-plane approach is in current designs drag is still number one energy drain, going more horizontal will just increase drag (square of velocity) even if we get savings on weight due to lift (low craft weight - low effect of wings) or centripetal force (linear gain from orbital speed).
Also the EVA part of my flights is really pumping adrenaline for me haha <3 KSP.

Holy Kerbin Batman, you are making this look routine. :cool:

I'll have to edit the front later, got to go now... Still, you should video this. Good free recorder: http://www.d3dgear.com/

September 10, 2012

I think now is a good time to turn this into a thread about magic turbines.
Max altitude: 261334 m
Fully stock, and craft file included. Just trim roll controls left as far as they can go, spool up the jet engine, and release clamps.

I'll put you on the front, but I can't give an award for something so utterly blatantly physically impossible.

50,492m! : D
The rest of the pics: http://imgur.com/a/vcClj
The craft file is pretty much the same as the last one only every fuel tank is double stacked with jet engines(one more half-size fuel tank added as well).
Edit: Here's the craft file if anyone wants it: [ATTACH]32754[/ATTACH]

iplop, you have not only beat your own height, but also the crazy Fooly Coolyness of Nao, who apparently can get back into a free falling cockpit in atmosphere. There is some pure crazy in this thread!

September 9, 2012

I'll have to revise my design. O.o
Anyways, 45,485m altitude
Turns out fins for helicoptering down are lighter than a parachutes.
Edit:
49,002m altitude!
The ring of engines near the center are double stacked (engines mounted on the top + bottom).
Emptying the tanks:
Hairy landing; my fins broke:
The ship file: [ATTACH]32700[/ATTACH]

Wow, those wings seriously are lighter, aren't they... though the real trick was landing using just the canards, I've only done that a few times in truely desparate situations and did not think of using them as the only safety device! You are winning the stock challenge now.

Highest I got was 43 Km. When I add more jets to my design it gets out of control at a certain height.

Yeah, an Advanced SAS is pretty much manditory for this.

Using something like Neo's I made it 48.75km, I kept adding to get the result below but even with <1L of fuel left in the tanks before you drop off in climbing speed I was still under. Seems more jets does not work :~(
Next step is multiple stages maybe
http://imgur.com/uf9pN

What a monster! Not sure how multiple stages would help... The purpose of stages in normal rocketry is reduce weight by throwing out empty fuel tanks. Here we should be should be using every fuel tank to support as many thrusters as possible, to maximize thrust to weight!

September 9, 2012

Here it is! http://kerbalspaceprogram.com/forum/showthread.php/15348-0-16-Spaceplane-parts-rescales-edits-and-additions?highlight=ramjet

Ah yes I've tried that myself, the credit is yours.

iplop, nice distance! It's interesting how you stacked using the jet cooling part, I have not seen that before. I put you on the first post too.

September 8, 2012

Challenge Completed...
Rocket Design
Engine Shutoff
Apogee
Had to use a ramjet mod but it's still air to space.

Great work! Link me the mod, I'll check it and give you credit.

Fendleton, I'm giving you the "Insane Crash" award! Such improbable physics certainly deserves recognition.

September 8, 2012

Does this count?
I went straight up 'till I reached ~26k m, then used RCS to do the rest.
Unfortunately I wasted 4 RCS tanks trying for orbital insertion. It could definitely go higher.
That was a really lazy build. Other folks can definitely do better.

That is some great height! But I amended the competition to specifically exclude RCS thrusters, that competition has already been done.

September 8, 2012

You should only use the jets that you have in the middle there since the outer ones don't work anywhere near as good high up. Also the air intakes are dead weight.

Yes, especially since the turbofans have 50% more max thrust. http://kspwiki.nexisonline.net/wiki/Turbofan_Engine

September 7, 2012

If I am reading this correctly, the requirement is not 50 m altitude, but 50 m downrange.

That's difficult considering that the launch pad and runway at the Kerbal Space Center are at ~65m altitude.

September 7, 2012

I've done it before in this. RCS rocket challenge

Welp, I'm impressed! I thought those little gas thrusters had more to it than it seemed.

Is the best strategy here to go straight up so that after your air-breathing engines give out, you have to coast through the least amount of atmosphere?

That is my theory. Possibly, you could go horizontal, gain speed and then go vertical. You would not only have more momentum, but your engines may work longer because they would be drawing in air at a faster rate. However, controlling such a monster could be frustrating to impossible.

September 7, 2012

What about rcs? That should be excluded.

If you can get into space using RCS, I will be VERY impressed.

September 7, 2012

My best rocket can get to 39.3km.

If I Eva I can get to this

How does your rocket launch off so fast at the start?

I am using a few tricks to get to max speed...

First, light as possible! As of the current version, 1.6, you do not need air intakes for jet engines to work. Of course, you can't improve air flow with better intakes either... But regardless, you can save the weight of that.

Also, I have my engines fire for a while before letting go, same as you have set up. First, this lets them spin up to full power (takes a few seconds). Second, I want to burn at least half of the fuel. This is all about thrust to weight ratio!

Great idea with the EVA! That might work for getting out of the atmosphere! But I'm going to have to get the mod that lets you put a parachute on your Kerbal.

September 7, 2012

I made it to 45 km! Can you make it to the official Kerbal edge of space, 69,077.55 meters?

Many mods do not actually have air-breathing engines for their "jets", and thus would be disqualified.

Edit: Also specifically not allowed are RCS thrusters, that has already been done (see replies).

Any system that does not return the pilot safely to Kerbin's surface is only qualified for honorable mention, as surviving pilots will be able to brag much longer.

Awards thus far!

Greatest Height without Mods: Nao spacewalked to 55,262 meters, getting back into the ship though nerves of steel and a mind of madness! http://kerbalspaceprogram.com/forum/showthread.php?p=261670#post261670

Second place: iplop has made it to 50,492m, beating my greatest height and surviving!

Greatest Height with Mods: Cooly568 at 89,015 meters with a very nice mod pack: http://kerbalspaceprogram.com/forum/showthread.php/15348-0-16-Spaceplane-parts-rescales-edits-and-additions?highlight=ramjet

Honorable Mentions

EVA FTW: eppiox at 48,488 meters (no survivors)

Insane Crash: Fendleton with magic canards at 272,239 meters. lucidLemon following with 226,000m.

September 7, 2012

I submit this wackiness, successfully clearing... about the length of a runway!

September 7, 2012

I think this is a fine proof of concept, especially since it was done only with stock parts! Hoping for new options in 0.17.

This is also to get attention to the lack of engine glow! It works on my laptop but not my PC.

Edit: However, Kerbin's atmosphere officially ends at 69,077.55 meters. However, given that Kerbin's atmosphere gets exponentially less dense as altitude increases (5 km scale height) and density == 1.2223*exp(-alt(m)/5000), the density is only 0.0001508438 kg/m3 at the highest point I reached of 45,000 m. That is ~0.012% of the density at the surface, so that's pretty close to a vacuum!

Source: http://kspwiki.nexisonline.net/wiki/Kerbin

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