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Ion glider collier trophy!


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I was quite happy to see it go above 100k apoapsis but then I noticed that I'd get sunlight back before I dropped below 90k and managed to use the remaining fuel to circularise.

Congratulations!

Now do it with a passenger/pilot. :)

Just scale up the vessel until it can carry whatever payload you desire. Might take all night or require a liquid helium-cooled computer, but IT CAN BE DONE!

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Congrats to all the submission in this thread (and of course to MabDeno big time congrats).

I tried myself (without submitting cause I was still far from anything good enough) so I know how hard it can be.

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I've put mine in orbit this morning too.

http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/Voyager%203

74x72 equatorial orbit. The pictures that say "orbit" in the title are of this run.

So now that we've established that, time to do it with a Kerbal on board!

Some thoughts on where we're at now:

Mab Deno's design had more guts overall. It's comprised of 4 engines, 8 tanks, and 32 strakes. a 1:2:4 ratio

Mine is a good deal lighter. 3 engines, 5 tanks, and 20 strakes. 1:1.67:6.67 ratio. The "perfect" proportions are somewhere in this neighborhood.

Judging by MabDeno's result and the improvement I got by reducing my wing panel count in the voyager series, the ideal wing/ engine ratio is closer to 4. Judging from empirical testing, the ideal tank/ engine ratio is still closer to 1.67.

Using this going forward, we should be able to put a Kerbal in orbit.

Rather than lifting a 40kG probe controller, now we're dealing with roughly 200KG of payload.

Best,

-Slashy

Edited by GoSlash27
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Still pushing the envelope manned:

First manned flight to beat 1000m/s, just a shade below 30k.

Flight was sub-optimal again, made a very clumsy high altitude turn that shed a lot of fuel/speed/altitude. Design-wise, this is a step improvement for me, first time I've really beaten the wall.

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I'd like to see some of the successful orbiters modified for manned attempts - after all, what good's a SSTO glider if it doesn't deliver a payload, and what payload could be more valuable than a real live Kerb? It would help me to know where this glider's performance falls in the overall pecking order.

Edited by The_Rocketeer
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I'll be attempting a manned flight next, have to find a suitably brave and stupid Kerbal first though.

Slashy: A ratio I've been looking at is the lift rating to mass ratio. Most of our designs have been around the 8.5 - 9 lift per T, any more than that just seems like extra weight and any less wont get the ship high enough before the sunlight runs out. The thrust to weight ratio of around 0.3 seems to be quite a common trend too.

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Still pushing the envelope manned:

First manned flight to beat 1000m/s, just a shade below 30k.

Flight was sub-optimal again, made a very clumsy high altitude turn that shed a lot of fuel/speed/altitude. Design-wise, this is a step improvement for me, first time I've really beaten the wall.

I'd like to see some of the successful orbiters modified for manned attempts - after all, what good's a SSTO glider if it doesn't deliver a payload, and what payload could be more valuable than a real live Kerb? It would help me to know where this glider's performance falls in the overall pecking order.

Congratulations on clearing the 1K hurdle. 30KM is just around the corner.

The current unmanned designs probably won't be successful by slapping on a command chair, but they have created a knowledge base to build on. It's just a matter of scaling the same concepts enough to cope with the drag and mass of a kerbal.

I'm sure MabDeno will take point on this effort and I will be happy to provide tech assistance, but my back problems are limiting my ability to fly a lot of attempts. I will still do what I can and pass on what I learn and (of course) keep the leaderboard in order.

Best,

-Slashy

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I'll be attempting a manned flight next, have to find a suitably brave and stupid Kerbal first though.

Slashy: A ratio I've been looking at is the lift rating to mass ratio. Most of our designs have been around the 8.5 - 9 lift per T, any more than that just seems like extra weight and any less wont get the ship high enough before the sunlight runs out. The thrust to weight ratio of around 0.3 seems to be quite a common trend too.

I concur. .34 t/w was a minimum set back in the .24 KSP by Tsevion and it still seems to hold up pretty good. The old lift/ mass seemed to be closer to 20:1 with the old swept wings, but the reduced drag numbers of the strakes have reduced that a lot and they *may* have also reduced the minimum t/w ratio.

Best,

-Slashy

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Ratio data are interesting, I had begun to draw up a comparison table for my trial-and-error designs but now I can skip ahead to hypothetical builds and be a bit more scientific.

I forgot to say before, the last attempt was the "Shrike II". Cutting out those solar arrays seems to have made most of the difference - can't believe I missed that!

Edit: Also, I think a commemorative sig badge for successful orbiters in this challenge would be appropriate considering the difficulty. I'm not much of an artist tho. Anybody know someone good?

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OK after duct taping a command seat to the double dart I have achieved a height of 37,000 at about 1500m/s.

I ran out of fuel before the sun went down so logically I strapped another engine and 8 wing strakes to it and sent it up again. This got me to 36,000m at 1500m/s and ran out of fuel with alot of daylight to spare so 1 extra fuel tank might get somewhere.

Current craft has: 1 kerbal, command seat, small reaction wheel, battery, 40 wing strakes, 5 engines and 8 fuel tanks.

At nearly 500 parts its starting to tax my computer a bit too so I'm not too sure I can complete this.

BTW does anyone know how much drag a Kerbal has?

Edited by MabDeno
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BTW does anyone know how much drag a Kerbal has?

I was trying to find that out yesterday, but no luck. I may have to do a drop test to find out.

*Edit* According to my drop tests, kerbals have extremely low drag.

Best,

-Slashy

Edited by GoSlash27
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BTW does anyone know how much drag a Kerbal has?

No. The persistent.sfs has no entry for Drag that I can see.

However, you can test for comparison by jumping out of a (relatively) slow falling rocket at low altitude (praise be to the Kraken!). If the Kerb had more or less drag than the rocket, it should fall slower/faster. I haven't specifically tested this, and off the top of my head I can't remember whether there's much difference or not.

On another note, you guys were running East into orbit, right?

I ask because I tried to make a benchmark test running due west for maximum solar exposure, but actually got a worse result than my record run with the crappy turn. Since I'm measuring surface speed and not orbital, I would have expected a nice linear push to be better, but it seems not.

I'm wondering if on these very lightweight crafts, and low speeds and altitudes, if I'm just experiencing a very noticeable Oberth effect? My other guess is that turning causes a very small amount of infiniglider-thrust from the tailfin surface.

In any event, all the more reason to run East!

Edited by The_Rocketeer
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YERTLtest_zps280baf90.jpg

This is what I'm working on at the moment: Project Y.E.R.T.L. (Yield Evaluation Reactive Thrust Launcher)

The pilots call it "Yertl the Turtle" (or that freakin' deathtrap, according to mood).

It's got 3 engines, 5 tanks, and 16 wings. 1.91t and 181 parts.

My first successful run (running out of gas before losing control) was 31,167 @ 1,211.7. I'm sure I can get a bit more out of it, but I'm also sure it won't be going to space today.

Edited by GoSlash27
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Also FWIW the Structural D panel isn't worth the effort.

I ran a head- to- head comparison between the strake and the structural D on an identical testbed and identical profile. I balanced the number of wing panels used to yield the same lift.

The strake was far superior. It made it over the hump and got to nearly 33KM at 1.4Km/sec, while the structural D was only able to muster 28KM at 1Km/ sec flat. The strake also out-performed the structural D in time to climb at both 10KM and 20KM.

So there's that...

Best,

-Slashy

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Latest manned attempt has 5 engines 9 tanks and 40 wing strakes netting 39000m and 1700 m/s. Not bad but I cant see it getting anywhere near orbit soon.

just saying, try to go as small as possible. If possible, try using the command seat instead of all the pods.

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