Ion Plane Research Challenge

[The_Rocketeer]

@Draconiator I like. Would you be willing to upload the .craft?

[Draconiator]

9 minutes ago, The_Rocketeer said:

@Draconiator I like. Would you be willing to upload the .craft?

Gladly!   Catch: https://app.box.com/s/l7cg30x4a8lzho4k8caycj5fmb1zx5zw

I did it...

[Deddly]

Good job, @Draconiator! I'm looking forward to seeing how you can tweak your design so it works without infinite electricity.

@MoeslyArmlis, Great work! The second video is sadly unwatchable on my tablet so I'll have a look when I have access to my computer. Did you manage to get sustained flight?

[Draconiator]

6 hours ago, Deddly said:

Good job, @Draconiator! I'm looking forward to seeing how you can tweak your design so it works without infinite electricity.

@MoeslyArmlis, Great work! The second video is sadly unwatchable on my tablet so I'll have a look when I have access to my computer. Did you manage to get sustained flight?

Working on that issue now.  I wanted to be sure before I locked horns with this challenge.

[Draconiator]

That didn't take long.

 

[virchau]

Hmmm.... this seems pretty interesting. I might start to test this out.

[Deddly]

@Draconiator - wow, those large solar panels used to rip off with the wind! Amazing plane, well done!

Edited May 6, 2016 by Deddly

[EpicSpaceTroll139]

46 minutes ago, Deddly said:

@Draconiator - wow, those large solar panels used to rip off with the wind!

Are you thinking of the Gigantors? Because Draconiator's using O-Stat XLs I think... But if you are thinking of the static panels, then I'd like to see what you're doing to rip them off!

[The_Rocketeer]

@Draconiator, why carry so much ballast? Back in the Collier Trophy days, the crafts carried almost nothing except control/lift/thrust components (allowing there were a few massless parts used as hardpoints/spacers etc). On the other hand, if it's there as to represent payload then that's cool.

[Jetski]

Looks like around 3000m is the magic number where you can sustain with enough lift.  Now to trim it down so that it can make orbit next

 

[Draconiator]

1 hour ago, Deddly said:

wow, those large solar panels used to rip off with the wind! Amazing plane, well done!

They still do rip off, although only anywhere above 80-90m/s, I just stayed below that speed.

Edited May 6, 2016 by Draconiator

[Deddly]

4 hours ago, EpicSpaceTroll139 said:

Are you thinking of the Gigantors? Because Draconiator's using O-Stat XLs I think... But if you are thinking of the static panels, then I'd like to see what you're doing to rip them off!

He's using Gigantors

[Moesly_Armlis]

14 hours ago, Deddly said:

Did you manage to get sustained flight?

Sustained flight did not happen.  More like very slow falling.

Sustained flight might happen if the craft can get near 3km altitude.  That means a launcher will have to become mobile.

The research into the pin and sleeve bearing is using up a lot of my time.  On the other hand I now have a Bueller on the tarmac. 

 

More details in the trebuchet thread.  The root of this Bueller might make a splash today.

 

[REAPER7]

 

Ion Drone on top of reaction wheels and large wings. Found out if you put enough reaction wheels and rotate it lifts.

This is like the 50th iteration. Most stable config (PM for tips).

Went unstable few times, stopped realigned restarted rotation, got tired at 16k altitude.

Separated.

Turns out drone isnt powerful enough to orbit.

Will try again later.

[Deddly]

@REAPER7, that is really great work! Did you manage to sustain level flight with the drone, and if so, what was your maximum altitude? Looks like you lost a lot of altitude after separating, but maybe that was to build up speed? 

I'm impressed at how high you managed to get the "helicopter"

[REAPER7]

@Deddly , it didnt level out gonna add more engines.

Also gonna try to make it more stable, I separated at nearly 17k, gonna try to push it till it stops gaining altitude then separate.

[The_Rocketeer]

@REAPER7 speaking from former ion SP experience, your spaceplane looks short on lift and heavy on thrust. Back in the day, ion spaceplanes used huge amounts of wing and only 4 or so engines. There was a precise ratio for mass : lift : thrust that was viable, and anything that strayed too far from it would never work. Also by far the hardest part of any ascent was getting from ~20,000m to ~35,000m, because that was when lift started to fall off but drag was still a problem. Of course much has changed since then. Atmospheric heating may also be a problem if you can build up enough speed - IIRC the key to success was to maintain acceleration (at the cost of altitude if necessary) until speed approached orbital velocity, which isn't such a great plan anymore.

[REAPER7]

@The_Rocketeer , how much lift do I need? The probe is 5.66 tonnes and current lift is 7.8*2=15.6

[Archgeek]

 

36 minutes ago, REAPER7 said:

@The_Rocketeer , how much lift do I need? The probe is 5.66 tonnes and current lift is 7.8*2=15.6

Probably more than that.  Here's my recent and inconclusive experiment with hiding the engines and xenon tank in the hollow of a structural fuselage: 

Dragged up about a km using some ditched juno-powered landing gear.  It's not quite maintaining flight (it's losing speed here), but as you can see, it's got nearly 26 lift and only weighs in at around 2.7 tonnes.  There's also the drag to contend with now, so mass:lift:thrust is no longer the whole equation.

[The_Rocketeer]

1 hour ago, REAPER7 said:

@The_Rocketeer , how much lift do I need? The probe is 5.66 tonnes and current lift is 7.8*2=15.6

I'd love to give you a precise answer, but the truth is I'm far too lazy to crunch the numbers in KSP - I leave that to the real nerds

Besides which, any numbers I might have used were based on the old aero model. I'm really just chipping in with pointers here, sorry I can't offer more.

[REAPER7]

@The_Rocketeer, also I think you didnt factor in the fact that I'm launching at 16k not sea level. This is gonna take a lot of R&D.

Maybe I should just use a teleport mod to get it to 16k to facilitate testing. It takes a long time to get up there and I cant even speed up cos it causes too much imbalance.

[The_Rocketeer]

No, I'm realise that, but it doesn't really make any difference to anything except your fuel requirement. [EDIT: What I mean is, actually the places you need/we needed lift most weren't on the tarmac, they were above 20k].

Did u read Go_Slash27's thread (linked by Deddly earlier in this thread)? We had loads of us attempting SSTO runs at about an hour a time. I myself put over 10 hours into the flights alone, and I didn't even get to orbit.

Edited May 10, 2016 by The_Rocketeer

[Deddly]

As Kurt J Mac is so fond of saying, "It's not so much about the destination as about the journey there."

And, @The_Rocketeer, even if you didn't get to orbit, yours were the coolest-looking crafts. That counts for something in my book even if it doesn't show up on the scoreboard.

Edited May 10, 2016 by Deddly

[Archgeek]

More annoyingly inconclusive research results!

'Built another size 0 craft with the same amount of wingage as the structural fuselage test to find out if I was really saving any drag:

Spoiler

 

Roughly the same altitude, speed, AoA, and thrust as before, engines are quite exposed...and it's got quite a bit less drag than the shielded variety.  Well then.

 

Maybe the adapter in front providing the shielding was too blunt?  So, I try again with an empty fuel tank in front, here seen in exploded view so as not to spoof the CoM and with the jet wheel system I've been using to get these things to altitude:

Spoiler

 

Yeah, this thing was just plain unstable, so no in-flight shots were managed, but it liked very much to veer to the right, and seemed to have very similar drag to the blunt-nosed mk1-based one.

 

I think next is to replace the middle wing layer with actual wings and less anemic control surfaces, plus more panels and engines.  There's just not enough fuselage room to get enough lift while keeping the CoL in the right place.

[Deddly]

@Archgeek So does it actually help to have the engines inside the structural fuselage? Sorry I didn't quite get whether it's worth it or not from your post.

As for wings, remember that those little fins you're using can be placed on to each other as well.