Project G42-200 StarLiner

[Grover]

dont worry about it, ill just play with the internet for a while.

cant wait to see the results!

 

[Hlynkacg]

Well you can always cheat on the fuel.

That said yes I was considering using it as a lunch vehicle and perhapse piggy-backing it on a design of my own. (Yes I am one of those player who upon downloading the XR2 immediatly tried velcroing it to an Energia :lol

your best bet, use a series of flights to stack up a trans-lunar vessel... much cheaper than an Apollo-like approach, and you might even be able to use the transfer craft again if desireable

Why do you think I want to know the cargo bay dimmensions? If I'm going to use the G42 to get my lander and modules into orbit I need to know what my max wheight limitations are.

That or I could just cheat and use an xr5 or the scenario editor.

 

[Grover]

And you probably suceeded getting it onto an energia, since the energia can attach any vessel as a payload

 

[Moach]

ok, progress update!

some more detail...

and... the visor!

here you can see how the two panels on top of the nose are retracted, opening up the field-of-view from the cockpit... it's actually a much less bulky piece of hardware than i would have thought... it doesn't even extend as far downwards as the canards housing....

that's a good thing! leaves lots of room for the nose gear, canard actuators and RCS thingies :hmm:

i think so far so good... notice the "wedge" i was talking about just after the upper inlet splitter - not that big a stress point, it just rips through the air, like any other leading-edge surface would :thumbup:

i've already separated the panels that openn up the cargo bay, as you can clearly see...
the nose has been reworked a bit... although that's not in the first picture (see the second one)

 

[HarvesteR]

The inlet splitter (the horizontal wedge) seems alright for hypersonic flight... but what about reentry? will it survive the bashing of mach 20+ air at a 40 deg AoA?

On that note... how is the reentry profile anyways?

Looking good!! I like the overall shape of the nose. Wasn't too sure about it from the 3-views... the mesh looks very clean, and that's always a good thing.

Oh, and I just thought that those canard 'rails', or protrusions, could make an excellent place to have the forward RCS thrusters... like the DG has those bulges on each side of the nose... just extend the leading edge of those rails, and you got a good place for 'em.

you might even have RCS doors there, like the retro doors on the DG... they could open like this ( XY cross section, nose on Z axis):

.   / °°° \  
.  (## O ##)         RCS retracted and covered by paneling
.   \     /  

.  )/ °°° \(  
. ##   O   ##   RCS extended and panels open
.  )\     /(

Cheers

 

[Grover]

not half bad at all. and if that thing flies at about 5* AoA there should be no problems whatsoever with aerodynamics that i can see

will the canards open flat onto the vessels x axis? they should really ne angled downwards so when the vessel pitches up for its Angle of Attack they are THEN level, because when they are used at takeoff, and without any flaps (a delta wing has no need for them) you will be as high as 10* AoA, maybe even 15, and at that AoA, you really want your canards at peak efficiency, not creating more drag than lift

nice work Moach!

 

[Moach]

not half bad at all. and if that thing flies at about 5* AoA there should be no problems whatsoever with aerodynamics that i can see

will the canards open flat onto the vessels x axis? they should really ne angled downwards so when the vessel pitches up for its Angle of Attack they are THEN level, because when they are used at takeoff, and without any flaps (a delta wing has no need for them) you will be as high as 10* AoA, maybe even 15, and at that AoA, you really want your canards at peak efficiency, not creating more drag than lift

nice work Moach!

thanks! :thumbup:
i already have conceived the canards extending at a non-flat angle...
but then, there's really no problem if the canards are only stowed at a flat angle...
when extended, they hinge about their center-of-lift and position themselves entirely at the proper angle...

hence, no need to dwell much on what angle the canards have when closed, since when open, they really don't have any fixed parts - it's like the canards on an EF-2000... the whole things move, not just the trailing edge :hmm:


and indeed, i devised that visor setup with the idea that whenever those things are open, you'd have enough AoA to avoid doom-bringing airflow penetration... not that i'd be a huge problem, tho... as long as you remember to bring them up before going supersonic :lol:

 

[HarvesteR]

Hmm, good point.

Well, they appear to be servo-controlled... so they could in theory auto-trim themselves when deploying, and rotate into the AoA once they're clear of the fuselage.

Moach says it's all fly-by-wire anyways, this would be a simple matter of coding that behaviour onto the control processes (and assuring the canards have a good travel range). (well, for an orbiter craft it just means more work)

Cheers

 

[Moach]

The inlet splitter (the horizontal wedge) seems alright for hypersonic flight... but what about reentry? will it survive the bashing of mach 20+ air at a 40 deg AoA?

On that note... how is the reentry profile anyways?

Looking good!! I like the overall shape of the nose. Wasn't too sure about it from the 3-views... the mesh looks very clean, and that's always a good thing.

Oh, and I just thought that those canard 'rails', or protrusions, could make an excellent place to have the forward RCS thrusters... like the DG has those bulges on each side of the nose... just extend the leading edge of those rails, and you got a good place for 'em.

you might even have RCS doors there, like the retro doors on the DG... they could open like this ( XY cross section, nose on Z axis):

.   / °°° \  
.  (## O ##)         RCS retracted and covered by paneling
.   \     /  

.  )/ °°° \(  
. ##   O   ##   RCS extended and panels open
.  )\     /(

Cheers

that's actually a good idea... but i'm afraid those bulges are otherwise occupied by the canards extension mechanism... not much room there to stuff RCS jets... they'd have to be quite tiny for that... and the G42 is pretty huge...

on the other hand, look at that big stretch of nose between the visors+canards and the heatshield... i bet we could stuff a lot of RCS thrusters in there...

the backwards RCS jets in particular, i had planned to make a bit oversized...
the G42 has no "retro" like the DG... so it would be nice to have a little more power to make corrections without having to turn 'er all the way around - so that calls for bigger-than-usual thrusters...

i have actually devised a way to pack them that doesn't look like it's gonna fall apart... let me draw it up

 

[Grover]

ARGH

nearly had the 100 series into orbit (thought he main tank had to borrow some RCS fuel) but halfway through the orbital sync burn (and dangerously close to the ISS) the tanks ran empty and i became a satalite

so, some suggestions for this one based on my last flight of the WIP:
some method of telling when to switch engine modes, at a simple level, a G meter like that in the XR vessels, or an engine thrust readout. at a more complex level, a projection of the main contributing elements into engine thrust (like dynamic pressure, freestream velocity or whatever) so the pilot can tell whether he needs to go up a notch, or whether he's ballsed it up and needs to abort

second: get rid of the current throttle system where the rocket engines have a system for smooth throttle changes, it just puts off your instruments

make main engines and main tank defines as engine and tank 1, not 2, otherwise orbiter cant use align plane MFD, IMFD etc

increase range (and easiness for noobs) by either increasing total delta-V, allowing bay (auxillary) tanks or making a JATO/RATO extention

put a docking MFD into the rear view VC (that was a nice addition )

and otherwise make the craft handle better under aerodynamic forces, the 100 had a wierd oscillation with pitch and it somehow generates slip all throughout the ascent (about 3*...)


im off now to put it onto a TX and get it to orbit that way... hopefully

 

[Moach]

(...)
some method of telling when to switch engine modes, at a simple level, a G meter like that in the XR vessels, or an engine thrust readout. at a more complex level, a projection of the main contributing elements into engine thrust (like dynamic pressure, freestream velocity or whatever) so the pilot can tell whether he needs to go up a notch, or whether he's ballsed it up and needs to abort

roger, will do! - i already had in plans to make an ascent director instrument of some kind... never really got around to doing it tho... :hmm:
do mind, that being WIP, the -100 has the majority of its flight instrumentation missing.... free time is a scarce resource back here

second: get rid of the current throttle system where the rocket engines have a system for smooth throttle changes, it just puts off your instruments

for rockets it makes sense... as for the remainder of the "stages", a little ramp-up time is expected... the EICAS displays will cover most stuff you need to know to handle that...

on the turbo-rockes, just as when reheat is engaged, the afterburner / rockets should have no delay on response... as long as you have your fuel pumps on and nominal fuel pressure...

the afterburner is affected by turbine RPM a little more on airbreathing mode than it is on rocket mode, tho... this is normal due to the hybrid nature of the RT-66 engines

make main engines and main tank defines as engine and tank 1, not 2, otherwise orbiter cant use align plane MFD, IMFD etc

that's probably a good idea... the '100, last time i checked, had a little buffer tank as tank 1... prehaps i should leave that one as last, then put the actual tanks "up front" :lol:

increase range (and easiness for noobs) by either increasing total delta-V, allowing bay (auxillary) tanks or making a JATO/RATO extention

DARTs (Disposable Auxiliary Rocket Thrusters) are already in plans - they are to be fitted behind the ramcaster exhausts for takeoff, and should make for one hell of a ride :headbang:

put a docking MFD into the rear view VC (that was a nice addition )

there's gonna be a panel with at least 2 MFD's there - that's a definite will-do

and otherwise make the craft handle better under aerodynamic forces, the 100 had a wierd oscillation with pitch and it somehow generates slip all throughout the ascent (about 3*...)

yeah, i know, it's unstable like jello nailed to a wall... that's what you get when flying a delta-wing without rudders at mach >5 with off-axis thrusters as well...

even with the supposed fly-by-wire... it would not have been realistic to make it any more stable... hence, the departure to a more coherent design, the '200

im off now to put it onto a TX and get it to orbit that way... hopefully

good luck with that, i'll have beer now

 

[Grover]

well, i got the G42 up, but i had to ditch the Tx somewhere on the east coast of USA

the G42-100 is hard to re-enter without any autopilots, but i managed it, with some overshoot landing wasnt too bad, but two things came to my attention:

pressing j moved the CoG further back, but so does the K key. so although your instruments may say your CoG is centered, it isnt. this also causes the thrusters to move, (see point 3) which gives your engine exhausts about 10 m behind the vessels mesh

i get a wierd bug whereby the view sometimes changes when i go grom glass cockpit view to VC view, putting the veiwepoint well behind the pilots seat, so youre a good 20 yards from your flight instruments. (this is probably due to the CoG shift bug)

finally, there are hover thrusters on this, which act as main engines, and take fuel from a mysterious 4th tank (i think its the oxidiser) but not the main propellant tank :hmm:

i only give these bugs from an obsolete version in case you copy the coding straight over from the 100 to the 200, and from what ive seen so far: its best to leave the old one and start afresh

thanks moach!

 

[Moach]

well, i got the G42 up, but i had to ditch the Tx somewhere on the east coast of USA

the G42-100 is hard to re-enter without any autopilots, but i managed it, with some overshoot landing wasnt too bad, but two things came to my attention:

pressing j moved the CoG further back, but so does the K key. so although your instruments may say your CoG is centered, it isnt. this also causes the thrusters to move, (see point 3) which gives your engine exhausts about 10 m behind the vessels mesh

i get a wierd bug whereby the view sometimes changes when i go grom glass cockpit view to VC view, putting the veiwepoint well behind the pilots seat, so youre a good 20 yards from your flight instruments. (this is probably due to the CoG shift bug)

finally, there are hover thrusters on this, which act as main engines, and take fuel from a mysterious 4th tank (i think its the oxidiser) but not the main propellant tank :hmm:

i only give these bugs from an obsolete version in case you copy the coding straight over from the 100 to the 200, and from what ive seen so far: its best to leave the old one and start afresh

thanks moach!

you've stumbled onto a nice boatload of bugs and unfinished business of mine there :lol:
yeah, about that C-G shifting feature... that's all messed up... my advice is to not use it until i get it straightened out... lest all sorts of mayhem ensue...

i remember there is some VC bug too... can't recall how it was caused, but anyways, hit TAB to alternate the cabin mode and back, that should fix it for now...

she is a handful to reenter... it's got way too much lift... i suggest you fly a skip trajectory with the '100... as it's got some serious overshoot issues otherwise...

the '200 has the folding wings, and can bring them up to dump some deflection lift for reentry... i'm still working on that. tho


well, for sure, you have discovered the true meaning of WIP :lol:
that's what we get for having almost no free time at all to pull off stunts like coding a G42 :facepalm:

surely, that whole "sleep" thing has gotta go...

 

[Grover]

i think the VC problem was linked to the COG, for two reasons:

it wouldnt go away with teh Tab switch (and both views were messed up)
it got worse as i moved the CoG further away

make sure you fix that got the '200, maybe rather than moving the mesh, just change the coding to shift the Center of lift?

 

[Moach]

(...) maybe rather than moving the mesh, just change the coding to shift the Center of lift?

yeah, that was my first idea, but somehow, one thing is strangely tied to the other... not too sure how that goes... maybe we could ask Martin, he might know :hmm:

 

[Grover]

is anyone does, its him.

 

[Moach]

alright! - today's fun: the variable wings

takeoff configuration:

a mild dihedral is added to gain a little stability, but mostly the wings are kept as flat as possible for maximum lift area



hypersonic config:

visors up 'n wings down! the shockwaves from the body under the wings are deflected by the downswept surfaces, creating compression-lift at otherwise uncooperative mach numbers :hmm:


reentry config:

wings go up to minimize the deflection lift effect, this setup should also create a shuttlecock effect, reducing the heat load and increasing stability (or so i read...)


i have yet to figure out how to deal with the gaps between the wing sections... i'd bet that would not be compatible with a safe reentry after which the ship and crew can be reused...
some sort of extendible shielding is required, for sure....

after the worse of the reentry is past, the wings can go down again, allowing the G42-200 to glide down onto the runway for a nice landing...

then a tug would hopefully be on standby to "taxi" 'er back to the ramp... :thumbup:

 

[Grover]

do those last two renders show the visor in its raised position? thats what i had in mind: a seamless nose section

a safe reentry after which the ship and crew can be reused...

:rofl: <-- all that needs to be said

and ive decided that the tug shouldnt really be needed, since if the main engines work with just the jet part (no AfterBurner) it would be damn efficient, and you wouldnt need to play with any addons, of course, it would always be added later in a post-release.

and i stil believe that External Fuel tanks (expendable) would be a great idea for the newbies (like me) to practice with and/or make trips to higher orbits.

finally, whats the software that you've used for your plan drawings? it looks pretty nice

thanks Moach

 

[HarvesteR]

I believe you will need some sort of fairings or canoes on those wing pivots...

This wing twisting business probably calls for some great big heavy hydraulics and linkages, and it would make more sense if they were housed in a mid-wing bulge.

this bulge would serve a number of purposes, first, it would house the pivoting mechanism. second, it would protect it from hypersonic abuse, third, it would simplify a lot the meshmaking process, since you can hide the spot where it looks ugly :thumbup:

I envision something like this:

As you can see, the pivoting mechanism is mostly contained in the main wing. But it's protruding sections are safely covered by the "bulge".

Cheers

 

[Grover]

a fine idea! perhaps it could also house a backup electrical system for deflecting the wings.

i also had two good ideas when playing with my new base:
put a local light source in the top of the cargo bay, to illuminate your docking target (and possibly one inside the cockpit so you can see the controls on the dark side of the planet)
size the cargo bay to accomodate UGCO, whats the point having teh cargo bay if you cant put stuff in it. (you can then consume fuel from cargo to increase range)

ill keep on churning these ideas out... maybe i should write them all down