Project G42-200 StarLiner

[Moach]

then again, if its flying someone important, they're gonna have some overkill saftey protocols. (pun intended.) plus the last thing anyone wants is someones remains shipped back in a box, military or not. we prefer not to use UCGO coffins.

do i hear a call for an Air-Force-One repaint within those lines? :lol:

 

[Eli13]

well as nice as that would be.... sure why not?

 

[Fabri91]

I'll bet Raymond Loewy, who designed the livery, would never have guessed what one day would wear it!

 

[Eli13]

His Stute Avanti perhaps? Man i love that car.

 

[Moach]

(...) commercial aircraft don't go into space. The G42 does.

it sure does!

yes - this means i have succeeded in finding a realistic setting in which the G42-200 is capable of SSTO operation! :woohoo:


this pic was taken a few mins after MECO from the test ascent - about 15% oxy remained in the 85k tank... fuel had a little more slack - an excellent result, considering this test launch was for a direct-up ISS shuttle scenario without any actual cargo in the bay...


i reckon this should guarantee the ability to fly the infamous intercept-leg (which allows KSC-to-moon* launch) whilst being fuel-tight enough so that DARTS and external tanks would be needed to pull off such a stunt with a heavy payload :thumbup:

also, the slack in fuel vs oxidizer should also allow something quite unprecedented in space-flight -- the G42 can perform a powered approach and landing :yes: - and quite possibly, taxi itself back to the ramp afterwards :tiphat:

and most gloriously, the launch was done with an 80% fuel load in the main tanks (205k max, took off with ~180k)
this means we can also taxi TO the runway before a flight


i think i'm happy with the engines, now... -finally- that is :lol:

guess now we need those OMS jets

 

[halcyon]

And yet the crew of a submarine doesn't usually wear scuba gear.

Okay, question.
Will the G42 go completely into space? At least to LEO?
From what I've seen, the answer is yes.
The space shuttle also goes into LEO.
They wear suits on ascent and reentry, in case the cabin loses pressure.

And we're talking about space lol.
What does a submarine have to do with it?

 

[Eli13]

I think hes referring to leaks, scuba as a crude comparison to ACES suits. I got what he was saying, as in leaks and human safety.

 

[Moach]

ok, the '42 is now reentry-rated :thumbup:

i have successfully (perhaps not too graciously, though) completed a reentry, descent, approach and landing - following the same test flight i started earlier...

it was NOT a standard reentry, i must say... i'm not quite sure what series of pilot-mistakes
on my end put me in this situation, but it's nice to know that the G42 can handle a "spiral reentry" as i call it... :lol:

i had done this before, and the idea is this - instead of using high AoA to stall 'er and bluntly descend into subsonic flight (which requires heavy RCS correction throughout the descent) i flew a VERY off-course glide path... aerobrakeMFD was showing my impact point somewhere in the amazon, rather than KSC, which i had targeted

but if one turns the ship to almost 90 degrees of bank, all that lift energy is converted into direction change... i did manage to somehow keep it under control (X52 FTW), and did a high-velocity fly-by of the Caribbean, Mexico and other parts of the gulf, before gliding it back to Florida :blink:

the toughest part of the flight involved an ill-advised but survivable 5g turn... nothing the G42 can't handle, but mostly incompatible with space-tourism flights, i guess...

the RCS system was switched OFF as soon as i got any responsiveness from the ACS... i did not have to turn it back on after that

anyways, i got it to stop just around the KSC area... a few more turns to bleed off excess velocity and i went subsonic just over the runway... after i glided her down below 10k, i ram-started the engines and flew it down just like a regular airliner to a very satisfying centerline touchdown



the OMS thrusters are still not installed, tho :hmm:

 

[halcyon]

So the reentry is similar to the shuttle s-turns to maintain a high AoA without skipping out of the atmosphere?

Cool! Maybe I can use GlideslopeMFD on the WIP-1 test.

 

[Grover]

But if we can get attitude hold AP, along with CoG shift, then high AoA reentry will be possible, and not so heavy on the RCS either.

Should be an interesting WIP test, with mostly manual controls, theres sure gonna be variety

 

[Moach]

But if we can get attitude hold AP, along with CoG shift, then high AoA reentry will be possible, and not so heavy on the RCS either.

Should be an interesting WIP test, with mostly manual controls, theres sure gonna be variety

yeah, i tried the high-AoA approach first... but it seems impossible without being able to throw the CoG towards the back, or would require unreasonable amounts of RCS thrust (i've even considered a pitch-booster as an option)

but flying this "G-turn" pattern (it does look like the letter 'G') seems to suit the G42 rather well... :thumbup:
i wonder if there would be enough mass left in the tanks to throw the CoG far back enough for a "blunt" reentry to work, anyways... :hmm:

 

[Grover]

90* AoA is no good, you descend too fast for a "tiled" heatshield to cope.

and ive done the theory, and a high AoA re-entry is the best option, if you plan to simulate hull heating accurately.

the problem with having a low nose, is that you create a narrower shock cone in the air, and the heating effect is greater on the hull. if you pitch up, creating more of a blunt body (and larger exposed surface area) the shock cone is much wider, and heating is more concentrated on the air, not the hull, meaning that you can afford to have the less efficient heatshields like those found on the shuttle, rather than the much heavier ones that would otherwise be needed in the nosecone.

put short: high AoA= better for realism and cost-efficiency (if you're bothered about that)
low AoA, you'll need to sacrifice a lot of realism for super heatshields

CoG shifting is definatley needed, and anything else you can come up with to hold the nose up, without sacrificing stability of course

 

[HarvesteR]

i wonder if there would be enough mass left in the tanks to throw the CoG far back enough for a "blunt" reentry to work, anyways... :hmm:

Hmm, interesting point here... CoG shifting on reentry requires the ship to be packing, well, basically ballast during reentry... not optimal, indeed.

You can't rely on using whatever is left of propellant mass for that... too inconstant, sometimes there may be 20% left, sometimes none at all...

And having some kind of special CoG-ballast is ridiculous, really... It's hard enough getting the important stuff up there.

I guess that leaves two options... one is some kind of elevator-trim-on-steroids, to force the nose up... the other is a very nicely contructed heat shield to go in head first...

Since you got the visor already, it COULD in theory be heat shielded enough to survive a low AoA, or even zero AoA entry. (those are very fun to do, in fact. Once, I was on fire up until 700m/s2 :lol

The ship, while streamlined, has quite a big enough cross section to provide the much needed braking power there...

IDK... your choice really... or "people's choice", depending on the amount of peer pressure here :thumbup:

Cheers

 

[Moach]

90* AoA is no good, you descend too fast for a "tiled" heatshield to cope.

and ive done the theory, and a high AoA re-entry is the best option, if you plan to simulate hull heating accurately.

the problem with having a low nose, is that you create a narrower shock cone in the air, and the heating effect is greater on the hull. if you pitch up, creating more of a blunt body (and larger exposed surface area) the shock cone is much wider, and heating is more concentrated on the air, not the hull, meaning that you can afford to have the less efficient heatshields like those found on the shuttle, rather than the much heavier ones that would otherwise be needed in the nosecone.

put short: high AoA= better for realism and cost-efficiency (if you're bothered about that)
low AoA, you'll need to sacrifice a lot of realism for super heatshields

CoG shifting is definatley needed, and anything else you can come up with to hold the nose up, without sacrificing stability of course

yes, i am aware of that... perhaps i should try the high-AoA again, this time with a shallower angle - i might have come too steep at first, which would explain my inability to keep the some up :facepalm:

the CoG-shift thing should definitely help, i guess :roleyes:

---------- Post added at 11:47 AM ---------- Previous post was at 11:37 AM ----------

Hmm, interesting point here... CoG shifting on reentry requires the ship to be packing, well, basically ballast during reentry... not optimal, indeed.

that was my main concern...

I guess that leaves two options... one is some kind of elevator-trim-on-steroids, to force the nose up... the other is a very nicely contructed heat shield to go in head first...

Since you got the visor already, it COULD in theory be heat shielded enough to survive a low AoA, or even zero AoA entry. (those are very fun to do, in fact. Once, I was on fire up until 700m/s2 :lol
(...)

well, we must keep in mind that the G42 would not be heat-shilded with TPS tiles like the shuttle... c'mon, who would pay billions for a ship that can't even take a little rain? :lol:

and those are WAY too high-maintenance for a ship like this... remember, with 85 meters across, the G42-200 is more than twice the size of the shuttle orbiter, can you imagine how many tiles that would take? :blink::uhh:

i figure something like this would have more advanced composite shielding... something more like the SKYLON would use :hmm:


so if you remember that whatever heat-shielding is used, must also cope with the abuse of scram-ascent, it's not THAT unreallistic to fly a nose-first reentry with this ship...

i wouldn't try that on the shuttle with a gun to my head, though :rofl:

 

[HarvesteR]

Nice! Nose-first reentries are a lot of fun!!

Just by locking a target attitude on AttitudeMFD, and playing around with the elevator trim, you can pretty much land on a dime, every time.
Plus, you get to see those nice flames pretty much all the way to the runway :lol:

Hmm... new idea here:

If the ship is capable of powered descent/landing with whatever is left of fuel after reentry, we need a new mechanism for restarting the turbines in-flight...

I don't think a starter motor is a lot of fun though... And they're a needless heavy thing most of the time... so why not use the wild rush of air outside to do the same job?

Something like a ram air powered turbocharger, to spin them blades up

That would allow the engine to spool up very fast, and basically kick start the engine...
And it would create some fun mechanics where you need external starter power on the ramp, and engine spool up time kinda depends on airspeed.

So you flick a switch, and a small door opens up near the engines... air rushes in, and makes the turbines spin... then you throw some fuel in there, light the candles, and off you go.

Remember, this is all during sub-sonic, or at most trans-sonic flight, no need to worry about blowing the ship apart with this... Hmm, Actually, it should be quite the fun little breaking point if done wrong :blink:


Cheers

 

[Moach]

If the ship is capable of powered descent/landing with whatever is left of fuel after reentry, we need a new mechanism for restarting the turbines in-flight...

i not only have considered this, it's actually done already :lol:

the engines have a ram-start feature, this is mostly automated, but there's a switch on the overhead panel marked "starter source" or something, where you can select "bleed" or "ram" ("auto" in the middle), this allows the engines to be started in-flight using the ram-stream to spool up :thumbup:


if you try this while supersonic, the ship blows up

i've not programmed this ATM, but then, neither have i programmed any of the startup procedures... for now, you just flick the switch to "start" and blast away...
in WIP-2 this will not be so easy... there are fuel pumps and an APU to get running before the engines will even budge

 

[HarvesteR]

Nice! that's efficiency right there! a feature implemented BEFORE the actual request :thumbup:

Hmm, I guess then the cockpit will need an indicator of when the ship is too fast for some operations... maybe mark these flick-and-die switches with some kind of notation to indicate that flicking this while that big red "supersonic" light is on, will kill you

Cheers

 

[Moach]

i figured unless a "master override" switch is engaged, the ship would try to foolproof itself against unadvised pilots.... then whenever an impossible and/or deadly operation is toggled (like gears down during reentry or alike), the "fault" light (which most switches have) comes on indicating that whatever you're trying to do is not gonna happen :lol:

which gets me thinking.... where should i put that master-override switch? :hmm:

 

[jangofett287]

Out of view. Maybe overriding the system will require you to push several breakers and override key-switches under several hidden panels all over the VC. Or you could just put it on the engineers armrest, hidden just below the cup holder, out of view but in easy reach. But if it is going to be just one switch, It should defiantly be on the engineers side.

 

[Moach]

i think something like that should be in easy reach for both the pilot and engineer... it is the type of thing you'd wanna use in a hurry...

shouldn't be anywhere that you could accidentally "bump into"... i was thinking maybe in a forward-facing panel behind the APU box (far back of the center console) - although that would make cockpit access a bit cumbersome when gravity is "on"... :hmm:

another option would be in a flip-up-covered box somewhere below the forward overhead panel... those are always fun :lol: