Project G42-200 StarLiner

[squeaky024]

Okay, i want to read the documentation due to the insane number of buttons on the VC but when i open the doc, click on Flight Operations, it doesn't seem to load.

Another thing you should try is to use Note mfd, I loaded up the checklist on the first page into that mfd and put it on both sides of the vc, it helped me all the way up.

Also I have an issue, i'm not sure if this is a one time thing, but between T2 and T3 on the ramcaster ascent, my engines completely stalled. I have no idea what caused that, and despite numerous attempts to relight the engines they only restarted when I fell back down to the T2 point on the ascent profile. Could it be that I drifted slightly out of the ascent profile as I'm searching the vc preparing for the rocket phase?

 

[Grover]

either you fell out of the envelope, or you accidentally hit a critical switch, most likely (due to the failure to relight) you were at the bottom edge of the envelope, and drifted out of it, so you were too slow to use your ramcaster effectively, so you slowed down even more.

in that case, you should drop down a stage (ramcaster HI>LO or LO>turbofan+AB) and descend a little bit, then fly level into the envelope, hit the centre of it and carry on climbing!

 

[Luke Skywalker]

and FYI, the flight op manual is on the first page of this thread if you need it

good luck!

Well that's something i didn't notice :facepalm:, i usually read the documentation but this seems better.

Thanks. :tiphat:

 

[Proximus]

Looking good Moach, cant wait for WIP4 :thumbup:

Edit WIP5

 

[Grover]

had a great idea for the systems list:
Automatic burns and orientation

now hear me out on this one, and lets see what we think about this one
first, nice and simple, an automatic burn system, to control precise burns with the OMS (or even rocket engines for emergency de-orbits)
REASON: no MFDs can get a handle on the selected (active) engine
USE: simply program in the dV or burn time, and the onboard systems engage the active engine (the one controlled by the joystick throttle) for the appropriate thrust and time
BENEFITS: we can finally do precise orbital changes, the way an actual 'naut would, and ties into the second idea of mine:

Secondary attitude system
REASON: makes for more fuel efficient attitude changes, and more realistic control over the craft
USE: select an attitude program and wait for the system to get you pointed in the right direction
BEHIND THE SCENES: RCS fire on full for a short while to increase angular velocity to no more than 2*/s (the shuttle does it at 1*, but i guess we can go higher, perhaps the speed could be predefined in-sim?), and slows down as it enters an acceptable range (no more than 2 or 3 degrees from the target attitude), whereupon the engines work in RCS-Fine similar to the standard orbiter controls, where the maximum speed of rotation is limited severely (say 0.2*/s)
BENEFITS: realistic control, more reliable than the orbiter standard since its ship-specific, uses less fuel per attitude change due to the conservative nature of the program, could be extended to further lengths (like aiming for the "golden zone" where you can burn at full throttle, reducing speed, but nor reducing PeA, useful for that leftover fuel from a lunar mission (which may be possible with this craft given some minor modifications and a fuel stop))


any thoughts? i think its a great idea... but im biased

 

[MaverickSawyer]

Looks like a useful idea, but that's Moach's call.

 

[Grover]

Looks like a useful idea, but that's Moach's call.

especially since its his hard work to code it that would put it in there at all, but now at least he is armed with the choice to do it

 

[Keatah]

While I do indeed like the ongoing work with this add-on, I don't like all the minutiae surrounding the throttle control.

 

[Grover]

While I do indeed like the ongoing work with this add-on, I don't like all the minutiae surrounding the throttle control.

as one of the main controls, its important to get that realistic, since thats where alot of attention is when youre doing actions with this thing (its not ALWAYS the throttles and burns, but alot of it is)

plus, it adds to realism to have procedures to follow when doing burns, and its especially realistic if they're automatic procedures (the real life shuttle pilots dont actually use the throttle lever for burns, just a keypad and possibly the RCS control knob (please correct me if im wrong (Very likely))

 

[Cras]

The Shuttle was all automatic. You entered the guidance, either manually or more likely via MCC uplink, and that data corresponded to a solution. The astronaut only needed then to load the data, execute the attitude adjustment, which was then done automatically by the DAP, and calculated by the GPC, confirm the engine configuration (RCS only, Left OMS, Right OMS, both OMS), activate the coundown timer, then confirm the burn at T-15 seconds. The computer did the rest. If the computer did a poor job with the timing, like if the OPS202 display was showing significant delta v still required on certain axis, then use translational control of the RCS to null those out.

The idea of flying a ship with a throttle, changing orbits by the seat of your pants is all fun and all in Orbiter, but when you start to venture into realistic flight procedures, that has got to be one of the first habits to go. You can already use a mixture of Attitude MFD and Burn Time calc you set up ship attitude and a set burn time, but the math and timing is still up to you.

But I do like both of your ideas Grover.

and Moach, that payload bay texture looks fantastic.

 

[PhantomCruiser]

I just gave the WIP-3 a go. All I can say is WOW!

The checklist was well worth printing out and having right there in front of me (perhaps as a mouse-pad). Between judicious use of the [R] key, the checklist and the eicas display, getting her into orbit was no drama at all.

I really, really, really like this craft. It's a challenge, but not so hard that it can't be overcome. I like that a pilot has to fly it to orbit, rather than point up and go.

No I need to do it all again without slowing the time index down.

Is there any advice on reentry procedures?

Again, fantastic work so far.

 

[Moach]

for reentry, just bring up basesync and aerobrake MFD's - use BS DEO program to figure a ~1.0 degree descent path, then flip wings up, point prograde, level up and set pitch to about 50~60 degrees nose up (push "-" a couple of times to bring the CoG back)


then have attitudeMFD lock your attitude and manage around aerobrake so you don't over/undershoot your mark


if all is done well - you wont even get flames out of it :thumbup:

 

[Hurricane]

Well, sure look awesome. But, just a question, where do you get your aerodynamic & engine data? How can you be certain that it's accurate?

 

[Moach]

hmm, that's a tricky one, actually....


i did a hefty amount of research on existing concepts for craft of this type.... then i went on and estimated towards what i hope is a good approximation for how a ship like this would fly... mostly working out from figures on real-world aircraft

so most of the engine and wing dynamics are based on lookup code that interpolates over values from educated assumptions based on similar aircraft...
a good amount of it is also tuned out by "feel" (i have flow real aircraft before, and have some years of experience building flying models - so i like to think i got a good "eye" for how something should fly)

another conceptual loophole i've never been shy to exploit - is that the '42 features a powerful fly-by-wire SAS device.... so any handling instabilities are ironed out by the flight computer in such a way that cuts a few corners, simulator-wise....

i mean, i wouldn't model a handling "problem" just so i had to code a "solution" around it later.... not if doing this meant neither would be apparent to the player - remember, it's a simulator, not a digital analysis tool.... so if something doesn't "look like" it's there - it may as well not be and save us a couple of CPU cycles :hmm:



but i don't expect any of it to hold up to an analytical level of precision - still it should be "close enough" for most purposes... i.e. you wouldn't really notice any more precise modeling in a simulation like this, specially since there's nothing to compare by


anyways, as of WIP-3 in the form it's currently released, the wings code is pretty much rubbish....
i took it out from the stock DG sample, and have only updated it recently (will be in WIP-4) to match up with the actual design of the '42 a little better

the engines have also been significantly revised... the dynamics are still lookup-interpolation based, but now this is done by a combination of dynamic pressure and mach number, rather than altitude and mach.... so it should converge on a more coherent flight model, i expect (i say "coherent" instead of "realistic", as the latter is well unfeasible since this ship does not exist)


still making changes to it tho.... will be done when its done..... and 'till then, i'm still learning and whenever i see something that could be made more "correct" - i go back and make it happen (which also explains why we can't have a full flight manual at this time, too many changes to keep up with)

 

[Hurricane]

Seems legit. Keep up the awesome work!

 

[ganlhi]

Hi there!

I made few other attempts, an I almost achieved orbit insertion. I mean I flew out of the atmosphere, but I was not able to circularize, because Ecc was too high.

Plus, I found the OMS to be very weak, for me who flies XR2 and DG4 all the time, but I think it's normal.

Now, I really would like someone tell me what is a good ascent profile with this ship (like what altitude, attitude and speed at each phase of the flight), or someone to post a video of a successful flight to orbit. Anyone could do that ?

Moach, pretty good job! This plane is amazing, and the sounds are really immersive.

EDIT: I tried to use Attitude MFD but it seems this is only working with RCS. I would need something like that for the atmospheric part of the flight... How do you handle this ?

 

[Grover]

ok, im gonna write a litle guide, please dont :ninja: me guys, ganlhi, ill be with ya in a few minutes

 

[PhantomCruiser]

@ ganlhi - The EICAS display on the center of the console (colored graph with the T1, T2 and T3 circles on it) has a set of cross-hairs that follow your ascent. If one keeps the cross-hair in the blue band you shouldn't have any trouble maintaining the "right" profile.

It's a bit of a challenge at first, but gets easier with practice (of course).

 

[Grover]

for a start, heres how the spacecraft propulsion systems pan out:
OMS engines are meant to be weak yes, they provide almost 1m/s^2 acceleration when the craft is lightened by losing most of its fuel for ascent

RAMCASTER engines are your primary ascent engines, you spend most of your time with these firing

main engines are quite complex, they have 3 stages:
Normal ext mode. here, they function as normal turbofan (jet) engines, like you would find on an airliner
afterburner ext mode the afterburners ignite, so you have a less fuel-efficient jet engine, like you find on jet fighters

INT mode here, only the afterburners are used (almost at least) and instead of using the atmosphere for air, it relies on internal oxygen stores (because these are used when there is no atmosphere)


now, in your cockpit you actually have an instrument to gauge your ascent profile, and match it to an ideal ascent. look at the central console, to the left of your engine management "MFD" there is a graph. two lines will move across this, one horizontal one that moves up as you ascend, and one vertical one that moves right as you speed up. the intersection of these lines (the +) marks the part of the ascent you are up to.

on the graph, there is a lower zone, a red area, where RAMCASTERS will not function. above this are two curved lines punctuated with circles. between these lines, the ramcasters work with varying levels of efficiency. you should activate RAMCASTER:LO as soon as you enter the first circle (T=1), and then do your best to fly nice and smooth between the two curves of maximum and minimum flight profiles. at the second circle (T=2) switch the RAMCASTERS to HI mode, and follow the same rules

once you reach the T=3 circle, engage the final mode of your main engines and hand over to main engines, relieving the exhausted RAMCASTERS (note, the RAMCASTERS flame out if you fly out of the curved lines, or beyond T=3)

from here, heep the nose below 20* and keep picking up speed, once your ApA reaches 220Km (or something else, mission-appropriate), its MECO time. this should leave you with low enough eccentricity to circularize with OMS engines, just make sure to burn at least 15* before ApA (1m/s^2 isnt much)

from here, just fly as normal, but beware the low thrust. just assume a constant acceleration of 0.9m/s^2 and calculate your burns manually (divide your dV by 0.9 to get the burn time) and get the bird to the station!


if you need anything else, dont hesitate to ask dude!

 

[Cras]

I will offer one tip, and leave the rest to Grover.

Trim. Use it to control your vertical speed whilst in the atmosphere. Do not try to control the V/S in any other fashion (RCS, control surfaces). Just a little bit of touch on the trim, and you are on your way. And keep it a light touch, or you will find yourself bouncing over and under the ascent envelope.


And I will say again, the OMS are fine. They feel just like they are supposed to IMHO. They may seem like weak sauce compared to firing the XR-2's MPS in Orbit, but this ship is considerably less magic than the XR-# or the DGIV.