Project Tug eXperimental Reloaded

Lisias

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Greetings, Orbiters.

This is a RFC (Request For Comments) :) about an ongoing effort to revitalize the TX vessel from Kulch (and the VC version from vchamp).

Back in the middle of the first 2k's decade (not sure when, but I used the 2006 not P1 version), I got in contact with Martin Schweiger's excellent Orbiter Space Flight Simulator, after looking for something that could replace the (at its time excellent, but very aged at the time) Space Simulator from Microsoft.

One of the very first third party ships I tried was TX, a somewhat unforgiving ship that for some reason I enjoyed a lot. I still do, it's far my favourite one.

However, some limitations had have bugged me since that time.

Recently I got back to Orbiter, and found the yet more excellent Total Immersion TX from vchamp, giving new life to this old friend. But a lot of the original problems and idiosyncrasies are still there. Worst, TX didn't works with VELCRO - a very interesting add-on that is giving me a lot of fun and amusement (and unrealistic or impossible flights!) - what was annoying, to say the least.

So I decided to do something about it. After contacting vchamp, who kindly agreed on releasing me his code tree, I started to study, refactor and rework this fantastic vessel. This is the first (beta) public release to be criticized (and believe me, there's a lot to be criticized!).

A full change log can be found in the zip file. It's too numerous to enumerate here, so to avoid the TL;DR effect, I will disclose them on the comments on homeopathic doses. :)

Some changes came clearly for the better, some others I don't know. A few, definitively, I almost regret being done but I want to receive feedback before I rip them off of the codetree.

This is not a new fork of the Vessel - it's a prototype (a branch, if you like) that will be used for testing the bug fixes and the new ideas. This codetree (or at least its good part) will be merged back into Total Immersion TX in a near future. There's no plans on merging into Kulch's codetree.

To install, unzip the contents into Orbiter's root directory as usual. No pre-existing files will be overwritten - TX5 and Ti-TX will be operational (as long you don't mix the vessels into the same Scenario). It's mandatory to install TX5 from Kulch, as I didn't duplicated any original resources. Installing TI-TX from vchamp is far from a bad idea, I strongly recommend installing it too.

To download TXR, get the TXR_lst.zip file from my Google Drive. Updates will be regularly posted there.

To download TX5 from Kulch, click [ame="http://www.orbithangar.com/searchid.php?ID=421"]here[/ame].

To download Total Immersion TX from vchamp, [ame="http://www.orbithangar.com/searchid.php?ID=3789"]here[/ame].

To download the latest R028 Release : https://drive.google.com/folderview?id=0BwrmWoWz2Swzdm9majN2WkJVUE0&usp=sharing.

To download an old Release : https://drive.google.com/open?id=0BwrmWoWz2Swzbkx2UU9nWjRXTmM.

Best Regards, and hoping you all enjoy it!

---------- Updated at 2015-0804 R025----------

BUG FIXES:
- Preventing VELCRO to crash when reconfiguring TX thrusters when changing from AIR to PRESPACE and then to SPACE

- Eliminating annoying JET sound when turning Landing Lights ON.

- Preventing TX HUD to be drawn when HUD is OFF
-- Affects only TX original Code, TI code already handles that correctly.

- Minor fixes on Saving and Loading Scenarios.

- Remembering current HUD Mode while turning it ON/OFF
-- It used to reset to Orbit Mode.

- Some fixes on engine modelling (Economic RamJet enabled)

- Force Closing the Covers now automatically switches to LRE.
-- Disabling Force Closing switches back to RamJet if possible.

- Added CTRL-D for Undocking

- Better Ramjet modelling
-- The Engine Mode doesn't shifts crazily on re-entry anymore
-- While in Override Mode, the Ramjet engines can still be enabled, but will not thrust.
-- After re-entry, the Engine Mode now shifts to RamJet economic mode (2 turbines).
--- It's more then enough to fly to the airport.
--- You can even take-off on an empty TX...
-- Ramjet behaviour while over-speeding.
--- On re-entry, the Shutter will close and LRE will be enabled automatically.
--- On Override mode, the shutter will close automatically unless thrust is applied.
---- Perhaps Damage modelling on the future?

- Adapting HUD for 16:10 and 16:9 screen ratios
-- No more overlapping widgets on screens that are not 4x3.

- Turning off TX's HUD widgets
-- CtrL-H changes between NO HUD, Standard HUD, Kulch's TX HUD and Enhanced TX HUD.

---------- Post added at 07:37 PM ---------- Previous post was at 07:33 PM ----------

ENHANCEMENTS

- New TX Hud Style, aiming to declutter a little the view and provide better Engine status information.
-- Turning Off/On the HUD commutes between new and old style.
-- Shows Engine Cover status
-- Shows Currently Docked Vessel name when docked.
-- New Widgets
--- New HUD widget to signal the Wing is currently forced into close.
--- New HUD widget to signal the Wings are closing (as opposed to opening)
--- "Angel" Landing Gear and Landing
---- Widget to show altitude at landing (500 meters, between wheels widget)
---- Wheel breaks
---- Wheel steering
----- Front wheel blinks yellow if ground speed is too high for steering
---- Wheel Load
----- Front wheel blinks red if it is going to touch down first
----- Side wheels blinks yellow if one of them if going to touch down first
----- Side wheels blinks red if overloaded
--- Wing Load Factor (g) Widget
--- Vessel Attitude (Landed, Taxing, Flying, Orbiting, etc)
--- "Jouliette"
---- Hull Heat Flux meter
-- Persisted on scenario saving on HUD_STYLE keyword.
-- Defaults to Original style.

- Engine Override Mode.
-- CTRL-E To On/OFF, HUD will show a frame around the MAIN ENGINE STATUS when Override is ON.
-- E increase Engine Mode, Shift+E decrease Engine mode
-- The modes are: RAMJET, LRE, LRE+ECONOMIC and RAMJET+ECONOMIC
-- In Override Mode, the Flight Computer *WILL NOT* change the engine during flight. Use with caution. LRE mode will deplete your fuel fast!

- Damage Modelling
-- Landing Gear Stress

- A slightly better Cover animation sequence.

- Landing Gear and Canards Operating Speeds were converted to Dynamic Pressure
-- Now you can expand the Canards or lower the gears on space.
-- Or you can try a landing on Mars!

- Docking bay automatically closes if undocked and max operational dynamic pressure is reached.
-- No docking on Venus surface!

- Alert Sound when a command cannot be obeyed or can provoke damages (with tip on the Console):
-- Trying to close bay doors while docked
-- Trying to lower the gears at too much speed
-- Trying to upper the gears while grounded.
-- No fuel
-- etc

- Warn Sound when (with tip on the Console):
-- Changing Engine Mode Override
-- Forcing Canards to be closed
-- Low fuel

- Better vessel attitude modelling implemented using FSM.
-- The code that handles the vessel behaviour that depends on the current aircraft attitude are way simpler now.
-- Some interesting alarms are now possible
-- No more hacking trying to detect current vessel attitude
--- And no more glitches from it
-- Information displayed on New HUD.

- Better reentry detection based on heat flux
-- Feeds the Attitude FSM
-- Displayed on New HUD Widget

- Alarms
-- to fly too low without landing gears
-- to handle landing gear overspeeding while on ground.

- Engine Override mode now also overrides:
-- RCS mode change. Use the slash key '/' (the one near the right shift)
--- Numeric Keypap / now commute between rotation and translation modes normally
--- I intented to use CTRL-Num/ , but Orbiter seems to not recognize this key combo.
-- Wing mode.

- Animation Dialog for Scenary Editor
-- Gear
-- Canard
-- Docking Bay
-- Air Breaks
-- Engine Cover
--- (bug) After closing, reactivation of Auto mode only when flying!

---------- Post added at 07:38 PM ---------- Previous post was at 07:37 PM ----------

QUESTIONABLE CHANGES

- Banking right and left on RCS rotation now fires thrusters on noose.
-- It's not symmetrical, it probably won't work right in Real Life(tm).
-- VTOLX demonstrates that you don't need RCS thrusters on the nose
--- but its weird to me.

- A slightly better Cover animation sequence.
-- I used atan to make the cover works more aesthetically

---------- Post added at 07:41 PM ---------- Previous post was at 07:38 PM ----------

TODO (or to don't) LIST

- Merge vchamp's Virtual Cockpit

- Adding a Instrument Panel (probably a rip off from DeltaGlider...)

- TX State/Attitude MFD
-- So we can turn-off TX specific HUD if desired (CTRL-H)

- Scenario Editor
-- Add page for crew

- Replace the landing gear lights for something using a local light source
-- something as [ame="http://www.orbithangar.com/searchid.php?ID=5182"]Spotlight 2[/ame]
-- currently it is being simulated by thrusters.

- TX are not being correctly recorded on Flight Recorder!
-- Custom commands (as Override) are not recorded
--- changing Control Modes isn'too;
-- Some animations are not being triggered
--- As Engine Shutter - the HUD states it's closed, but the mesh renders it opened!

- Better UMMU Support
-- Transfers
-- EVA

- Ramjets should only work in oxygen rich environments.
-- It should not be working in Mars!
-- How to implement it? Locking the Ramjet to Earth?

- How about adding Life Support for the Crew?
-- Where I can find the TX conceptual documents? We need to be faithful to the concept specifications!

- Implement Damage ?
-- Kinetic ?
--- G Force ?
--- Torque ?
--- Langing Gear
---- Research about AN-225 and Be-2500 , take their landing and cargo limits and interpolate into TX. Instantly retracts langing gears if landing parameters are exceeded.
-- Heat (reentry, at least) ?
-- Lack of Life Support?
-- Ramjet damage by over-speeding in Override Mode?

- There's a potential memory leak.
-- To prevent Velcro from crashing, I prevented the destruction of Thrusters on demand.
-- Now the thrusters are created but not destroyed.
-- Old thruster are still active if overwritten?

- We can't mix TXR, TI/TX and Kulch's TX in the same scenario.
-- Something on Payload Manager, as it appears...

- Check D3D9 client compatibility

- Check orbiter_ng compatibility

- TX5 Scenario "The Power of the Deltaglider!" doesn't work - the vessels spins crazily without any chance of control (even by zeroing angular speeds on Scenario Editor)

- The payload separation acceleration while jettison is lost (I inadvertently deleted that piece of code). Recover the feature.
 
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Interceptor

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This project looks great,I am going to check it out tonight,thanks for making Kulch TX even better.:cheers:PS will this work with the D3d9 client too?
 
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Lisias

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This project looks great,I am going to check it out tonight,thanks for making Kulch TX even better.

It is a bit soon to state "better", but that's what's I'm aiming. :)


PS will this work with the D3d9 client too?

I don't have a clue.... My current machine can't run D3D9 client (too old of a CPU, the Athlon XP doesn't have SEE3 instructions, used by D3D9). I'm upgrading the machine to something a bit less older in the near future - D3D9 client is promising, it would be a shame if it could not run TX.

My current guessing is that it probably will not run now - the HUD uses GDI primitives for drawing (and the enhanced HUD does even more), and I don't know (yet) if D3D9 client will accept GDI primitives drawing on the screen the way it's done now.

I will add this to the TODO list, thanks!
 

TachyonDriver

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Oh SWEET! I will check this out! I loved the Tx, shame it didn't work in the D3D9 client. Here's hoping you succeed in getting her fully sorted! :cool:
 

Lisias

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Hi. Here come some Screenshots demonstrating the visible enhancements of the project:

1) New HUD, 4:3 Aspect Ratio:
1024_4x3.PNG


2) New HUD 16:10 A/R:
1024_16x10.PNG


3) New HUD 16:9 A/R:
1024_16x9.PNG


Enhancements:

1) Better positioning (at least, for me) of HUD widgets across the usable area

2) Air Intake widget now stats the Cover Attitude (percentage of intake aperture). Useful to be aware of the engine - denser atmosphere will lead the shutter to start closing itself to protect the engines from over pressure.

3) New Vessel Attitude widget, stating what the vessel is doing at the moment (landed? taxing? taking off? etc)

4) New Heat Flux widget ( codenamed "Jouliette" =P ), top left, sided with the (standard) Engine/Fuel widget. It gives the current heat flux, in Joules/Sec. You will need this in order to maximize the engine thrusting without barbecuing your crew.

Not shown in this screenshots:

1) Docking widget states the docked vessel name when docking.

2) Override Mode active (a frame around the engine mode widget)

3) Canards closing widget

4) Canards forced into close widget.

Hit "W" while grounded to check he Canards widget.

Known Problems:

The HUD drawing code were optimized for the standard A/R. Some not so standard resolutions are not being correctly handled.

---------- Post added at 10:54 AM ---------- Previous post was at 10:26 AM ----------

Now some more screenshots of the HUD while flying:

1) Climbing and turning to 180° for a Polar Orbit. Note the Canard Closing widget and "Jouliette" indicating heat flux at 150 Joules/Sec. Vessel Attitude is Flying.
10_Climbing.PNG


2) Thrusting to Space, reaching Low Atmosphere border. Note "Jouliette" indicating above 600 J/s, when Plasma Sheath starts to form. (Yeah, this is a problem while ascending!)
20_Accelerating.PNG


3) Maximing Thrust before jumping into Orbit. The Maximum RamJet thrusting is 10.0 Mega Newtons (wow!). But I only reached this at Mach 12.41, what at 33Km altitude leads to more than 3k J/s. I hope you enjoy Barbecuing.
30_MaximizingThrust.PNG


I think that it's clear that the current RamJet modelling is either not accurate, or it's accurate but unfeasible in reality. I found this modeling code somewhat loose in the codetree (the used modelling were way too simpler and unrealistic).

This is my worst conceptual problem at the moment.

---------- Post added at 01:13 PM ---------- Previous post was at 10:54 AM ----------

And, by last (and at last!), a very fast and stupid way to reach a 380Km "orbit" using Override Mode. :)

Now, TX don't need to be jealous from Space Shuttle anymore - if you don't mind going on the meteor way while going back to home. :)

(I give up using Google Photos to share GIFs or MNGs. The link below goes to meu google drive, you can download and see them with your favorite Image Viewer - I use Irfan View on Windows).

GoogDrive Sharing
 
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TachyonDriver

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I LIKE IT! the TXR setup works well on my screen, but not in D3D9 as you correctly surmised. (Someday maybe??) At first I thought that Jouliette was a fuel flow gauge.. but then Ah! joules is energy and J/s is energy being generated over time somehow, then I knew: A fancy hull temp gauge :D By the way it can go over 12000 J/s and the ship doesn't melt.... :rolleyes: :rofl:

Nice fix on the landing lights not having any jet noise! :cool:

She seems to handle quite well. Not tried to get her into orbit yet.
 

Lisias

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I LIKE IT! the TXR setup works well on my screen, but not in D3D9 as you correctly surmised. (Someday maybe??) At first I thought that Jouliette was a fuel flow gauge.. but then Ah! joules is energy and J/s is energy being generated over time somehow, then I knew: A fancy hull temp gauge :D

Yeah! Glad you enjoyed! :)

The need for the "Jouliette" (pun really intended! =P ) happens because you will want to get the most from the Ramjets in order to save fuel. You can get 10 Mega Newtons from them in ideal conditions. However, the ideal conditions also happens to produce a LOT of heat on the hull. So you have to fight the heat by climbing, but when you climb, the air is less dense and this affects Ramjet's performance - so you climb a little, then gain speed for a while and when heat starts to be a problem again, you climb a little more.

If can climb to space faster avoiding that "level stops" to gain Mach to maximize the thrust - but you will get 8.0 Mega Newtons at max, will reach orbit with less horizontal speed and will burn more fuel while LREing into orbit. It's feasible, but you will end up with only 2 to 5% of fuel in the tanks (if you get there - I commonly end up without fuel before reaching a stable orbit).

There's a Flight Record those scenario is called "Recording_<something>" with a full flight from takeoff to orbit. You can stablish a stable orbit of 232Km before reaching Bingo Fuel (10% of the fuel) without payloads by going west (Orbiter takes going east into account while calculating the vessel acceleration? )

By the way it can go over 12000 J/s and the ship doesn't melt.... :rolleyes: :rofl:

There's no damage modelling in the vessel - I reached 3K J/s on a slideshow I'm trying to upload right now to demonstrate the Override Mode (why in ******* hell nobody likes GIF or MNG files? Damn!).

It's something I plan to implement, but not for now. I already had my hands full trying to fix my own bugs! =P


Nice fix on the landing lights not having any jet noise! :cool:

That annoyed me a lot too! :)

She seems to handle quite well. Not tried to get her into orbit yet.

Reaching orbit is easy. Saving fuel to get back home is the real trick! :)
 
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Lmoy

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Wow, this looks amazing! I'm definitely going to be following this development, as I'd love to see an up-to-date TX (especially with damage modeling!), specifically for use as a "realistic" reusable launch vehicle for spaceplanes.
 

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I use the TX more as a hypersonic transport and it's awesome like that. I have found that it's low speed handling is utterly terrible so I am very keen to give this a go.

Thanks for your work here!
 

TachyonDriver

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Got her into a stable orbit (about 183km by 220km) with nearly 15% fuel remaining...and she had a Delta Glider on her back.

---------- Post added at 10:53 PM ---------- Previous post was at 10:32 PM ----------

Gary - Low speed handling seems OK to me for a huge plane. Depends upon what you mean by low... IMHO she flies around quite happily at about 160-170 m/s, plenty of power available (I did just take off and go around). Watch the descent rate though - I crashed on landing ;)
 

Lisias

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I have found that it's low speed handling is utterly terrible so I am very keen to give this a go.

I'm afraid that this vessel will continue being terrible at low speeds (and I agree with you). I'm not an aircraft engineer (all I have are private pilot lessons when younger and thousands of hours of flying in computer simulators =P ), and it's my understanding that this (huge) airframe format was made to let she being maneuverable at high speeds (Mach 2 and above).

This vessel should not even takeoff without the Cannards deployed. :)

Originally, the Canards were retracted when the vessel reaches 170M/s (IIRC) ground speed, what made no sense to me: it's the TAS (True Airspeed) that matters (don't even confound it with IAS - indicated Air Speed!).

However, Orbiter gives us the Dynamic Pressure what's even better!

So I let Orbiter calculate for me the Dynamic Pressure reached at 170 M/s at sea level (intending to respect Kulch's design) and programmed the Canards to retract at that pressure.

But this leaded to you being able to use Cannards above Sound Speed at high altitudes, and the frame shape doesn't appears to protect the Cannards from the sonic shockwaves - what would simply being rip off in real life.

So, the flight computer also retracts the Canards at Mach 0.96 (what is not the best solution neither: I should had calculated the acceleration versus speed versus time and started to retract the Canards in time to let them being fully retracted when you reach Mach 1).

---------- Post added at 01:40 PM ---------- Previous post was at 01:14 PM ----------

Got her into a stable orbit (about 183km by 220km) with nearly 15% fuel remaining...and she had a Delta Glider on her back.

You appears to be a better pilot than me, my current "record" is about 12 to 13% of fuel left. :)

(did you managed to keep "Jouliette" below 1K J/s ?)

About the payload, I recently detected that one of the originals TX Scenarios (the power of the Delta Glider!) doesn't work with TXR - the vessels crazily spins without any chance of control (zeroing the rotational speeds of the vessels on Scenario Editor doesn't helps, it's something that is being actively (mis)done by the code). Of course, this scenario works perfectly with TX5.

(not tested yet with TI-TX)

Since there's an obvious error on the code (perhaps the COG calculation), perhaps the error had propagated the the total weight calculation.

Please try again this setup on the next release.

Gary - Low speed handling seems OK to me for a huge plane. Depends upon what you mean by low... IMHO she flies around quite happily at about 160-170 m/s, plenty of power available (I did just take off and go around).

I think that the Canards (new) policy helps a little in this issue (as the flight computer will keep it deployed more times). Try to do it again with the Canards forced into close (hit "w" - you don't need to be in Override Mode), and you will see. :)


Watch the descent rate though - I crashed on landing ;)

About it... This is a "damage" that it's easy to implement: what do you think of the gears being suddenly retracted if you hit the ground with too much vertical speed (again, the best solution would be weight versus vspeed, but I don't know - yet - what would be a realistic value for these gears)?

I already implemented a "belly landed" vessel attitude.
 
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TachyonDriver

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Hi Lisias - yes Jouliette was below 1K. I cruised up to 10km alt, then full throttle, just trying to follow the vague instructions in the original Tx manual. I got lucky I guess! :)

Suddenly retracting the undercarriage (no animation) would simulate a crash landing quite nicely given the limitations of the sim and the Tx code :cool: A realistic value for breaking the undercarriage? Not sure. Most modern large (huge? :D ) aircraft cannot take a landing with full fuel (hence they have to dump fuel before landing in an emergency as you know). You could possibly try and find data for the max landing weight of various aircraft versus their max take off weight, then apply that as a percentage to the weight of the Tx. What do you think?

One last thing: The TXR doesn't appear to spawn into a scenario properly when using the scenario editor:

I called up a Carl Sagan spaceport (CSSC) scenario which just has a DG on a landing pad. No original TX5's present. I created a TXR at that location, then moved it to the runway. Everything appeared to work EXCEPT for aileron (roll) control. No animation was displayed either. The speedbrakes, elevator & yaw functions & animations worked, just no roll.
 
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Lisias

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Hi Lisias - yes Jouliette was below 1K. I cruised up to 10km alt, then full throttle, just trying to follow the vague instructions in the original Tx manual. I got lucky I guess! :)

EXCELLENT ASCENSION. :) I let Joulitte reach 1.2 J/s.

Anyway, this engine model needs to be revisited. Mach 12 is too much for Ramjets, as far as I know. =D

(I'm trying some ascensions variations besides the "Kulch Manoeuvre" :) , but it appears that this is the most cost/effective one.)


Suddenly retracting the undercarriage (no animation) would simulate a crash landing quite nicely given the limitations of the sim and the Tx code :cool: A realistic value for breaking the undercarriage? Not sure. Most modern large (huge? :D ) aircraft cannot take a landing with full fuel (hence they have to dump fuel before landing in an emergency as you know). You could possibly try and find data for the max landing weight of various aircraft versus their max take off weight, then apply that as a percentage to the weight of the Tx. What do you think?

It worths a try! Added to the backlog. :thumbup:

It appears to me that TX should have be able to land with cargo in his back, or it will not be that useful. The biggest cargo aircraft I know is the Antonov AN-225, but suddenly I found this beast:

http://www.beriev.com/eng/Be-2500_e/Be-2500_e.html

ONE THOUSAND TONS payload. This pretty lady is begging to be implemented in Orbit....

One last thing: The TXR doesn't appear to spawn into a scenario properly when using the scenario editor:

I called up a Carl Sagan spaceport (CSSC) scenario which just has a DG on a landing pad. No original TX5's present. I created a TXR at that location, then moved it to the runway. Everything appeared to work EXCEPT for aileron (roll) control. No animation was displayed either. The speedbrakes, elevator & yaw functions & animations worked, just no roll.

The Override Mode was activated? It appears that you are in Prespace mode. To confirm it, press CTRL-E and hits Slash (the / near a shift key) until RCS Mode is "Air" again.

However, I downloaded and launched the CSSC Scenario, spawned an TXR on scenario, replaced her into the CSSC tarmac and as it appears, everything was fine to me (except by that damned cheap joystick I'm using - I need to replace it ASAP - may I suggest you try to adjust the joystick configurations?)

by the way, did you tried to locate the TX into CSSC landing pad 4? :)
 

TachyonDriver

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...by the way, did you tried to locate the TX into CSSC landing pad 4? :)

Not as far as I know... why? Pad 4 is located at the spaceplane processing facility - the TXR is far too big :thumbup:

Thanks for the advice regarding the RCS mode - I never checked that at the time! :facepalm:

The TX carries hundreds of tons of fuel (500+) - I agree it should be able to land with a cargo on its back, but not with full fuel - say half fuel with cargo? or 1/3 remaining?
 

Lisias

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Not as far as I know... why? Pad 4 is located at the spaceplane processing facility - the TXR is far too big :thumbup:

It was a funny view - the vessel could carry the whole building in her back!


The TX carries hundreds of tons of fuel (500+) - I agree it should be able to land with a cargo on its back, but not with full fuel - say half fuel with cargo? or 1/3 remaining?

The gross takeoff mass of the vessel is 825 tons if you intent to goes to LEO (210 of the vessel, 555 of fuel, 10 of rcs fuel and 50 for payload) - I'm supposing that this lady can carry more if you keep her under 50Km of altitude.

Lets do some googling.

The heaviest aircrafts that I found in a quick research were AN-225 and that impressive BE-2500. The BE-2500 is waaaaaay bigger, that thing is being projected to takeoff with 2500 tons of gross weight!

But the Antonov 225 is closer to TX. 640 tons max on takeoff, 285 tons of empty weight, 250 tons of payload and 300 tons of fuel (of course, you can't have max payload and max fuel at the same time). Well, since the AN225 must land with the payload, it's clear that is can land with 285+250 = 535 tons of cargo. Since the vessel should land with enough fuel to get her into the alternative port and keep flying for 30 minutes more in case of problems, she can land with something more than 535 tons of gross weight.

I didn't found yet the maximum landing weight of the Antonov, but found something interesting: the A380 could land with 591.7 tonnes gross weight on some technical trials made by Airbus (the nominal landing weight is 394 tons).


EDIT: 2015-08-03

I made a very stupid mistake, I did mistaken MASS as WEIGHT. :facepalm:

There's nothing near TX out there, the closest thing minimally plausible I found was the BE-2500.

The right TX numbers are on the spreadsheet I published in the post below. The numbers I'm using now are:

OEW (Operating Empty Space or Vessel Weight) (Tons) 2060.1
Max Fuel Weight (Tons) 5542.65
Max Payload Weight (Tons) 490.5
MZF (Max Zero Fuel) Weight (Tons) 2550.6
MTOW (Max Take Off Weight) (Tons) 8093.25
MLW (Max Landing Weight) (Tons) 3104.865
Fuselage Length (M) 110.5
Fuselage Width (M) 13.4
Fuselage Height (M) 8.5
Wingspan (M) 82
Wingarea (M²) 1103
Wing Aspect Ratio' 6.0961015413
Max Thrust (N) 5530002

/EDIT

Now things got interesting. TX has more wingspan than A380, just a bit less than AN225, and more engine power in her weakest engine mode than both together. EDIT And she will need every Newton, with that weight!/EDIT

An225 has 6 x 228.5 KN, and the most powerful A380 uses 4 x 340 Kn.

TXs has 3.33 *MEGA* Newtons on Ramjet "economic", 10 in Ramjet full mode and 12 in LRE. (this model will be revised, the economic ramjet should be 1/3 of the nominal ramjet, 10/3 = 3.33 MN - I already fixed this!). NOTE: At takeoff, without dynamic pressure to correctly feed the Ramjets, the values are ~1.8 MN at Economic, and 5.53 MN at full thrust. Yes, you get little more that half the maximum thrust with the vessel at rest...

I think it's feasible that TX could take off with something like 1.000 tons of gross weight, and land with something like 400 to 500 tons. I will do interpolations using the data from the aircraft I mentioned and see what figures I get.EDIT I managed to land with 1800 Tons in a "rough landing" one, but crash is the common outcome at this payload!/EDIT

In the end, what's really matter is how much kinetic energy (weight x vspeed) the landing gears can take, not the gross weight alone - I suspect that the A380 that landed with ~590 tons had a very narrow landing envelope.

---------- Post added at 10:04 PM ---------- Previous post was at 09:44 PM ----------

If anyone wants to keep track about what I'm thinking (and double check my interpolations), it would be more than welcome.

here, a Airbus technical PDF for the A380.

FAA documentos. The chapter 13 taught me more about Landing Gears that I would ever need!

AMT Airframe Handbook Volume 2 (full version) (FAA-H-8083-31)

NASA Books.

---------- Post added at 11:12 PM ---------- Previous post was at 10:04 PM ----------

Interesting. I found a discussion where an alleged aircraft designer states that there are some numbers in which every aircraft are designed around.

The landing gears should be projected to get a sink rate at touchdown of 400 fpm (121.92 M/m or 2.032 M/s) at maximum takeoff weight, 600 fpm (182.88 M/m or 3.048 M/s) at maximum landing weight. These are breaking down limits, not operational ones.

The optimum sink rate is around 200 fpm (60.96 M/m or 1.016 M/s) at maximum landing weight.

You can hit the ground with more fpm if you are lighter, so the math implies that you can land heavier if you manage to keep your fpm lower.

To get a lesser sink rate, you will have to have somewhat more horizontal speed - you need to keep the vessel flying. So you'll have to take the maximum landing gear operational IAS in consideration too. Further more, there's the maximum operational ground speed to be taken in consideration - if you land with a ground speed bigger than the landing gear can take, you will get dirt in your belly for sure.

I also found in another forum that regulations demands that any vessel that hits the ground over 1.8g measured with an 8 samples per second accelerometer at maximum landing weight (or 1.9g if the accelerometer takes 16 samples per second), the aircraft should be inspected for damages. It's the "hard landing inspection".

I think that I have some good numbers to work on.

---------- Post added 07-31-15 at 12:19 AM ---------- Previous post was 07-30-15 at 11:12 PM ----------

Since the regulations state that landing with > 1.9g leads the vessel to inspection, the landing gear should stand and keep operational under a force of 1.9g , where g is the Load Factor given by Lift / Weight (do not confuse it with G, the Earth Gravity, as I did!).

But we're talking about space crafts. We should be talking about Mass and Kinetic Energy, not in Weight and Earth's Gs.

So, Mass = Weight (on Earth) / G (where G = ~9.81 on Earth EDIT 2016-0804 Another mistake! G = 9.81 M/s on Earth, what's 1.0 is the "g" (little g, used to measure load factor on the wings!)/EDIT). And we can get the Kinetic Energy using Ek = (Mass * velocity**2) /2 .

Now I have to convert all the landing specs and limits to Ek, and we will have a landing gear modeling that will work on any celestial body.
 
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TachyonDriver

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Whilst running the TXR test scenario, I encountered the same "pre-space" configuration - no aileron & couldn't fix it using override mode & cycling through the RCS options. I shut orbiter down. Later I went back in and she was working fine. In fact new personal record - circularised LEO whilst carrying a DG, of around 220 x 185 km approx. with just under 18% fuel remaining :cool: In fact, just for laughs, I decided to try and get the dynamic pressure readout on the bottom of the screen to zero (0.0000), but gave up when the orbit got to 340km and was still reading 0.0003, so I made the eccentricity of the orbit zero instead :D : Fuel remaining 17% :eek:

EDIT - too tired to investigate how I "fixed" the AF only issue (it's now gone 2 am over here!). It might have had something to do with switching views between the take off TXR and the docked, orbiting TXRs.
 
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Lisias

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Whilst running the TXR test scenario, I encountered the same "pre-space" configuration - no aileron & couldn't fix it using override mode & cycling through the RCS options. I shut orbiter down. Later I went back in and she was working fine.

I think you found a bug on the persistence routines. I must had messed up some enumeration...

In fact new personal record [...]

:cheers: !

---------- Post added at 02:14 AM ---------- Previous post was at 01:05 AM ----------

Whilst running the TXR test scenario, I encountered the same "pre-space" configuration - [...]

EDIT - too tired to investigate how I "fixed" the AF only issue (it's now gone 2 am over here!). It might have had something to do with switching views between the take off TXR and the docked, orbiting TXRs.

I FOUND THE PROBLEM!

The code is good, it's the Scenario that is bugged!

Press F3 and select any vessel. Then select the one you want to fly. This will fix the issue.

When I hand crafted the Scenario, I inadvertently set the Camera showing a vessel while the focus is given to another one. Your commands was being obeyed, but the vessel obeying is not the one you are seeing!

When you exited the Orbiter, the Current Scenario.scn is written with the glitch solved, being this the reason everything worked fine on relaunching it.

I will fix this scenario for the next release.

---------- Post added at 02:34 PM ---------- Previous post was at 02:32 PM ----------

I'm mounting a Libre/Open Office spreadsheet with the specifications from the Aircrafts I mentioned before, to interpolate data for TX.

If anyone wants to follow the work, it's here. This is the "public repository" for the time being, anything I would share, will be shared here. Feel free to add a link to your personal Google Drive to get updates.
 

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Update:

I figured out some reasonable operational limits for the TX, they're on the Spreadsheet above on the columns TX to LEO and TX ATM (The Nonsense column is just nonsense =P). I tried to derive these numbers comparing my numbers with the ratio and correlations from another heavy cargo lifters.

Trying to land this lady at MLW will be challenging.

At the same time I read some essays about RAMJETs and SCRAMJETs, and got to the conclusion that TX uses a revolutionary TurboRamjet/SCRAMJET hybrid propulsion engine. Turboramjet engines are not novelty, they were used on the SR-71 Blackbird, but to make TX's engine model be somewhat plausible, I need to pull some rabbit out from my hat, since we need to get to ~Mach 10 to get enough energy to be kicked out to space.

That rabbit is the SCRAMJET. Since some clever engineer had put together a Afterburner from the TurboJets into a Ramjet (the Turboramjet), let's pretend that an yet more clever one figured out how to dynamically control the engine inlet to convert it from Ramjet to Scramjet.

I don't see a way to use Ramjets alone until space, even by shutting the cover to lower the air pressure: by compressing the air, you heat it and above Mach 5 or 6, the difference between the compressed air temperature and the burnt air in the combustion chamber is too low to produce thrust. The best performance for Ramjets are around Mach 2 or 3, by the way (being this the reason the Engine Cover closes as the speed increases).

This the reason Scramjets were invented, to bypass the compression phase in order to prevent the air from being heated by the process.

The engine shutter helps to keep the inlet pressure reasonable to Ramjeting for some more time, but not forever. Sooner or later the kinetic energy added by the combustion chamber will be nullified by the air pressure outside. So the Scramjet is still needed.

So the Engine Shutter will, then, be closing after Turboramjet mode changes to Ramjet trying to get the most from it until Mach 5 or 6, when the engines will reconfigure itself to Scramjet, and the shutter will open again, and then (or perhaps, I need to study Scramjets a little more) starts to close again trying to keep the Scramjets at optimum propulsion until the engine, finally, switches to LRE.

I don't know, yet, how to model the fuel consumption on this process.

I found some really nice books about this matter with excellent performance charts for TurboJets, Turboramjets and Scramjets, but the PDFs I have access are free samples with incomplete information and, well, I don't plan to spend money on the project. :)

I'm trying to find something good and for free on NASA's site.

---------- Post added at 05:49 PM ---------- Previous post was at 04:39 PM ----------

To keep everything in one place: here is a good source of (simplified) performance charts.

---------- Post added at 07:18 PM ---------- Previous post was at 05:49 PM ----------

I think I found a "flaw" on the engine modelling that should be fixed in order to bring TX to something more feasible.

Reading the TX Manual, I found that TX carries oxidant to be burnt in space, but takes the oxidant (O2) from atmosphere when in atmospheric flight. Based on the code where I found two different ISP (one for air, another for space), I determined that TX's fuel is LOX/RP-1, as the air ISP is near the RP-1 ISP, and the space ISP is something I would expect from a LOX/RP-1 mixture being burned.

Since a good part of the TX's ascending is made on atmospheric flight, and some of you guys use TX as intra-planet cargo transporting, I think that a good engine modelling should keep LOX and RP-1 in separate tanks, so one can save weight (or gain fuel) on using RP-1 only on the tanks. Moreover (this is make-believe anyway), the oxidant tank could be convertible to fuel tank, adding range to the vessel on atmospheric only flights.

TX would be prone to flameouts if using this engine model.
 
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TachyonDriver

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So the TX has 6 TRJ/SJHPE's ...or is that 12? :) Doesn't roll off the tongue either way!

Ah, poking fun aside - your research into remodelling the Tx with more plausibility is fascinating! Thank you. :cool:
 
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