Space Shuttle - Release and Dev Change Log

[GinGin]

November 2019 Stable Release

New release that can be downloaded directly on the FG launcher
It is coming as usual with nice manual additions : http://www.science-and-fiction.org/bookstore.html




Some interesting changes



FDM

-New drag coefficient for atmospheric flight, even closer to reality performances for ascent ( benchmarked against real datas of first stage flown)
-New J3 non spherical gravity adjustments for target on Orbit for better rendez vous experience
-Improvement of Shuttle Dry weight taking account of real datas for equipment ( cryo tanks weight, ..)
-Body flaps implementation ( allowing trimming and elevons load relief)







-Better shuttle behavior in case of central engine failure
For very low fuel in the ET, the engines were unable to vector through the CoG, leading to loss of control (like in reality, very exotic situation)





Graphics


-Rework of Cap Canaveral, high degree of fidelity compared to Google Map ( Lego custom scenery)

https://github.com/legoboyvdlp/Florida-fg-CustomScenery

Unzip anywhere and specify the correct link in Add Ons








-Hubble ( Thanks to Wayne)






-Better plasma effect during Re entry






Display


-Improvement of many small things on PFD
For example, Inertial Speed ( Vi) displayed during ascent and Relative Earth Speed ( Vr) displayed during entry




-Graphical improvement of Display screens
Size of the gpc number driven the IDP, bigger HAC when closing in,..







Failures

New failures to play with

-GPC failures, with now the possibility to have a vote between them to detect the failed one




-Crack windshield and depressurization





Scnario

-Scenario available in game to quickly access a particuliar situation ( Prox Ops, ISS docking, Satellite ..)

-New entries within Mission file : Custom shape for stage 1/2 display ( Ground speed vs pitch angle), Adjustable nominal throttle






New features

-Payload Grapple and retrieval





-Once the Rendez Vous is completed, Eileen is available as a copilot to perform Station Keeping while you are playing with the RMS or taking pictures



-Cue Cards on velcro ( customisable)




-Emergency Light in case of black out

[GinGin]

June 2020 Dev Version



Some News about the Dev version and what happened on it those last months





Dev version available here: https://sourceforge.net/p/fgspaceshuttledev/code/ci/development/tree/
Easy to install: Download Snapshot, and then specifiy the path in FG Launcher settings

Or the tuto for a proper dev install(easier to update once installed when something is pushed on it)

https://forum.flightgear.org/viewtopic.php?f=87&t=36292



Main Changes:

System

Deep and extensive simulation of Helium MPS Subsystem
10 Helium tanks allowing to pneumatically activate some valves,and to close as a back up hydraulically activated engine main valves,...
Plus the dump of every feedlines going from ET to SSME ( km and km of them and 5 klbs to purge after MECO)

What is truly simulated now is the Helium crossfeed between different engines, in case of leak in one Helium subsytem or engine failure.
Without crossfeed in a defaillant helium system, engine would have been shutdown earlier than expected, to avoid catastrophic explosion within Oxidizer Turbopump ( where LH2 from PreBurner and LOX from Pump would have been in contact without a seal filled with inert Helium).


More infos about that Subsytem there: https://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts-mps.html

And I thrust Thorsten when he said that it was tough to code with all those ramifications




Helium MPS Subsystem switches, right side of the Pilot







Engine Model


Some new things there.

Enhancement in SSME performances regarding several points.

Most important of them are:

- LH2/LOX weights at LiftOff
-Correct mixture ( 6.35 in real, 6.25 in sim)
-Thrust: 470000 pounds for 100% of thrust in Vacuum
-Nozzle ratio for correct Sea Level thrust



Some changes in Launch AutoPilot.

In addition to Apogee, we can now choose a specific flight path angle at MECO ( typically ranged from 0 to 1.2°)
Datas for that are available in SCOM, perfomance section ( part 9)
It allows us to choose the initial orbit shape after MECO ( time to Apogee)
Particularly useful to replicate Real insertion shape and use real values for PEG 4 OMS burn or AOA PEG 4 values available in FDF.
New mission files are already set up with realistic apogee, flight path and MECO altitude targets, and can be of course adjusted at your wishes like before.

Changes in fuel consumption are really interesting.
Even more accurate datas when we compare SCOM and after flight datas with what we have in sim.
Tighter abort boundaries, under a percent of prop remaining at MECO at max load.
We just hit the Final Performance reserve planned by NASA ( less than 1% ie. 8000 lbs ish)



Some interesting graphics to sum up that:

First graphic



Direct insertion in red.
Classic for late STS flight to ISS.
MECO around 350 kfeet, max weight around 40 klbs.
8mn30s for insertion and low on propellant as forecasted at MECO

Purple one is a standard insertion, typical from first missions
More lofted ( MECO at 400 kfeet).
A bit more of propellant remaining in the example ( light payload)


Red curve to be compared with dashed one ( 57° Orbit) below, taken from SCOM performance part section 9





Second graphic




Velocity vs Time
Same as before, red curve reflects a standard launch towards ISS, and to be compared with dashed line from SCOM below:




Quite close, really cool.
Those tiny changes in SSME model have an effect on many other subparts ( like RTLS trajectory, Payload chargeable vs Launch Inclination, etc)

Also more precision in AP for launches close to eastwards ( or westwards) azimuth
An example here, less than 0.05° of Relative Inclination at MECO for Hubble





Hubble

Really good work on Hubble and RMS
We can now take Hubble as a payload, grapple it or retrieve it after a sucessful RendezVous.
It opens the path to very interesting Hubble STS mission revivals







Displays

Not yet on dev branch, but soon.

On my side, in addition of SSME perfos, I wanted some closer to reality PFD.
Lot of minors changed on colors, fonts ( thanks to SSU team for some really nice and accurate shuttle fonts) and overall look.

More details about that there:

https://forum.flightgear.org/viewtopic.php?f=87&t=37429


And to come then more enhancements for DPS displays etc now that I know a bit more how to do

[amalahama]

Thank you for the heads up! I find these bits very illustrative. Good job to those involved!

[GinGin]

November 2020 Dev Version


Some News about what was done and pushed on the dev version since the Summer






Dev version available here: https://sourceforge.net/p/fgspaceshuttledev/code/ci/development/tree/
Easy to install: Download Snapshot, and then specifiy the path in FG Launcher settings

Or the tuto for a proper dev install(easier to update once installed when something is pushed on it)

https://forum.flightgear.org/viewtopic.php?f=87&t=36292



Main Changes:


Caution and Warning system


Some fine tunning and refinement of the CWS system and fault annunciator logic.
It is a complex system, old, with a lot of small differencies between the type of failure.




Almost all the Primary CW failure are annunciated on the F7 CW Annunciator Matrix.
Different tones and alarms depending of the severity of the failure.

More informations here: https://spaceshuttleguide.com/system/caution_and_warning_system.htm
In the SCOM part 2.2 for a general philosophy about Caution and Warning system.
End at the end of every system chapter, there is a part about "That system" Caution and Warning Summary that will explain well what is behind each light of that F7 panel ( implemented at 90%)





Fault display will look almost like that .
With a precise meaning for every symbols and numbers written on the display, that can help to identity what is happening ( everything explained in the SCOM).





Many small differences between PASS and BFS to implement, but that makes ( at least for me ) a nice difference about immersion when simulating failure scenarios.








A Fault message Summary can be found here.
APU/HYD , and ECLSS messages are not implemented yet, but will be soon.

https://spaceshuttleguide.com/system/caution_and_warning_system.htm#Shuttle_Fault_Message_1



Miscellaneous

A lot of small things here and there, more quality of life orientated.

For example:

Correct logic for some switches that are spring loaded ( Some electrical ones, cryo and fc switches)




SSME stow position depending on Hydraulic available, Isolation valve position, computer OPS





Displays

For the next dev update, an overhaul of the dps display for all OPS currently available.
More informations here: https://forum.flightgear.org/viewtopic.php?f=87&t=37429

More immersive than ever