Board index FlightGear Development Spaceflight

Space Shuttle - Development

Discussion about development and usage of spacecraft

Re: Space Shuttle - Development

Postby radi » Thu Apr 25, 2019 5:51 am

That's too high framerate.

LOL, that's one lovely problem to have.
OSM buildings for LOWI, EDDC
Custom scenery for VHXX YMML
Edit .stg via the FG Object Placement Tool
radi
 
Posts: 643
Joined: Mon Aug 25, 2008 4:24 pm
Location: YMML, EDDC

Re: Space Shuttle - Development

Postby Thorsten » Tue May 07, 2019 5:35 pm

I've spent some time with the body flap today - at least for a nominal entry, it should now work in auto mode to ease the load of the elevons, and the in-cockpit manual control should also be working properly now.

I've played a bit with CoG by using different tank loads and it seems to work okay - let me know if anything unexpected happens though...
Thorsten
 
Posts: 10939
Joined: Mon Nov 02, 2009 8:33 am

Re: Space Shuttle - Development

Postby GinGin » Wed May 08, 2019 8:45 am

Nice. I even didn’t notice, but it was a place holder before ?
GinGin
 
Posts: 731
Joined: Wed Jul 05, 2017 10:41 am
Location: Paris
Callsign: Gingin

Re: Space Shuttle - Development

Postby Thorsten » Wed May 08, 2019 9:20 am

Pretty much... There's no gradual loss of control so even if the elevons are struggling you don't usually notice, and within a reasonable entry CoG the elevons can fly the Shuttle no matter the body flap trim, but there's a few marginal cases where it really would matter.
Thorsten
 
Posts: 10939
Joined: Mon Nov 02, 2009 8:33 am

Re: Space Shuttle - Development

Postby GinGin » Sun May 12, 2019 7:26 pm

Nice, indeed it seems to have a critical role in a lot of contigency abort.
For Nominal operations, I read that Body flap was usually trim upwards to have a "more" downwards deflection of elevons, hence putting them a bit more in the relative wind and adding control.
Smart one :)

I will test that, and off nominal stuff with manual body flap setting
GinGin
 
Posts: 731
Joined: Wed Jul 05, 2017 10:41 am
Location: Paris
Callsign: Gingin

Re: Space Shuttle - Development

Postby GinGin » Wed May 15, 2019 5:18 pm

I am working on a printed paper version of Ascent and Entry checklist close to reality


Ideally, I am aiming for that:

Image



I contacted a professional printer for the double A 5 format and some rings to attach everything with a 100 gr paper ( quite stiff)
I am looking for the good infills now ( at least 15 for the ascent one)

Should be good and usefull


I already tried to print and put on a solid cardboard the contigency abort cue cards available for the mission specialist and all the Commander/ pilot cue cards ( Ascent profile, Abort Boundaries mainly)


Image

It will add a layer of realism on the desk :)
GinGin
 
Posts: 731
Joined: Wed Jul 05, 2017 10:41 am
Location: Paris
Callsign: Gingin

Re: Space Shuttle - Development

Postby GinGin » Wed May 22, 2019 10:22 am

@Thorsten: I started to play with the body flap .
Nice to see it moving :)

I saw that usually it was trimming full downwards.
I was thinking that at least for the first part of entry if would be the opppsite to force a downward movements of the élevons to put them more into the relative wind at high angle of attack .

I saw that it was staying full downwards for landing also , tail scrape :)
GinGin
 
Posts: 731
Joined: Wed Jul 05, 2017 10:41 am
Location: Paris
Callsign: Gingin

Re: Space Shuttle - Development

Postby Thorsten » Wed May 22, 2019 10:47 am

I was thinking that at least for the first part of entry if would be the opppsite to force a downward movements of the élevons to put them more into the relative wind at high angle of attack .


The body flap auto mode is written to relieve elevon trim load as much as possible, i.e. it tries ideally to zero elevon position. Whether it trims up or down really depends on your precise CoG during entry - I assume for a perfect weight distribution it wouldn't do much...

BF auto mode currently ends at TAEM interface, the flap remains in whatever position it is then (elevon action is huge anyway by then, so it doesn't really matter).

There's more that needs to be done - at the moment this is in a testing phase.
Thorsten
 
Posts: 10939
Joined: Mon Nov 02, 2009 8:33 am

Re: Space Shuttle - Development

Postby GinGin » Wed May 22, 2019 4:02 pm

Alright thanks for the insight
I ll try to play with it in manual


Anyway , that is another very nice addition :)


Edit: the stuff I was talking about is for a particulier use of body flap with aileron saturation, so not relevant there.

I tried several entry with different cog , body flap works well at maintening elevons close to the neutral position
GinGin
 
Posts: 731
Joined: Wed Jul 05, 2017 10:41 am
Location: Paris
Callsign: Gingin

Re: Space Shuttle - Development

Postby Thorsten » Thu May 23, 2019 3:09 pm

Look what we can find at 330 miles altitude

Image


Image

(Big thanks to Wayne :D )

(It's not all committed yet, I still need some testing, but handover seems to work reasonably well so far)
Thorsten
 
Posts: 10939
Joined: Mon Nov 02, 2009 8:33 am

Re: Space Shuttle - Development

Postby eatdirt » Thu May 23, 2019 4:14 pm

HOLY COWS!!!!!!! I have goose bumps right now!!!!!!!!! :shock:
eatdirt
 
Posts: 357
Joined: Wed Aug 15, 2018 2:06 pm

Re: Space Shuttle - Development

Postby wlbragg » Thu May 23, 2019 8:44 pm

We're going to need a satellite tracking program before long so we can safely enter orbit. :lol:
Kansas(2-27-15)/Ohio/Midwest scenery development.
KEQA (2-27-15), 3AU, KRCP Airport Layout
User avatar
wlbragg
 
Posts: 4874
Joined: Sat Aug 25, 2012 11:31 pm
Location: Kansas (Tornado Alley), USA
Callsign: WC2020
Version: next
OS: Win10/Debain/nVGT640

Re: Space Shuttle - Development

Postby Thorsten » Fri May 24, 2019 6:24 am

Well, given that we can only specify one orbital target at the moment...

I've just pushed the HST management class - you can get to see it by changing 'ISS' to 'HST' in the mission file orbital target section.

If you think of changing altitude, don't - you'll be in for a nasty surprise during phasing because there's a bug in the precession of the ascending node longitude - we'll get to that shortly (but I'll probably also try to improve the altitude modulation a bit).
Thorsten
 
Posts: 10939
Joined: Mon Nov 02, 2009 8:33 am

Re: Space Shuttle - Development

Postby GinGin » Fri May 24, 2019 1:59 pm

Very nice, great work.
Big thanks to our 3D modeler and Flight dynamics officer :)

I have tested Body flap with aft COG ( no dump during Abort)
It works well, keeping elevons within nominal range.

Is the elevons trim also included to manual trim the beast ?


I played a lot with manual ascent lately, lof of fun.
I was following a typical Nasa ascent profile for an ISS launch with full payload

Image


That works really well ( different profil than what the AP commands)
Always a good surprise to see physics and coding in game close to the real stuff

Here a MECO at 25800 ish ft/s, 350 kfeet, Apogee at 120 Nm with an OMS 2 burn forecasted around 40 mn into the mission, really close to real profil for a direct insertion to ISS :)

Image


PS: I noticed that at OPS 104 transition, the speed in PFD is now well the inertial speed that was in MM 103 and stays in OPS 2/3 until MM 304
Did you change something?
GinGin
 
Posts: 731
Joined: Wed Jul 05, 2017 10:41 am
Location: Paris
Callsign: Gingin

Re: Space Shuttle - Development

Postby Thorsten » Fri May 24, 2019 3:00 pm

PS: I noticed that at OPS 104 transition, the speed in PFD is now well the inertial speed that was in MM 103 and stays in OPS 2/3 until MM 304
Did you change something?


Yes, we needed inertial speed/1000 here, right?

Is the elevons trim also included to manual trim the beast ?


No... Offhand I'm not sure how it would tie in with the rate-controlled DAP - it kind of automatically trims by definition. The only situation I remember where manual trim was needed was when rudder and elevons fight for lateral control, each trying to cancel each other. I know the kind of situation actually can arise in the simulation, but I find it (luckily...) hard to trigger it
Thorsten
 
Posts: 10939
Joined: Mon Nov 02, 2009 8:33 am

PreviousNext

Return to Spaceflight

Who is online

Users browsing this forum: No registered users and 1 guest