Board index FlightGear Development Spaceflight

SpaceShipTwo V.S.S Enterprise

Discussion about development and usage of spacecraft

SpaceShipTwo V.S.S Enterprise

Postby omega95 » Thu Aug 09, 2012 6:48 pm

I've been doing some research on Scaled Composites, the SS1 and the SS2 (Virgin GALACTIC) and I just HAD to make the SS2! Initially, I wanted to work on the SS1 but as it's already in FG (not a good one though, I wasn't able to get it over 120000 ft - it's supposed to go uptil 320000! and it's feathering doesn't work at all!) I decided to go for the SS2... I think that looks pretty "sexy" (as Richard Branson says) too, it'd be cool. :)

Well, as for the systems, I need to do a little more research on FG JSBSim rocket engines, changing wing positions (that shouldn't be difficult, I just need to find out exactly what happens when you feather, and use the feather-norm as a product in the elements in the fcs. Another thing is, I wanted to make the White Knight 2 separately so that MP pilots can carry you upto 55000 ft and release.

@Thorsten, is it possible to go past 150 km altitude now? Last time I tried with the vostok (AFTER removing the nasal warning script) a couple of variables became NaN and my laptop got stuck... :shock:

Anyway, I've started working on the model. :wink: I'll get back to this aircraft as soon as I make tutorials for the new ATR 72-500(C)

Image
Image
Image
Merlion Virtual Airlines - the experience of a flight time...
Get high quality aircraft, airports, video tutorials or development tools from my hangar.
omega95
 
Posts: 1223
Joined: Sat Jul 30, 2011 12:59 am
Location: -unknown-
Callsign: MIA0001, OM-EGA
IRC name: omega95
Version: 2.12 git
OS: Ubuntu 13.04

Re: SpaceShipTwo V.S.S Enterprise

Postby omega95 » Thu Aug 09, 2012 8:42 pm

Started texturing it... :)

Image

Image

Image
Merlion Virtual Airlines - the experience of a flight time...
Get high quality aircraft, airports, video tutorials or development tools from my hangar.
omega95
 
Posts: 1223
Joined: Sat Jul 30, 2011 12:59 am
Location: -unknown-
Callsign: MIA0001, OM-EGA
IRC name: omega95
Version: 2.12 git
OS: Ubuntu 13.04

Re: SpaceShipTwo V.S.S Enterprise

Postby Thorsten » Fri Aug 10, 2012 6:28 am

@Thorsten, is it possible to go past 150 km altitude now? Last time I tried with the vostok (AFTER removing the nasal warning script) a couple of variables became NaN and my laptop got stuck...


We do have a working patch - I've been with Vostok at 800 km altitude and with the ufo about 10.000 km away. I don't know if the patch made it to GIT next, if you haven't succeeded, then probably not.

I hope all it needs is some persuasion in the right places to get it done if we need it...

Btw. - I thought you wanted to do the Space Shuttle :?:
Thorsten
 
Posts: 10955
Joined: Mon Nov 02, 2009 8:33 am

Re: SpaceShipTwo V.S.S Enterprise

Postby omega95 » Fri Aug 10, 2012 2:27 pm

We do have a working patch - I've been with Vostok at 800 km altitude and with the ufo about 10.000 km away. I don't know if the patch made it to GIT next, if you haven't succeeded, then probably not.


Do you have it in a private repository or a clone? I could work with that till it's merged into git.

Thorsten wrote in Fri Aug 10, 2012 6:28 am:Btw. - I thought you wanted to do the Space Shuttle :?:


Yea, actually I did but then after I did a little research, the space shuttle is VERY complicated and I couldn't get enough resourced on the systems. And as I don't have much time for now, I decided to go into something simple, like the SS1.. but then as it's already there, I decided to make the SS2. :)

The SS2 would be a little more complicated than the Space Shuttle when it comes to things like the FDM as understanding and implementing the feathering would be difficult. I talked to AndersG and he suggested that I make 2 different datcom models- 1 normal and 1 feathered and interpolate the values from the table data into 1 FDM. I was also thinking of getting just the new characteristics, like reduction in active wing area, lift, focusing in a certain direction etc.

And atm, i don't understand FG's Rocket Engine and Nozzle thruster properly yet, I'm looking into the Vostok for that, so temporarily I have a simple nasal engine (which creates external reactions for main RM2 Thrust and the nose thrusters used to change the aircraft's orientation out of the atmosphere) but I'll get back to the FGRocket Engine after I get the rest working fine.
Merlion Virtual Airlines - the experience of a flight time...
Get high quality aircraft, airports, video tutorials or development tools from my hangar.
omega95
 
Posts: 1223
Joined: Sat Jul 30, 2011 12:59 am
Location: -unknown-
Callsign: MIA0001, OM-EGA
IRC name: omega95
Version: 2.12 git
OS: Ubuntu 13.04

Re: SpaceShipTwo V.S.S Enterprise

Postby omega95 » Sat Aug 11, 2012 3:52 pm

Right, so I got the feathering working almost perfect (I think) :D When you feather, a nasal script reduces the effective wing area (/fdm/jsbsim/metrics/Sw-sqft) and like in the real thing, the elevator-cum-ailerons go up with the feathered tail upto about 50 degrees, so I got the trimmer to go upto 50 degrees automatically when you feather. The feathering also affects your roll, pitch and yaw moments, as the surfaces are in a completely different position now. To feather, you just use the control to get your flaps down but the effect is completely different. After a few tries, my last feathering test worked out great! I started at 60000 ft with around 200 kts IAS, first got it to fly level and slow down to around 150 kts, emptied my fuel tanks and then I feathered. The aircraft at first pitched up to around 45 degrees (like it should, I've seen a couple of videos) and then when the tail is completely feathered, it maintains from -5 to 25 degrees pitch automatically and falls at around 90-160 fps till you de-feather. Once I de-feathered (for this test, I did it only at 20000 ft as I only started at 60000 but generally, it's done at from 40000 to 60000 ft after the re-entry) the aircraft first pitched down a little but then got back up. I had to push forward on the stick a little to maintain level but then once it's completely de-feathered, you can glide like you would normally, :)

Image

What's really troubling me is actually maintaining 320000-360000 ft for around 5 minutes... It's much easier in the Vostok-1 as you gradually reduce the climb rate by controlling pitch so you'll be almost level at 120-140 km but then here, you're supposed to go straight up, burning the engines for 80-90 seconds (87 is what I've read) and it should automatically slow down and maintain that altitude before re-entry.
Merlion Virtual Airlines - the experience of a flight time...
Get high quality aircraft, airports, video tutorials or development tools from my hangar.
omega95
 
Posts: 1223
Joined: Sat Jul 30, 2011 12:59 am
Location: -unknown-
Callsign: MIA0001, OM-EGA
IRC name: omega95
Version: 2.12 git
OS: Ubuntu 13.04

Re: SpaceShipTwo V.S.S Enterprise

Postby Thorsten » Sat Aug 11, 2012 4:14 pm

Yea, actually I did but then after I did a little research, the space shuttle is VERY complicated and I couldn't get enough resourced on the systems.


Have you tried contacting some NASA press office? I could imagine they'd be quite open to the idea of a simulation and help you out. NASA even has a few free 3d models from spacecraft.

Do you have it in a private repository or a clone? I could work with that till it's merged into git.


I only have a GIT repo of FGData, but the patch goes to the flightgear repo. It was published at the mailing list (and possibly also in the Vostok thread here) - maybe you can try digging it up from there. But the SS2 is supposed to go 110 km only, so that should be fine.

What's really troubling me is actually maintaining 320000-360000 ft for around 5 minutes... It's much easier in the Vostok-1 as you gradually reduce the climb rate by controlling pitch so you'll be almost level at 120-140 km but then here, you're supposed to go straight up, burning the engines for 80-90 seconds (87 is what I've read) and it should automatically slow down and maintain that altitude before re-entry.


No way. This is a ballistic trajectory spaceplane like the X-15 - it goes straight to peak altitude and falls down again, it doesn't maintain the altitude. I don't know if you have tried it yet, but take our X-15 for a tour, that will give you the impression - the performance of SS-2 seems vaguely similar. The whole ballistic flight regime (i.e. after the engine cuts out till re-entry) might last about 5 minutes.
Thorsten
 
Posts: 10955
Joined: Mon Nov 02, 2009 8:33 am

Re: SpaceShipTwo V.S.S Enterprise

Postby omega95 » Sat Aug 11, 2012 4:29 pm

No way. This is a ballistic trajectory spaceplane like the X-15 - it goes straight to peak altitude and falls down again, it doesn't maintain the altitude. I don't know if you have tried it yet, but take our X-15 for a tour, that will give you the impression - the performance of SS-2 seems vaguely similar. The whole ballistic flight regime (i.e. after the engine cuts out till re-entry) might last about 5 minutes.


Ahh, I didn't mean that it actually maintains the exact altitude, according to Rutan, it goes over 320000 ft, and upto 360 but then you'll feel the weightlessness for about 5 to 10 minutes before the actual re-entry. I suppose that means it just stays above the atmosphere but does ascend/descend over there. And yea, I'll try out the X-15 now but unfortunately, I can't keep FG running for over 5 to 10 minutes now due to heating problems.

Anyway, the problem I faced with the SS2 is that after it passes about 250000 ft and even if I cut off the engines, it just keeps going till 500000+ ft adn FG crashes. :shock:

Btw, I won't be leaving the Space-shuttle project completely, I'll go back there when I get some time and get some more experience with (sub-)orbital flight first.
Merlion Virtual Airlines - the experience of a flight time...
Get high quality aircraft, airports, video tutorials or development tools from my hangar.
omega95
 
Posts: 1223
Joined: Sat Jul 30, 2011 12:59 am
Location: -unknown-
Callsign: MIA0001, OM-EGA
IRC name: omega95
Version: 2.12 git
OS: Ubuntu 13.04

Re: SpaceShipTwo V.S.S Enterprise

Postby Thorsten » Sat Aug 11, 2012 4:40 pm

Ahh, I didn't mean that it actually maintains the exact altitude, according to Rutan, it goes over 320000 ft, and upto 360 but then you'll feel the weightlessness for about 5 to 10 minutes before the actual re-entry.


Yes, you feel it during ballistic flight - i.e. right after the engine cuts out, you feel weightless even with a lot of climbing still to do. Right up and down again to 70.000 ft or so when the atmosphere starts dragging significantly.

Anyway, the problem I faced with the SS2 is that after it passes about 250000 ft and even if I cut off the engines, it just keeps going till 500000+ ft adn FG crashes.


You climb too steeply? I climb the X-15 with about 45-55 deg to reach an altitude above 100 km and still get a controlled state falling down. If you climb 90 deg like a rocket, you'll get much higher, but going down becomes dangerous.
Thorsten
 
Posts: 10955
Joined: Mon Nov 02, 2009 8:33 am

Re: SpaceShipTwo V.S.S Enterprise

Postby omega95 » Sat Aug 11, 2012 4:47 pm



It seems to be going quite steep there... :|

And you are talking about X15-new, right?
Merlion Virtual Airlines - the experience of a flight time...
Get high quality aircraft, airports, video tutorials or development tools from my hangar.
omega95
 
Posts: 1223
Joined: Sat Jul 30, 2011 12:59 am
Location: -unknown-
Callsign: MIA0001, OM-EGA
IRC name: omega95
Version: 2.12 git
OS: Ubuntu 13.04

Re: SpaceShipTwo V.S.S Enterprise

Postby Thorsten » Sat Aug 11, 2012 4:50 pm

You have too little weight then, or your rocket engine has too much power. Ballistic trajectories are terribly simple to compute - there's nothing involved that can be wrong. Basically all that determines your peak altitude is velocity when the engine cuts out and the angle.
Thorsten
 
Posts: 10955
Joined: Mon Nov 02, 2009 8:33 am

Re: SpaceShipTwo V.S.S Enterprise

Postby omega95 » Sun Aug 12, 2012 5:14 pm

Thorsten wrote in Sat Aug 11, 2012 4:50 pm:You have too little weight then, or your rocket engine has too much power. Ballistic trajectories are terribly simple to compute - there's nothing involved that can be wrong. Basically all that determines your peak altitude is velocity when the engine cuts out and the angle.


Yea, you're right I had the passenger weights added and it works fine now. The procedure now is:
  • Start at FL500-FL550 at around 200-220 kts IAS
  • When separated from the Mothership by a minimum of 1000 ft (basically, after you fall 1000 ft) ignite the engines and keep at full throttle
  • During the next 10 to 15 seconds, slowly pull up on the stick (make sure you don't pull too many Gs) until the ss2 is pitched at 50 degrees to vertical, I've tested at vertical and it gets the ss2 upto 370000ft and at 50 degrees, around 320000ft.
  • Once your engines burn out, feather the ss2 and enjoy the weightlessness as you go upto 320-360000ft and come back.
  • When you're inside the atmosphere again (you'll see the airspeed going up) maintain -5 to 30 degrees pitch on re-entry.
  • De-feather at around 50000-60000 ft, this is sorta important not only because you need enough time to glide to the airport/spaceport (I chose KMHV- Mojave Spaceport) but for some reason, continuing feathered flight at that speed is kind of difficult as when you feather, you don't have as much control.
  • Navigate to the space-port and perform a normal glider landing. :D

Image

Image

Image

Image
Merlion Virtual Airlines - the experience of a flight time...
Get high quality aircraft, airports, video tutorials or development tools from my hangar.
omega95
 
Posts: 1223
Joined: Sat Jul 30, 2011 12:59 am
Location: -unknown-
Callsign: MIA0001, OM-EGA
IRC name: omega95
Version: 2.12 git
OS: Ubuntu 13.04

Re: SpaceShipTwo V.S.S Enterprise

Postby omega95 » Sun Aug 12, 2012 7:32 pm

Made some re-entry animations.. Basically it's just a nice textranslate animation. :P

Image

Image
Merlion Virtual Airlines - the experience of a flight time...
Get high quality aircraft, airports, video tutorials or development tools from my hangar.
omega95
 
Posts: 1223
Joined: Sat Jul 30, 2011 12:59 am
Location: -unknown-
Callsign: MIA0001, OM-EGA
IRC name: omega95
Version: 2.12 git
OS: Ubuntu 13.04

Re: SpaceShipTwo V.S.S Enterprise

Postby omega95 » Tue Aug 14, 2012 8:44 am

Does anyone have an idea of the instrumentation onboard the SS2? I have some data on the TONU and stuff on the SS1 but it seems the SS2 is a little more advanced. I sent an e-mail to Scaled Composites but if you guys already have something, that'd be cool. :mrgreen:
Merlion Virtual Airlines - the experience of a flight time...
Get high quality aircraft, airports, video tutorials or development tools from my hangar.
omega95
 
Posts: 1223
Joined: Sat Jul 30, 2011 12:59 am
Location: -unknown-
Callsign: MIA0001, OM-EGA
IRC name: omega95
Version: 2.12 git
OS: Ubuntu 13.04

Re: SpaceShipTwo V.S.S Enterprise

Postby Hooray » Tue Aug 14, 2012 11:03 am

According to the number (and size!) of the MFDs, it looks like a sure candidate for the new canvas system:
Image

EDIT: Fail, that's the mothership ... here's a shot of SS1:
Image

Also, check out these links:

http://www.flightglobal.com/blogs/hyper ... ckpit.html
http://orbiter-forum.com/showthread.php?t=14727

Regarding the features, I'd second Thorsten's suggestion and try to get in touch with the press department of Virgin or the manufacturer of the avionics ...

The SS1 EFIS seems to be a D10 from Dynon: http://www.dynonavionics.com/docs/news_spaceship1.html
Please don't send support requests by PM, instead post your questions on the forum so that all users can contribute and benefit
Thanks & all the best,
Hooray
Help write next month's newsletter !
pui2canvas | MapStructure | Canvas Development | Programming resources
Hooray
 
Posts: 11329
Joined: Tue Mar 25, 2008 8:40 am

Re: SpaceShipTwo V.S.S Enterprise

Postby omega95 » Tue Aug 14, 2012 1:58 pm

EDIT: Fail, that's the mothership ... here's a shot of SS1:


Actually, I'm working on the SS2, who's cockpit is quite different from the SS1, mainly for the fact that you have a pilot and a co-pilot. The avionics manufactures seems to be the same but anyway, the mothership's cockpit seems to be closer to the SS2s... But yes, the canvas system should be VERY useful there, and looking at the TONU display, I was thinking if the canvas system could 'project' a 3D object into 2D view (so as to create the globe) :)

http://www.flightglobal.com/blogs/hyper ... ckpit.html
http://orbiter-forum.com/showthread.php?t=14727

Regarding the features, I'd second Thorsten's suggestion and try to get in touch with the press department of Virgin or the manufacturer of the avionics ...

The SS1 EFIS seems to be a D10 from Dynon: http://www.dynonavionics.com/docs/news_spaceship1.html


Thanks for the links, but I guess for better documentation, I still have to contact Scaled Composites or Virgin... Btw, Dynon only created the Skyview instrument. (a larger version-Skyview1000 is used in the Jab170)
Merlion Virtual Airlines - the experience of a flight time...
Get high quality aircraft, airports, video tutorials or development tools from my hangar.
omega95
 
Posts: 1223
Joined: Sat Jul 30, 2011 12:59 am
Location: -unknown-
Callsign: MIA0001, OM-EGA
IRC name: omega95
Version: 2.12 git
OS: Ubuntu 13.04

Next

Return to Spaceflight

Who is online

Users browsing this forum: No registered users and 10 guests