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Re: Space Shuttle

Postby amalahama » Tue Jan 23, 2018 11:38 am

Thorsten wrote in Mon Jan 22, 2018 6:23 am:It's not implemented to get the inertial values automatically, no (this is moderately complex, because you need a predictive solution where EI-5 will be and use the transformation matrices between inertial and LVLH to get an inertial attitude there) - just maneuvering to an approximate LVLH attitude by hand seems quite doable... :mrgreen:


Since you need to solve the trajectory anyway in OPS 301 when executing item 22, maybe you can save EI-5 position as well - so it would be just a matter of getting the LVLH + 40º attitude at that point. The INRTL attitude value could then be saved and propagated through OPS 3 so in OPS 303 is available.

The thing is that now it's impossible to do it automaically or semiautomatically, since in Transition DAP, LVLH is not available and the only way I can think of is switching back to OPS 201 (I'm using easy GPC so it's doable, but a pain in the neck in realistic GPS), set the attitude there and then switch to OPS 303 again. And if it's done manually, we don't have error needles (since the solution hasn't been calculated) and everything needs to be done approximately.

I'm sorry, I'm a bit of a OCD person sometimes :mrgreen:

Use the S-band antenna - if you're not over a ground site, you might need to switch it to TDRS and pre-amplify the signal to compensate for the range, but for 90% of the orbit this will give you a link.


Thanks! I didn't know the communications were so well simulated now, I need to check

Regards!
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Re: Space Shuttle

Postby Thorsten » Tue Jan 23, 2018 5:50 pm

The thing is that now it's impossible to do it automaically or semiautomatically, since in Transition DAP, LVLH is not available and the only way I can think of is switching back to OPS 201 (I'm using easy GPC so it's doable, but a pain in the neck in realistic GPS), set the attitude there and then switch to OPS 303 again. And if it's done manually, we don't have error needles (since the solution hasn't been calculated) and everything needs to be done approximately.

I'm sorry, I'm a bit of a OCD person sometimes


Okay... I'm just having a big grin (not an evil one, mind you) - because this project grew in a flightsim community and I didn't think anyone would hesitate a second to just pitch this thing up to 40 degrees and zero sideslip by the instruments (the LVLH DAP doesn't work, but the LVLH ADI mode does - so you just flick the ADI into this mode and target the zero yaw and 40 deg pitch line rather than the error needles - you do in fact get the attitude alphanumerics as well, so you can target better than 0.1 degree that way - certainly better than the DAP requires to engage correctly).
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Re: Space Shuttle

Postby amalahama » Tue Jan 23, 2018 6:18 pm

Thorsten wrote in Tue Jan 23, 2018 5:50 pm:Okay... I'm just having a big grin (not an evil one, mind you)


It's a strange feeling, but I find more enjoyable flying the Shuttle by GNC, than by hand - smashing the keyboard trying to understand the logic behind the DPS and making any sense out of the phosphorous green displays, it's fun and challenging! My father used to work in a nuclear power station and it reminds me a lot his stories from his old days :D

Regards!
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Re: Space Shuttle

Postby Thorsten » Tue Jan 23, 2018 6:26 pm

Well, it's not an unreasonable request and it's definitely doable, so I'll insert it into the ToDo list.
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Re: Space Shuttle

Postby amalahama » Wed Jan 24, 2018 12:11 am

Nice!! Looking forward to it!

Regards!
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Re: Space Shuttle

Postby bob755 » Fri Feb 02, 2018 2:50 pm

Hello,

I'm just starting out with the Sapce Shuttle and have tried my first launch. I followed the wiki launch tutorial and everything goes smoothlly except when the shuttle gets to the end of the ascent trajectory and the engines shut down I'm at an altitude of about 135km but the apoapsis remains at 172km whereas I should be going to 320km.

What's wrong?

Thanks
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Re: Space Shuttle

Postby Thorsten » Fri Feb 02, 2018 3:08 pm

You do know that the Shuttle avionics displays apses in nautical miles, right? And 172 miles happen to be rather close to 320 km... which gives rise to a suspicion that really nothing is going wrong at all.
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Re: Space Shuttle

Postby bob755 » Fri Feb 02, 2018 3:11 pm

Thorsten wrote in Fri Feb 02, 2018 3:08 pm:You do know that the Shuttle avionics displays apses in nautical miles, right? And 172 miles happen to be rather close to 320 km... which gives rise to a suspicion that really nothing is going wrong at all.


On the HUD it indicates km as the units.
I found I hadn't set the Target apoapsis in the Launch Guidance. The tuto actually says not to change it. It was initially set to 90miles.
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Re: Space Shuttle

Postby Thorsten » Fri Feb 02, 2018 3:23 pm

Assuming this is an odd coincidence and you're really going to 172 km, you might have run out of propellant (I suppose dependent on payload, launch latitude and target inclination that may happen), you might have lost an engine and then run out of propellant, you might have launched onto a retrograde orbit - there's a couple of things that might have happened, you might have entered a different target apsis by accident - it's hard to tell without getting a lot more details.



In the event, the condition is not problematic and the solution is simple (and in fact as in reality when the desired orbit wasn't made during ascent) - do an OMS-1 burn some two minutes after MECO to get to the target apoapsis.
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Re: Space Shuttle

Postby Thorsten » Sat Feb 03, 2018 6:58 am

It was initially set to 90miles.


Ah, okay, I seem to have overread this before. I guess that explains it. Enjoy your further space adventures!
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Re: Space Shuttle

Postby bob755 » Sat Feb 03, 2018 11:58 am

Now I'm in orbit ok but the altitude continues to increase with a +ve vertical speed. Is this normal? If not how do I correct it?
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Re: Space Shuttle

Postby Thorsten » Sat Feb 03, 2018 6:20 pm

How else did you think you're getting from 135km MECO altitude (= near periapsis) to 320km apoapsis if not by picking up a vertical speed? :D Unless you're in a circular orbit, you're going to have a rising and a descending part of the orbit - this ain't an airplane any more.
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Re: Space Shuttle

Postby bob755 » Sun Feb 04, 2018 11:27 am

Thorsten wrote in Sat Feb 03, 2018 6:20 pm:How else did you think you're getting from 135km MECO altitude (= near periapsis) to 320km apoapsis if not by picking up a vertical speed? :D Unless you're in a circular orbit, you're going to have a rising and a descending part of the orbit - this ain't an airplane any more.


Effectively! I'm having trouble transiting from Airbus!
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Re: Space Shuttle

Postby Thorsten » Sun Feb 04, 2018 5:45 pm

Airbus is probably not a bad preparation - usually 'flying' the Shuttle involves more talking to the avionics than actual piloting (though you can do nearly all by hand...). Anyway - expect to be reading a lot of background material to get most of the simulation.
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Re: Space Shuttle

Postby bob755 » Mon Feb 05, 2018 2:24 pm

Sorry if this is a newbie question but how do I get the panel legends to light up?
I never see the main engines burning either from external views
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