Space Shuttle - Help

[Thorsten]

Use this thread to ask for how to solve a problem. Be sure you've taken a look into the manual (which you can get here first - many issues and problems are already discussed there.

[Captain97]

how are you supposed to launch the shuttle? And where? because every I try to launch the shuttle, I always get blown up...

[wlbragg]

Hi Captain 97. Start here and read the Shuttle manual. If that doesn't work maybe by then you'll have a specific question that can be answered.
Thorsten has put a lot of effort into a manual that was created to answer this type of question.

[Thorsten]

how are you supposed to launch the shuttle? And where? because every I try to launch the shuttle, I always get blown up.

Please don't use the Shuttle development thread for such questions - if you need a follow-up, bring this into the help thread.

[GinGin]

@Captain 97 : Hello, you can have a look there http://wiki.flightgear.org/Space_Shuttle#Nominal_Operations and there http://www.science-and-fiction.org/bookstore.html to guide you

[GinGin]

@Thorsten: Hey, I got a question about Spec 34 in Game.
Do you use Compute T2 during your rendez vous phase (from what I understood, it should null relative velocity at T 2 time ?)

[Thorsten]

It (kind of) does - but:

* The computation is based on the velocity differences with the finite burn duration just estimated and shifting the burn by half the burn time, so the numerical accuracy is not on par with T1

* If you hand over to the detailed proximity simulation of ISS, the nature of the orbiting target changes from semi-analytical to J3, so the intercept point the T2 burn is computed for won't be the actual intercept point, the velocity vectors will also be different, and so the T2 burn will go wrong

I don't have a good feeling for how much you will miss, I've tried only once and I had some 2.5 m/s residual after coming in from a fast (and rather inefficient) 30 minute trajectory with high relative velocity.

So the answer is - yes, I use it, but I don't rely on it.

[GinGin]

I see, thanks for the explanations.

How did you perform for your sucessfull Rendez Vous mission?

[eatdirt]

Hi there, I am lagging behind by a year or so in terms of training my landing...

I do really suck with Live Data for the weather, my landing is really approximate as soon as the x-wind gets above 10kts. I remember Thorsten saying to do decrabbing, I think I do now (never flew a plane before, virtual or real), but with a x-wind of 12kts, rudder pushed to maximum, I am barely able to land straight. And once on the lane, rudder locked to maximum, brake only on one wheel to maximum, no way, I am drifting out of the lane following the wind...

I really do think this is the wind that makes it hard. Even after wheels stop, I can measure it with the Shuttle's instruments, got a number around 8-10 on the HUD even at rest. And if I put a good weather, the landing is easy. So guys, any tricks to share?

I have duckduckgoed a bit, found this:

https://www.nasa.gov/centers/kennedy/news/releases/2003/release-20030128.html

The peak cross wind cannot exceed 15 knots

for landing at KTTS. I've found peace watching this...

Well, this seems to happen even to the best

[GinGin]

The trick is to respect the IRL limitations
It was really sensitive to X wind component and quite unstable even with "Fly by wires" compared to normal airplanes.

As for decrabbing, it is indeed a good practice for X wind landing.
Aligned the plane with rudder during flare and some roll into the wind to counter the induced roll created by the rudder impulsion.

As a side note, Shuttle being heavily controled with computer even in CSS, it can create some control conflict if you use too much rudder while deccrabing.

Modern jets that use Fly by wires like Mirage or F 16 normally don't decrab with X wind to not mess up with the computer.

[eatdirt]

IRL limitations

I feel ashamed, but I've even tried a web search before asking, what are the IRL limitations? The 12kts x-wind limit?

If so, I do agree

[wlbragg]

I just saw the video of this less than perfect landing for the first time. I was surprised to see that rough of a landing. You think the pilot had to clean his shorts afterwards?

[wkitty42]

that was what? a three or four point landing?

[GinGin]

Hello,

I got a question about Star Tracker

use UNIV PTG to track ISS with the -Z axis to get a star tracker fix

Is it now possible to use the Star Tracker to Update the prop SV like we do with RR ?

[Thorsten]

Should be - if you have a valid fix, you should see residuals and ratios, these you can AUT or FORCE into the filter, then the filtered state vector displays the changes, and then you can do FLTR TO PROP to update the propagated state vector.

It did work when I tried yesterday (initially there was some weird pointing issue, I have no clue what I triggered to make it go away, as far as I know I just plotted stuff, but eventually it worked that UNIV PTG orients the Shuttle and the star tracker gets a fix).

Doesn't do anything about range though - you need an RR fix for that. And you need daylight to use the star tracker, it won't see any ISS during night.