Flight Question shuttle main engines have no power?

[javajames97]

Every time i launch the space shuttle; i fly up nice and cleanly with the SRB's, but then when they are jettisoned, i have a problem; the main engines on the space shuttle don't seem to work, you can see blue jets out the back but i'm not sure if thats right? (see photo - and i don't want anyone telling me you jettisoned the SRB's too early, i know, i did that so that i could quickly demonstrate what the main engines on full throttle looks like to me.) So the problem is that i would attain the speed and i would fly about 30 degrees above horizontal (and sometimes even further for experiment - i have tried vertical as well, still didn't work) and then the SRB's would fall away, and, well, so would i! The shuttle litterally drops out of the sky! And i have got limited fuel on. Is there a different control for the SSME's or do i have to enter the cockpit (if the control includes the numpad you will have to direct me to the keyconfigure file as i don't have a keypad!)

 

[Urwumpe]

Disable unlimited fuel - your Shuttle is simply too heavy for the thrust of the SSMEs, if you don't burn as much fuel during the first 104 seconds of flight, as the real one.

(Yes, I have read your post. But your symptoms describe perfectly what happens if you have overweight)

 

[Poscik]

Yes, they are functioning correct. Just see:

Shuttle launch is little bit tricky. The best way to learn it is to download playback from orbithangar and observe some MFDs.

 

[kevin580]

That's normal. The SSMEs are not so powerful.
Or, when they have not so much power, maybe you edited something in the .cfg

Questions:

1. Is it a clean Orbiter installation?
2. When 'No' to question 1., what add-ons do you have?
3. Any other things???

Edit: :ninja:

 

[javajames97]

i Definetely have limited fuel ON, it is atlantis, so it came with orbiter 2010, And i whatched a video, and it showed someone launching, but the exhuast burning colour was more orange??? (i have posted an image, the red circle indicates the brighter white colour of the ouput, unlike my blue flame). I have only edited the keyconf file (and have back up), but when i was using an externel keypad and thus the normal settings i still had this problem. I think it is something wrong with my SSME's, (but if you spot another problem don't be deterred to answer by that)

 

[javajames97]

i usually throttle up to max right from the beginning (extra info)

 

[Urwumpe]

Shouldn't be a problem - also the video is likely an add-on, that had the colors simply wrong.

(In reality, at this altitude you wouldn't see any visible exhaust at all, so most orbiter add-ons are wrong there)

Please remember that your total acceleration will drop to less than one g right after SRB separation, because the ET + Shuttle is still pretty heavy. You should be able to continue launch, if you are on the right trajectory, but for example flying vertical with it would be impossible, you would just drop before the acceleration can really counter gravity. The acceleration will slowly increase to 3g shortly before MECO, at this point the main engines are usually throttled down to keep constant 3g until shutdown.

 

[javajames97]

ahh.. i see, so the fact that i'm dropping is simply because i am not following the correct trajectory! not a problem, (as you can probably see, i am very new, i will just try to follow some instructions and see how that turns out!

---------- Post added at 07:16 PM ---------- Previous post was at 07:15 PM ----------

??? MECO = main engine cut off doesn't it?

---------- Post added at 07:17 PM ---------- Previous post was at 07:16 PM ----------

Was the posted photo one of an actual launch?

 

[Krikkit]

I had similar problems many years ago when I first started messing with orbiter but hadn't taken my first physics class yet and didn't understand what was going on.

First make sure you are launching East with a normal inclination 30<inc<60. Atlantis is not capable of retrograde or polar orbits. At least I have never been able to achieve them. Also be sure to build up your ground speed before SRB sep, and not just use them for altitude.

 

[javajames97]

What inclination is that (in degrees above horizontal - if in degrees from vertical pls specify)?

 

[Rtyh-12]

ahh.. i see, so the fact that i'm dropping is simply because i am not following the correct trajectory! not a problem, (as you can probably see, i am very new, i will just try to follow some instructions and see how that turns out!

[ame="http://orbithangar.com/searchid.php?ID=4864"]This should help out[/ame]

??? MECO = main engine cut off doesn't it?

Yes, yes it is.

Was the posted photo one of an actual launch?

As much as we would want it to be from Orbiter, it's real.

 

[diogom]

Try this, it's what I usually do and works:

till 1.5km, pitch at 60/70º
when you reach 7km set pitch at 50º
when you reach 20km set pitch at 40º
when you reach 40km set pitch at 20º
SRB sep, gradually decrease pitch.
Get to 140km alt at least, then try to keep vertical speed at 0
When you apoapsis (high point of orbit) is high, like 200-300km, MECO

This takes training and some understanding of the basic MFD's.

 

[javajames97]

what i meant about MECO was the impossibility for the engines to keep going after MECO which was made apperent in the fith post above this

---------- Post added at 07:31 PM ---------- Previous post was at 07:30 PM ----------

6th post above (7th above this one

 

[N_Molson]

Well, at this point the external tank should be empty.

After MECO, you rely on the OMS to change your orbit.

 

[Krikkit]

Wouldn't you know it after I said it couldn't be done I just got Atlantis into a retrograde at about ap = 190km inc=60 without using OMS. I have only been able to do that with the Velcro shuttles before.

What inclination is that (in degrees above horizontal - if in degrees from vertical pls specify)?

From the equator.

 

[javajames97]

congratutlations KriKKit