Problem Shuttle doesn't reach orbit. Help?

[Longjap]

All of them btw. I have shuttle fleet 4.7 and ISS Space Station addons installed.
Rockets throttle up by autopilot, it rotates to desired heading and then it just seems that it lacks the power? I barely hit 25 KM have to jettison everything then I get a fuel tank in my face and have to pull off a hasty retreat to KSC.. Also the stock shuttle has the same problem. Yesterday in the same configuration it worked flawlessly. I'm really new (1 week) to orbiter so maybe i'm missing something here but if someone could help i would really appreciate it.

 

[Eli13]

Did you leave unlimited fuel on?

 

[diogom]

Did you enable "limited fuel"? If you didn't, the Shuttle will be too heavy to reach orbit.

 

[Longjap]

Ah, doH! Thanks for your help Diogom.

 

[fireballs619]

Also, if you are very new to Orbiter, I recommend following the tutorials in Go Play In Space. It will greatly increase your understanding of the maneuvers involved, as opposed to just having the autopilot do everything.

 

[Eli13]

Though, I have to say, they can save you some time. But honestly, I prefer to do it manually when i have the time to do so. You may also, want to see some of the playbacks included in the default orbiter installation.

 

[Longjap]

Hi fireballs, isn't the fuel tank in real life filled to the max? That's why i thought that it couldn't be the problem. If so, it is a bit weird that unlimited fuel would add weight, I mean almost unlimited fuelweight would mean sinking to earths core . Well I did read Go Play In Space, very helpfull indeed. I do not yet know how to manually take off or set the autopilot in the Shuttle Fleet/ISS addon. The scenario will do it for me. But after reaching orbit in most of the scenario's I lose a lot of fuel doing the plane alignment burns because apparently the autopilot is not that accurate.

 

[Eli13]

It means that during ascent, you burn fuel, which means less mass, which means that you can achieve orbit. Simple.

 

[HarvesteR]

The fuel is filled to the max, but it burns off as the shuttle rises into orbit. About 2 minutes into the flight, it's burned more than half it's weight in fuel.

Unlimited fuel doesn't mean infinite fuel weight also ...it just means the tanks are always at 100%, which also means the shuttle won't lose the needed weight to be able to accelerate into orbit before plummeting back down again.

Cheers

 

[fireballs619]

Hi fireballs, isn't the fuel tank in real life filled to the max? That's why i thought that it couldn't be the problem. If so, it is a bit weird that unlimited fuel would add weight, I mean almost unlimited fuelweight would mean sinking to earths core . Well I did read Go Play In Space, very helpfull indeed. I do not yet know how to manually take off or set the autopilot in the Shuttle Fleet/ISS addon. The scenario will do it for me. But after reaching orbit in most of the scenario's I lose a lot of fuel doing the plane alignment burns because apparently the autopilot is not that accurate.

I don't think the problem is that unlimited fuel adds weight, persay, but rather it makes it impossible for weight to be lost through the burning of fuel. One of the main features of a rocket is that it propels itself through the expulsion of some of it's mass - having unlimited fuel directly contradicts this. Is fictional craft, however, where the fuel is extremely efficient, ot can still propel it's full mass, fuel included, and therefore unlimited fuel works. So yes, you're right, having a full fuel tank to start with isn't a problem, but having a tank that never empties is :thumbup:

EDIT: Ninja'd by HarvestR!

 

[Longjap]

Come to think of it, that makes sense. Thanks

Though, I have to say, they can save you some time. But honestly, I prefer to do it manually when i have the time to do so. You may also, want to see some of the playbacks included in the default orbiter installation.

You mean manually set the autopilot, or flying it yourself? Because I do know how to set the autopilot in the stock Atlantis by the terminal MFD, but with shuttle fleet you have to edit the scenariofile i believe. But i then don't know where the ISS is. Anyway, I could overload you all with questions but maybe I should do some research.

 

[Eli13]

well with default shuttle fleet scenarios, all you have to do is engage full thrust, it should take you to orbit, where you do the ET jettison manually i believe, and i know for certain that you do the OMS burns manually to stabilize orbit, from there you do what ever your mission requires.

 

[RangerPL]

If you're new to Orbiter, I'd recommend practicing these maneuvers using the stock DeltaGlider, the DeltaGlider IV or any of the XR-series spacecraft. The learning curve on them is easier as they have more powerful and efficient engines which allow you to easily correct mistakes you may make.

That GoPlayInSpace guide that was posted in this thread is a great start.

The Shuttle is pretty unforgiving to newcomers (requires you to launch fairly precisely since its OMS engines aren't very powerful), so I'd recommend practicing this stuff on one of the aforementioned vessels. That's how I learned to fly.

 

[HAL9001]

Space-Shuttle-Atlantis-launch is hard, but it gets easy if you have a protocoll how to do it - [ame="http://www.orbithangar.com/searchid.php?ID=3972"]this[/ame] includes what you need!