How to make an actually controllable Space Shuttle?

[Kerb24]

I have been trying to make a space shuttle in KSP, but the orbiter is uncontrollable in the Atmosphere.

Steam Workshop::WIP Space Shuttle (steamcommunity.com) Link to the craft file to see for your self.

[cantab]

I don't have the mods needed.

If it's on launch, you probably aren't able to get the thrust pointing through the centre of mass. The game's SRBs don't have thrust vectoring so you need to rely even more on the main engines - the real Shuttle boosters have gimballing nozzles. Raising the external tank can help. Look at a side view of NASA's shuttle, such as at http://www.nycaviation.com/2011/07/photos-space-shuttle-atlantis-lifts-off-on-final-mission , and see how the butt of the external tank is well forward of the rear of the shuttle - AND consider that because they used low-density hydrogen and denser oxygen, with the oxygen at the front, the centre of mass is towards the front of the ET too. This all means the main engines don't need to be so angled and don't need to gimbal so much.

If your problems are when gliding or on re-entry. You want centre of lift a bit behind centre of mass, and you want elevons a good distance from centre of mass.

Edit PS: A NASA-style Space Shuttle is one of the hardest things to build in KSP. Expect to do a fair bit of design work to get it flying well.

Edited April 20, 2022 by cantab

[Akagi]

Easiest thing to do is to attach four boosters to the actual shuttle and take off the external tank. 

[KerikBalm]

On 4/21/2022 at 1:30 AM, cantab said:

If it's on launch, you probably aren't able to get the thrust pointing through the centre of mass. The game's SRBs don't have thrust vectoring

2 of the new ones do:

https://wiki.kerbalspaceprogram.com/wiki/S2-33_"Clydesdale"_Solid_Fuel_Booster - only 1 degree though

https://wiki.kerbalspaceprogram.com/wiki/S2-17_"Thoroughbred"_Solid_Fuel_Booster - only 2 degrees

 

 

[Jaq]

By uncontrollable, do you mean that it just tips forward/backward on launch, or it just spins out of control when you are in the atmosphere?

If it's the first one, you could try rotating the engines on the actual shuttle piece towards the center of mass, as said by Cantab, but if that doesn't work for some reason or is just too hard to get working, you could simply just mount two shuttles on either side of the big fuel tank like this:

This works quite well, but is pretty cursed and might not satisfy you if you're trying to build one similar to or a replica of the American space shuttle.

If it is the second thing, it might be caused by there being too much weight at the top of the craft, which you can fix by simply doing a steeper gravity turn, adding more fins to the sides of the orbiter, or maybe both if one doesn't fix it. Again, adding fins might ruin the American-space-shuttle feel your going for, but do remember that the space shuttles were some of the hardest to fly spacecraft ever made, and you might not get the hang of the art of space shuttling on your first few goes.

Hope that helped, Jaq

Edited May 1, 2022 by Jaq

[Kerb24]

In testing, I did put two orbiters on one external tank, and it was stable, but I was eventually able to make a space shuttle that was controllable and looked somewhat accurate.