Is landing with this thing even possible?

[The Aziz]

So I built a shuttle. Typical construction, it flies, gets into orbit (thought reeeeeeeally slowly), survives the re-entry. But crashes everytime cause I can't pull up. Too heavy? Not enough lift? Control surfaces? Help. Here be pics.

http://imgur.com/a/QNpet

how to make those fancy imgur galleries anyway?

[Alshain]

More likely your CoM/CoL relationship is off. That is the usual cause of a lawn dart.

Post some pictures with CoM & CoL visible in the SPH. If you can, use RCS Build Aid and show us DCoM as well, because sometimes the effect only occurs when it is out of fuel (i.e. Dry). You typically will have no fuel by the time you land so you need to make sure it is balanced in that state. Also, you typically won't have payload when landing so make sure that is gone too. With a shuttle, this is even easier than a SSTO. You really only have to balance it one way because the external tank and SRB's usually bring the CoM forward and you don't have to worry about just how far behind the CoM your CoL is because your thrust to weight is so high.

Edited October 13, 2015 by Alshain

[The Aziz]

Here is one with empty tank.

Full one looks like this:

[Alshain]

I edited above but you came back too fast, does that have a payload? Remember you aren't bringing a payload back to the surface and balancing for the ascent is less important on a vertical launch as I mentioned above. If not, move the wings forward so the CoL ball is touching the CoM.

Imgur galleries are done using the imgur tag and the album id (which can be found in the URL). You have to configure the album through the imgur website.

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Edited October 13, 2015 by Alshain

[Snark]

Yeah, there are two problems going on there.

The first problem is that your center of lift is way behind your center of mass (even when it's empty), so it's going to want to nose down.

The second problem is that you don't have any effective control surfaces for steering. Look at where all your control surfaces (including airbrakes) are located, and look at where your center of mass is. They're really close together (especially when empty). That means that you have very little torque to work with, so they can't steer much.

Suggestion: Stick some control surfaces up at the front of the shuttle-- for example, a couple of AV-R8 winglets on the sides of the cockpit up front. Not only will that shift your center of lift forward (thus making it less nose-heavy), but also those winglets are very far from the center of mass, meaning that they'll generate a lot of steering torque.

Depending on the mass of your shuttle, a couple of AV-R8 winglets might not be enough, but it's a start.

You could also try scootching your wings forward a bit-- that would help move the center of lift forward a lot.

[The Aziz]

Okay, so I did what you suggested, and...

At least they survived. "touchdown" speed was reduced to ~70m/s, angle was better too. I will be working on it.

I mean, mostly on my landing skills.

[GoSlash27]

In my shuttle, I balanced the center of lift much closer to the empty CoM. I also have body flaps at the bottom of the rear of the fuselage to aid in pitch control.

Best,

-Slashy