I need help about my rt-10 test mission on 100km orbit.

[tuncas]

Unfortunately I took a mission in my career mod as "test rt-10 "hammer" on 100000m orbiting kerbin. I almost have basic equipments. How should I do this. I completed orbiting kerbin. But I can't do this. I need to fire rt-10 while in orbit of kerbin. I don't want to decline this quest. I have 30 parts limit and 140 tons limit. Also I googled videos for this mission but no luck. Thanks.

[Gaarst]

Empty it: right click on it in the VAB, and remove all the solid fuel but a few units.

This will make your booster a lot lighter, so easier to orbit; and letting a few solid fuel units in it will allow you to test it anyway.

[tuncas]

26 minutes ago, Gaarst said:

Empty it: right click on it in the VAB, and remove all the solid fuel but a few units.

This will make your booster a lot lighter, so easier to orbit; and letting a few solid fuel units in it will allow you to test it anyway.

I have tried many things but will try this too. Anymore suggestions folks just in case? Thanks!

[numerobis]

Even better than flying with it empty: use it on the way up! You can rearrange your stages in flight just like you can in the VAB. This lets you stage the engine a second time. I use that trick for all my "splashed down" and "suborbital on Mun" tasks.

[Snark]

The main thing to deal with will be placement.  If you're putting it at the bottom of the rocket, you'll need to mount your engines to the side of it (since you need to lug it along).  If you put it up front (i.e. empty), then having that big bulky light thing in the front of your rocket will tend to make you aerodynamically unstable, so you'll need to come up with a way to cope with that.

Perhaps the easiest solution might be to just put two Hammers on, for symmetry: attach them radially to the bottom stage, then do as @numerobis suggests and use them as your first stage, just as you'd normally use SRBs for.  The only difference is that you don't jettison them after they burn out.