You can't craft rocket parts by hand, they only exist in silos.

Edit: Also, after testing in the sandbox an issue is that you can't enter the tardis if you're using the mechsuit because you fly over it.

In release 1.0.3, I removed rocket parts and slightly rebalanced recipes.
I reworked the TARDIS entry algorithm. Now, when a player is airborne, the entire TARDIS surface is checked instead of just the door, and hitboxes have been adjusted.
However, there may still be occasional misses because entry is checked every sixth tick - the faster you move, the higher the chance of skipping the check window.