In (K)Ubuntu (which LMCE is installed on top of), you can press <Ctrl><Alt><F1> (or F2, F3, F4) to get a textmode screen that offers a login shell. You can press <Alt><F7> from there to restart the X session that I presume will return you to the undisturbed (except by the results of any commands you execute in the login shell) LMCE Launch Manager window,. Though I've never tried it on any machine but a hybrid (ie. including an Orbiter) - but the <Ctrl><Alt><Fn> for the login should always work, and <Alt><F7> should return you to the X screen you had stopped.
There might be other ways to start a terminal in the Launch Manager's X session, but the way I described should work. You can also ssh into the core from a remote machine on the network.