YMMV / Heroes of the Desk

• Aluminum Christmas Trees: Magnetohydrodynamic engines really do exist. They're just impractical and not used outside of prototypes (though they've shown up in fiction before), but they sound really awesome, so... The trend continues with magnetoplasmadynamic engines—it appears SPEAR's device can switch between the two at will, but the second mode of operation uses far more energy than the first.