with a dry mass less than 3600.0, what bipropellant rocket engine uses the fuel unsymmetrical dimethylhydrazine?
(AND spaceflight.bipropellant_rocket_engine (AND (JOIN spaceflight.bipropellant_rocket_engine.fuel m.017q1y) (lt spaceflight.rocket_engine.dry_mass 3600.0^^http://www.w3.org/2001/XMLSchema#float)))