Unsymmetrical dimethylhydrazine (UDMH) (1,1-Dimethylhydrazine) is a hypergolicrocket fuel[?] ingredient, often used in combination with the oxidiser, nitrogen tetroxide.
UDMH is toxic, and can explode in the presence of oxidisers.
... referred to as Dead Heads[?], would follow the band on tour. In contrast to many other bands, the Grateful Dead encouraged their fans to tape their shows. For man ...